Theories of Development by Sigmund Freud, Erik Erikson, Jean Piaget, and Lawrence Kohlberg

Sigmund Freud, Erik Erikson, Jean Piaget, and Lawrence Kohlberg (famous psychologists) described development as a series of age-related changes that occur throughout life.

Stage is defined as a development period in which people show characteristic behaviour patterns and establish specific abilities. The various stage theories share the following three assumptions: 

1) People follow a specific order to pass through different development stages, and the abilities developed in the previous stage form a base for each stage. 

2) Development stages are age-specific. 

3) Development is discontinuous as different qualitative abilities emerge in each stage.

Sigmund Freud’s Theory of Personality 

Through the clinical work with mental illness patients, Sigmund Freud came to a conclusion that an individual‟s behaviour is influenced by childhood experiences and unconscious desires. He stated that conflicts in each stage can have a lifelong impact on personality and behaviour. The psychosexual theory of Sigmund Freud states that child development is a series of stages focused on different pleasure areas of the body. In each stage of development, a child faces conflicts that significantly affect the course of development. This theory suggested that energy of the libido focused on different erogenous zones at specific stages. If a child fails to progress through a stage, that point of development becomes fixed, and may influence adult behaviour.

Following are the stages of childhood psychosexual development: 

1) The Oral Stage (Birth to 1 Year): The sensory area of the mouth delivers the maximum level of sensual satisfaction by sucking, biting, chewing and vocalising for an infant during this period. 

2) The Anal Stage (1to 3 Years): During the toddler period, the second and third years of life, defecating provides the most pleasurable pleasure in the anal and urethral areas. At this point, the atmosphere surrounding toilet training is favourable. 

3) The Phallic Stage (3 to 6 Years): Children get more interested in the genitalia and sensitive areas of the body during this stage. The difference between the sexes is recognised by them and become curious about differences. The oedipal stage occurs at the end of the phallic stage, and it is during this period when the child loves the parent of the opposing sex as a source of fulfilment. 

4) The Latency Stage (6 Years to Puberty): Children build on previously learned qualities and skills, as well as create close relationship with others of their own age and sex during this stage. 

5) The Genital Stage (Puberty to Death): Along with maturation of the reproductive system and the synthesis of sex hormone, secondary traits appear in both sexes throughout puberty. 

Erik Erikson’s Theory of Psychosocial Development 

Erik Erikson believed that personality development occurs throughout life. He proposed a theory in the early 1960s, according to which there are eight stages of development, and in each stage people face new challenges. How people handle these challenges influence the result. There are total eight stages of this theory, which are as follows: Stage 

1: Trust versus Mistrust: Less than 1 year old infants are totally dependent on adults for basic needs (food, comfort, and warmth). If these needs are fulfilled by the caretakers, the infants become attached and develop a sense of trust and security; or else, they develop a mistrustful and insecure attitude. Stage 

2: Autonomy versus Shame and Doubt: 

One to three years old toddlers start becoming independent and learning new skills (toilet training, feeding, and dressing). If they face these challenges effectively, they develop a sense of autonomy; or else they develop a sense of doubt and shame about themselves. Stage 

3: Initiative versus Guilt: 

Three to six years old children start controlling their impulses and become social. If they can do this efficiently, they develop selfconfidence; or else, they develop a sense of guilt. Stage 

4: Industry versus Inferiority: 

Six to twelve years old children face peer pressure in school and prepare to take on adult roles. At the end of this stage, they either develop a sense of competence or inferiority. Stage 

5: Identity versus Role Confusion:

 In the period between puberty and adulthood, the adolescents try to determine their identity and direction in life. If they do so successfully, they develop a sense of identity; and if they fail, they remain confused about their aims and goals.

Stage 6: Intimacy versus Isolation: 

Young adults face the challenge of developing intimate relationships with others. If they fail to do so, they may become isolated and lonely. 

Stage 7: Generativity versus Self-Absorption: 

Middle-aged adults work to become productive members of society through jobs or parenting. If they fail to do so, they become self-absorbed. Stage 

8: Integrity versus Despair: 

Old people examine their lives and develop either a sense of satisfaction or a sense of disappointment about their lives. 

The theory of psychosocial development addresses stability as well as change in personality. Personality is stable to some extent because childhood experiences influence people even as adults. Personality also changes and develops throughout life as people face new challenges. This theory of Erikson has a disadvantage that he described only a typical pattern with many stages of development. This theory failed to acknowledge the differences among individuals.

Piaget’s Theory of Cognitive Development 

Jean Piaget‟s theory of cognitive development describes and explains the development of an individual‟s thought processes, and their effect on our understanding and interaction with the world. The theory of cognitive development includes the steps and sequence of children‟s intellectual development: 

1) Sensorimotor Stage: 

It is the time period between birth and 2 years of age during which an infant‟s knowledge about the world is limited to his/her sensory perceptions and motor activities. The infant‟s behaviour is limited to simple motor responses to sensory stimuli. 

2) Pre-Operational Stage: It is the time period between 2 to 6 years of age during which a child learns language. However, he/she does not understand the real logic, cannot mentally manipulate information and cannot take the opinion of others. 

3) Concrete Operational Stage: It is the time period between 7 to 11 years of age during which a child gains better understanding of mental operations. He/she starts thinking logically about real events but is not able to understand abstract or hypothetical concepts. 

4) Formal Operational Stage: It is the time period between 12 years of age to adulthood when an adolescent starts thinking about abstract concepts, and develops skills of logical thinking, deductive reasoning, and systematic planning.

Fowler’s Theory of Spiritual Development 

According to Fowler, faith is a universal human quality exhibited through religious beliefs, rituals, and symbols. It is a multi-faceted and a method to learn about life. Spirituality affects the person mind, body and spirit. Following are the stage of development of faith: 

Stage 0- Undifferentiated: 

During infancy, children have no concept of right or wrong, no beliefs, and no convictions to guide their behaviour. Stage 1- Intuitive Projective: Toddlerhood is mainly about copying actions of others. The religious gestures and behaviour is copied by the children without understanding the significance or purpose of the activity. 

Stage 2- Mythical Literal: 

During this time, spiritual growth is closely linked to children‟s experiences and social connections, and it occurs at the same time as cognitive development. Bad behaviour is penalised and good behaviour is rewarded. 

Stage 3- Synthetic Convention: 

As children approach puberty, they become more sensitive of spiritual dissatisfaction. They may begin to abandon or change some religious behaviour as they learn that prayers are not always answered. 

Stage 4- Individuating Reflexive: 

In this period, adolescence becomes more conscious of self and others‟ emotions, personalities, patterns, behaviours, ideas, thoughts, and experiences. They begin to compare and contrast their parent‟s religious beliefs. Self-concept determines the way that an individual describe themselves. All of an individual‟s concepts, beliefs, and convictions that make up his or her interaction with others are referred to as self-concept.

Kohlberg’s Theory of Moral Development 

Lawrence Kohlberg focused on moral reasoning, and proposed that people pass through the following three levels of moral development (each level divided into 2 stages): 

Level 1: The Pre-conventional Level: 

At this level, children ascribe great importance to the authority of adults. In the first stage of this level, an action is wrong if it is punished; and in the second stage, an action is right if it is satisfied. 

Level 2: The Conventional Level: At this level, children follow rules to get approval from others. In the first stage of this level, children want the approval of closed ones; and in the second stage, they become more concerned with the rules of broader society. 

Level 3: The Post-conventional Level: At this level, people become more flexible and consider those personally important to them. In the first stage of this level, people want to follow society‟s rules, but do not see those rules as absolute; and in the second stage, they decide what is right and wrong for them, based on ethical principles. 

Child Welfare and Rights of Children in India

Child welfare includes various services designed to provide safe circumstances to the children and to provide support to the families in caring their children properly. 

Child welfare agencies aim for: 

1) Providing support and managing services against child abuse and negligence. 

2) Providing social protection to the required families and care for their children. 

3) Handling reports of possible child abuse and negligence. 

4) Assessing child and family needs, strengths, and resources. 

5) Arranging accommodation for children when safety cannot be ensured at home. 

6) Ensuring the health, educational needs and well-being of children living with relatives or foster families. 

7) Family reunification, adoption, or other permanent family connections for children and youth leaving foster care. 

Rights of Children:-

 Rights of children are categorised under human rights that are exclusively designed according to the children needs, desires and overall welfare. These rights are drafted as per the age requirement, fragility, and specificities. These rights aim to fulfil all the requirements for healthy child development.

In the year 1991, India becomes an ethical labour market to international corporations that had been ratified in the year 1992 at the United Nations Convention on the Rights of the Children. This initiative was based on the Jebb‟s

desire to end children‟s sufferings, instead of providing them healthy, happy and safe atmosphere to nurture them physically, mentally and psychologically. In the convention, all the rights of children are explained under the following heads while considering various articles and research studies:

1) Right to Identity: 

Each child should be entitled to a name, legally registered with the government, and a nationality (to belong to a country). They also must have the right to an identity in public records. Such arrangement ensures national support and also access to social services. 

2) Right to Health: 

Under right to health, medical care, nutrition, protection from harmful habits (including drugs) and safe working environments are included. In articles 23 and 24 of the right to health special care and support for children with special needs, and quality health care (including drinking water, nutrition, and a safe environment) are included, respectively. 

3) Right to Education: 

In India right to education is a fundamental right for children. According to this, under article 21a of the Indian constitution it is the duty of the state to provide free and compulsory primary education for every child between the ages 6 and 14. It helps in developing discipline, life skills while discovering a safe and healthy environment to nurture a child‟s physiological development. 

4) Right to a Family Life: 

It is the fundamental right of children to live with their parents until they are not harmed anyway. Though, „family reunification‟, which means asking for permission from respective governments to travel to renew contact between family members, if they are living in different countries. If family members are not available, children have the right to be looked after by caretakers. Under this right, there is a provision that children should be provided privacy against attacks on their living style and personal history, under their ward of a caretaker or family. Special care must be given to the children who do not have access to a family life. In such cases, children are looked after by people of their ethnic group, religion, culture and language. Special protection and help are provided to the refugee children. In case of any offense or violation, children have the right for any legal help under a juvenile justice scheme, with the transparent and quick resolution of the events. 

5) Right to be Protected from Violence: 

According to this right it is the duty of state to protect child from violence which may extend even to family members, and should ensure that children should not suffer ill-treatment or sexual or physical violence. This describes use of violence as a means of discipline. Any form of sexual exposure and physical abuse is unacceptable. This Article also stands against the sale of children, child prostitution and child pornography. 

6) Right to an Opinion or Freedom of Expression: 

It is the right of all children to express their opinions, free of criticism or contempt as long as they are not harming others with their opinions and actions. In case of minority, where adults are actively deciding upon choices on behalf of children, in the latter phase child‟s opinions are taken into consideration. As most of time children‟s opinion may not be based on facts, it is however an important source of insight for parents, and should be considered. But it mainly depends on the maturity level and age of the child. 

7) Right to be Protected from Armed Conflict: 

Armed conflicts often result to vast destruction and disturbances, and in case of children this condition becomes more adverse. Such circumstances convert innocent children into refugees, prisoners, or participants in armed conflicts. Any such spirit of War or any armed struggle can severely damage a child‟s moral as well as perceptions of ethics, and this must be corrected and rehabilitated in a nurturing safe environment. While seeking to rehabilitate children affected by war, it is the duty of the government to ensure that children are not forced to participate in any armed struggle. 

8) Right to be Protected from Exploitation: 

Protection of children from violence is critical for freeing children from exploitation that may include abuse, negligence and violence by parents, even if it is justified as an instrument of achieving discipline at home. Along with this, any dangerous or difficult work is totally avoided for children. Anyone cannot force them to work, and if children want to work voluntarily may go for safe works that do not compromise their health, or access to education or play. Sexual exploitation, another aspect of exploitation or an activity that takes advantage of them, is a crime. Special rehabilitation facilities are provided for the survivors of neglect, abuse and exploitation so that they can recover and reintegrate into society as early as possible. Children cannot be punished with cruelty, even if it is under the ambit of the justice system. Severe punishments like death or life sentences, and sentences with adult prisoners, are completely prohibited. 

National Policies Related to Child Health and Welfare:-

According to the national policy of child health and welfare “it shall be the duty of the state to provide required services to children, both before and after birth and during their growing age. As well as state should ensure full physical, mental and social development of children of the country. The state shall gradually increase the area of these services so that state can provide optimum condition for healthy and balanced growth for all their children within a reasonable time”. 

Following measures are adopted to achieve the objectives of this policy:

 1) All children of the country shall be covered by a comprehensive health programme. 

2) Various schemes shall be designed and implemented to provide nutritional services aiming to remove deficiencies in the diet of children. 

3) Running various programmes to upgrade child health and for care, nutrition and nutritional education of expectant and nursing mothers. 

4) The state shall provide free and compulsory education for all children up to the age between 6 and 14. 

5) State shall provide out-of-school education for those not having access to formal education. 

6) State shall promote games, recreate and extracurricular activities in schools and community centres for overall growth of the children. 

7) For children belonging to weaker sections of society special programs shall be designed which ensure equality of opportunity and special assistance. 

8) Facilities for education, training and rehabilitation for socially backward children.

9) Protect children from negligence, cruelty and exploitation. 

10) No child under 14 years shall be allowed to involve in any hazardous occupation or heavy work.

 11) For physically handicapped, emotionally disturbed or mentally retarded children special treatment, education, rehabilitation and care shall be provided by the state. 

12) In times of distress or natural calamity children shall be given priority for protection and relief. 

13) Special programs should be formulated to spot, encourage and assist gifted children belonging to weaker sections of society. 

14) In all legal disputes priority shall be given only to the interest of children. 

15) All the efforts should be made to strengthen family ties so that children may get chance to grow within healthy family, neighbourhood and community environment.

National Legislations Related to Child Health and Welfare:-

Under child welfare legislation such laws and acts are included which provide care, protection, welfare and rehabilitation to children, also covering conflict with law can be ensured. These legislations are empowered by the various constitutional provisions (like articles 24, 39, and 45), national policy for children, provisions adopted by government of India in 1974 and United Nations declaration on rights of children. 

Legislations 

1) The Child Marriage Restraint Act, 1929. 

2) The Child Labour (Prohibition and Regulation) Act, 1986. 

3) The Juvenile Justice (Care and Protection of Children) Act, 2000. 

4) The Infant Milk Substitutes, Feeding Bottles and Infant Foods (Regulation of Production, Supply and Distribution) Act, 1992. 

5) The Pre-conception and Pre-natal Diagnostic Technique (Prohibition of Sex Selection) Act, 1994. 

6) The Persons with Disabilities (Equal Opportunities, Protection of Rights and Full Participation) Act, 1995. 

7) The Immoral Traffic (Prevention) Act, 1956. 

8) The Guardian and Wards Act, 1890. 

9) The Education for All Handicapped Children Act, 1975. 

10) Health Maintenance Organisation Act, 1973.

Menstrual Hygiene for Girls

Female empowerment and welfare around the world are largely based upon the menstrual hygiene. Although sanitary pads and proper toilets are necessary; another important aspect is to make such an environment for the female that supports their ability to handle their menstruation with dignity. Menstrual Hygiene Day is celebrated on 28th May every year.

Measures Taken To Maintain Menstrual Hygiene 

1) The girls should bath or shower at least one time in a day. 

2) Good quality sanitary napkins should be used. Those having sensitive skin should not use plastic-lined sanitary napkins as it causes rashes and itchiness on rubbing against the skin. 

3) They should wear clean underwear and change it daily. 

4) Washing genital area with soap or vaginal hygiene products should be prohibited as the good bacteria may get killed. After using toilet or after urination, vaginal area should be cleaned with warm water. 

5) Genitals should be always washed or wiped from front to back as chances of bacterial infection increase while cleaning from back to front (i.e., from anus to vagina and urethral opening). 

6) To avoid vaginal irritation, it should be dried properly after each wash. It is recommended to use antiseptic powder for keeping the genital area dry, before wearing sanitary napkin, and after washing the vagina. 

7) For protection against infections, they should be advised to change sanitary napkins in every six hours and tampons in every two hours. 

8) After changing sanitary napkins, tampon or menstrual cup, hands should be washed properly with warm water and soap. 

9) Females should wear loose and comfortable clothes during periods to allow air flow in the vaginal areas and avoid sweating around the sensitive areas. 

10) Menstrual hygiene is very important for health, welfare, strength and productivity of all females. 

Materials Used In Menstrual Hygiene 

1) Menstrual Cloth: 

These cloths are recyclable fabric pieces used for external purpose, as undergarments and to absorb menstrual fluid. These cotton fabrics are mostly new or are the old reused ones. 

2) Reusable Pads:

 These are worn externally to the body inside the underwear for the absorption of menstrual fluid. Various natural and synthetic materials are used for making sanitary pads. They can be reused for around a year by washing and drying after use. 

3) Disposable Pads: 

These are also worn externally to the body inside the underwear for the absorption of menstrual fluid. These are available in different sizes, absorbing range and are made up of mixture of plastics, rayon and cotton. They should be discarded after 8 hours of use. 

4) Tampons: 

These are absorbent materials that are inserted into the vagina to absorb the menstrual fluid to prevent leakage by their property of expanding with moisture. They are available in different sizes, and are made from cotton and/or rayon. They should be disposed of after 8 hours of use. 

5) Menstrual Cup: 

It is a bell-shaped device that is inserted into the vagina for the collection of menstrual fluid. It is kept in place by the vaginal walls and develops a seal. It is made up of medically-used silicone. It is used for 6-12 hours and collects three times more blood than pads or tampons. It collects three times more blood than pads or tampons and should be emptied every 6-12 hours. After which it should be rinsed and re-inserted. The menstrual cup should be boiled for at least 5-10 minutes after each menstruation cycle

Role of Parents in Sex Education

Sex education provides knowledge, ability and encouragement for making healthy choices about sex and sexuality. Children should understand that no one should touch their body without their permission. They should know that other people can touch them in some ways but not in wrong ways. They should know that except for their parents or health-care providers, no one should ask them to touch their genitals. If they know about what is right and what is wrong, they will be more able to tell their parents about sexual abuse (if they experience it). Children should learn to ask before touching someone (e.g., hugging, tickling). 

They should learn about limits (e.g., understanding when someone takes a step away, and should respect that person’s signal for space). Children should be taught about privacy around body issues (e.g., they should know when it is appropriate to be naked). Children should learn about other body parts and their functions. For example, some children of this age think that girls have one opening for both stool and urine, some believe that babies grow in the same place their food goes, and so on. 

Steady growth and development occur in the school-age years. Staying physically active during this developmental phase builds up the fundamental skills required for a healthy and active life as an adult. These skills include agility, balance, coordination, and endurance. Learning and developing these skills will also affect the child’s confidence and self-respect, and will provide them with a sense of accomplishment and independence.

Objectives and Importance of Sex Education 

1) To teach children about the reproductive structures of men and women and to provide information about birth. 

2) To educate children to understand their role and responsibility of their own gender by obtaining sex knowledge. For the development of their future relationships with friends and lovers, the children need to understand the differences and similarities between the body of male and female. 

3) Sex education helps the individuals to accept themselves and teach how to deal with their personal relationships. 

4) It also makes individuals aware of their responsibility towards others and oneself. 

Process of Sex Education 

1) Choose the Right Time, Ask Questions and Provide Answers: 

i) Sex education should be provided in suitable situations. 

ii) Children should be made to watch relevant TV programmes to make them think and ask questions about it. 

iii) Discussion of sex with children in the presence of other people should be avoided as they may feel discomfort or embarrassed.

2) Establish their Confidence and Holistic Development: 

Children should be educated to have relevant and positive thoughts of sex to obtain self-acceptance. 

3) Use Proper Materials Keep-up with Time:

i) The growth of children’s intelligence should be understood to provide answers even for the same question to fulfil their curiosity. 

ii) Before giving answers to children’s questions, their knowledge about the topic should be evaluated and then answer using the words they know. 

4) Understanding Themselves and their Children 

i) Mutual trust is very essential to establish. 

ii) Parents should take part in the children’s activities and conversations to understand their way of thinking and their values and also to develop the communication with children to teach concepts about sex. 

iii) Parents should discuss about sex issues of children and give related solutions. 

5) Be Kind and Patient:

i) Parents should listen to their children carefully, be kind and patient to them, and talk in a soft and natural way. 

ii) Instead of getting angry when the views of children about sex differ from that of parents, they should listen to them and peacefully explain their views to them. 

6) Be Honest and Objective:

 i) Parents should give honest and relevant answers to children’s questions on sex. 

ii) Parents should find out whether or not the children know the answers. If not, they should help them to search the answers in books or from other sources. 

7) Make use of Education Materials: For better discussion on sex education, many books or videotapes can be used by the parents. 

8) Broaden their Social Circle and Seek Support: 

i) For expanding the social circle of children, they should be encouraged to participate in extra-curricular activities. 

ii) Parents should know the content of sex education being provided to schools for better coordination with them. 

iii) Parents should take part in programmes organised for parents based on children’s growth and sex education to obtain suitable information. 

Bones in Human Body, types of bones and structure of bones?

Definition of Bones:

Osteology is the study of bones and teeth. It is usually applied in the fields of anthropology, forensic science, and archaeology for various functions like the determination of nutritional value, health, and also to determine the position of bone within the body.

Types of Bones in Human Body:

Bones are categorised into five classes on the basis of the following salient features:

1) Long Bones: 

These bones are characterised by the presence of a shaft. They have longer lengths as compared to the widths. They end in a number of extremities, e.g., femur, tibia, fibula, humerus, ulna, and radius. They are usually slightly curved, thus impart high strength to these bones.

2) Short Bones: 

These bones are characterised by an almost equal length and width, e.g., ankle and wrist bones. They are more or less cubical in shape. 

3) Flat Bones: 

These bones are characterised by a thin shape or structure. They offer wide surfaces for muscle attachments and thus provide substantial mechanical protection, e.g., cranial bones (protecting the brain), the sternum and ribs (protecting the organs in the thorax), and the scapula (shoulder blades). 

4) Irregular Bones: 

As the name suggests these bones are asymmetrical in shape and therefore are said to have complicated shapes. They are shaped to fulfill certain specific functions within the body. For example, the vertebrate and some facial bones; provide major mechanical support to the body while also protecting the spinal cord. 

5) Sesamoid Bones: 

These bones develop in some tendons in areas where there is considerable friction, tension, and physical stress. Therefore, these bones are formed in the palms of the hands and the soles of the feet [patellae (knee caps)]. 

6) Sutural Bones: 

These bones are very small and are found within the sutural joints in between the cranial bones. They are categorised on the basis of their location and not shape. For example, suture bones are present in the cranium.

Macroscopic Structure of Bones:-

Internally, bones differ in their structural composition and comprise the following structures: 

1) Compact Bone: 

It is the hard outermost layer of bone. This bone is named compact as it has minimum voids and gaps and hence is also known as dense bone or cortical bone. The tissue is responsible for providing a smooth, white, and sturdy outlook to the bones. 

Haversian systems or osteons are the main characteristics of compact bone (figure 4.2). These are minute cylindrical structures. Osteons consist of concentric layers of collagen called Haversian lamellae; within these lamellae a central Haversian canal is present. These Haversian canals carry blood vessels, lymph vessels, and nerve fibres. A transverse canal known as Volkmann’s canal is found to connect Haversian systems with one another. Small tiny spaces known as lacunar are present in compact bones. These lacunae have tissue fluid and spider-shaped osteocytes. 

These osteocytes have long processes known as canaliculi, which join with each other and form a network. Periosteum covers the outer surface of bones. It is made up of a dense layer of vascularised connective tissue. 

It has two layers, the internal layer is osteogenic while the outer layer is fibrous in nature. Periosteum does not cover the joints. It is heavily innervated with nerves, blood vessels, and lymph vessels.

Cross-Sectional Structure of Compact and Cancellous Bone

2) Trabecular Bone: 

It is also known as spongy bone or cancellous bone. The interior of the bone is filled with trabecular bone tissue. This tissue is a network of open cells containing spongy or cancellous bones. The trabecular bone contains rods and plate-like elements which make the overall network of bones lighter and provides space for blood vessels and bone marrow. This lighter mass constitutes 20% of the total mass of bone but has ten times greater surface area than the compact bone.

Microscopic or Cellular Structure:

Bones are made up of different types of cells such as: 

1) Osteoblasts: 

These are mononucleate cells formed by the precursor osteoprogenitor cells. They are present on the outer portion of osteoid seams and lead to the formation of a proteinaceous mixture called osteoid. The osteoid gets mineralised by the addition of calcium and phosphorus to form the bone. 

2) Osteocytes: 

Osteoblasts that have migrated into the bony matrix gets trapped and give rise to osteocytes or mature bone cells. They occupy specific spaces called lacunae. They are the mature cells of bone. They tend to regulate the response of bone to stress, probably due to the presence of mechano-sensory receptors. 

3) Osteoclasts: 

These are large, multinucleated cells responsible for remodelling of bone in order to reduce their volume. This process is also known as bone resorption. These cells are located in small depressions on the surface of bones which are called Howship’s lacunae or resorption pits. In case of fracture or breakdown of bones, these resorption pits are left behind and appear as scalloped surfaces. 

i) They also consist of collagen fibres lying parallel to other fibres present in that layer.

ii) In lamellar bone, the direction of fibres is opposite in each alternate layer. This arrangement gives strength to bones so that they can withstand torsion forces. 

iii) When a bone breaks, the lamellar bone is replaced with a woven bone (since it grows rapidly) and this is termed as a bony substitution. It takes place on the hyaline cartilage which is then calcified. 

What is Cell in Human Body ? Functions and Components of Cell?

A cell is the basic structural and functional unit of all living organisms. All living organisms can be categorized into unicellular (e.g., protozoa, yeast, and bacteria) or multicellular organisms (e.g., plants and humans). A human body consists of about 100 trillion cells with a size and mass of 10µm and 1 nanogram respectively.

Cells are of two types: 

1) Prokaryotic Cells: 

These cells do not have a well-developed nucleus, though they have some other organelles present as in the eukaryotic cells. For example, archaebacteria, etc. 

2) Eukaryotic Cells: 

These cells have a well-developed nucleus and other organelles. For example, plants, animals, etc. A cell performs the following functions: 

1) Cell Growth and Metabolism: 

Cells grow either by increasing their number or their size. During the metabolism, various anabolic and catabolic processes occur. In catabolic processes, the breakdown of complex molecules occurs within the cells to produce energy; while during the anabolic processes, cells utilize energy to synthesize complex biomolecules and perform other biological functions. 

2) Cell Division: 

It involves the splitting of a single cell, i.e., the mother cell splits into two daughter cells. This results in the growth of multicellular organisms and the breeding (vegetative reproduction) of unicellular organisms. During the cell division, DNA is also synthesized and the process is known as replication. 

3) Protein Synthesis: 

It occurs within the cells, by two major steps, i.e., transcription and translation. 

4) Molecule Transport: 

The cell must be able to acquire nutrients and other molecules to survive.

Components of Cell 

A cell comprises the following three basic components: 

1) Cell membrane (or plasma membrane), 

2) Cytoplasm, and 

3) Nucleus. 

Cell Membrane/Plasma Membrane:-

The cell membrane is a selectively permeable biological membrane, allowing only certain substances to pass through it. It acts as a barrier between the inner and outer surface of the cell. It is also known as the plasma membrane or plasmalemma. It comprises mainly of proteins and lipids, along with other living molecules. These molecules are important for the normal functioning of the cells, e.g., in an ion channel conductance, cell adhesion, and cell signalling.

Properties of Cell Membrane:-

 1) It guards the cell against the external environment. 

2) It allows cellular transport between cells. 

3) It has transmembrane receptors (binding the signaling molecules) which helps in signal transduction and provide selective receptivity. 

4) It helps in recognising a cell. 

5) It has binding sites for the constituents of the cytoskeleton present in the external environment. 

6) It divides the cell into smaller sections having different structures and functions. 

7) It offers a stable site for the catalysis and binding of enzymes.

8) It allows the fusion of cell membrane with other membranes of cell organelle through special points of attachment. 

9) It regulates the transfer of certain specific molecules through the cell membrane, e.g., gap junctions. 

10) It enables motility of the cellular organelles. 

Structure (Fluid Mosaic Model):

To explain the nature and functions of cell membrane various models had been proposed in past, as mentioned below: 

1) Danielli and Davson model/Lamellar theory, 

2) Unit Membrane model, 

3) Robertson’s model, 

4) Lipid Bilayer model, and 

5) Fluid Mosaic model.

Structure of the Cell Membrane

However, out of the above given models, the Fluid Mosaic Model (figure 2.2) is the most accepted one. The fluid mosaic model of the plasma membrane was given by S.J. Singer (University of California) and G.L. Nicholson (Salk Institute) in the early 1970s. 

According to this model, proteins do not form a continuous layer extending from one side of the membrane to the other rather it is present in the form of globules, dotted randomly in a mosaic pattern. Some globules of the protein penetrate into the membrane to deeper extents; some of them remain attached to the membrane surface, while some globules extend through it and adhere to the other side. It explains the rigidity of the cell membrane. Experiments on viscosity of membrane show that it has a fluid-like consistency. This fluidity allows movement of lipid and protein molecules within it. Due to the fluidity and mosaic arrangement of the protein molecules, this model is known as the Fluid Mosaic Model.

Functions of Cell Membrane:

Cell membrane has the following functions: 

1) Protection of Cells: The receptors present on the cell membrane allow chemical messages to pass between the ells and systems, and thus provides protection to cells.

2) Providing Cytoskeleton and Mechanical Support: It provides a specific shape to the cell. It provides mechanical support and maintains the membrane potential. Attachment proteins present on cell membrane bind the extracellular and intracellular components. 

3) Separation from Surroundings: In an animal cell, it separates the internal environment from that of the external. Other organisms, including fungi, plants and bacteria, consist of an additional layer known as cell wall, forming the outermost protective layer. 

4) Permeability: It is a selectively permeable membrane as it allows the passage of solvent and several selected solutes while holding back the others. 

5) Tissue Formation: Groups of similar cells together form tissues. 

6) Particle Transportation: This occurs by various mechanisms like ion channel, carrier proteins, and ion pumps. Chemical exchange of solute between extracellular medium and cytosol is mediated by transport of channel and carrier proteins. 

7) Contribution to Enzyme Activity: It controls the activity of enzymes which further participate in metabolism and immune system. 

8) Control of Neurohormonal Flow: Receptor proteins on cell membrane mediate the flow of neurohormonal and other chemical information from extracellular medium to the cytosol. 

What is the meaning of Human Anatomy and Physiology?

The systematic study of the human body is performed under two disciplines, i.e., anatomy (structure) and physiology (function). Anatomy is the study of different structures of the human body and their relationship with each other, while physiology is the study of the functioning of these structures. Anatomy is made up of two Greek words, ana means up and temos means to cut. Anatomy is the science of body structures and coordination among the various body structures. It is a general term which includes human anatomy, animal anatomy (zootomy), and plant anatomy (phytotomy).

Anatomy is sub-divided into: 

1) Gross Anatomy: It is also known as topographical anatomy, regional anatomy, or anthropotomy. It includes the study of such anatomical structures which can be seen with the naked eyes. 

2) Microscopic Anatomy: In this type of anatomy, very minute anatomical structures (tissues and cells) are studied with the help of microscopes. 

3) Superficial Anatomy or Surface Anatomy: This type of anatomy is of prime importance as it includes the study of anatomical structures that can be seen from the body. With the knowledge of superficial anatomy, physicians or veterinary surgeons gauge the position and anatomy of the associated deeper structures. 

4) Comparative Anatomy: In this type of anatomy, the comparison of anatomical structures both gross and microscopic present in different animals is studied

The Greek words physics (nature) and logos (study) combine to form the term physiology, which covers the study related to the mechanical, physical, and biochemical functions of living organisms. It can be also defined as the study related to the science of various body functions and their working.

Scope of Human Anatomy and Physiology:- 

The anatomy and physiology together form the foundation of medical sciences; their scope is vast that can be summarised in the following terms: 

 1) Study of human anatomy provides an essential base for the understanding of physiology and pathophysiology, 

2) Helpful in the study of human evolution and development, 

3) Inquiring into the fascinating complexity of the structure and function of the human body, 

4) Mass therapy and athletics health-related field training,

5) As a foundation for advanced scientific studies, 

6) To understand the pathology of disease and pathological changes, 

7) To determine the techniques of surgeries, 

8) To know the parameters of normal health, 

9) To understand the effects of various factors in the physiological processes and its effects like a change in the environment, etc., and 

10) Overall effective maintenance of individual and community health.

Definition of Various Terminologies Used in Anatomy 

For study point of view, medical science divides the body into various anatomical planes (flat surfaces), which are the imaginary lines (vertical or horizontal) drawn through an upright position of the body.

 The anatomical terminology of the body can be studied under three groups: 

1) Directional terms, 

2) Sectional planes/planes of the body, and 

3) Body cavities

Directional Terms 

Directional terminologies are used to locate one body structure with respect to the other. The anatomical position of a human can be described with the help of the following terms: 

1) Superior (Upper, Cranial) End: The end of the head lies in the uppermost position, therefore it is known as the superior end of the extremity. 

 2) Inferior (Lower) End: This part starts from the extremity of the main body or the trunk along the legs in the downward direction or ground. 

 3) Anterior or Ventral End: This includes the body parts present on the front side, like chest, nipples, abdomen, and external genitalia. 

4) Posterior or Dorsal End: This includes the body parts present on the back side, i.e., vertebral column (also known as the backbone), shoulder blades, and buttocks. 

5) Supine Position: In this position, the face is towards the upper side (roof) while the back faces downwards. 

6) Prone Position: In this position, the face focuses downwards or towards the ground. 

7) Medial Position: It is an imaginary line passing through the longitudinal axis of the body, dividing it into two equal halves from the middle, starting from front to the back. 

8) Lateral Position: It is that anatomical position of the body in which it is divided into two fragments through the midline and the body structures remain away. 

9) Proximal: It describes a body part that is closer to a point of attachment or closer to the trunk of the body than another part. For example, the elbow is proximal to the wrist

10) Distal: This position is the opposite of proximal. It means that a particular body part is farther from the point of attachment or farther from the trunk of the body than another part. For example, the fingers are distal to the wrist. 

11) Superficial: This position means situated near the surface. 

12) Peripheral: This position means outward or near the surface

Planes of the Body

 Following are the various planes in which the human body is classified: 

 1) Sagittal: 

In this plane, an imaginary line slicing the body (from head to toes) into two halves with erratic proportion is drawn, from top to the down. A mid-sagittal plane runs parallel to the medial plane, i.e., the plane of sagittal runs from the middle. Distinct to that of coronal plane, it starts from the nose to back of the head and moves vertically from one ear to the other.

2) Horizontal: 

This plane is parallel to the ground and passes through the body at the 90° angle to both coronal and medial plane. 

3) Coronal: 

This plane divides the body into anterior (front) and posterior (back) portion, by passing through the body at a right angle to the medial system. Medically, anterior means the front portion and posterior means the back potion. Some terms can be used interchangeably like ventral for front and dorsal for the back. 

4) Lithotomy Position:

 In this position, the individual is lying on the back with thighs fully stretched and knees directing towards the roof.

Body Cavities

 Cavities are the spaces of the body, containing viscera and internal organs. The two main cavities of the body are dorsal cavity and ventral cavity. Ventral cavity is a large cavity which is further subdivided into the thoracic and abdominopelvic cavity. Both these cavities are separated by dome shaped respiratory muscles called diaphragm. 

The different types of body cavities are

1) Thoracic Cavity: 

This cavity is present ventrally on the upper side of the body. It is also known as the chest cavity, which is laterally attached to the ribs (covered by costal, pleura) and caudally to the diaphragm (covered by the diaphragmatic pleura). This cavity contains the trachea, lungs, heart, oesophagus, nerves, and large blood vessels. 

2) Abdominal and Pelvic Cavity: 

The ventral cavity is also known as the abdominopelvic cavity. This cavity is further divided into two parts: 

i) Abdominal Cavity: This cavity is laterally attached to the body wall, posteriorly by the pelvic cavity, and anteriorly by the diaphragm. This cavity contains maximum part of the gastrointestinal tract, kidneys, and adrenal glands. 

ii) Pelvic Cavity: This cavity is bounded dorsally by the sacrum, laterally by the pelvis, and anteriorly by the abdominal cavity. The pelvic cavity contains the maximum part of the urogenital system as well as the rectum. 

3) Dorsal Cavity: This cavity is the smallest amongst the other two main cavities. In this cavity, the organs are situated more posteriorly within the body. Further, the dorsal cavity is sub-divided into two parts. The first part includes cranial cavity (upper portion which houses the brain,) and the second part includes spinal cavity (lower portion which houses the spinal cord).