CLEAVAGE

 The human egg is alecithal because it is contain a negligible or no yolk .

Thus the cleavage division in human is holoblastic i. e. it divides the zygote completely into daughter cells or blastomeres .

It is a series of mitotic division of zygote ,resulting increase in the number of cell .

These cells which becomes smaller with each cleavage divisions are know as blastomeres .

The first cleavage division occurs approximately 30 hours after fertilization to form two cell stage .

Approximately 40 hours after fertilization four cell stage occurs .And three days after fertilization 12-16 cell stage are formed .

Until the eight cell stage they form a loosely arranged clamp. After the third cleavage however blastomeres maximized their contact with each other forming a compact ball of cells held together by tight junction this process is called compaction .

The process compaction segregates inner cells which communicate extensively by gap junction from outer cells .

Approximately days after fertilization cell of the compacted embryo divided again to forma 16 cells morula .

The inner cell of the morula constitute the inner cell mass and surrounding cell compose the outer cell mass .

The inner cell mass gives rise to tissues of the embryo proper and the outer cell mass forms the  trophoblast which later contributes to form the placenta .  

IMMUNITY

 Immunity is the ability of an organisms to resist a particular infection or toxin by the action of specific antibodies .

  The immunity is two types 

 I- Innate immunity or non-specific defance mechanism

II- Acquired immunity or specific defence mechanism 

1- Innate immunity 

This type of immunity is present in an organisms by birth.

The innate immunity includes certain barriers and defence  mechanism that keep foreign particles out of the body .

 There are 4 types of barriers  

a- physical barriers

b- physiological barriers 

c- cellular barriers

d- cytokine barriers

a - physical barriers 

These includes the skin , nasal , hairs , mucous , membrane of nose ,respiratory tract and digestive tract.

These form the first line of defence .

They prevent the entry of pathogens into the body primarily .

b- physiological barriers 

These includes 

Lysozymes - These are present in tears and is bacteriolytic and digests the bacterial walls .

Acid in stomach - The HCL is secreted in side the stomach which kills most of the ingested microorganisms .

Saliva - The antibacterial properties of saliva prevent many harmful pathogens from eating the body .

 Cellular barriers - certain types of leukocytes of our body like polymorpho-nuclear leukocytes monocytes and natural killer in the blood as well as macrophages in tissues can phagocytocite and destroy microbes .

d- cytokine barriers 

virus infected cells secreted proteins called interferons which protect non-infected cells from further viral infection .

II- Acquired immunity 

The immunity which develops during lifetime by exposure to suitable foreign agents like microorganisms is called acquired immunity .

It is pathogen specific and is characterized by memory .

When the body first encounter a pathogen it produce a response which takes long time to developed and of low intensity called as primary immune response .

And if the body encounters the same pathogen second time it produce highly intensified and quick response called as secondary immune response .

The primary and secondary immune responses are carried out with the help of two special type of lymphocytes present in our blood .

They are a-  B-lyphocytes - These are produce from the bone marrow and get matured in the bone marrow .

They produce an army proteins in response to pathogens into our blood to fight with them called antibodies .

T-lymphocytes - These are produce from the bone marrow but they migrate to the thymus for maturation .

The T-cells themselves do not produce antibody but helps beta cells to produce them.   

    

GESTATION PERIOD OR PREGNANCY

The period of embryonic development in side the womb or uterus starting from fertilization of to birth or parturition is called gestation of pregnancy .

The human gestation period being with the last menstrual cycle and end with the birth of child .

The pregnancy or gestation period lasts about 9 month or 40 week or 280 days . The gestation period is divided into 3 trimester , consisting of 3 month each .

FIRST TRIMESTER 

It is consider 1st week to 13th week .

It is the initial period of development where the complex processes are being carried out .

These include the cleavage division , morula  and blastula formation , gastrulation ,formation of notochord.

Then the organogenesis bring about formation of organs and organ system from the three germ layers i.e. ectoderm , mesoderm and endoderm .

Limbs of the embryo big in to develop as well as the gonads  i.e. testis or ovary.

The baby heart begins to beat .

The nerves and muscles begin to work together . The make a first the eyelids close to protect the developing eye . They will not open again until week 28 .

At this time baby is about 7.5 C.M. long and weight almost 28 grams .

SECOND TRIMESTER

It is consider 14th week to 27th week.

Development of heart is improved or more and now it beats - 150 beats per minute .

The baby is more active . the mother might feel movement or kicking .

The eyes , nose , ears and face develop so that it begins to look like human .

The baby begins sucking motions with mouth .

Eye brows ,eye lashes ,fingernails and toenails have formed the baby can even scratch itself .

The babys bone marrow beings  to make blood cells . The hairs begin to grow baby head . The baby weight about 680 grams and 30 C.M. long .

THIRD TRIMESTER

It is consider 28th week to birth .

Rapid growth of the foetus takes place . The baby is getting bigger and has less space to move around .The movement are less forceful but the mother will still feel them .

Final differentiation of tissues and organs takeplace 

The development of  the brain is advanced .

Grasp and suckling reflexes are apparent . 

The baby bones are soft but fully formed . The eyes can open and close .

The baby organs are capable of  functioning on their own .As  the due date is near the baby may turn into a head down position for birth 

The average birth weight is between 2.8K.G. to 4.1 K.G. and  average length is 48 to 53 inches long .Most full term babies fall within  these ranges but healthy babies come in many different and sizes .     

    

OOGENESIS

 It is the process of production of eggs or ova from the germ cell which are derived from germinal epithelium of embryo .

The entire process of oogenesis divided into three phases .

1- Multiplication phase

2- Growth phase 

3- Maturation phase 

1 - Multiplication phase 

During this phase the primary germ cell divides mitotically to produce a large number of daughter cell called oogonia .

The oogonial cell contain diploid number of chromosomes  .

2 - Growth phase 

Phase of multiplication replaced by phase of growth .

Where oogonial cell is simple enlarged in size due to the absorption of nutritive material from the surrounding medium and also due to synthesis of nucleic acids and proteins .

After this changes each oogonial cell is then called the primary oocyte , having diploid number of chromosomes  .

3- Maturation phase 

During this phase the primary oocytes undergo reduction cell division .

The primary oocytes under go meosis -1 to form 2 unequal haploid daughter cell .

The large one is called as secondary oocyte and the smaller one is called first polar body .

The secondary oocytes then under goes meosis -2 to form 2 unequal haploid daughter cells. the larger one is called ovum or egg and the smaller one is called second polar body .  

GAMETOGENESIS

 It is the process of formation of gametes i.e. sperm and ovum in the gonads  i.e. testis and ovary .It involves two process .

1- SPERMATOGENESIS

2- OOGENSIS 

1- SPERMATOGENESIS

Spermatogenesis is the process of formation of sperm in the testis of male 

It involves two process

A - Spermatogenesis

B- Spermiogenesis 

A - Spermatogenesis

It is the formation of spermatids from primordial germ cells.

It is divided into three phase .

a- Multiplication phase 

b-Growth phase

c- Maturation phase

a-Multiplication phase 

It is the phase , primordial  germ cells divided repidly but mitotically to produce a large number of spermatogonia having diploid number of chromosome 

b-Growth phase 

During this phase the size of nucleus as well as spermatogonial cell enlarge .

This enlargement in the size of the cells due to absorption of nutritive material form adjoining cells and also due to synthetic activity of nuclei ,acid and proteins .

These enlarged cells are now called the primary spermatocyte again having diploid number of chromosome .

During this phase splitting of chromosomes . Linkage and crossing over also take place .

c- Maturation phase 

During this phase , the primary spermatocyte under go two successive reductional cell division .

First of fall it under go miosis -1 to form two equal but haploid cells called secondary spermatocytes.

These secondary spermatocytes undergo miosis-2 to form spermatids having haploid no of chromosomes .

 B- Spermiogenesis 

It is the formation of spermatozoa from spermatids .

This process involves the formation of head , neck , middle piece and  tail .

PNEUMONIA

Pneumonia is an infection in one or both lungs .

It can be caused by bacteria ,viruses or fungi .The bacterial pneumonia is the most common type in adults 

Pneumonia causes inflammation in the air sacs or alveoli of the lungs because the alveoli fills with fluidor pus , making it difficult to breathe .

The most common symptoms of pneumonia may include cough ,fever sweating ,chills shortness breath and chest pain.

Pneumonia can be classified according to an organisms that causes the infection .

1- Bacterial Pneumonia 

The most common cause of bacterial pneumonia is by streptococcus pneumonia .

Clamydophila pneumonia  and legionella pneumophila can also cause bacterial pneumonia .

2- Viral Pneumonia 

Respiratory viruses are often the causes of pneumonia ,especially in  young children and older people. It is usually not serious and lasts for a shorter time than bacterial pneumonia .

3- Mycoplasma Pneumonia 

The mycoplasma are not bacteria and viruses but have traits common to both .They can cause pneumonia in people  with chronic diseases or weakened immune system 

Example - pneumonia cjirovecil pneumonia 

 

RING WORM

It is a fungal infection  on the surface of the skin or scalp .

The medical term for ring worm tinea .The skin disease is further named for the site of the body where the infection occurs .

Some types of ring worm infection include .

Tinea beard-on the beard .

Tinea corporis - on the body .

Tinea pedis - infection of feet .

Tinea capitis - on the scalp .

Tinea craris - grain area .

Tinea facie - on the face .

The ring worm causes  a scally ,crusted rash that may appear as round , ring -likered patches on the skin .

The other symptoms and signs of ring worm include patches of hair loss or scaling on the scalp , itching and blister -like lesions .

Ring worm is contagious and can be passed through directly contact from person to person or by sharing combs , brushes , clothing and other personal care items .

Ring worm can be successfully treated with  antifungal medication used either topically or orally .

PREVENTION

The skin and feet has to be cleand  dry .

The clothing ,tovels , hair brushes , combs , headgear or other personal care items should not be shared .

Sandals or shoes are be used at gams , lockers and pools .

Touching of pets with bald spots can be avoided .  

COMMON COLD

The common cold is an upper respiratory tract infection causes by different viruses called Rhino virus.

It affects nose and respiratory organs.

The common cold transmitted by virus infected air borne droplets or by direct contact with infected secretion .

Being in cold weather does not cause the common cold , but cold weather promotes close contact.

The symptoms of the common cold included cough , sore throat , coughing , sneezing and runny nose .

There is no treatment for common cold but some alternatives are used to get relief .

Symptoms-

Taking rest , drinking plenty of fluids ,gargling with warm salt water . 

Using nasal spry to help relieve nasal symptoms . 

STRUCTURE AND FUNCTION OF PLACENTA

 Placenta is a temprorary endocrine structure i. e. formed between mother and the foetus .

 The placenta has two component 1- a foetal portion formed by the chorionforandosom.

                                                       2-a meternal portion formed by the deciduabasalis .

The placenta connect to the body via the umbilical cord .

The human placenta is called chorioallantoic placenta because a large chorion is fused with the alontois .

The blood of the mother and the feotus do not mixed at all in the placenta or at any other place.

Function ;  Placenta provides food and oxygen to the embryo .

It helps to removal of metabolic wastes such as carbon dioxide and urea from the foetal to maternal blood.

 It provides immunity on the foetus against certain diseases , such as diptheria , smallpox and measles.

It stores fat , glycogen and iron for the embryos liver is formed . 

Placenta acts as an endocrine gland and secret placental hormones i.e. estrogen progesterone CGH and placental lactogen 

TYPHOID

 Typhoid is a bacterial fever caused by the bacteria salmonella typhi .

It is transmitted by ingestion food or water contaminated with the faeces of an infected person .

It affects small intestine, hence the name enteric fever and migrates to other parts of the body through blood .

SYMPTOMS 

The symptoms of typhoid includes ,malaise or weakness ,abdominal pain ,constipation ,encephalitis ,loss of appetite ,ulcers ,severe headache and irritation , dehydration ,hallucination ,dearrhoea ,high fever, skin rashes .

The typhoid fever is diagnosed by the widal test .

The typhoid fever is prevented by 

Washing hands before eating or preparing of food and after using toilet .

By avoiding drinking contaminated water .

By avoiding row fruits and vegetables.

By avoiding food that stored or served at room temperature steaming hot foods are best to serve.

MALARIA

Malaria is a vector born disease by protozoa - plasmodium.

That are affects liver and RBC . Transmitted by biting of female anopheles mosquito which acts as a vector .

SYMPTOMS- High fever occurring alternating days ,chill, vomiting are the common symptoms .

Malarial parasite required two hosts to complete there life cycle . Human is a secondary host and female anopheles is a primary host .

The infective stage of plasmodium vivax is sporozoites .

The plasmodium protozons are 4 types 

1- p .vivax -It causes benign tertian malaria

It fever occurs every 48 hours.

Death rate is low 

2- p. ovale - It causes mild tertian malaria.

It fever occurs every 48 hours .

3- p. malariae-  It causes quartan malaria .

It occurs every 72 hours .

4- p. falceparum -It causes malignant tertian or subtertian malaria .

It  fever occurs every 48 hours .

Death  rate is high .

NATURAL HALLUCINOGENS

 1- LSD -Lysergic Acid diethylamide

 It is derive from ergot fungus .

It is most power full hallucinogen which causes horrible dreams chronic psychosis and server damage to the central naervose system .

LSD also brings about chromosomal and foetal abnormalities .

2- Mescaline

 It is a naturally occurring psychedilic alkaloid .

It is derived from the peyote cactus , the sanpedro cactus ,the peruvian torch and other members of the plant family cactaceoue .

It causes hallucinations , change in moods,day dreams , delusions and depersonalization .

3- Psilocybin 

These are obtained from the psilocybin mushrooms .

These are obtained in the from of liquid or power .

These drugs block the action of serotonin .

Product of hemp plants 

The bhang ,ganja, charas and marijuana are the four drugs obtain from the dried leaves and flower of the hemp plants. 

MTP - Medical Termination of Pregnancy

 Intentional or voluntary termination of pregnancy before full term is called MTP or induced abortion .

45 to 50 million MTPs are performed in a year all over the world .

MTP helps to decrease population .

Many countries have no legalised MTP due to emotional ,ethical ,religious and social issues.

Government of India legalised MTP  in 1971 with some strict condition  to check illegal female foetisides  It is essential in cases where continuation of pregnancy could be harmful  to the mother or to the foetus or both .

MTPs are safe during the first trimester and second trimester abortion are very risky.

CHROMOSOMAL THEORY OF SEX DETERMINATION

Sex determination is a genetic process of determining the sex of organisms .It helps to determine whether the sex of the organisms will be male or female .

Chromosome are of two types 

a- Autosomes or somatic chromosomes- these are regulates somatic characters

b- Allosomes or heterosomes or sex chromosome- these chromosomes are associated with sex determination.

The sex chromosomes first discovered by MC Clung in grasshopper ,X-chromosome was discovered by Henking in 1891and called X-body .

Willson and stevens proposed chromosomal theory of sex determination .

It is evident that the chromosomal mechanisms of sex determination varies in different organisms. 

ANTIBODY

Antibody are the proteins with two long heavy chains and two light or short chains.

The antibody belong to the family of proteins known as immunoglobulin 

Antibody are of five types 

1- IgA - It has dimer structure . It is about 10-15percent in serum antibodies .

It is present in tears ,saliva ,intestine ,milk ,blood and lymph.

Function - It gives protection to mucosal surfaces and provides immunity to infant digestive tract .

2- IgM- It has pentamer  structure . It is about 5-10 percent in serum antibody .

It is present in blood, lymph ,beta cell surface .

It is first antibody produce during infection .

Function - It is effective against  microbes and egg lutinating antigens .

3- IgG-It has monomer structure .It is about 80 percent in serum antibody .

It is present blood, lymph  and intestine .

 It is transferred from mother to foetus through placenta .

Function - It enhances phgaytosis ,neutralizes  toxins and viruses ,protects foetus new born . 

4- IgD - It has monomer structure . It is about 0-2percent in serum antibody .

It is present in beta cell surfaces ,blood and lymph .

Function - create uncertain 

5- IgE - It has monomer structure . It is about 0.002 percent in serum antibody .

It is found attached to most cells and basophils through body ,blood .

Function - It helps to stimulates allergic reaction and lysis of worms.

VACCINATION

It is a process of introduction of vaccines into the body to produce antibody against the antigens to neutralize the effect of the pathogens during actual infection.

Vaccines are the dead or weakened pathogens introduce into the body.

The dead or weakened pathogens leads to production of antibodies which neutralized the pathogenic agents during  actual infection with some pathogens

TYPE OF VACCINES

1- Atenuated whole-agents vaccines - Here the living attenuated microbes are used .

Example - sabin polio vaccine ,vaccine for measles ,mumps and rubella and typhoid vaccines

2- Toxoids - These are inactivated toxins which acts as a vaccines against diseases like tetanus and diphtheria .

3- Inactivated whole agent vaccines - Inactivated vaccines are use against disease like cholera ,rabies, pneumonia etc .  

4- Subunit vaccines - These are antigenic fragments of microbes that stimulate immune responsible .

5- Nucleic acid vaccines - DNA and RNA  acts as a vaccines .

6- Conjugated vaccines - polysaccharides along with proteins together form conjugated vaccines , which is effective against haemophilia influenza  

BIOPATENT

1-The patent is the right granted by a government to an inventor to prevent others for commercial use of his invention .

2- A patent is granted for

a-An invention 

b-An improvement in an earlier invention 

c- The process of generating a product , 

d- A  concept or design 

3- A biopatent is a patent granted by government to the inventor for biological  entities and for product obtained from them .

4-The biopatent are awarded for GM sequences or protein encoded encoded by them ,by different industrial processes various biotechnological producers and products .

5- Biopatent provided incentive for new inventions discoveries they protect intellectual property of an inventor.

Example of biopatent neem and its product , haldi and its product are granted patent to India .

The developed countries like USA, Japan ,European countries granted biopatent .

GENE THERAPY

 It is the clinical therapy of manipulating the genes to treat the genetic disorders.

In this therapy the faulty or non-functional genes are replaced by the functional gene .

The gene therapy is two type 

1- Germline gene therapy 

2 - Somatic cell gene therapy 

Germline gene therapy - The germ cell i.e. sperm and ova are modified by the introduction of functional genes.

Somatic cell gene - The functional gene is introduced only in somatic cell .

Example of gene therapy are;

The first clinical gene therapy was given in 1990 to a four year old girl with ADA .

Most common gene therapy is GENEAUGMENTATION THERAPY 

The over production of proteins to use GENE INHIBITION THERAPY .

DRUG

 A drug is a chemical substance which when taken changes the body function.

DRUG ADDICTION

It is a condition of physiological and psychological dependence on certain drug due to repeated use of drugs for longer period.

Types of drug 

1.Psychotropic drugs -These drugs act on the brain and change behavior  and consciousness, 

Example-Antianxiety drugs ,Anti-psychotic drugs , Diazepam ,Nitrazepam ,etc .

2.Sedative -hypnotics - It is sedative drug. It reduces excitement ,pain and lowers the physiological activity, drowsiness and sleep ,

example - Thiopentone , Secobarbital ,etc .

3. Anti-depressants- these drugs elevate mood in depressive illness and phobic state 

Example - Monoamine oxidase inhibitor- A, monoamine oxidase inhibitor -B.

4. Antimanic drug -These drugs control mania .The abnormal psychological state of excitement . 

Example - Lithium 

5. Opiates narcotics - These are derived from opium . opium is a dried latex of unripe fruit of poppy plant  .

Example - Morphine , codeline ,

The synthetic opiates are hiroin ,pethidine methadone .

6. stimulants . These drug stimulates the nervous  system and make person more active .

Example - Caffeine , cocaine ,amphetamine 

7. Psychodelic drugs or hallucinogens 

These drugs change ones mood ,behavior and thought 

Example - LSD , mescaline ,psilocybin 

8. Hemp plant product - these drug contain THC which is used for hallucinogen 

Example - bhang , ganja , charas.

THALASSEMIA

It is an autosomal recessive blood disorder which occur due to mutation in the genes responsible for the formation of globin chains of haemoglobin .

Due to this disorder the body produces an abnormal form of haemoglobin which results in excessive destruction of red blood cells and further leads to anemia .

The genes for the synthesis of globin chain are present on autosomes i.e. 1-formation of alpha chain is  controlled by two genes i.e. HBA1 and HBA2 present on chromosome no 16 and 2-formation of beta chain is controlled by one gene HBB present on chromosome no 11

This disorder when the progeny receives defective genes from both the parents as THALASSEMIA is expressed in homozgyous  recessive condition 

there are 2 primary forms of THALASSEMIA 1-ALPHA THALASSEMIA 

                                                                            2-BETA THALASSEMIA 

1-ALPHA THALASSEMIA

Normally each person has four genes for alpha globin 

It occurs when one or more of the gene that control the making of alpha globin is absent of defective .There are four main type of alpha thalassemia 

a. Alpha thalassemia major

b. Alpha thalassemia minor

c. Haemoglobin H disease

d. Silent alpha thalassemia carrer

2-BETA THALASSEMIA

It occurs when there are problems with one or both of the beta globin genes. This is the most common type of thalassemia.

Two genes are involved in making the beta haemoglobin chain . Thus beta thalassemia is of  2 types 

a. Thalassemia major

b. thalassemia minor     

AMPHIMIXIS

 The membrane of the head and middle piece of sperm dissolves nucleus centrosome and mitochondria ,when it enters into the secondary oocytes .

Now the sperm nucleus enlarges to form pronucleus and egg those parts rotate through an angle of 180degre so that the mitochondria and proximal centriole of the associated middle place assume the leading position .

The initial path where the sperm penetrates the egg is called penetration path where the secondary path where male pronucleus fuse with female pronucleus is known as copulation path .

the mixing of male and female pronucleus to form zygote is called as AMPHIMIXIS or KARYOGAMY.

The mother is now said to be pregnant.

BLASTOCYST OR BLASTULA

 The blastocyst is composed of an outer layer of tropoblast and inner cell mass

The blastocyst forms when the outer layer of cell of morula absorbs fluid which is called collected in a cavity from with in the cell mass .This cavity is called as blastocoel.

The tropoblast surrounds the blastocoel and the inner cell mass.

The inner cell mass taken part in the formation of the embryo ,where as the tropoblast give rise to the extra embryonic membrane such as chorion and amnion . 

The zona pellucida disappears during blastocyst formation .

HUMILIN

HUMULIN

It is combination of two words human + insulin .The human insulin consist two polypeptide chins i.e. chain A and chain B . Linked by disulfide bridge .

Gene for coding insulin .From human to bacteria is transferred and insulin produced is called HUMULIN .In 1983 ,American company Eli Lily produce genetically engineered insulin called HUMULIN .with the help of E . coli plasmid clone. 

 In 1983 ,Eli Lilly ,an American company  ,prepared two DNA sequences coding for chin A and chin B .