Biology and Biotechnology

Lactation Colostrum .  ( 1 ) Colostrum is the first milk which is sticky and yellowish secreted by the mammary glands soon after the parturition .  ( 2 ) Being high protein in its content , it nourishes the newly born child .  ( 3 ) The antibodies present in it helps in developing resistance for the newborn baby at a time when its own immune response is not fully developed . Lactation (lak-TAˉ-shun) is the production and ejection of milk from the mammary glands. A principal hormone in promoting milk production is prolactin (PRL), which is secreted from the anterior pituitary gland. Even though prolactin levels increase as the pregnancy progresses, no milk production occurs because progesterone inhibits the effects of prolactin. After delivery, the levels of estrogens and progesterone in the mother’s blood decrease, and the inhibition is removed. The principal stimulus in maintaining prolactin secretion during lactation is the sucking action of the infant. Suckling ini...

  Placenta .  1) Placenta is a temporary organ derived from the tissues of the fetus as well as the mother.   2) Human placenta is called chorionic placenta as it is made up of chorion which is an extra-embryonic membrane.Only  (3) Blood vessels from the allantois vascularize the placenta. Branching villi emerge from the chorior and penetrate into the corresponding pits which are located in the uterine wall.   4) There are two parts of placenta, viz. fetal placenta and maternal placenta.   5) Foetal placenta is formed of chorionic villi.   (6) Maternal placenta is formed of uterine wall which is in intimate contact with the chorionic villi.   (7) Chorionic villi receive the blood from the embryo by the umbilical umbilical vein returns the blood back to the embryo.  (8 ) Human placenta is said to be haemochorial because a part of placenta is from fetus which has chorionic villi. The other highly vascularized part is...

  Mammary glands. (1) Mammary glands are accessory organs of female reproductive system. These glands are essential for lactation after parturition  (2) They are modified sweat glands present in the subcutaneous tissue of the anterior thorax. They are in the pectoral region in the location between 2nd to 6th rib.   (3) Each mammary gland consists of fatty connective tissue and many lactiferous ducts.   (4) Each breast has glandular tissue which is divided into 15-20 irregularly shaped mammary lobes. Each lobe has an alveolar glands and lactiferous duct.  (5) Milk is secreted by alveolar glands and it is stored in the lumen of alveoli. The alveoli open into mammary tubules and these in turn forms a mammary duct.   (6) All the lactiferous ducts converge towards the nipple.   (7) The nipple is surrounded by a dark brown colored and circular area of ​​the skin called heqing tabori areola. Structure of mammary gland Mammary Glands Ea...

Alzheimer's disease. ✓ (1) Alzheimer's disease is the most common form of dementia.  (2) Its incidence increases with the age.  (3) Symptoms include loss of cognitive thinking, remembering, functioning, reasoning and behavioral abilities. It interferes with the person's daily life and activities.   (4) It occurs due to loss of cholinergic and other neurons in the CNS and accumulation of amyloid proteins.   (5) There is no cure for Alzheimer's, but treatment slows down the progression of the disease and may improve the quality of life. Alzheimer’s disease (AD) (ALTZ-hı¯-merz) is a disabling senile dementia, the loss of reasoning and ability to care for oneself, that afflicts about 11% of the population over age 65. In the United States, about 4 million people suffer from AD. Claiming over 100,000 lives a year, AD is the fourth leading cause of death among the elderly, after heart disease, cancer, and stroke. The cause of most AD cases is still unknown, bu...

Islets of Langerhans .  What does mean Islets of langerhans? Endocrine cells of pancreas form groups of cells called Islets of Langerhans. There are four kinds of cells in islets of Langerhans which secrete hormones.  (1) Alpha (x) cells: They are 20% and secrete glucagon. Glucagon is a hyperglycemic hormone. It stimulates the liver for glucogenolysis and increases the blood glucose level.   (2) Beta (B) cells: They are 70% and secrete insulin. Insulin is a hypoglycemic hormone. It stimulates liver and muscles for glycogenesis. This lowers blood glucose level.   3) Delta (8) cells: They are 5% and secrete somatostatin. Somatostatin inhibits the secretion of glucagon and insulin. It also decreases the gastric secretions, motility and absorption in the digestive tract. In general it is a growth inhibiting factor.   (4) PP cells or F cells: They form 5%. They secrete pancreatic polypeptide (PP) which inhibits the release of pancreatic juice...

Sympathetic Nervous system (1) Sympathetic Nervous System is formed by 22 pairs of sympathetic ganglia. These ganglia are linearly arranged on two sympathetic cords. Sympathetic nerve cords run on either side of the vertebral column.   (2) Sympathetic nerve cords are connected to CNS by rami communicans of spinal nerve fibers.   (3) This system works during stress, pain, anger, fear or emergency. It is supposed to bring about fight, flight or fright reactions.  (4) Action of sympathetic nervous system is dependent on adrenaline or noradrenaline. The neurotransmitter is secreted by the sympathetic nervous system as an emergency hormone.   Parasympathetic Nervous system (1) Parasympathetic nervous system consists of nerve fibers of some cranial nerves, sacral nerves and parasympathetic ganglia.   (2) These parasympathetic ganglia are present on the sides of visceral organs like heart lungs, stomach, kidney, etc.   (3) Parasympathetic p...

 Human reproduction : 1 ) Sequential steps in the process of human reproduction gametogenesis , insemination internal fertilization , zygote formation and embryogenesis , gestation and parturition followed by lactation . ( 2 ) Primary Sex organs - testes ( testis : singular ) in male and ovaries ( ovary : singular ) in female .   ( 3 ) Secondary or accessory Sex organs - Organs other than testis in male and organs other than ovaries in female .   4) Secondary sexual characters in males - Presence of beard , mustache , hair on the chest , muscular body , enlarged larynx ( Adam's apple ) , etc.   5) Secondary sexual characters in females - Developed breast , broader pelvis , high pitched voice , etc.   6) Sexual dimorphism: The phenomena by which sexes can be identified externally.

Parturition Process 1. Parturition is the birth process which is accompanied with labor pains .   2. It is a neuro - endocrine mechanism which involves rise in estrogen : progesterone ratio and increase in oxytocin receptors in myometrium of uterine wall .   3. The fully developed foetus gives signals for the uterine contractions by secreting Adrenocorticotropic hormone ( ACTH ) from pituitary and corticosteroids from adrenal gland .   4. This triggers release of oxytocin from mother's pituitary gland , which acts on uterine muscles of mother and causes vigorous uterine contractions .   5. This leads to expulsion of the baby from the uterus .   6. Parturition involves three stages, viz. Dilation stage, expulsion stage and after birth or placental stage. Oxytocin During and after delivery of a baby, oxytocin affects two target tissues: the mother’s uterus and breasts. During delivery, stretching of the cervix of the uterus stimulates the ...

Infertility treatment  1. Infertility is defined as the inability to conceive naturally after ( one year of ) regular unprotected intercourse .   2. Today infertile couples have many options to have a child such as fertility drugs, test tube babies, artificial insemination, IUI, surrogate motherhood, etc.   (1) In Vitro Fertilization (IVF): When the fertilization process is carried out of the body and the embryo is transferred back into the mother's body, then it is called IVF technique. ( Commonly known as test - tube baby . )  ( 2 ) Zygote Intra Fallopian Transfer ( ZIFT : The embryo is transferred in the fallopian tubes by ZIFT ( Zygote Intra Fallopian Transfer ) technique.   3 ) Gamete Intra Fallopian Transfer ( GIFT ) : Transferring the ovum collected from the donor into the fallopian tube of another female who can act as a surrogate mother ( a female with suitable environment for fertilization and development ) is called GIFT.   4 ...

  Sexual transmitted diseases (Some diseases may lead to death also) Sexually Transmitted Diseases A sexually transmitted disease (STD) is one that is spread by sexual contact. In most developed countries of the world, such as those of Western Europe, Japan, Australia, and New Zealand, the incidence of STDs has declined markedly during the past 25 years. In the United States, by contrast, STDs have been rising to near-epidemic proportions; they currently affect more than 65 million people. AIDS and hepatitis B, which are sexually transmitted diseases that also may be contracted in other ways, are discussed in Chapters 22 and 24, respectively. Gonorrhoea   1 ) Gonorrhoea is a sexually transmitted veneral disease caused by Diplococcus bacterium , Neisseria gonorrhoeae .  ( 2 ) The incubation period 2 to 14 days in males and 7 to 21 days in females . 3 ) Infection sites are mucous membrane of urino - genital tract , rectum , throat and eye .   (4) Males show the ...

  Seminal Vesicles , prostate gland and Cowper's glands are associated with human male reproductive system . 1 ) Seminal Vesicles :  ( i ) Seminal vesicles occur in pair present on the posterior side of urinary bladder Its secretion consists about 60 % of the total volume of the semen . The secretion is an alkaline seminal fluid containing fructose, fibrinogen and prostaglandins.  iii) Fructose helps in the movement of sperms by providing energy to them.  iiii) Semen is coagulated in bolus by fibrinogen. This helps in faster movements of sperms in vagina after insemination .   (iv) Reverse peristalsis in vagina and uterus for faster movement of sperms towards the egg in the female body is aided by prostaglandins.   2 ) Prostate gland :  ( i ) It is a single gland located under the urinary bladder . It has about 20 to 30 separate lobes which open separately into the urethra.   ( ii ) Prostatic fluid secreted by this gland is milky...

Anemia Anemia (a-NE¯-me¯-a) is a condition in which the oxygen-carrying capacity of blood is reduced. All of the many types of anemia are characterized by reduced numbers of RBCs or a decreased amount of hemoglobin in the blood. The person feels fatigued and is intolerant of cold, both of which are related to lack of oxygen needed for ATP and heat production. Also, the skin appears pale, due to the low content of red-colored hemoglobin circulating in skin blood vessels. Among the most important causes and types of anemia are the following: CLICK HERE 👇👇 • Inadequate absorption of iron, excessive loss of iron, increased iron requirement, or insufficient intake of iron causes iron-deficiency anemia, the most common type of anemia. Women are at greater risk for iron-deficiency anemia due to menstrual blood losses and increased iron demands of the growing fetus during pregnancy. Gastrointestinal losses, such as those that occur with malignancy or ulceration, also contribute to this t...

PKU - Phenylketonuria (1) PKU means phenylketonuria which is an autosomal recessive inborn error metabolism of due to phenylalanine does not occur deficiency of phenylalanine hydroxylase (PAH) enzyme.   2 ) In this disorder the metabolism of phenylalanine does not occur due to deficiency of phenylalanine hydrolase ( 3 ) This enzyme necessary to metabolize the amino acid phenylalanine to the amino acid tyrosine .   4) When PAH activity is reduced, phenylalanine accumulates in blood and cerebrospinal fluid and is converted into phenylpyruvate or phenyl-ketone which is a toxic compound. This may cause mental retardation. Excess phenylalanine is excreted in urine, hence this disease is called phenylketonuria.   ( 5 ) PKU is caused by mutations in the PAH gene on chromosome no . 12.   6) Untreated PKU causes abnormal phenotype which includes growth failure, poor skin pigmentation, microcephaly, seizures, global developmental delay and severe intelle...