Biology and Biotechnology

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Liver And Gallbladder

Introduction : What is liver? • The liver is the heaviest gland of the body, weighing about 1.4 kg (about 3 lb) in an average adult. Of all of the organs of the body, • it is second only to the skin in size. The liver is inferior to the diaphragm and occupies most of the right hypochondriac and part of the epigastric regions of the abdominopelvic cavity • The gallbladder (gall- -bile) is a pear-shaped sac that is located in a depression of the posterior surface of the liver. • It is 7–10 cm (3–4 in.) long and typically hangs from the anterior infe- rior margin of the liver Anatomy of the Liver and Gallbladder The liver is almost completely covered by visceral peritoneum and is completely covered by a dense irregular connective tissue layer that lies deep to the peritoneum. The liver is divided into two principal lobes—a large right lobe and a smaller left lob e—by the falciform ligament, a fold of the mesentery . Although the right lobe is c...

Lactation (colostrum)

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...

Fatel Circulation Placenta

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 and vulva

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.

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 ( Pancreas )

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 and Parasympathetic Nervous system

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

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

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 in Male and Female

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 ...