NEET Biology Chemical Coordination and Integration MCQs Set 11

Answer: (c) Water and bicarbonate ions in pancreatic juice

Explanation:
1. Secretin stimulates the release water and bicarbonate ions in pancreatic juice.

Answer: (c) Portal blood vessel

Explanation:
1. Regulating hormones that are secreted by neuroendocrine cells of hypothalamus is carried to adenohypophysis via hypophyseal portal blood circulation.
2. Hypothalamus Hypothalamic neurons Portal circulation Posterior pituitary Anterior pituitary.

Answer: (a) Somatotrophin

Explanation:
1. The anterior pituitary hormone that stimulates the release of growth hormone is known as GHRH (growth hormone releasing hormone) or Somatocrinin.

Answer: (c) Helps in release of the ovum from the ovary

Explanation:
1. The luteinising hormone in female helps in release of ovum form the ovary.
2. The mature graffian follicles that release the ovum, convert to corpus luteum under the influence of FSH. The corpus luteum secretes progestrone.

Answer: (c) Atrophy of adrenal cortex

Explanation:
1. Surgical removal of pituitary gland results in non-release of ACTH which stimulates adrenal cortex of the adrenal gland to release corticoids.
2. Absence of the ACTH results in atrophy of adrenal cortex.

Answer: (c) ADH

Explanation:
1. ADH hormone released by posterior pituitary enhances the arterial blood pressure by causing narrowing of arterioles.

Answer: (a) Thyroid gland

Explanation:
1. Largest endocrine gland is thyroid gland.

Answer: (a) Calcitonin

Explanation:
1. Hormones that are secreted by parathyroid glands are PTH (parathyroid hormone) and calcitonin.
2. Oxytocin : Secereted by hypothalamus Vasopressin : Secereted by hypothalamus Gonadotrophin : Secereted by hypothalamus.

Answer: (b) Cretinism

Explanation:
1. Myxoedema : (Caused by deficiency of thyroxine) Puffy appreance, lacking alertness, intelligence and alterness.
2. Cretinism : (Caused by deficiency of thyroxine) Patient is pot-bellied, pigeon-chested and has a protruted tongue.
3. Cushing’s Syndrome : (Oversecretion of cortisol) Obesity and wasting of limbs muscles.
4. Males : Excessive hair growth (Hrisutism) Females : Masculinization, beard and moustache development.

Answer: (a) Thyroxine

Explanation:
1. Hormone responsible for cretinism is thyroxine.
2. Deficiency of thyroxine from childhood results is stunted growth and mental retardation, known as cretinism.

Answer: (c) Addison’s disease

Explanation:
1. Addison's disease in caused due to hyposecretion of adrenal cortex hormones.

Answer: (a) Low plasma Na+, high plasma K+, increased urinary Na+, low blood sugar, vomitting, nausea and diarrhoea

Explanation:
1. Function of adrenal cortex' hormone (mineralocorticoids) → Increase blood levels of Na+ and water → Decrease in blood K+ level → Tubular reabsorption of Na+ → Glycogenolysis A destruction of adrenal cortex by diseases like tuberculosis produces addison disease due to the deficiency of both glucocorticoids and mineralocorticoids.
2. This condition is known as addison's syndrome and the consequent symptoms.
3. Imbalance of K+ leads to vomitting, nausea and diarrhoea.

Answer: (b) Excess secretion of sex corticoids

Explanation:
1. Adrenal virilism : Caused due to excessive secretion of sex corticoids released by zona reticulata of adrenal cortex.
2. Symptoms : Produces male type external sex characters such as beard and moustaches and male voice in women.

Answer: (b) Diseased adrenal cortex

Explanation:
1. Adrenal cortex releases mineralocorticoids which increases Na+ and decreases the K+ ions in the blood by increasing the Na+ absorption in the renal tubules and increase K+ excretion in the urine.
2. Diseased adrenal cortex results into deficiency of hormone.

Answer: (d) All of these

Explanation:
1. Insulin secreted by pancreas (a) Promotes uptake of fats (b) Promotes proteins synthesis (c) Promotes glycogenesis.

Answer: (c) Pineal

Explanation:
1. Pineal gland was earlier considered to be vestigial gland which was later found to be responsible for secretion of melatonin which controls circadian rhythm.

Answer: (a) Thymus

Explanation:
1. Thymus gland present on the dorsal side of the heart which degenerates as the age increases.

Answer: (d) Ovary

Explanation:
1. Relaxin is secreted by ovary and placenta.
2. Corpus luteum of ovary secretes the hormone in a regular menstrual cycle while relaxin is secreted by placenta after pregnancy.

Answer: (d) All of these

Explanation:
1. Gynaecomastia is the development of mammary glands in the males and the main reason is the hormone inbalance.
2. While all men have some level of oestrogen but usually have much higher level of testosterone.
3. Newborn baby boys : Newborn baby boys may be affected by gynaecomastia because oestrogen passes through placenta from mother to baby.
4. This condition is temporary and will disappear within weeks.

Answer: (b) Castration

Explanation:
1. Castration : is the surgical or chemical action by which males loses the activity of testes.
2. The testosterone hormone secteted by testes is responsible for development of secondary sexual characteristics in males which also involves converting the high pitch voice of males at puberty to low pitch, hoarse voice.
3. Ovarictomy : is the removal of one or both ovary.
4. Synorchidism : is the congenital fusion of testes in the abdominal cavity.

Answer: (d) Insulin, Glucagon, Thymosin

Explanation:
1. Adrenal cortex : Glucocorticoids, mineralocorticoids, and sexcortiocoids Adrenal medulla : Epinephrine, Nor-epinephrine, adrenaline Ovary : Relaxin, oestrogen progestrone Pancreas : Insulin, glucagon Thymus : Thymosin.

Answer: (d) All of these

Explanation:
1. Production, secretion and ejection of milk requires synergistic effect of estrogen, progesterone and oxytocin.
2. Progesterone : Influences the growth in size of alveoli, high levels of progesterone inhibit lactation before birth.
3. Progesterone level dorps after birth, this triggers the onset of copious milk production.
4. Estrogen : Stimulates the milk duct system to grow and differentiate.