Question

19. Emulsification of lipids requires __ which are produced in the ___

a. bile salts; liver

b. enzymes; pancreas

c. acid; stomach

d. cholesterol; gallbladder

43. Which of the following hormones do not respond to hormones form the anterior pituitary

a. thyroxine

b. parathyroid hormone

c. cortisol

d. estrogen

7. Peristalsis movements ___ segmentation movements ___

a. churn and break apart for; propel food forward

b. propel food forward; churn and break apart food

c. both churn and break apart food

d. both propel food forward

Answer 1

19. Emulsification of lipids require bile salts which are produced in the liver.

Explanation: - Bile acids are steroid acids produced from cholesterol in the liver. Examples of bile acids are cholic acid and chenodeoxycholic acid.

- These primary bile acids combine with glycine and taurine residues to from bile salts. Examples of bile salts are glycocholic acid, glycochenodeoxycholic acid, taurocholic acid and taurochenodeoxycholic acid.

- Bile salts perform the function of emulsification of lipids and help in their digestion from intestine. Emulsification means solubilization of lipids (fats) which helps in their digestion and absorption.

- Gall bladder temporarily stores the bile and helps in its concentration and later release the bile into the duodenum.

43. Which of the following hormones donot respond to hormones from anterior pituitary?

Answer: b) Parathyroid.

Explanation:

- Chief cells of parathyroid gland secretes parathormone (parathyroid hormone) in response to low serum calcium ions level. The function of parathormone is to increase the serum calcium ions by increasing the osteoclastic activities of the bone which increases the bone resorption and leads to increased serum calcium ions level. Parathormone secretion is not influenced by anterior pituitary gland hormones.

- Thyroid stimulating hormone (TSH) of anterior pituitary stimulates the thyroid gland to secrete tri-iodothyronine (T3) and tetra-iodothyronine (T4). T4 is also known as thyroxine.

- Adrenocorticotropic hormone (ACTH) of anterior pituitary gland stimulates the zona fasiculata layer of adrenal cortex to secrete cortisol (glucocorticoid) which helps in metabolism of carbohydrates, protein and fats.

- Follicle-stimulating hormone (FSH) of anterior pituitary gland regulates the development of ovarian follicles during the follicular phase of ovarian cycle. The granulosa cells of developing ovarian follicle secrete estrogen which maintains the secondary sexual characters in females as well as regulate the the proliferation of uterine endometrium during the follicular phase (proliferative phase) of ovarian cycle.

7. Peristalsis movements propel food forward; segmentation movements churn and break apart food.

Explanation:

- Peristalsis is reflex response of gastrointestinal tract (GIT) which results in organised propulsion of luminal contents of gut in forward direction. It is present in the entire GIT from esophagus to rectum. It occurs mainly due to contraction of longitudinal muscle layer of muscularis externa of GIT.

- Segmentation mainly occurs in the small intestine and is characterized by closely spaced contraction of circular muscle layer of muscularis externa of GIT (mainly intestine). These contractions divide the small intestine into many segments hence it is called segmentation. Its main function is to churn and break the food and mix it with pancreatic enzymes and digestive secretions. Hence, segmentation is also called as mixing movements.