HORMONES

Question 1

What is a protein hormone?

Answer 1

Protein hormones are composed of amino acids and are water soluble. They cannot pass through the cell membrane so that act on cell membrane receptors to send signals inside the cell.

Question 2

What is a steroid protein?

Answer 2

Steroid hormones are composed of cholesterol and are not water soluble, but instead lipid soluble. They are able to pass directly through the membrane and bind to receptors inside the cell and activate them. This initiates the production of proteins (transcription).

Question 3

Where is the hypothalamus and what does it function to do?

Answer 3

The hypothalamus is from the hypothalamus gland. It releases hormones (via nerves) to control the pituitary gland, which in turn, controls other endocrine glands.

Question 4

What is the anterior pituitary lobe?

Answer 4

The anterior pituitary lobe is one part of the pituitary gland and is controlled by hormones released from the hypothalamus.

Question 5

What is Prolactin (PRL)?

Answer 5

Prolactin is a hormone released from the anterior pituitary. It stimulates the mammary glands and milk synthesis after birth. Suckling stimulates the release of it.

Question 6

What is the growth hormone (GH)?

Answer 6

GH is a hormone released from the anterior pituitary. It stimulates cell division, protein synthesis, and bone growth by binding to target tissue and causing them to release IGF. It also stimulates the conversion of glycogen to glucose and fats to fatty acids. GH limits the uptake of glucose by cells to keep them available to tissues between meals. An underproduction of GH will result in pituitary dwarfism and an overproduction of GH will result in pituitary giants.

Question 7

What is Melanocyte-Stimulating Hormone (MSH)?

Answer 7

MSH is a hormone released from the anterior pituitary. It causes the darkening of skin by dispersing the melanin and is usually more pronounced in pregnant women. It is caused by a dispersal of melanin in melanocytes so that it covers a greater area.

Question 8

What are tropic hormones?

Answer 8

Tropic hormones are a group of hormones released from the anterior pituitary that that control other endocrine glands.

Question 9

What is thyroid stimulating hormone (TSH)?

Answer 9

TSH is a tropic hormone that stimulates the thyroid.

Question 10

What is adrenocorticotropic hormone (ACTH)?

Answer 10

ACTH is a tropic hormone that secretes glucocorticoids from the adrenal cortex.

Question 11

What is follicle stimulating hormone (FSH)?

Answer 11

FSH is a tropic hormone that stimulates egg and sperm development.

Question 12

What is luteinizing hormone (LH)?

Answer 12

LH is a tropic hormone that regulates ovulation in females and secretes male sex hormones.

Question 13

What are gonadotropins?

Answer 13

FSH and LH are further classified as gonadotropins because they both target the gonads (organ that produces gametes)

Question 14

What are endorphins?

Answer 14

Endorphins are a hormone released by the intermediate lobe that act as neurotransmitters and inhibit pain perception.

Question 15

What is the posterior pituitary lobe?

Answer 15

The posterior pituitary lobe is a part of the pituitary gland that is controlled by nerve impulses from the hypothalamus.

Question 16

What is oxytocin?

Answer 16

Oxytocin is a hormone released from the posterior pituitary. It stimulates contractions in the uterus and stimulates milk release in the mammary glands.

Question 17

What are antidiuretic hormones (ADH)?

Answer 17

ADH is a hormone released from the posterior pituitary. It helps regulate water balance by stimulating the kidney cells to absorb more water from the urine so that blood volume is increased. ADH does this by making the upper part of the distal tubule and collecting duct permeable to water so that water osmotically moves into the interstitial fluid.

Question 18

What are osmoreceptors?

Answer 18

Osmoreceptors are specialized nerve cells in the hypothalamus that detect changes from the blood’s osmotic pressure (detect increased Na+ concentration due to salty meal or dehydration).

Question 19

How do ethanol and caffeine affect ADH?

Answer 19

Ethanol and caffeine inhibit ADH. This increases urine output as the body is not reabsorbing water.

Question 20

How do severe injuries affect ADH?

Answer 20

When severe injuries result in blood loss, ADH is increased as the body tries to regulate blood pressure.

Question 21

How does nicotine and emotional stress affect ADH?

Answer 21

Nicotine and emotional stress stimulates ADH so you retain water because your body is reabsorbing too much of it/

Question 22

What is the thyroid gland?

Answer 22

The thyroid gland is an endocrine gland that is located in the throat. Its hormones regulate the rate of metabolism.

Question 23

What are Thyroxine (T4) & Triiodothyronine (T3)?

Answer 23

T4 and T3 are made of amino acids, however, are lipid soluble and therefore passes through the cell membrane. Once inside the cell, T4 gets converted to T3. T3 enters the nucleus and acts as a transcription regulator, increasing transcription and therefore increasing metabolism.

Question 24

How does the negative feedback system of thyroxine work?

Answer 24

1. The hypothalamus secretes TRH that stimulates the anterior pituitary
2. The anterior pituitary released TSH into the bloodstream
3. TSH targets the thyroid gland and causes it to secrete T4 into the bloodstream. T4 stimulates increased cellular respiration in target cells throughout the body. 4. High levels of T4 cause negative feedback on the pituitary and hypothalamus, inhibiting the production of TSH.

Question 25

What is calcitonin?

Answer 25

Calcitonin is a hormone secreted by the thyroid. It helps control blood calcium as it lowers the level of Ca2+ in the blood by inhibiting the ongoing release of calcium from bones. Calcitonin secretion is stimulated when Ca2+ levels are too high and is inhibited when Ca2+ levels are too low.