Metabolism - 5

Question 1

Definition:

Butterfly shaped gland located inferior to the larynx and anterior to the trachea.

Answer 1

thyroid gland

Question 2

What 2 cells make up the thyroid gland?

Answer 2

follicular and parafollicular

Question 3

Definition:

Stimulated by TSH to produce thyroxine (T4) and triiodothyronin (T3) collectively known as thyroid hormones.

Answer 3

Follicular cells

Question 4

Thyroid hormones function to:

Answer 4

• increase BMR
• help maintain normal body temp
• stimulate protein synthesis
• increase the use of glucose and fatty acids for ATP production
• upregulate beta receptors that attach to catecholamins
• work with hGH and insulin to accelerate body growth

Question 5

What do parafollicular cells produce?

Answer 5

calcitonin

Question 6

What does calcitonin do?

Answer 6

helps regulate calcium homeostasis by stimulating osteoblasts and inhibiting osteoclasts which lower the level of calcium in the blood

• also prevent reabsorption of calcium in kidneys

Question 7

Where are the parathyroid glands found?

Answer 7

Posterior aspect of each lobe of the thyroid gland (a total of 4 pea-sized lobes, 1 superior and 1 superior)

Question 8

What glands contain cheif/parietal cells responsible for producing PTH?

Answer 8

Parathyrdoid glands

Question 9

PTH acts to:

Answer 9

• increase the number and activity rate of osteoclasts
• increases rate of calcium and magnesium reabsorption in the kidneys
• promotes formation of calcitrol in the kidneys which acts to increase absorption of calcium and magnesium from GI tract

Question 10

definition:

Works with calcitonin and calcitriol to regulate calcium homeostasis

Answer 10

PTH

Question 11

Where are the adrenal glands located? What do they consist of?

Answer 11

On top of each kidney, consist of an outer cortex and inner medulla

Question 12

What types of hormones are secreteted by the adrenal cortex?

Answer 12

• mineralocorticoids
• glucocorticoids
• androgens

Question 13

Definition:

Regulates mineral homeostasis

Answer 13

Mineralocorticoids

Question 14

Glucocorticoids affect what?

Answer 14

glucose homeostasis

Question 15

Definition:

Hormones with masculinizing effects

Answer 15

androgens

Question 16

What is the major mineralocorticoid?

Answer 16

Aldosterone

Question 17

What does aldosterone do?

Answer 17

Help regulate sodium and potassium homeostasis (maintain blood osmolarity)

Question 18

What controls the secretion of aldosterone?

Answer 18

renin-angiotensin aldosterone (RAA) pathway

Question 19

Secretion of glucocorticoids (cortisol) is regulated by what?

Answer 19

Reales of corticotropin releasing hormone

Question 20

Secretion of glucocorticoids (cortisol) functions to help control:

Answer 20

• protein breakdown
• glucose formation
• lipolysis
• resistance to stress
• inflammation
• immune responses

Question 21

What stimulates the adrenal medulla?

Answer 21

sympathetic nervous system

Question 22

What does stimulation to the adrenal medulla cause?

Answer 22

The secretion of catecholamines such as epinephrine (adrenaline) and norepinephrin (noradrenaline) both of which are involved in the fight or flight response

Question 23

T/F: pancreas can be classified as both an exocrine and an endocrine gland

Question 24

What do the exocrine cells of the pancrease do?

Answer 24

produce digestive enzymes that are delivered to the GI tract through ducts

Question 25

# Definition: Cluster of endocrine tissues scattered among exocrine cells in the pancrease

Answer 25

pancreatic islets (islets of Langerhans)

Question 26

Where are alpha and beta cells found in the pancreas?

Answer 26

islets of langerhans

Question 27

# Pancreas What do alpha cells do?

Answer 27

Secrete glucagon to increase blood glucose levels

Question 28

# Pancreas What do beta cells do?

Answer 28

secrete insulin to decrease blood glucose levels

Question 29

# Definition: Pineal Gland

Answer 29

Attached to the roof of the third ventricle of the brain and secretes melatonin

Question 30

# Definition: Released in a diurnal rythm linked to the dark-light cycle which helps regulate the body's biological clock

Answer 30

Melatonin

Question 31

What is seasonal affective disorder (SAD) thought to be due to?

Answer 31

Over-production of melatonin

Question 32

# Definition: Required for the synthesis of molecules and include growth hormone, insulin-like growth factor, insulin, testosterone and estrogen

Answer 32

Anabolic hormones

Question 33

# Definition: Catabolic hormones

Answer 33

Stimulate the breakdown of molecules and the production of energy. These include cortisol. glucagon, adranaline/epinepherine, and cytokines.

Question 34

What are the main hormones that aid in the regulation of metabolism?

Answer 34

Insulin, Glucagon

Question 35

# In a fed state blood glucose leveles are HIGH Explain how insulin helps regulate metabolism

Answer 35

- increase in insulin secretion - increases glucose uptake - increase glucose metabolism - energy stored as glycogen and fat - increased use of amino acids

Question 36

What is the goal of insulin?

Answer 36

To get glucose IN the cells

Question 37

# In a fasting state: Blood glucose levels are LOW Explain how glucagon regulate metabolism

Answer 37

More glucagon is released - breakdwon of glycogen - formation of new glucose - release of glucose from liver formation of keytones

Question 38

What is the goal of glucagon?

Answer 38

When all the blood glucose is gone, think GLUCAGON (ie. more glucose in the blood)

Question 39

Review glucose and glucagon regulation.