Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

ANSC 311 - Metabolic Physiology > Midterm 3 - Lecture 17 > Flashcards

Midterm 3 - Lecture 17 Flashcards

1
Q

What is metabolism?

A

A set of chemical reactions that modifies a molecule into another for storage, or for immediate use in another reaction or as a byproduct
- anabolism = build up
- catabolism = break down

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

6 metabolic hormones

A
  1. insulin
  2. glucagon
  3. growth hormone (somatotropin)
  4. thyroid hormones (T3, T4, thyroxine)
  5. cortisol (broadly, glucocorticoids)
  6. epinephrine (or adrenaline)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the metabolic response to hormones dependent on?

A

concentration and exposure duration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the 4 hormone classes?

A
  1. peptide and protein
  2. amino acid derivatives
    - thyroid hormones and catecholamines
  3. fatty acid compounds
  4. steroid
    - confined to adrenal cortex, sex glands, and placenta
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

2 pancreatic hormones

A

insulin and glucagon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What cells of the pancreas produce insulin and glucagon? What are these regions known as?

A
  • region: islets of Langerhans
  • b-cell: insulin
  • a-cell: glucagon
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

When are insulin levels high?

A

when plasma glucose levels are high

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How does the hypothalamus and pituitary gland work?

A
  1. hypothalamic-pituitary portal system transports neurohormones from hypothalamus to the anterior pituitary
  2. hypothalamic neurohormones bind to receptors on endocrine cells in the anterior pituitary
  3. regulate hormonal secretion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the central link between CNS and the endocrine system?

A

hypothalamic-pituitary portal system
- allows high concentration of hormone without being diluted in the systemic circulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the ‘Master Gland’?

A

anterior pituitary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the hormones of the ‘master gland’?

A
  1. follicle-stimulating hormone
  2. luteinizing hormone
  3. growth hormone aka somatotropin
  4. thyroid stimulating hormone
  5. adrenocorticotropic hormone (ACTH)
  6. prolactin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are tropic hormones?

A

hormones that regulate secretion of other hormones
- ex. anterior pituitary hormones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the common glucocorticoids in mammals vs birds and rodents?

A

mammals = cortisol
birds and rodents = corticosterone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Does cortisol have a negative feedback effect?

A

Yes
- negative feedback in pituitary (stops ACTH production) and hypothalamus (stops ACTHRH production)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are glucocorticoids essential for?

A

Essential for promotion of gluconeogenesis and lipolysis in starvation
- transcription of genes necessary for these processes requires presence of glucocorticoids
- increases blood glucose by stimulating gluconeogenesis and inhibiting glucose uptake (anti-insulin)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What would happen if an animal had no glucocorticoids?

A

no glucocorticoids = no living due to hypoglycemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Circadian rhythm

A

ACTH and cortisol highest early in the morning and lowest in the evening

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is a glucocorticoid deficiency disease?

A

Addison’s Disease
- dogs
- autoimmune disease destroying adrenal cortex
- dizziness from reduced blood pressure
- inappetant and weak
- depressed, dehydrated, and vomit
- ACTH produced in excess (no cortisol for negative feedback)

19
Q

What is a glucocorticoid overproduction disease?

A

Cushing’s Disease
- dogs, cats, horses
- excessive ACTH
- eat and drink more, lose hair, thin skin, weak muscles
- anti-insulin effect of glucocorticoids leads to diabetes mellitus in some patients

20
Q

What is epinephrine a potent inducer of?

A
  • glycogenolysis
  • most important during stress
  • secondary means to increase blood glucose availability during exercise
21
Q

What are the 2 adrenergic receptors?

A
  1. Alpha-adrenergic receptors
  2. Beta-adrenergic receptors
22
Q

Alpha-adrenergic receptors

A
  • increases calcium in target cells and stimulates their activity
  • same affinity for epinephrine and norepinephrine
23
Q

Beta-adrenergic receptors

A
  1. Beta 1
    - found in heart
    - increase HR and SV
  2. Beta 2
    - found in heart, liver and skeletal muscle
    - inhibitory
    - induce hyperglycemia and glycogenolysis in liver
    - increased breakdown of triglycerides in adipose
    - increased HR
24
Q

Where is growth hormone produced? What does it stimulate?

A
  • in anterior pituitary and stimulates growth of body mass and elongation of bones
  • expression regulated by stimulatory and inhibitory mediators from hypothalamus, GHRH and GHIH
  • GH production also affected by plasma nutrient concentrations (glucose, FFA, AA)
  • stimulated by sex hormones during puberty
25
Q

What increases the release of growth hormone?

A
  1. strenuous physical activity
  2. starvation
  3. stress
  4. low plasma glucose
26
Q

What cells produce insulin-like growth factor 1 (IGF-1)?

A

Produced by many cells, but mostly in liver in response to GH release
- primary mechanism GH stimulates growth

27
Q

What does insulin-like growth factor 1 stimulate?

A

Stimulates cell growth and proliferation in almost every cell of the body
- muscle, bone, liver, kidney, nerves, skin, lungs, hematopoietic

28
Q

Does GH stimulate IGF-1 secretion in underfed animals?

A

no

29
Q

Where is the thyroid gland located?

A

2 lobes located on either side of the trachea

30
Q

What are characteristics of the thyroid gland?

A
  • hollow spheres of interspersed with capillaries
  • colloid (center of sphere) is where synthesis occurs and is stored)
  • C-cells produce calcitonin
  • PTH produced by spherical cluster of parathyroid cells
  • Calcitonin and PTH regulate calcium concentration
31
Q

Where are calcitonin and PTH synthesized?

A

Thyroid gland
- C-cells produce calcitonin
- cluster of parathyroid cells produce parathyroid hormone

32
Q

What does calcitonin and PTH regulate?

A

calcium concentration

33
Q

What are the two thyroid hormones?

A
  • T3 and T4
  • 3 and 4 refer to # of iodide atoms
  • T4 and T3 circulate bound to proteins
34
Q

How is the thyroid regulated?

A

Thyroid stimulating hormone (TSH) is a glycoprotein secreted by thyrotropes
- feedback controlled by T3 and T4
- TSH acts on thyroid gland to stimulate synthesis and secretion of T4

TSH also increases number and size of follicular cells
- prolonged increase results in hyperplasia and hypertrophy = goiter

35
Q

What are the actions of T3 and T4

A
  1. increase metabolic rate in all tissues except brain, gonads and spleen resulting in increased O2 consumption and heat production
    - acts by binding nuclear receptors on DNA
    - induce expression of genes
  2. increases secretion if prolonged cold exposure
    - increased metabolic rate to stay warm
36
Q

How are T3 and T4 synthesized?

A
  1. iodide taken up by active transport
  2. iodide oxidized by thyroperoxidase (TPO)
    - T4 and T3 formed by iodination of thyronine
  3. during secretion small colloid-containing vesicles are taken up by follicular cells from follicular lumen
  4. thyroid hormones are released from thyroglobulin by lysosomal enzymes
  5. free hormones diffuse out of cells
  6. transported throughout body bound to thryoid-binding globulin

*T4 is converted to T3 in the liver bc T3 is more potent

37
Q

Hyperthyroidism

A
  • excessive production of thyroid hormone
  • elevated HR, wt loss, increased appetite
38
Q

Hypothyroidism

A
  • most common endocrine disease in dogs
  • reduced thyroid hormones results in reduced GH secretion and reduced heat production
  • animal = sluggish, reluctant to move, overwt, and appetite reduced
  • can be induced by inadequate iodine intake
39
Q

How does insulin effect the liver, muscle and apdipose?

A

LIVER
- increase glycogen synthesis and glycolysis
- decrease glycogenolysis, gluconeogenesis, ketogenesis

MUSCLE
- increase glucose and AA uptake
- decrease proteolysis

ADIPOSE
- increase glucose and FFA uptake
- decrease lipolysis

40
Q

How does glucagon effect the liver, muscles, and adipose?

A

LIVER
- increase glycogenolysis, gluconeogenesis, ketogenesis

MUSCLE
- minimal action

ADIPOSE
- increase lipolysis

41
Q

How does cortisol effect liver, muscles, and adipose?

A

LIVER
- increase glycogenolysis, gluconeogenesis

MUSCLE
- decrease AA uptake and insulin action
- increase proteolysis

ADIPOSE
- increase lipolysis
- decrease insulin action

42
Q

How does growth hormone effect liver, muscles, and adipose?

A

LIVER
- increase gluconeogenesis, IGFs/IGFBP

MUSCLE
- increase AA uptake
- decrease glucose uptake

ADIPOSE
- increase lipolysis
- decrease glucose uptake

43
Q

How does epinephrine effect liver, muscles, and adipose?

A

LIVER
- increase glycogenolysis, gluconeogenesis, ketogenesis

MUSCLE
- increase glycogenolysis
- decrease insulin action

ADIPOSE
- increase lipolysis
- decrease insulin action

ANSC 311 - Metabolic Physiology (17 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions