Endocrine Physiology - Part 3 Flashcards

1
Q

What is the name of the endocrine tissue in the pancreas?

A

Islets of Langerhans

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2
Q

What are the 4 cell types within the Islets of Langerhans? What do they produce?

A

a-cells: produce glucagon
b-cells: produce insulin
D-cells: produce somatostatin
PP-cells: produce pancreatic polypeptide

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3
Q

What is the half life of insulin?

A

5-8 mins

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4
Q

What is the effect of insulin on carb, fat and protein metabolism?

A
  • stimulates glucose entry and increases glycogen storage in muscles and fat tissue
  • increases glycogen production and storage in the liver
  • decreases gluconeogenesis by the liver
  • promotes fat synthesis
  • promotes protein synthesis
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5
Q

What is the general effect of insuli?

A
  • decrease plasma conc. of glucose
  • increase cell stores of glycogen
  • decreased plasma conc. of FFA
  • increased cell stores of triglycerides
  • decreased plasma conc. of AAs
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6
Q

What is the most powerful stimulator of insulin production?

A

rising blood glucose level above normal

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7
Q

What are some stimulators of insulin production?

A
  • rise in blood AA and FA levels
  • vagus stimulation
  • someGI hormones
  • hyperkalemia
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8
Q

Where is glucagon secreted?

A

by alpha cells of the pancreas

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9
Q

What is the effect of glucagon?

A
  • catabolism of nutrients, especially between meals.
  • results in an increase in blood glucose levels
  • opposite of insulin
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10
Q

How is glucagon regulated?

A
  • increased secretion from decreased blood glucose levels as in exercise, starvation, sympathetic activation, etc.,
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11
Q

How do bird glucagon levels differ from mammals??

A

birds have nearly twice as much glucagon - presumably due to higher energy requirements

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12
Q

What happens if there is too much glucose in plasma?

A
  • glucosuria (in urine)
  • polyuria (frequent urination) due to osmotic diuresis
  • polydipsia (thirst) due to osmotic diuresis
  • swelling of eye lense
  • chronic bladder infections
  • oxidative damage to capillaries
  • poor circulation in eye
  • cataracts
  • ketoacidosis
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13
Q

How does the body regulate glucose homeostasis

A
  • insulin after feeding

- glucagon in starved state

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14
Q

What is the effect of catecholamines on blood glucose level?

A
  • increases blood glucose level

- helpful to combat stress situation in particular during physical activity

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15
Q

What is the effect of glucocorticoids on blood glucose levels?

A
  • increase blood glucose level

- necessary for long term starvation and during stress

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16
Q

What is the effect of GH and Thyroid hormones on blood glucose levels?

A
  • increase blood glucose level

- GH promotes fat and protein metabolism

17
Q

What is diabetes millitus?

A

lack of insulin function or glucagon excess

18
Q

What is diabete insipidus?

A

lack of ADH function

19
Q

What are the symptoms of diabetes mellitus?

A
  • hyperglycemia
  • glycosuria
  • polyuria
  • polyphagia
20
Q

What is Type I DM?

A
  • total lack of insulin
  • requires exogenous insulin for survival
  • results from autoimmune destroying beta cells
  • most common type in dogs
21
Q

What is Type II DM?

A
  • non-insulin dependent DM
  • insulin secretion normal or increased but target cells don’t respond
  • most common type in cats
22
Q

Where are the parathyroid glands?

A

beside or within the thyroid gland

23
Q

What is secreted by the parathyroid glands?

A

parathyroid hormone (PTH)

24
Q

What is the action of PTH?

A

increase plasma Ca++ and lower (PO4)3-

25
What is the target tissue of PTH?
bone, kidneys and intestine
26
How is PTH regulated?
- low plasma Ca++ level triggers secretion | - parathyroid cells have Ca sensing receptors on their surface
27
What is the action of Calcitonin?
- produced by C cells of thyroid gland | - decrease plasma Ca++ level (weak affect)
28
What is the most important hormone in regulating Ca in fish
stanniocalcin
29
What animals may require vitamin D suplementation
heavily furred animals, animals at high latitudes, animals kept indoors, etc.
30
What is the function of Vitamin D?
enhances: - intestinal absorption of Ca++ and (PO4)3- - increased bone mineralisation
31
What disease can be caused by Vitamin D deficiency in animals?
rickets in prepubertal animals | osteomalacia in adults
32
What disease is caused by lack of Ca++ in lactating cows?
parturient paresis (milk fever)
33
What other organs have secondary endocrine functions?
- intestines - kidneys - heart - gonads
34
What hormone is produced by the heart?
atrial natriuretic peptide (ANP)
35
What stimulus releases ANP?
increased BP, increased blood volume, increased blood Na+
36
What is the target tissue of ANP?
renal tubules mainly
37
What is the effect of ANP?
increases Na+ secretion mainly
38
What hormones are released from the kidneys?
1. Erythropoietin | 2. Renin-angiotensin-aldosterone system (RAAS)