Quiz 8 Flashcards

1
Q

Endocrine vs. exocrine

A

endocrine- secrete hormones directly into ECF (pituitary, adrenal, etc)
exocrine- products discharged through ducts (salivary, sweat)

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

What are hormones?

A

chemical messengers; either proteins, pepties, amino acid derivatives, or steroids

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

paracrine vs. autocrine

A

paracrine- hormone acts on neighboring cell

autocrine- hormone acts on itself

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

Second messenger system

A

Hormone binds to receptor, activates G protein, which activates enzyme, which causes production of “second messenger”- causes reaction

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

Endocrine System characteristics

A
  • slow, prolonged
  • hormones broken down by liver, excreted in urine
  • supplies all cells with receptor
  • UNCONSCIOUS
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Neuro System characteristics

A
  • fast
  • can “switch off”
  • supplies ONLY muscles and glands
  • hypothalamus controls ANS
  • conscious brain can control
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Negative feedback loop

A

stops production and secretion of hormone once specific response has occured

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

What are glands stimulated by?

A
  • changing blood levels
  • stimulating hormone
  • nerve stimulus
  • gene expression
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Adrenal cortex and its hormones

A

glomerulosa- “salts” -aldosterone
fasciculata- “sugars” - glucocorticoids
reticularis- “sex” - androgens

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

Aldosterone

A

major role in ECF Na and K concentrations and total fluid balance

  • 60% bound to plasma proteins
  • 20 minute half life
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What stimulates aldosterone release?

A
  • HYPERKALEMIA
  • angiotensin II
  • hyponatremia
  • ACTH
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

RAAS

A

1) renin released from kidney in response to hypovolemia, SNS stim, hypotension, hyponatremia
2) renin acts on angiotensinogen to form angiotensin I
3) angiotensin I -> angiotensin II by ACE in lungs
4) angiotensin II causes vasoconstriction and release of aldosterone

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

Where does aldosterone exert effects and what does it do?

A

DCT and principal cells of collecting ducts- reabsorption of Na, secretion of K (expands ECF and elevates BP)

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

What is the major glucocorticoid?

A

cortisol/hydrocortisone

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

How much cortisol produced daily?

A

15-30 mg/day, mostly in the morning

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

Cortisol characteristics

A
  • highly protein bound
  • free cortisol is active form
  • stress/surgery increases production (100 mg/day)
  • ACTH controls secretion
  • metabolized by liver
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Cortisol negative feedback loop

A

1) cortisol inhibits release of CRH from hypothalamus

2) cortisol decreases ACTH synthesis and release from anterior pituitary

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

Glucocorticoids effect on carb metabolism

A
  • stimulates gluconeogenesis
  • decrease glucose uptake and use by muscles
  • overall increase blood glucose concentration
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Glucocorticoids effect on protein metabolism

A
  • decrease synthesis and increase catabolism in all body cells except liver
  • effect on skeletal muscles- weak and atrophic
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Glucocorticoids effect on fat metabolism

A
  • FFA mobilized from adipose tissue
  • enhanced oxidation of FFA
  • enables use of FFA for energy when glucose limited
  • distinct obesity- chest, abd, intrascapular, buffalo torso, moon face)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Glucocorticoids effect on inflammation and immunity

A
  • diminishes inflammatory response
  • suppresses proinflammatory cytokines
  • decreases antibody production
  • decreases eosinophils and lymphocytes
  • stablizes lysosomal membranes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the primary androgen?

A

testosterone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Catecholamines of medulla

A
  • 80% epi
  • 20% NE
  • both metabolized in liver and kidney by COMT
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Where are catecholamines stored and how are they released?

A

chromafin granules; released by stimulation of sympathetic nerves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Anterior and posterior lobes of anterior pituitary
anterior- adenohypophysis | posterior- neurohypophysis
26
Hormones of anterior pituitary
FSH, LH, ACTH, TSH, prolactin, GH (FLAT PiG)
27
hormones of posterior pituitary
ADH, oxytocin
28
growth hormone
skeletal development and body growth, regulates protein and carb metabolism
29
Adrenocorticotropic hormone (ACTH)
regulates release of hormones from adrenal gland and growth of adrenal cortex
30
TSH
controls growth and metabolism of thyroid gland and secretion of thyroid hormones
31
FSH
stimulates ovarian follicle development in females and spermatogenesis in males
32
LH
induces ovulation in females, stimulates testes to produce testosterone in males
33
prolactin
promotes mammary gland development and milk production; inhibits synthesis and secretion of LH and FSH; increased in pregnancy
34
What inhibits ACTH?
increased cortisol levels and opioids
35
What stimulates ACTH?
corticotropin releasing hormone, hypoglycemia, stress, trauma, sepsis, alpha adrenergic stim, decreased cortisol, circadian rhythm
36
When is ACTH the highest?
2 hours before and just after awakening
37
Growth hormone characteristics
- aka somatotropin - release stimulated by GHRH from hypothalamus - inhibited by GHIF (somatostatin) - secretion also stimulated by stress, deep sleep, exercise, hypoglycemia
38
Where are the posterior pituitary hormones synthesized?
hypothalamus- travel down via pituitary stalk
39
oxytocin
stimulates milk secretion and contraction of uterus
40
ADH/vasopressin
acts on collecting ducts to increase free water reabsorption through aquaporins (increases blood volume, urine osmo, decreases serum osmo)
41
What stimulates ADH?
1) increase in plasma osmo (osmoreceptors in hypothalamus) 2) decrease in blood volume by >10-20% (peripheral varoreceptors and atrial stretch receptors)- afferent signal through vagus/glossopharyngeal nerves)
42
Factors that influence ADH release
hypotension, stress, pain, PPV, hyperthermia, beta adrenergic stim, histaimes, volatile agents, smoking, nausea
43
Pancreas functions
- exocrine- acinar cells (synthesize digestive enzymes and bicarbonate for digestion) - endocrine- islets of langerhans (4 types of cells)
44
Islet of Langerhans cells
Beta- secrete insulin and amylin alpha- secrete glucagon delta- secrete somatostatin pancreatic polypeptide -inhibits exocrine pancreatic secretion
45
Glycolysis
breakdown of glucose to pyruvate or lactate
46
glycogenesis
storage of glucose as glycogen
47
gluconeogensis
formation of glucose from lactate, pyruvate, aa, and glycerol
48
lipogenesis
formation and storage of fat as triglycerides
49
lipolysis
breakdown of stored triglycerides to FFA and glycerol
50
Obligate vs. facultative tissues
- obligate- can only use glucose as energy (brain, medulla, RBCs)- ketones used during starvation - facultative- use glucose for energy if available (can use amino acids or fats)- muscles and most other tissues
51
Insulin
- secreted in capillaries and portal circulation - 50% removed by 1st pass - daily secretion 60 units/delivery is 30 units
52
Metabolic effects of insulin
- liver and muscle- promotes storage of glycoge, inhibits gluconeogenesis - stimulates uptake of amino acids- promotes protein synthesis and inhibits breakdown - carbs are converted to FFA and glycerol- stored as triglycerides, inhibits breakdown, limits use of fats for fuel when glucose high
53
Insulin effect on ion transport
stimulates uptake of K, Mg, and phosphate into cells
54
Factors that stimulate insulin release
amino acids, GI hormones, PSNS stimulation, beta adrenergic stimulation, ACTH, vagal stimulation
55
Factors that inhibit insulin release
hypoglycemia, somatostatin, glucagon, cortisol, GH, alpha adrenergic stimulation, stress
56
Glucagon
- biological antagonist to insulin - increases plasma glucose and enhances hepatic glucose output via gluconeogensis and breakdown of liver glycogen - blood glucose <90 stimulates release - works with GH, cortisol, and epi
57
Somatostatin
- inhibits insulin and glucagon secretion - decreases motility of stomach, duodenum, and gall bladder contraction - decreases GH release - decreases secretion and absorption within GI tract - extends time over which food and nutrients are digested and absorbed
58
Type 1 diabetes
- absolute insulin deficiency- dependent on exogenous insulin - beta cell destruction (symptoms when >80% destroyed) - prone to DKA
59
Type 2 diabetes
- impaired insulin secretion, peripheral insulin resistance, abnormal fat metabolism, excess hepatic glucose production - obesity - insidious onset - prone to HHS
60
What connects 2 lobes of thyroid?
isthmus
61
Follicles of thyroid
- lined by epithelial cells | - produce and secrete T4 and T3
62
Thyroid hormone functions
- increase cellular activity - required for normal growth - growth and development of brain during fetal and postnatal - augment HR and contraction - enhance secretion of digestive juices and GI motility - increased hormone secretion of most endocrine glands ( especially pancreas)
63
What is necessary for T4 and T3 production?
iodine
64
Regulation of thyroid hormone secretion
1) TRH released from hypothalamus 2) TRH causes ant. pituitary to produce and secrete TSH 3) TSH causes increased thyroid gland activity 4) if overactivity, excessive amounts of TH produced
65
Calcium regulation
- 99% in bone - 1% in ECF - changes in protein may affect Ca status - alkalosis- increases protein binding, decrease serum iCal
66
3 forms of serum calcium
9%- nonionized, bound to anions 41% non ionized, bound to proteins 50%- ionized and diffusible, active
67
PTH
- secreted from chief cells of parathyroid in response to low serum iCal, high phosphate, low mag - increases extracellular calcium concentration, decreases phosphate
68
Direct effects of PTH
bone resorption (osteoclasts), increased reabsorption from DCT, phosphate excretion in PCT
69
Indirect effects of PTH
promotes formation of vitamin D which enhances calcium and phosphate absorption from intestines
70
PTH feedback loop
small decrease in circulating iCal produces rapid increase in PTH secretion and vice versa
71
Difference b/w calcium chloride and gluconate
calcium chloride has higher concentration
72
Vitamin D
- absorbed from GI or produced enzymatically by UV light - inactive form converted in liver and kidney to active - active increases Ca, Mg, phosphate absorption - inadequate- rikets, osteomalacia
73
Calcitonin
- secreted by thyroid in response to elevated iCal - lowers serum calcium - weak effect- inhibits osteoclasts (osteoblasts more prevalent)
74
Symptoms of hypocalcemia
hyperreflexia, muscle spasm, tetany, perioral paresthesias, laryngospasm, Chvostek (twitching of face), Trousseau's (flexion of wrist and thumb)