Brainscape's Knowledge GenomeTM

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


See full index

MCAT 2015 > The Endocrine System > Flashcards

The Endocrine System Flashcards

You may prefer our related Brainscape-certified flashcards:
MCAT flashcards
1
Q

hormones

A

endocrine signaling involves secretion of these directly into the bloodstream
travel to distant target tissues, where they bind to receptors and induce a change in gene expression or cell function

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

peptide hormones

A

composed of amino acids and are derived from large precursors that are cleaved during post translational modification
polar and cannot pass through plasma membrane
bind to extracellular receptors where they trigger transmission of a secondary messenger
usually have rapid onset but are short-lived
travel freely in the bloodstream and do not require a special carrier

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

steroid hormones

A

derived from cholesterol
minimally polar and can pass through plasma membrane
bind to intracellular or intranuclear receptors, where they promote conformational change and bind to DNA, affecting transcription of a particular gene
usually have slow onset but are long-lived
cannot dissolve in the bloodstream and must be carried by specific proteins

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

amino acid-derivative hormones

A

modified amino acids
chemistry shares some features with peptide hormones and some features with steroid hormones; dif ones share dif features with other hormone classes
common ex’s: epinephrine, norepinephrine, triiodothyronine, thyroxine

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

direct hormones

A

have major effects in non-endocrine tissues

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

tropic hormones

A

have major effects in other endocrine tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

hypothalamus

A 
bridge between nervous and endocrine systems
release of hormones from here mediated by a number of factors: projections from other parts of brain, chemo- and baroreceptors in blood vessels, and neg feedback from other hormones
stimulates anterior pituitary gland through paracrine release of hormones into the hypophyseal portal system which directly connects the two organs
antidiuretic hormone (ADH or vasopressin) and oxytocin synthesized here
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

negative feedback

A

final hormone (or product) of a pathway inhibits hormones (or enzymes) earlier in the pathway, maintaining homeostasis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

gonadotropin-releasing hormone (GnRH)

A

promotes the release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH)

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

growth hormone-releasing hormone (GHRH)

A

promotes release of growth hormone

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

thyroid-releasing hormone (TRH)

A

promotes release of thyroid-stimulating hormone (TSH)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

corticotropin-releasing factor (CRF)

A

promotes release of adrenocorticotropic hormone (ACTH)

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

prolactin-inhibiting factor (PIF or dopamine)

A

inhibits release of prolactin

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

anterior pituitary

A

releases hormones in response to stimulation from hypothalamus
FSH, LH, ACTH, TSH are tropic hormones
prolactin, endorphines, growth hormone are direct hormones

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

follicle-stimulating hormone (FSH)

A

promotes development of ovarian follicles in females and spermatogenesis in males

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

luteinizing hormone (LH)

A

promotes ovulation in females and testosterone production in males

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

adrenocorticotropic hormone (ACTH)

A

promotes synthesis and release of glucocorticoids from adrenal cortex

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

thyroid-stimulating hormone (TSH)

A

promotes synthesis and release of triiodothryonine and thyroxine from the thyroid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

prolactin

A

promotes milk production

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

endorphins

A

decrease perception of pain and can cause euphoria

21
Q

growth hormone (GH)

A

promotes growth of bone and muscle and shunts glucose to these tissues
raises blood glucose concentrations

22
Q

posterior pituitary

A

releases two hormones produced in the hypothalamus

23
Q

antidiuretic hormone (ADH or vasopressin)

A

secreted in response to low blood volume or increased blood osmolarity and increases reabsorption of water in collecting duct of nephron, increasing blood volume and decreasing blood osmolarity

24
Q

oxytocin

A

secreted during childbirth and promotes uterine contractions
also promotes milk ejection and may involved in bonding behavior
has a positive feedback loop

25
Q

thyroid

A

located at base of neck in front of trachea

produces three key hormones

26
Q

triiodothyronine (T3) and thyroxine (T4)

A

produced by follicular cells and contain iodine
increase basal metabolic rate and alter utilization of glucose and fatty acids
required for proper neurological and physical development in children

27
Q

calcitonin

A

produced by parafollicular (C) cells
decreases plasma Ca concentration by promoting Ca excretion in kidneys, decreasing Ca absorption in gut, and promoting Ca storage in bone

28
Q

parathyroid glands

A

release parathyroid hormone (PTH)

29
Q

parathyroid hormone (PTH)

A

increases blood Ca concentration
decreases excretion of Ca by kidneys and increases bone resorption directly to increase blood Ca conc
activates vitamin D, which is necessary for Ca and phosphate absorption from gut
promotes resorption of phosphate from bone and reduces reabsorption of phosphate in kidney, but vitamin D promotes absorption of phosphate from gut; two effects on phosphate conc somewhat cancel each other out

30
Q

adrenal cortex

A

produces three classes of steroid hormones: glucocorticoids, mineralocorticoids, cortical sex hormones

31
Q

glucocorticoids

A

i.e. cortisol, cortisone
increase blood glucose conc, reduce protein synthesis, inhibit the immune system, and participate in the stress response
release is stimulated by ACTH

32
Q

mineralocorticoids

A

i.e. aldosterone
promote Na reabsorption in distal convoluted tubule and collecting duct, thus increasing water reabsorption
also increases K and H ion excretion
regulated by renin-angiotensin-aldosterone system

33
Q

cortical sex hormones

A

i.e. androgens (testosterone) and estrogens in both males and females

34
Q

adrenal medulla

A

derived from nervous system

secretes catecholamines into bloodstream

35
Q

catecholamines

A

i.e. epinephrine and norepinephrine (involved in fight-or-flight response)
promote glycogenolysis, increase basal metabolic rate, increase heart rate, dilate bronchi, alter blood flow

36
Q

pancreas

A

produces hormones that regulate glucose homeostasis

37
Q

glucagon

A

produced by alpha cells, raises blood glucose levels by stimulating protein and fat degradation, glycogenolysis, and gluconeogenesis

38
Q

insulin

A

produced by ß-cells and lowers blood glucose levels by stimulating uptake by cells and anabolic processes

39
Q

somatostatin

A

produced by ∂-cells and inhibits insulin and glucagon secretion

40
Q

gonads

A

produce hormones that are involved in development and maintenance of reproductive systems and secondary sex characteristics

41
Q

testes

A

secrete testosterone

42
Q

ovaries

A

secrete estrogen and progesterone

43
Q

pineal gland

A

releases melatonin

44
Q

melatonin

A

helps regulate circadian rhythms

45
Q

secretin, gastrin, cholecystokinin

A

produced by cells in stomach and intestine

46
Q

erythropoietin

A

secreted by kidneys

stimulates bone marrow to produce erythrocytes (RBC’s) in response to low oxygen levels in blood

47
Q

atrial natriuretic peptide (ANP)

A

secreted by atria of heart

promotes excretion of salt and water in kidneys in response to stretching of atria (high blood volume)

48
Q

thymosin

A

secreted by thymus

important for proper T-cell development and differentiation

MCAT 2015 (66 decks)

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