Brainscape's Knowledge GenomeTM

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


See full index

endocrine > physiology > Flashcards

physiology Flashcards

1
Q

what is the hypothalamus

A

a neuroendocrine hormone as it releases neurone in the brain that travel in the blood to cells

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

another definition of endocrine gland

A

ductless gland

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

autocrine secretion

A

cells that secrete chemicals that bind to the same receptors on the cell that secreted it

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

what are ducted exocrine glands

A

deliver secretions to the external environment such as bile, sweat and saliva

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

paracrine secretions

A

chemicals diffuse in ECF to affect neighbouring cells and don’t travel in the blood

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

peptide/protein hormones

A

composed of chains of amino acids ( most common )

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

amine hormones

A

all derived from one or two hormones (tryptophan or tyrosine)
only melatonin comes from tryptophan)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q
A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

steroid hormones

A

derived from cholestrol

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

stalk that connects the hypothalamus and pituitary gland

A

infundibulum

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

describe features of anterior pituitary

A
  1. connected to hypothalamus via capillary portal system
  2. treu endocrine tissue of epithelial origin
  3. makes up 2/3s of the gland
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

describe features of the posterior pituitary gland

A
  1. continuation of hypothalamus
  2. consists of axons and nerve terminals of hypothalamic neurone
  3. is neuroendocrine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what does non-tropic mean

A

neurohormones produced in the hypothalamus and travel to the posterior pituitary where they are released into the blood

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

what does tropic mean

A

neurohormones secreted into capillaries travelling to anterior pituitary and govern released of anterior pituitary hormones

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

name 2 hypothalamic non-tropic hormones

A
  1. vasopressin- ADH
  2. oxytocin- aids expression of milk from lactating breast
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

describe the hypothalamus-hypophyseal portal system

A

tiny vessels which transfer tropic hormones from hypothalamus to anterior pituitary. very rapid

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

what does trophic action mean

A

indirect effects in promoting growth

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

mechanics of action of peptide hormones

A
  1. mRNA binds amino acids onto peptide chain called preprohormone. Goes straight to ER.
  2. Enzyme in the ER chop off the signalling sequence creating an inactive prohormome
  3. Prohormone passes through the Golgi apparatus
  4. secondary vesicles containing prohormones and enzymes bud off the golgi and chop prohormones into active segments/
  5. secretory vesicles release content by exocytosis into extracellular space
  6. hormone moves in circulation for transport to target organ
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what receptors do peptide hormones bind too

A

g-protein coupled receptor activate a 2nd messenger system and gives a rapid response

tyrosine kinase linked receptor alters gene expression and gives a slower but longer lasting response

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

mechanism of action of steroid hormones

A

lipophillicity allows steroid hormones to readily cross the plasma membrane.
2. Activation of intracellular receptors leads to change in gene expression at the level of the nucleus
3. genes control the synthesis of proteins so these hormones increase or decrease protein synthesis

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

describe half life of steroid hormones

A

hours to days

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

describe half life of peptide hormones

A

usually minutes therefore requires continued secretion

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

describe the glucostatic theory

A

food intake is determined by blood glucose
As blood glucose increases the drive to eat decreases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

describe the satiety centre

A

promotes feelings of fullness by suppressing feeding centre

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

describe the lipostatic theory

A

food intake is determined by fat stores as fat stores increase the drive to eat decreases.

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

what does leptin do and what type of hormone is it

A

leptin is released by fat stores which depress the feeding centres reducing hunger and is a peptide hormone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what are the three categories of energy output

A

cellular work
mechanical work
heat loss

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

what is the only voluntary energy output

A

mechanical work by skeletal muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

when do we enter the absorptive state

A

after eating when the ingested nutrients supply the body with energy and the excess is stored
anabolic phase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

when do we enter the post-absorptive state

A

between meals and overnight as nutrients in plasma decrease and we rely on our bodies energy stores.
This is a catabolic phase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

what is the normal BG levels

A

4.2-6.3mM

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

what is the level of BG for hypoglycaemia

A

<3mM

30
Q

where are the hormones found in the pancreas

A

islets of langerhans

31
Q

name the 4 types of langerhans cells

A

alpha cells- produce glucagon
beta cells- produce insulin
delta cells produce somatostatin
F cells- unknown function

32
Q

simple function of insulin

A

stimulates glucose uptake by cells

33
Q

how is insulin synthesised

A
  1. As a large preprohormone (preproinsulin) which is converted to proinsulin in the ER
  2. Proinsulin is then packaged into vesicles and stored until secreted
34
Q

what form is excess glucose stored in the liver and muscle

A

As glycogen

35
Q

what form is excess glucose stored in the liver and adipose tissue

A

as triglycerols

36
Q

describe the primary action of insulin in terms of crossing into cells

A

1.insulin binds to tyrosine kinase receptors on the cell membrane of insulin dependent tissues to increase glucose uptake

  1. Stimulates mobilisation of GLUT 4 and it migrates to the membrane and able to transport glucose into the cell
37
Q

name 2 tissues that are insulin dependent

A

muscle and fat

38
Q

how do other tissues other than muscle and fat take up glucose

A

through other GLUT transporters which aren’t insulin dependent

39
Q

stimuli which increase insulin release

A
  1. increased BG
  2. increased amino acids in plasma
  3. glucagon
  4. incretin hormones which control GI secretion
  5. vagal nerve activity
40
Q

stimuli which inhibit insulin release

A
  1. low BG
  2. somatostatin
  3. sympathetic alpha 2 effects
    4 stress e.g hypoxia
41
Q

why take glucose orally vs IV

A

orally you have vagal stimulation which stimulates GI hormone release as well as insulin release

42
Q

primary actions of glucagon

A
  1. increase glycogenolysis
  2. increase gluconeogenesis
  3. formation of ketones from fatty acids
    All occur in the liver
43
Q

stimuli that promote glucagon release

A

1.low BG <5mM
2. high amino acids
3. sympathetic innervation and epinephrine
4. cortisol
5. stress

44
Q

stimuli that inhibit glucagon

A
  1. glucose
    2 FFAs and ketones
  2. insulin
  3. somatostatin
45
Q

parasympathetic innervation on islet cells

A

increase insulin and decrease glucagon

46
Q

sympathetic innervation on islet cells

A

increased glucagon, increase epinephrine and inhibition of insulin

47
Q

function of pancreatic somatostatin

A

surpresses release insulin and glucagon

48
Q

what happens if you have a SS secreting tumour

A

you have diabetes

49
Q

effect of exercise on BG

A

glucose can be taken up independently of insulin

GLUT 4 transporters can migrate to membrane without insulin being present

50
Q

what can hyperglycaemia cause

A

neuropathy
retinopathy
nephropathy
CVD

51
Q

hormones that contribute to growth

A

GH
IGF-1
thyroid hormone
sex steroids
glucocorticoids
insulin

52
Q

function of growth hormone

A

promote elongation of bones and increase height, weight and body mass

53
Q

function of sex hormones in growth

A

close epiphyses and stop boner elongation

54
Q

what happens in congenital hypothyroidism

A

babies are born of normal size but have retarded growth and development. They retain infantile facial features

55
Q

what is IGF-1

A

also known as somatomedin C as it mediates the action of GH

Has insulin like qualities as it stimulates glucose uptake in muscle and bone

secreted primarily by the liver and controls GH through a negative feedback loop

56
Q

things that stimulate GHRH (GH)

A

increased amino acids in the plasma
physical stress and illness
delta sleep
oestrogen and tesosterone

57
Q

stimuli that increase GHIH (somatostatin secretion)

A
  1. glucose
  2. FFAs
  3. ageing
  4. cortisol
58
Q

hypersecretion of GH

A

gigantism- excessive growth
acromegaly- enlarged hands and feet but long bones don’t increase

59
Q

2 active forms of thyroid hormones

A

T3 and T4

60
Q

2 types of cells present in thyroid gland

A
  1. C cells secrete calcitonin which is a calcium regulating hormone- fewer cells
  2. follicular cells which support thyroid hormone synthesis swell as thyroglobulin
61
Q

what is a thyroid follicle

A

spherical structure whose walls are made of follicular cells and centre filled with colloid= sticky glycoprotein metric and contains 2-3 mths of TH

62
Q

why does T4 have a longer half life than T3

A

thyroxine binding globulin has a high affinity for T4 releasing it slowly into the plasma

63
Q

how much more T4 do you have than T3 in the plasma

A

50x more T4

64
Q

key hormones in foetal development

A

thyroid hormone and insulin

65
Q

thyroid hormone function

A

Bind to nuclear receptors in target cells were they change transcription and translation to alter protein synthesis

66
Q

symptoms of hyperthyroidism

A
  1. increased metabolic rate and heat production
  2. increased protein catabolism- muscle weakness/weight loss
  3. altered nervous system function
  4. elevated cardiovascular function- increased HR
67
Q

causes of hypothyroidism

A

Hashimoto disease- autoimmune attack on thyroid gland and can’t produce hormone

deficiency of dietary iodine

68
Q

symptoms of hypothyroidism

A

weight gain and cold intolerant
brittle nails and thin skin
slow speech/ reflexes and fatigue
slow HR and weaker pulse

69
Q

what does goitre mean

A

enlargement of thyroid gland

70
Q

cause of hyperthyroidism

A

graves disease- antibodies produces that mimic TSH and continually activate thyroid gland

71
Q

function of adrenal medulla (central part and neural in origin)

A

modified sympathetic ganglion
secretes catecholamines from the postganglionic cell

72
Q

function of adrenal cortex

A

secretes 3 steroid hormones
1. mineralocorticoids
2. glucocorticoids
3. sex steroids

73
Q

3 zones in the cortex

A

zona glomerulosa- aldosterone
zona fasciculata- glucocorticoids
zona reticularis- sex hormones

74
Q

actions of cortisol on glucose metabolism

A
  1. gluconeogenesis
  2. proteolysis
  3. lipolysis
  4. decrease insulin sensitivity
75
Q
A

endocrine (3 decks)

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