Brainscape's Knowledge GenomeTM

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


See full index

MD4001 endocrine > Hypothalamic pituritary axis > Flashcards

Hypothalamic pituritary axis Flashcards

1
Q

what are the features of endocrine glands

A

ductless
may be endocrine, paracrine or autocrine
very vascular with fenestrated capillaries
some are discrete organs and some are associated with other tissues
may have complex embryology

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

what stimulated secretion of parathyroid hormone

A

low Ca blood conc

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

what hormone is released by the pineal gland

A

melatonin

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

what hormone is released by the thymus

A

thymopoietin

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

what hormone is released by adipose tissue

A

leptin

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

what structure encloses the pituritary gland superiorly

A

diaphragma sellae

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

what structures are the pituitary gland related to

A

optic chiasma and spenoid sinus

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

what is the neurohypophysis

A

posterior pituitary gland

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

what is the adenohypophysis

A

anterior pituitary gland

contains the pars anterior, pars tuberalis and pars intermedia

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

what is the pars intermedia derived from

A

rathke’s pouch

lies between the ant and post lobes
contains colloid filled, epithelial lined follicles
obscure function
contains basophilic cells

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

how does the anterior pituitary gland develop

A

up growth of epithelium from the oral cavity (Rathke’s pouch)
Rathke’s pouch loses contact with the oral cavity

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

how does the posterior pituitary develop

A

down growth from the brain infundibulum as a diverticulum

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

what is a craniopharyngioma

A

slow growing tumour which may develop along the track of Rathke’s pouch (benign)

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

how can secretory cells of the anterior gland be classified

A

how they stain

chromophils: acidophils (GH and prolactin)
Basophils (the others)

chromophobes do not stain

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

what neurohormones are released by the hypothalamus

A

Thyrotropin releasing hormone
corticotropin releasing hormone
growth releasing hormone
somatostatin growth hormone release inhibiting hormone
gonadotrophin releasing hormone
prolactin releasing factor
prolactin release inhibiting factor (PIF)

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

what neurohormones are released from the posterior pituitary

A

vasopressin
antidiuretic peptide
oxytocin

17
Q

what are trophic hormones

A

act on other endocrine glands

18
Q

what trophic hormones are released by the anterior pituitary

A

thyrotropin (thyroid stimulating hormone)
corticotropin (adrenocorticotropic hormone, ACTH)
Lutinising hormone
follicle stimulating hormone

19
Q

what hormones acting on peripheral targets are released by the anterior pituitary gland

A

somatotropin (growth hormone)
prolactin (PL)
melanotropin (melanocyte stimulating hormone)

20
Q

describe the release of growth hormone

A

cells in the arcuate nucleus secrete growth hormone releasing hormone that is released into the hypophyseal portal blood supply
this causes somatotrophs to release GH

in order to inhibit growth hormone somatostatin is released by cells in the periventricular region

21
Q

when is growth hormone release greatest

A

during sleep

22
Q

what are the functions of growth hormone

A

inhibits growth hormone release
increases cartilage and bone growth
increased protein synthesis, cell growth and proliferation
increased lipolysis
increased blood glucose and other anti insulin effects

23
Q

how does growth hormone increase cartilage, bone, protein synthesis

A

by stimulating insulin like growth factors from the liver

24
Q

what are the consequences of growth hormone release

A

increased linear growth and lean body mass
important for post natal development and rapid growth throughout puberty
maintenance of protein synthesis and tissue function in adults

25
Q

what are the effects of GH deficiency in children

A

dwarfism
decreased availability of lipids and glucose for energy

(treatment is effective with human growth hormone)

26
Q

what is the effect of GH excess before puberty

A

gigantism due to excess stimulation of epiphyseal plates

27
Q

what is the effect of GH excess after puberty

A

periosteal bone growth causing enlarged hand, jaw and feet
soft tissue growth leading to enlarged tongue, and coarse facial features
insulin resistance (diabetes)

can be treated with somatostatins (octreotide) varying success

28
Q

what are the signs and symptoms of acromegaly/ gigantism

A 
enlargement of hands and feet
rapid growth 
soft tissue swelling 
skin tags
muscle weakness
fatigue
skin changes
hirsutism 
coarsening of facial features 
joint pain 
amenorrhea
hyperhidrosis
sleep apnea
headaches
paraesthesia/ carpal tunnel 
impotence 
hypertension 
goiter
visual field defects
29
Q

where is vasopressin synthesised

A

neurosecretory cells in the supra optic nucleus and paraventricular nucleus

30
Q

what stimulates ADH release

A

increase in blood osmolality
decrease blood volume
angiotensin 2 release

31
Q

what are the effects of ADH

A

recruitment of APQ channels

water retention

32
Q

what are the causes of ADH deficiency (diabetes insipidus)

A

tumours, trauma, disease induced, familial disorders

nephrogenic - sex linked genetic defect in collecting tubule

33
Q

what are the symptoms of diabetes insipidus

A

polyuria and polydipsia

34
Q

where is oxytocin produced

A

hypothalamic neurons in the paraventricular and supraoptic nuclei

35
Q

where is oxytocin released

A 
posterior pituitary  (stored in vesicles in the expanded ends of the axons) 
release is controlled by impulses from the hypothalamus
36
Q

describe the hypothalamic control of milk production and ejection

A

sucking stimulus travels from breast to hypothalamus

dopamine release from the arcuate nucleus is inhibited

dopamine normally inhibits lactotrophs in the anterior pituitary.
prolactin is released which stimulates milk production

oxytocin is released from the paraventricular and supraoptic nuclei, it then travels to the posterior pituitary and is released into the blood

it travels to the breast and myoepithelial cells

GnRH is inhibited which inhibits the menstrual cycle

37
Q

where is the pineal gland

A

midline of the posterior part of the roof of the 3rd ventricle

38
Q

what hormone is melatonin derived from

A

tryptophan

39
Q

what are the features of melatonin

A 
secreted in darkness
regulates circadian rhythms
regulates onset of puberty
effects on aging and immune system 
accumulates calcium phosphate with time - 'brain sand' visible on x-ray

MD4001 endocrine (15 decks)

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