Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Endocrinology > The Hypothalamic pituitary axis > Flashcards

The Hypothalamic pituitary axis Flashcards

(67 cards)

Start Studying
1
Q

location of the hypothalamus and pituitary gland

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

Hypothalamus and pituitary gland form a complex functional unit that serves as the

A

major link between the endocrine and nervous system

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

what structure links the hypothalamus and pituitary gland

A

the infundibulum

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

hypothalamus and pituitary gland modulate (8)

A
  • Body growth
  • Repro
  • Milk secretion
  • Lactation
  • Adrenal gland function
  • Water homeostasis
  • Thyroid gland function
  • Puberty
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

structure of the pituitary gland

A

consists of two parts: anterior portion and posterior portion

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

anteiror pitutiary gland also known as

A

adenohypophysis

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

the a.pituitary is embryologically derived from

A

Rathkes pouch- primitive gut tissue

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

why is the posterior pituitary gland technically not a gland

A

since doesn’t produce the hormones that is releases- releases hormones produced in the hypothalamus

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

what is the p.pit also known as

A

neurohypophysis

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

the p.pit is embryologically derived from

A

neuroectoderm (primitive brain tissue)

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

p.pits anatomical position in relation to the hypothalamus

A

PP is physically connected to the hypothalamus, since the hypothalamus drops down through the infundibulum to form the posterior pituitary

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

what does the posterior pituitary release

A

Oxytocin and ADH produced by neurosecretory cells in supraoptic and paraventricular nuclei (collection of cell bodies with a similar function) of the hypothalamus

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

how are Oxytocin and ADH transported from the hypothalamus to the PP

A

Transported down nerve cell axons to the posterior pituitary

Prime example of neurocrine signalling (where hormone is transported down the axon of a neurone before it is released to act on a tissue)

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

Oxytocin and ADH are hormones because

A

Stored and released from posterior pituitary into general circulation to act on distant targets

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

oxytocin action

A
  1. Milk let down
  2. Uterus contraction during birth- Ferguson reflex
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

ADH (vasopressin) action

A

regultion of body water volume

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

the anterior pituitary endocrine function

A

Synthesises and releases many hormones

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

how is the AP controlled

A

by the hypothalamus

  • Hormones synthesised in hypothalamus are transported down axons and stored in median eminence before release into hypophyseal portal system
  • These hormones stimulate (or inhibit) target endocrine cells in the a.pituitary gland (neurocrine function)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q
A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

hormones released by the AP

A
  • TSH
  • ACTH
  • LH
  • Prolactin
  • GH
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

TSH

A
  • thyroid stimulating hormone- secretion of thyroid hormone from thyroid gland
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

ACTH

A

Adrenocorticotropic hormones- secretion of hormones from adrenal cortex

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

LH

A
  • Luteinising hormone- ovulation and secretion of sex hormones
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
PRL
- Prolactin- mammary gland development and milk secretion
26
GH
- Growth hormone- growth and energy metabolism- stimulates IGF
27
The hormones produced by nerve cells in hypothalamus act via two distance neurocrine pathways
1. Direct effects on distant target tissues via oxytocin and ADH hormones from PP 2. Hormones secreted exclusively onto hypophyseal portal system affect endocrine cells within the anterior pituitary
28
tropic
hormones that are affecting the synthesis and release of another hormone
29
tropic hormones of the hypothalamus
6 tropic hormones that have a direct effect on the release of anterior pitutiary hormoens * TRH * PRH * PHI * CRH * GnRH * GHRH * GHIH
30
TRH
Thryotropin releasing hormone - stimulates release of TSH from the AP - stimulates the thryoid gland to release T3 and T4 to icnrease metabolic rate
31
PRH
prolacting releasing hormone (TRH) - minor +ve control on prolactin release in AP - stimulates mammary glands grow and secrete milk
32
PIH
prolactin inhibiting hormone * inhibits release of prolactin from the AP * inhibits milk secretion from mammary glands
33
CRH
corticotropin releasing hormone * stimulates the AP to release Adrenocorticotropic hormones * ACTH stimulates the adrenal glands to secrete cortisol * stimulates stress response and metabolic actions
34
GnRH
gonadotropin releasing hormone * stimulates the release of LH and FSH from the AP * LH stimulates ovaries in females and testes in male to secrete sex hormones * FSH stimulates ovaries in females and testes in males in gamate production
35
GHRH
growth hormone releasing hormone * stimulates growth hormone to be released from the AP * the GH stimualtes many tissues including the liver to produce IGFs to increase growth
36
GHIH
growth hormone-inhibitng hormone (somatostatin) * inhibits the release of GH from the AP * reducing growth of tissue and release of IGF from the liver
37
how are pathways by which hypothalamic and AP hormoens are produced regulated
most often by negative feedback (Prolactin is under tonic inhibitory control by dopamine Anything blocking stalk will lead to prolactin disinhibition )
38
feedback loop for the hypothalamic pituitary-adrenala xis
* 2 levels of feedback * ACTH can also feedback to the hypothalamus and inhibit the release of CRH * E.g. when cortisol levels increase, negative feedback is sent to the hypothalamus (reducing CRH release) and AP (reducing ACTH release)
39
name the factors which influence growth
- genetics - nutrition - environment - hormones **(Growth Hormoen)**
40
hyerplasia
increase in cell number
41
hypertrophy
increase in cell size
42
atrophy
decrease in cell size and number
43
necrosis
cell death by damage
44
apoptosis
programme cell death e.g. when structures such as the hands are forming
45
GH structure
Protein hormone (191 aa) hass a signal peptide that must be cleaved before proper folding
46
what stimulates GH production in AP
GHRH (growth hormone releasing hormone)
47
what inhibits GH production in AP
somatostatin
48
growth promitng effects of GH mainly promoted
indirectly via insulin-like growth factors (somatomedins)
49
in response to GH the liver and s. muscle produce and secrete
IGF
50
function of GH in children
Essential for normal growth during childhood and teenage years * Stimulates long bone growth * Length and width prior to epiphyseal closure * Width after epiphyseal closure
51
function of GH in adults
GH and IGF help maintain muscle and bone and promote healing, tissue repair as well as modulating metabolism and body composition
52
when does a surge of GH secretion occur
after onset of deep sleep
53
what sort of sleep decreases GH secretion
REM
54
what else increases GH secretion
* stress * exercise * less glucose or fatty acids * fasting
55
what else decreases GH secretion
obesity
56
Feedback loop of GH
**Long loop** * Mediated by IGF * Inhibits release of GHRH from hypothalamus * Stimulates release of somatostatin from hypothalamus * Inhibit release of GH from anterior pituitary **Short loop** * Mediated by GH itself via stimulation of somatostain release
57
58
GH deficiency can cause
pituitary dwarfism * Proportionate type of dwarfism * Complete or partial deficiency * Both types respond to GH therapy * Height below 3rd percentile on standard growth charts * growth rate slower than expected for age * Delayed or no sexual development during teen years
59
GH excess in childhood
Gigantisms - rare - pituitary adenoma
60
GH excess in adulthood
acromegaly - large extremities: hand, feet and lower jaw
61
62
other hormones which influcne growth
isnulin, thyroid hormones, androgens, estorgens and glucocorticoids
63
molecular mechanism of GH
1. GH binds to janus kinase (JAK) receptors 2. Activating signalling pathway which leads to the activation of transcription factors and **IGF**
64
IGF action
Act through IGF receptors (distinct from GH receptors) to modulate * Cell growth- hypertrophy * Cell number – hyperplasia * Increase in rate of protein synthesis * Increase in rate of lipolysis in adipose tissue
65
major IGF in adults vs for fetal growth
Adult- IGF-1 Fetal growht- IGF3
66
what sort of signalling does IGF do
paracrine, autocrine and endocrine
67
IGF has some
homology with insulin receptors e.g. can get hybrid receptros (half insulin/ half IGF receptors)

Endocrinology (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions