Brainscape's Knowledge GenomeTM

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


See full index

Year 2 - T2 Theme 1 > L2 - Intro to HPA axis > Flashcards

L2 - Intro to HPA axis Flashcards

1
Q

What is the area directly above the pituitary gland

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

What is the pituitary gland connected to the brain via

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

What is the pituitary gland divided into

A
  • Anterior and posterior pituitary glands

- They effectively function independently

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

What is the posterior pituitary gland sometimes called

A
  • Is a ‘down growth’ from the brain

- It is sometimes called the neurohypophysis

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

What are the hormones secreted by the posterior pituitary gland

A
  • Antidiuretic hormone(ADH also called vasopressin)

- Oxytocin

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

What type of hormones are ADH and oxytocin

A
  • Peptide hormones

- Nine amino acids each, of which seven are identical

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

Where are ADH and oxytocin produced

A
  • Hormones are not synthesised within the gland, but are synthesised by the neurones of the hypothalamus
  • Supraoptic nuclei and paraventricular nucleus
  • These hormones are synthesised as inactive precursors and converted to active hormone within the posterior pituitary
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the inactive precursors of ADH and oxytocin transported via

A
  • Transported from the supraoptic and paraventricular nuclei along the hypothalamico-neurohypophyseal tract
  • They are then stored within the posterior pituitary
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is secretion of ADH influenced by

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

What does stimulation of V2 receptors cause

A
  • Stimulation of V2 receptors causes translocation of aquaporins to the membrane of the kidney tubule, thus allowing water reabsorption
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What does stimulation of v1 receptors cause

A
  • Vasoconstriction

- This does not occur at physiological concentration

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

What do disorders of ADH secretion lead to

A
  • Disorders of fluid balance
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Effect of oxytocin

A
  • Oxytocin acts via IP3 to cause contraction of the smooth muscle of the genital tract (uterus) and breast
  • During parturition, oxytocin causes contraction of the smooth muscle of the uterus to aid expulsion of the infant
  • Continued stimulation of the cervix causes continued secretion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is secretion of oxytocin stimulated by

A
  • Stimulation of the genitals and nipples
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

When is oxytocin most important

A
  • At parturition and during lactation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

When does oxytocin synthesis increase

A
  • During pregnancy, but there is a parallel increase in oxytocinase activity
17
Q

Is oxytocin necessary for initiation of normal labour

A
  • Oxytocin is not necessary for the initiation of a normal labour
  • But oxytocin may be administered to induce labour
18
Q

What is anterior pituitary gland also called

A
  • An ‘up growth’ from the palate
19
Q

Hormones secreted by the anterior pituitary gland

A
  • Growth hormone
  • Prolactin
  • Thyroid stimulating hormone
  • Adrenocorticotrophic hormone
  • Follicle stimulating hormone
  • Luteinising hormone
20
Q

Which cells synthesise thyroid stimulating hormone

A
  • Thyrotrophe cells
21
Q

Which cells synthesise adrenocrticotrophic hormone

A
  • Corticotrophe cells
22
Q

Which cells produce follicle stimulating hormone

A
  • Gonadotrophe cells
23
Q

Where are the releasing hormones secreted by the hypothalamus secreted into

A
  • Hypothalamico-adenohypopyseal portal vessel which carries them to the anterior pituitary
  • The releasing hormones do not enter the systemic circulation
24
Q

Biochemical tests that are part of clinical investigations

A

Start with Signs and Symptoms
Followed by
Biochemical Tests
(Basal Levels)

* TSH(not water soluble) & FT4(is free and therefore soluble)   
* Cortisol
* LH & FSH
* Prl
* Testosterone / “Periods”
25
Q

What is the test carried out after biochemical tests

A
  • Imaging(eg MRI)
26
Q

Tests carried out after imaging

A
  • Visual field tests

eg bilateral hemianopsia due to compression of optic chiasm

27
Q

Why is the timing of tests important

A
  • Diurnal rhythms
28
Q

Why do you have to measure FT4 levels

A
  • TSH is not biologically active
29
Q

Where is prolactin synthesised

A
  • Is 199 amino acid peptide, synthesised in the lactotrophe cells of the anterior pituitary
30
Q

What is prolactin secretion controlled by

A
  • The secretion of prolactin is under hypothalamic control by means of Prolactin Release Inhibiting Factor, which is DOPAMINE.
  • TRH stimulates prolactin synthesis.
31
Q

What is prolactin secretion stimulated by

A
  • Mild stress
  • Nipple stimulation
  • Coitus
32
Q

Primary role of prolactin

A
  • To promote lactation, and development of breast tissue
  • It is most important in females after puberty and during and after pregnancy
  • Prolactin is secreted in both males and females
33
Q

Where is growth hormone synthesised

A

• Growth hormone is synthesised in the somatotrophe cells of the anterior pituitary gland

34
Q

What is secretion of growth hormone secretion controlled by

A

• Secretion is controlled by the hypothalamus via
- Growth Hormone Releasing Hormone (GHRH) and Growth Hormone Release Inhibiting Hormone (GHRIH, somatostatin).

· Growth Hormone Releasing Hormone (GHRH) is more important in control than
Growth Hormone Release Inhibiting Hormone (GHRIH, somatostatin).

35
Q

What can secretion of growth hormone be stimulated by

A

· Secretion of growth hormone is stimulated by decreased carbohydrates and fatty acids and increased amino acids.

36
Q

What can GH act via in some tissues

A

· In some tissues, GH acts via second messengers which are produced in the liver

· Insulin-like growth factor 1

· Insulin-like growth factor 2

37
Q

What is the primary effect of GH

A

The primary effect of GH is to promote the linear growth of adolescence by increasing protein synthesis and collagen deposition

This is mediated via the nucleus

GH is also involved in tissue turnover and repair

38
Q

Effect of GH on foetal growth

A

Foetal growth is relatively independent of gH

Year 2 - T2 Theme 1 (20 decks)

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