Brainscape's Knowledge GenomeTM

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


See full index

Y3 Patient Sem 1 > Hypothalmic and Pitiutary Hormones > Flashcards

Hypothalmic and Pitiutary Hormones Flashcards

1
Q

where is the hypothalmus located?

A

located below the thalamus, just above brain stem

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

what is the role of the hypothalmus?

A

important for control of basic fucntions such as hunger, thirst, sleep.
it senses the internal and external environment.

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

where is the pituitary gland?

A

sits in the small bone cavity, below the hypothalumus.

it is the size of a pea and weight around 0.5g

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

what is the role of the pituitary gland?

A

Connects to hypothalamus via the infundibulum or pituitary stalk. There are different ways in which they will communicate

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

what are the parvicellular neurons?

A

secrete regulatory hormones into the bloodstream which travel thro’ the portal system to the anterior pituitary lobe triggering secretion of other hormones (circulatory system link)

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

what are the magnocellular neurons?

A

have long axons which extend down into the posterior pituitary lobe (direct neuro-endocrine link). It the neurones that secrete the hormones and carry the neurones down the nerve axons to the terminals which are found in the posterior pituitary.

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

The anterior pituitary does NOT have a direct nervous connection with the hypothalamus?

A

TRUE

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

what secretes hormones from hypothalmus which reach target sites?

A

hypothalamic-pituitary portal system

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

what are all the hormones produced by hypothalmus or pituitary gland?

A

peptides or small proteins (bar dopamine)

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

what is prolactin?

A

hypothetical hormone

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

where are hypothalmic regulatory hormones secreted directly into?

A

portal system = hypothalamic-pituitary portal vei

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

what are the tropic hormones?

A

FLAT

  • follicle stimulating hormone (FSH)
  • luteinising hormone (LH)
  • adrenocorticotropic hormone (ACTH)
  • thyroid stimulating hormone (TSH)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what are the non-tropic hormones?

A
  • prolactin (PRL)

- growth hormone (GH)

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

what is the functions of FSH and LH (gonadotropin)?

A
  • Synthesised, stored & secreted from gonadotropes FSH stimulates ovaries to produce estrogen & testes to produce testosterone
  • LH has a role in ovulation and the growth of the corpus luteum
  • LH stimulates androgen secretion by interstitial cells in testes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is the function of ACTH (corticotropin)?

A

• Synthesised, stored & secreted from
corticotropes
it also regualtes to levels of cortisol within the body

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

what happens when there is a decreased temperature?

A
  • change in temp
  • hypothalmus detects and release thyrotroping releasing hormones
  • this is detected by anterior pituiarty which secretes thryoid stimulating hormones
  • tropic then reaches endorcrine gland release thryoid hormoes and increases metabolsim and therefore increased heat production
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what is a short loop feedback?

A

it means it jumps up one endocrine axis

18
Q

what is a long loop feedback?

A

jumps up two levels in an endocrine axis

19
Q

whats an ultra short loop?

A

inhibits secretion of its own hormone

20
Q

what is the function of the anterior pituitary hormone?

A

Non-tropic hormones Prolactin and Growth Hormone (GH) (PiG) act directly on other tissues and do not work on another endocrine system

21
Q

what is prolactin?

A
  • 198-amino acid, single-chain polypeptide
  • Synthesized, stored, & secreted by lactotropes
  • Roles and functions complex
  • includes effects on breast tissue for lactation
  • Dysregulation causes multiple problems which affect many different body systems
  • Most common pituitary tumour is prolactinoma tumour of lactotrope cells
  • Treated using dopamine receptor agonists
  • e.g. bromocriptine, cabergoline
22
Q

what is growth hormone?

A

• 191-amino acid, single-chain polypeptide
• Synthesized, stored, & secreted by somatotropes in the anterior pituitary
• Stimulates growth, cell reproduction and regeneration of specific cells
- Hypersecretion of growth hormone causes gigantism in children….Before the long bones have fused you have lots of growth in these
- and acromegaly in adults this is after long bones have fused.
o enlargement of the head, hands, feet, lower jaw, tongue and lips
o excessive sweating, headaches and visual field loss, due to pressure on optic nerve from the tumour right next to the pituitary gland.

23
Q

what is the treatment for acromegaly?

A

• Somatostatin (growth hormone inhibiting hormone GHIH)
cf somatotropin (GH) – do not confuse the terminology!
• Regulates production of growth hormone (GH) AND…
• Affects cell proliferation & growth via somatostatin receptors
• Synthetic analogues have much longer half-life
• Sandostatin has only 8 AA and a 90 mins half-life vs 3 mins for endogenous ligand
• If there is a tumour it can be removed with surgery but drug treatment is always used for as it is hard to get access to the pituitary gland.

24
Q

when would you have insufficinet hormone production of growth hormone?

A
  • Hypothalamic or pituitary tumor not a tumor which is secreting too much but it is pressing too much on the stalk and prevents the signals getting from hypothalamus to the pituitary so can therefore reduce secretion of the hormone
  • (craniopharyngioma most common)
  • Mutation of GH genes
  • Head injury or infection
  • Radiotherapy
25
Q

what is GH resistance?

A

genetic
• GH binding protein mutations which carry the hormone in the blood
• GH receptor mutations

26
Q

how many prepartions of somatropin are there

A

seven

27
Q

what is a drug for severe hypopituirism?

A

protirelin

28
Q

what is gonadorelin?

A

induces FSH and LH

29
Q

what is the function of the posterior pituitary?

A
  • Magnocellular neurons (produce hormones) in the hypothalamus pass through the infundibulum and end in the posterior pituitary gland
  • These neurons synthesize and secrete oxytocin and vasopressin (ADH). Quite rare to have both secreted from one.
  • The hormones are released at the axon terminals, where they diffuse into the capillary network of the posterior lobe and then will be transported to rest of the body
  • ADH and oxytocin do NOT go thro’ the portal system moving directly to the capillaries which supply rest of the body
30
Q

what are the functions of oxytocin?

A
  1. Stimulation of milk ejection – not milk production!
  2. Stimulation of uterine smooth muscle contraction at birth
  3. Establishment of maternal behaviou
31
Q

how does oxytocin work?

A

During child birth positive feedback regulation. Pressure on cervix cause a reflex arc up to the hypothalamus and causes a release of oxytocin, this will be transported in blood and picked up in uterus and this causes the uterus to contract, this causes a cycle. Once baby is out of uterus the pressure will have gone and this would then mean there would no longer be a reflex arc so no more oxytocin being released.

32
Q

when would you use sythentic oxytocin?

A

for induction of labour, speeds up contractions but this can come with problems.

33
Q

what are the problems of inducing labour with syntheitc oxytocin?

A

If the contractions are too quickly and too strongly – this will cause a reduce blood supply to the baby and therefore this means there is less oxygen getting to the baby and it can cause cerebral palsy.
You therefore need to monitor very closely when it is given.

34
Q

what is the function of vasopressin (ADH)?

A

Binds to receptors on cells in the collecting ducts of the kidney
• When the hormone binds it causes Synthesis and insertion of aquaporins into kidney tubules
• Promotes reabsorption of water back into the circulation via aquaporin 2 channel

35
Q

what happens is the absence of vasopressin?

A

the collecting ducts are virtually impermeable to water, which therefore flows out as urine – reducing water content of the body and the blood. Important for water balance.

36
Q

what is a symptom of diabetes insipidus?

A

excessive urine production - as much as 16 litres a day

37
Q

what causes hypothalamic diabetes insipidus?

A
  • Deficiency in vasopressin secretion
  • Caused by: head trauma, infections or tumors involving the hypothalamus
  • Treat using exogenous vasopressin simply due to a lack of vasopression so can be given as an injection
38
Q

what causes nephrogenic diabetes insipidus?

A
  • Kidney is insensitive to vasopressin
  • Caused by: renal disease, mutations in the vasopressin receptor gene or in the gene encoding aquaporin-2, effector of vasopressin
  • Treat by increasing water consumption, no drug treatment as there isn’t a problem with the production of vasopressin. Not usually life threatening aslong as they can get the water.
39
Q

where is the pineal gland located?

A

Located in the epithalamus, between the 2 hemispheres, in centre of brain. Nothing to do with the pituitary- separate gland.
secrete melatonin

40
Q

what is melatonin needed for?

A
  • Melatonin helps regulate the circadian rhythm governs a lot of physiology and controls what happens in day and night as these do differ
  • Production of melatonin by the pineal gland is inhibited by light to the retina and permitted by darkness

Y3 Patient Sem 1 (20 decks)

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