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Flashcards in Neuro-endocrine interactions Deck (34)
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1

what is the significance of neurones-endocrine interactions?

Many physiological functions are dually regulated by the nervous and endocrine systems. (e.g. blood pressure)

2

where do the nervous and endocrine systems interact at?

at the hypothalamus and the pituitary gland

3

Describe the pituitary gland (aka hypophysis).

a small endocrine gland located in a bony cavity at the base of the brain just below the hypothalamus

4

what are the two lobes of the pituitary gland ?

-posterior pituitary /neurohypophysis
-anterior pituitary/ adenohypophysis

5

what makes up the two lobes?

-posterior - composed of nervous tissue
-anterior- consist of glandular epithelial tissue

6

When is there an intermediate lobe in humans?

During fatal development -site of release of MSH

7

How does the hypothalamus control the release of hormones from the posterior pituitary?

connects to the hypothalamus by a neural pathway

8

How does the hypothalamus control the release of hormones from the anterior pituitary?

connects to the hypothalamus by a unique vascular link

9

where does the hypothalamus lie?

lies at the base of the brain, just dorsal to the pituitary gland

10

how does the pituitary connect to the base of the brain?

the infundibular stalk

11

what are the 6 hormones released from the anterior pituitary and what are their functions?

-Growth Hormone (GH) - stimulates IGF-1 production

-Adrenocorticotrophic hormone- stimulates adrenal cortex to make corticosteroids
(ACTH, corticotrophin)

-Thyroid stimulating hormone
(TSH) - stimulates thyroid follicular cells to make thyroid hormone

-Prolactin (PRL) - initiates and maintains milk productions

-Luteinizing hormone (LH) - stimulates gonads (leydig cells/testosterone)

-Follicle stimulating hormone (FSH)-stimulates gonads

12

what are the 2 hormones released from posterior pituitary and what are their functions?

-arginine vasopressin (ADH) - promotes water retention
-Oxytocin - stimulates uterus to contract and promotes milk ejection

13

what two peptide hormones are classed as neuro hormones and why?

-Vasopressin and oxytocin - because they are synthesised and secreted by nerve cells

14

where are vasopressin and oxytocin stored?

Stored in vesicles in nerve terminals

15

How is the peptide hormones released?

action potential promotes exocytosis of hormone into the blood-directly released into systemic circulation

16

what lobe stores the hormones and release the hormones?

posterior pituitary does not produce hormones

17

what makes action potentials fire down nerves?

-during dehydration
- increased ECF osmolality
-hypothalamic osmoreceptors
-hypothalamic neurones fire
-posterior pituitary
-increased ADHp
-increased H20 permeability of kidney tubules
-increased H20 reabsorption in kidney
-decreased urine output

18

how are anterior pituitary hormones specialised?

one cell type produces mainly one hormone

19

what are the anterior pituitary cell types and what do they produce?

-Somatotrophs produce growth hormone
-Thyrotrophs produce thyroid stimulating hormone (TSH)
-Corticotrophs produce adrenocorticotrophic hormone (ACTH)
-Gonadotrophs produce FSH and LH
-Lactotrophs produce prolactin

20

what is the specialised blood supply that links hypothalamus directly to anterior pituitary?

hypothalamic- hypophyseal portal system

21

what hormones can stimulate and inhibit secretion?

hypophysiotropic hormones

22

what is the releasing factor and inhibiting factor?

-Growth Hormone Releasing Hormone (GHRH)
-Somatostatin (SS)

23

what is the releasing factor of the thyroid stimulating hormone?

Thyrotrophin releasing hormone (TRH)

24

what is the releasing factor and inhibiting factor of the prolactin (PRL)?

-Prolactin Releasing Factor (PRF)
-Prolactin inhibiting factor (PIF – dopamine)

25

what is the releasing factor of the adrenocorticotrophic hormone hormone (ACTH)?

Corticotrophin Releasing Hormone (CRH)

26

what is the releasing factor of the LH/FSH?

Gonadotrophin Releasing Hormone (GnRH)

27

what can overcome negative feedback of hormone secretion?

CNS via the hypothalamus

28

what are the two types of negative feedback loops can be observed?

Long-loop feedback
Short-loop feedback

29

what is the short feedback loop of hormone secretion?

inhibit hormone 2 by product of hormone 3

30

what is the long feedback loop of hormone secretion?

hormone 3 inbits secretion of hypothalamus