Pituitary Flashcards
1
Q
What hormones are secreted by the pituitary gland?
A
Anterior pituitary gland
- ACTH
- TSH
- GH
- FSH/LH
- Prolactin
Posterior pituitary gland
- ADH
- Oxytocin
2
Q
What hormones are secreted by the hypothalamus?
A
3
Q
What is the function of growth hormone?
A
- stimulated by hypoglycaemia, excercise, sleep
- Effects mediated by IGF-1
- Liner growth in children
- acquisition of bone mass
- Regulation of body composition
- psychological well being
- Stimulates
- protein synthesis
- lipolysis
- glucose metabolism
4
Q
What are the manifestations of GH Deficiency?
A
- Children- poor growth
- adults
- increase in abdominal fat, decrease in lean body mass
- impaired lipid profile
- decrease in muscle strength and excercise capacity
- impaired cardiac function
- decrease in bone mineral density
- impaired psychological well-being
5
Q
What is the function of prolactin?
A
- essential for lactation
- levels increase dramatically in pregnancy and during breast feeding
- Inhibits gonadal activity through central suppression of GnRH
- cause disease when present in excess
6
Q
What is the function of ACTH?
A
7
Q
What is the function of ADH?
A
- ADH is a polypeptide synthesised in supraoptic and paraventricular nuclei of hyothalamus
- Secretory granules migrte down the axons of the supraoptichypophyseal tract into the posterior lobe
- primary physiological determinent of the rate of free water excretion
- augments the water permeability of the luminal membranes
- Stimuli
- hyperosmolality
- effective circulating volume depletion
8
Q
What is the function of oxytocin?
A
- stimulates contraction of smooth muscle of breast and uterus
- under positive feedback
- Roles in
- milk ejection reflex
- Parturition(birth)
9
Q
What are the major causes of hypopituitarism?
A
- Pituitary/ parapituitary tumours
- radiotherapy
- pituitary infarction. Sheehan’s syndrome
- infiltration of the pituitary- sarcoidosis, haemochromatosis
- trauma
- Isolated hypothalamic releasing hormone deficiency- Kallman’s
10
Q
A
