Endocrinology- pituitary gland

Question 1

What is a hormone? How do they travel to targeted organ?

Answer 1

Messenger Travels via blood stream

Question 2

2 Types of hormones?

Answer 2

peptide and steroid

Question 3

How are each one synthesised?

Answer 3

Peptide- pro-hormone + requires further processing to activate Steroid- from cholesterol

Question 4

How are each one stored? And how do they bind to receptors

Answer 4

Peptide- in vesicles ( regulatory secretion) Bind rec on CM + 2nd signal using messaging system Steroid- released immediately (constitutive) Bind intra cel rep + change gene expression directly

Question 5

Annotate diagram of Pituitary gland

Answer 5

Question 6

What neurone regulated anterior pituaitary function?

Answer 6

hypothalamic parvocellular

Release hypothalamic releasing/inhibt factors into capillary eminence in m

Question 7

How do they work to reg function?

Answer 7

hypothalamic releasing/inhibt factor—> cappliary plexus (in median eminence)—–>portal ciculation—-> pit gland

Question 8

What cells in anterior pituarity?

How are regulated?

Answer 8

5-Somatrophs, lactorophys, cortiocptrpohy, thyrotrophs, gondatrophs

by hypothalamic releasing factors into hypophsyeal-pit portal system.

Question 9

explain example throid hormone production pathway from hypo thalamus to pit gland

Answer 9

hypothalamic cells TRH into hypothalamo-hypophsysialportal system—->

TRH stimulate thyrotrophs produce TSH (thyrotrophin) —–>

to thyroid gland produce throxine

Question 10

For each of somatrophy, lactotrophs thyrotrophs, gonadotrophs and corticotrophs cells:

What releasing hormones stimulate it?

What hormones release

Answer 10

Question 11

Where is target for each anterior pituitary gland hormone?

Answer 11

Growth hormone- genereal tissues (liver)

Prolactin- Breasts

TSH- T gland

LH and FSH- Testes and ovaries

ACTH- adrenal cortex

Question 12

How does a tumour in Pituarity tumour affect eye sight?

What is the condition called?

Answer 12

Bitemporal hemianopia

Fibres from medial retinae, info from lateral visual field, cross at optic chiasm.

Tumour compress optic chiasm + prevent info transmittion.

Question 13

explain steps of Reflect arc of milk production from hypo to breast?

Answer 13

Stimulation nipples activate afferent path—–> decrease dopamine from dopaminergic neurone in hypo

——–> less dop in portal system less inhibtion of lactotrophs

—–> increased prolactin so increased milk secretion

Question 14

How do growth hormones have effect on body tissue?

(how does it involve liver)

Answer 14

Directly- Somatotrophin on tissues

Indirectly- GP effect on liver

produced IGF-1 AND 2 (2 mainly for feutus)

Question 15

What is condition that causes excessive growth?

Answer 15

Acromegaly- excessive Growth hormone

NO increase in height as post-puberty so end bones fused

Question 16

what are features of Acromegaly?

Answer 16

coaresning of facial featues

large jaw

sweatiness

headache

macroglossia- big tounge

proganthism- extension of jaw

Question 17

what hormones does posterior produce?

Answer 17

Arginine vasopression (anti-diuretic hormone)

Oxytocin

Question 18

What is difference between posterior and anterior pituarity gland in structure?

Answer 18

• Anterior is anatomically contiounus with hypothalamus (nerve cells). Posterior is endochrine cells
• Cells nuceli located in supraoptic(AVP) and paraventricular (oxytocin) in hypo. Extend stalk to posterior where realease content into blood. Posterior has pit gland stimulate hormones from hypo.

Question 19

What is function/action of vasopressin?

Answer 19

stimulation water reabsoprtion in renal collecting ducts

concentrates urine through V2 receptor

ALSO vascocontrsictor via V1 reeptor and STIMULATE ACTH

Question 20

How does vasopression concentrate urine?

Answer 20

AVP bind to V2 receptor.

cascade rxns lead to aquaporin 2 migrate to tubular side

more reabsoprtion of water

Question 21

What are 2 actions of oxytocin?

Answer 21

1. Uterus contraction

Of myometrial cells at labour push baby, deilvery

2. Milk ejection

Contraction of mypoepithelial cells to expell milk during lactation