T1 L3 p1 :The Nuts and Bolts of the Endocrine System: Anatomy and Histology Roadshow

Question 1

what is the composition of a system

Answer 1

its a system of hormone secreting glands

Question 2

what is the hypothalamus

Answer 2

the major controlling centre of the ANS

Question 3

what does the hypothalamus regulate

Answer 3

temperature

circadian rhythms

Hunger

Question 4

what are the properties of endocrine glands (3m)

Answer 4

they are ductless

highly vascularised

travel via interstitial space-blood or lymph

Question 5

what is another name for the pituitary gland

Answer 5

the hypophysis

Question 6

describe the anatomy of the hypophysis (2m)

what is it suspended by and where is it located

Answer 6

its suspended by the infundibulum, located in the sella turcica

Question 7

what are the 2 structures that the hypophysis is split into (4m)

(science names and their type of part and growth from which part of the brain)

Answer 7

Adenohypophysis – glandular part; outpouching of ectoderm of oral cavity (fsh,lh,tsh)

Neurohypophysis – neural part; downgrowth from diencephalon of brain
(oxytocin,ldh)

Question 8

what is the blood supply to the hypophysis

Answer 8

Superior hypophyseal, supplies
median eminence
upper part of stalk

Inferior hypophyseal, supplies
neurohypophysis
lower part of stalk

Question 9

what signals are responsible for hormone release from the adenohypophysis and the neurohypophysis

Answer 9

Signals from the hypothalamus

Question 10

describe the anatomy of the thyroid gland (5m)

structure, location, what embryological part and a bit about function

Answer 10

Bilobed gland in the neck

They are connected anterior to the trachea

From oblique line of cartilage to 5/6 tracheal ring

From endoderm

Controlled by hypothalamus and hypophysis

Via T3 and T4 it regulates tissue metabolism growth and development

Question 11

what is the arterial supply to the thyroid gland

Answer 11

the super thyroid- from the ext carotid

inferior thyroid -from the subclavian

Question 12

what is the venule drainage of the thyroid

Answer 12

from ext plexus into :

the int jugular vein
&
The braciocephalic vein

Question 13

what are the structures contained in the thyroid gland

Cricothyrotomy

Answer 13

Recurrent nerve (from vagus)

Question 14

what is the anatomy of the parathyroid gland

Answer 14

there are 4, each to the side of the thyroid gland :

2 superior and 2 inferior embedded in the posterior aspect of the capsule of the thyroid

Question 15

what is the role of the parathyroid hormone

Answer 15

it regulates calcium and phosphate levels within homeostasis

Question 16

why must the parathyroids be reserved during thyroidectomy

Answer 16

If removed, calcium levels can fall, which means that muscles such as heart and those for resp go into tetanic contraction, leading to death

Question 17

what is the arterial and venule supply to the parathyroids

Answer 17

arterial - sup thyroid-ext carotid and inf thyroid-subclavian

vein: sup middle and inf thyroid

Question 18

innervation of the parathyroids

Answer 18

middle and inf cervical ganglions

Question 19

what is the role of the adrenal glands

Answer 19

Vital as a stress response

Question 20

Anatomy of the adrenal glands

Answer 20

At t12
retroperitoneal
the right is pyramidal and the left is semilunar

the cortex is derived from the mesoderm

the medulla is derived from the neural crest

Question 21

what is the function of the cortex of the adrenal glands

Answer 21

Releases corticosteroids

1)Cells subjacent to the capsule secrete minealocorticoids- aldosterone
Function to maintain electrolyte balance-sodium

2)Deeper part of the cortex
Secrete glucocorticoids -hydrocortisone affectisone affect metabolism and electrolyte balance

3)also produces adrenal androgens-testosterone

Question 22

what are the cells of the medulla

Answer 22

Chromaffin cells- secretory cells of the medulla, develop from embryonic tissue

Question 23

what is the adrenal medulla associated with

Answer 23

The medulla is regarded as a modified sympathetic ganglion (ANS)

Question 24

what does the adrenal medulla secrete

Answer 24

Medulla cells secrete adrenaline and smaller amounts of noradrenaline – i.e. catecholamines

Question 25

what response is the adrenal medulla responsible for

Answer 25

‘fight-or-flight’ response: affects heart rate, blood pressure and smooth muscle of viscera

Question 26

what is the blood supply for the adrenal medulla

Answer 26

supplied by the superior -(phrenic) Middle- (aortic) Inferior suprarenal arteries-(from renal)

Question 27

what do the rami supply

Answer 27

the cortex and the medulla as they branch before entering the capsule

Question 28

what do the cortical arteries give rise to

Answer 28

the subcapsular plexus

Question 29

what do the subcapsular plexus distribute too

Answer 29

Cortical cells

Question 30

what do the medullary arteries supply

Answer 30

the medulla - which also receives blood from the suprarenal arteries

Question 31

what cortical hormones influence the medulla and how

Answer 31

cortisol mediates NA conversion to adrenaline

Question 32

venous drainage of the adrenal gland

Answer 32

the adrenal veins - which drain into the IVC(r) or the renal vein (L)

Question 33

what is ACTH

Answer 33

adrenocorticotrophic hormone

Question 34

where is ACTH released and what is its function

Answer 34

The hypothalamus releases corticotrophin releasing hormone which causes the release of ACTH from the pituitary , which stimulates cortisol release

Question 35

what else controls the adrenal gland activity

Answer 35

Symp division of ANS: coeliac plexus; splanchnic n postganglionic fibres supply blood vessels preganglionic fibres ramify around cells of the medulla

Question 36

how does the ANS modulate the medulla

Answer 36

Has a fast response by impulses from preganglionic fibres that end in the chromaffin cells of the medulla. they then release catecholamines into adjacent circulation