Endocrinology

Question 1

What is a hormone

Answer 1

A messenger which is carried from one organ to target organ through blood stream to cause effect

Question 2

Peptide synthesis

Answer 2

Synthesised as prohormones which require further processing to activate (have inactive forms)

Question 3

Peptide storage

Answer 3

Stored in vesicles requiring regulatory secretion to trigger release of hormone

Question 4

Peptide binding

Answer 4

Bind to receptors on cell membrane which transduce signal using 2nd messenger signal

Question 5

Steroid synthesis

Answer 5

Synthesised through series of reactions from cholesterol

Question 6

Steroid storage

Answer 6

Released immediately through constitutive secretion

Question 7

Steroid binding

Answer 7

Bind to intracellular receptors (within DNA in nucleus) so change gene expression directly

Question 8

Where is the pituitary gland located

Answer 8

Sits within sella turcica of sphenoid bone
Hangs from infundibulum of hypothalamus
Close to optic chiasm

Question 9

What is infundibulum

Answer 9

Stalk of the hypothalamus from which the pituitary gland hangs

Question 10

2 sections of pituitary gland

Answer 10

Anterior and posterior

Question 11

Origin of anterior pituitary

Answer 11

Adenohypophysis

Epithelial origin derived from upgrowth from oral ectoderm of primitive oral cavitiy (rahkes pouch)

Question 12

Origin of posterior pituitary

Answer 12

Neurohypophysis

Neural tissue origin from downgrowth of diencephalon

Question 13

Which hormones are released by anterior pituitary

Answer 13

Somatotrophs - growth hormone (somatotrophin)
Lactotrophs - prolactin
Corticotrophs - ACTH + corticotrophin
Thyrotrophs - TSH
Gonadotrophs - LH + FSH

Question 14

Somatrophin

Answer 14

Growth hormone released by anterior pituitary

Affects general tissues + particularly liver

Question 15

What inhibits growth hormone release

Answer 15

Somatostatin

Question 16

What triggers growth hormone release

Answer 16

Growth hormone releasing hormone

Question 17

How does anterior pituitary release hormones

Answer 17

Needs trigger from hypothalamus (regulated)

Question 18

How is prolactin inhibited

Answer 18

Dopamine has inhibitory control

More dopamin = less prolactin (vice versa)

Question 19

Effect of prolactin

Answer 19

Breast of lactating women causing milk production

Question 20

What triggers corricotroph release

Answer 20

Corticotrophin release hormone

Question 21

What triggers TSH release

Answer 21

Thyrotropin releasing hormone

Question 22

Effect of TSH

Answer 22

Release of T3 + T4 in the thyroid

Question 23

Effect of corticotrophin

Answer 23

Causes adrenal cortex to release cortisol

Question 24

What triggers LH + FSH release

Answer 24

Gonadotrophin releasing hormone

Question 25

Effect of gonadotrophs

Answer 25

On testes/ovaries

Question 26

What cells is anterior pituitary made of

Answer 26

Endocrine cells

Question 27

Direct of somatotrophin

Answer 27

Binds to receptor on target tissue to stimulate growth

Question 28

Inderect effect of somatotrophin

Answer 28

Causes insulin like growth factor (somatomedin) to form in liver IGF-1/2 bind to different receptirs on same tissue as direct effect path

Question 29

Why does increased growth hormone not cause height increase after puberty

Answer 29

Growth plates have fused so height can no longer be increased

Question 30

What is acromegaly

Answer 30

High levels of somatotrophin (usually due to tumour) in adults

Question 31

Symptoms of acromegaly

Answer 31

Large hands Large jaw Soft tissue growth No change in height

Question 32

What is gigantism

Answer 32

High levels of growth hormone during puberty

Question 33

Symptoms of gigantism

Answer 33

Coarsening of facial features | Large height increase

Question 34

Gigantism vs acromegaly

Answer 34

Both are high levels of somatotrophin Acromegaly is in adults Gigantism is before/during puberty

Question 35

What difference is posterior pituitary

Answer 35

Doesnt produce hormones only stores them for release - made in hypothalamus

Question 36

What hormones does posterior pituitary release

Answer 36

Argonine vasopressin | Oxytocin

Question 37

Effect of argonine vasopressin

Answer 37

An antidiuretic hormone which regulates water balance by stimulating cascade causing aquaporin water channels to move into menbrane to increase water reabsorption from urine Causes concentrated urine (less water)

Question 38

Effect of oxytocin

Answer 38

Uterus at parturition causing contraction | Breasts during lactation causing contraction for milk ejection

Question 39

What are symptoms of pituitary tumour

Answer 39

Decreased peripheral vision | Increased hormone levels

Question 40

Why does pituitary tumour affect peripheral vision?

Answer 40

Fibres from nasal medial retinae (peripheral vision info) cross at the optic chiasm which is next to pituitary gland so tumour would compress it preventing transmission from lateral fields to the occipital lobe

Question 41

What is the thyroid gland attached to?

Answer 41

Thyroid cartilage

Question 42

How many lobes does the thyroid gland have?

Answer 42

2 lobes | Sometimes can have extra lobe which is just embryological remnant

Question 43

What is the isthmus on the thyroid?

Answer 43

Small middle area which connects the 2 lobes

Question 44

What are cells in thyroid

Answer 44

Circular follicular cells | Parafollicular cells

Question 45

What is the colloid? Thyroid

Answer 45

Centre of circular follicles which is thick mucus (?)

Question 46

What do parafollicular cells do?

Answer 46

Secretes calcitonin for controlling calcium

Question 47

Where are parathyroid glands?

Answer 47

2 parathyroid glands behind each thyroid gland | L/R superior and inferior parathyroid glands

Question 48

What do parathyroids do?

Answer 48

Calcium metabolism

Question 49

What happens if parathyroid take out/damaged in surgery?

Answer 49

hypoparathyroidism

Question 50

What nerve runs close to thyroid gland?

Answer 50

Recurrent laryngeal nerve which supplies the vocal cords

Question 51

How is the thyroid gland formed?

Answer 51

1. Originates from base of tongue through midline outpouching from floor of larynx 2. Develops thyroglossal duct which divided into 2 lobes 3. Duct dissapears leaving foramen caecum 4. Thyroid reaches final position by 7 week gestation and thyroid gland then develops