7.3 + 7.4

Question 1

Is the head of the pancreas closer of farther from the duodenum and uncinate process?

Answer 1

Closer

Question 2

What types of endocrine cells are in the pancreas, and which is the most prominent?

Answer 2

• Alpha
• Beta
• Delta
• Pancreatic Polypeptide

Question 3

Describe the action of glucose on skeletal muscle and adipose cells [mechanism]

Answer 3

Promotes exocytosis of vesicles containing GLUT4 transport proteins in their membranes. Increases glucose uptake.

Question 4

Insulin actions carbohydrates

Answer 4

• Glucose uptake (most cells)
• Stimulates glycogenesis and inhibits
  glycogenolysis (liver and muscles)
• Increases conversion of glucose to
  fatty acids (and ultimately
  triglycerides) in adipose cells
• Inhibits gluconeogenesis (decreasing
  availability of amino acids and
  inhibiting hepatic enzymes)

Question 5

Insulin action on fats

Answer 5

• Increases fatty acid uptake into adipose
• Increases fatty acid synthesis from
  glucose in adipose
• Decreases lipolysis in adipose

Question 6

Insulin action on proteins

Answer 6

1. Promotes the active transport of amino
   acids into muscle
2. Increases protein synthesis

Question 7

Glucagon actions

Answer 7

• Glycogenesis decrease
• Gluconeogenesis up
• Lipolysis
• Ketogenesis
• Inhibits protein synthesis, increases proteolysis

Question 8

Type 1 diabetes aetiology

Answer 8

Autoimmune destruction of beta cells; insulin secretion impaired

Question 9

Type 2 diabetes aetiology

Answer 9

Insulin sensitivity, often due to receptor downregulation

Question 10

Complications of diabetes mellitus

Answer 10

• Micro and macrovascular damage (kidney disease -> hypertension, retinopathy, ischaemia
• Peripheral neuropathy and ANS dysfunction (impaired bladder control, reduced sensation in extremities, gastroenteropathy)

Question 11

Describe the cellular composition of the posterior and anterior pituitary, including origins

Answer 11

Anterior: glandular epithelial (formed from the roof of the mouth)
posterior: nervous tissue (formed from floor of diencephalon)

Question 12

Describe the location of the hypothalamus and pituitary gland including their proximity with key structures

Answer 12

Pituitary:
- Sits within sella turcica
- Inferior to optic chiasm
Hypothalamus:
- Posterior to the optic chiasm
- Extensive neural connections

Question 13

List the five types of cells in the anterior pituitary. What do they release?

Answer 13

• Somatotrophs (Growth hormone)
• Lactotrophs (Prolactin)
• Gonadotrophs (FSH and LH)
• Thyrotrophs (TSH)
• Corticotrophs (ACTH)

Question 14

Thyrotroph pathway

Answer 14

TRH -> TSH -> T3 and T4

Question 15

Somatotroph Pathway

Answer 15

GHRH -> GH -> IGF-1

Question 16

Lactotroph Pathway

Answer 16

Prolactin

Question 17

Gonadotroph Pathway

Answer 17

GnRH -> FSH and LH -> testosterone/oestrogen and progesterone

Question 18

Corticotroph Pathway

Answer 18

CRH -> ACTH -> Cortisol

Question 19

What hormones are released from the posterior pituitary?

Answer 19

Oxytocin and ADH

Question 20

Where are oxytocin and ADH synthesised?

Answer 20

Cell bodies of neurons located in hypothalamus

Question 21

How do posterior pituitary hormones reach systemic circulation?

Answer 21

Travel along long-axon neurons and released into capillaries in the posterior pituitary

Question 22

How are anterior pituitary hormones secreted?

Answer 22

Hypophysiotrophic hormones are released from the neuron terminals of short axon neurons, where they flow through the hypophyseal portal system to the secretory epithelial cells of the anterior pituitary, triggering further hormone release.

Question 23

What is the name given to hormones that travel from the hypothalamus to the anterior pituitary?

Answer 23

Hypophysiotropic hormones

Question 24

What is the network of blood vessels that hypophysiotropic hormones travel through to reach the anterior pituitary?

Answer 24

Hypophyseal portal system

Question 25

What is the network of blood vessels that hypophysiotropic hormones travel through to reach the posterior pituitary?

Answer 25

They don’t, stupid. The neurons are released directly into capillaries that lead to system circulation from the neuron terminals of long-axon neurons

Question 26

Describe the growth-promoting actions of growth hormone

Answer 26

Promotes protein synthesis, fat breakdown and cell division.