Endocrine system

Question 1

Describe endocrine glands

Answer 1

Ductless glands

Secrete directly into the bloodstream

Question 2

What is meant by exocrine glands?

Answer 2

Glands with ducts
Secrete directly into/onto an organ/tissue

E.g.
- salivary glands, sweat glands, pancreas (digestive juices)

Question 3

What are the components of the endocrine system?

Answer 3

Pituitary 
 Thyroid
 Parathyroids
 Pancreas
 Suprarenals (adrenals)
 Gonads
 - Ovaries and testes

Thymus and Pineal gland

Question 4

Where is the pituitary located?

Answer 4

Between hypothalamus and pineal gland

Sits within sella turcica of sphenoid bone

Question 5

Describe the other structures around the pituitary

Answer 5

Sella turcica is below the pituitary
Hypothalamus is above
Infundibulum is the pituitary stalk

Question 6

What potential diseases are caused via the pituitary?

Answer 6

Secretions of pituitary include GH
Hypopituitarism
45.5 people out of 100,000
Most (61%) due to tumours

Hyperpituitarism - acromegaly/gigantism

Question 7

Where is the thyroid gland located?

Answer 7

Extends from levels C5 – T1
Positioned anterolateral to the trachea and larynx
Infront of 2nd and 3rd tracheal rings

Question 8

What is the structure of the thyroid gland?

Answer 8

L + R lobes joined by isthmus

• A pyramidal lobe is present in approximately 50% of the population, usually on the left side

Question 9

What is the arterial supply to the thyroid gland?

Answer 9

External + Internal common carotid arteries
Superior + Inferior Thyroid arteries
Thyrocervical trunk
Subclavian artery

Question 10

What is the venous drainage of the thyroid gland?

Answer 10

Superior, Middle and inferior thyroid veins

S + M drain into internal jugular veins
Inferior drains into braciocephalic vein

Question 11

Which muscles cover the thyroid gland?

Answer 11

The thyroid gland is covered by the infra-hyoid strap muscles

Question 12

Name the infra-hyoid muscles

Answer 12

Omohyoid (lateral)
Sternohyoid (medial)
Sternothyroid (deep)

Question 13

What is the function of the thyroid gland?

Answer 13

Thyroid gland uses iodine from foods to form two2main hormones:
Triiodothyronine (T3)
Thyroxine (T4)

Question 14

What are the parathyroid glands?

Answer 14

Two pairs embedded in the deep surface of the thyroid gland that produce parathyroid hormone

Question 15

What is the function of parathyroid hormones?

Answer 15

Regulate body’s Ca2+ levels

Question 16

What arteries supply the parathyroid gland?

Answer 16

Usually inferior thyroid arteries

Question 17

Describe the venous drainage of the adrenal glands

Answer 17

Venous drainage is (usually) via one large vein into the IVC (on the right) and the renal vein (on the left)

Question 18

Describe the arterial supply of the adrenal glands

Answer 18

Blood supply is from numerous small arteries from the renal artery, inferior phrenic artery and abdominal aorta

Question 19

What is the pampiniform plexus?

Answer 19

Loose network of small veins found within male spermatic cord

Question 20

What is the function of the pampiniform plexus?

Answer 20

Cool incoming arterial blood

Question 21

Where does the pampiniform plexus terminate?

Answer 21

The veins terminate into IVC (right side) and renal vein (left side)

Question 22

What forms the anterior neck triangle?

Answer 22

anterior border of scm/midline/ inferior border of mandible

Question 23

What structures form the posterior triangle?

Answer 23

posterior border of scm/ anterior border of trapezius/ superior border of clavicle

Question 24

What is the role of the accessory nerve?

Answer 24

Cranial nerve that supplies the sternocleidomastoid and trapezius muscles