6 - Endocrine Glands

Question 1

What are the main endocrine glands, where are they located and what do they release?

Answer 1

• Thyroid also releases calcitonin to lower blood Ca
• Adrenal also releases aldosterone, increases sodium reabsorption

Question 2

What other organs have endocrine function, what do they secrete and what do these secretions do?

Answer 2

Question 3

What are the diffferent types of hormones?

Answer 3

Question 4

What is the role of the hypothalamus?

Answer 4

• Thermoregulation
• Osmolality
• Heart rate, blood pressure
• Circadian rhythms
• Emotion, mood
• Lactation

Produces ADH and oxytocin (nervous)

Six hormones (blood)

Question 5

What is a portal system and where are they found?

Answer 5

• Hypothalamo-hypophyseal portal system
• Hepatic

Question 6

Why is there always a small amount of hormone in the blood?

Answer 6

Constitutive merocrine secretion

Question 7

What is the anatomical structure of the thyroid gland?

Answer 7

Question 8

What is the histiological structure of the thyroid gland?

Answer 8

Question 9

What is the function of the thyroid and how is it stimulated?

Answer 9

• Combine iodine and tyrosine to make T3 and T4
• Negative feedback of T3 and T4

Question 10

What is goitre?

Answer 10

Enlargement of the thyroid gland, can be due to iodine deficiency or hyper/hypothyroidism

Question 11

What is hypothyroidism?

Answer 11

• Hashimoto’s
• High TSH but low T3 and T4
• Due to antibodies, anti TG (thyroglobulin) and anti-TPO (attack thyroid cells)

Question 12

What is hyperthyroidism?

Answer 12

• Grave’s disease
• High T3/T4, low TSH
• Due to antibodies, anti-TSH and TSI (thyroglobulin stimulater)

Question 13

What is the anatomy and function of the parathyroid?

Answer 13

• 4 glands on posterior of thyroid gland
• Lots of adipose, chief cells and oxyphil cells
• Release PTH when blood Ca is low, raises blood Ca levels

Question 14

What is a chief cell and an oxyphil cell?

Answer 14

• Chief: cells in parathyroid that produce PTH
• Oxyphil: no known function but appear at puberty

Question 15

What is the structure of the adrenal glands?

Answer 15

LEFT = half moon

RIGHT = pyramid

Question 16

What are chromaffin cells?

Answer 16

• Epithelial cells classed as post-ganglionic sympathetic neurones
• Produce and secrete nor/adrenaline

Question 17

What are produced at each level of the adrenal cortex?

Answer 17

Question 18

What is the function of the following?

• Aldosterone (mineralcorticoid)
• Cortisol (glucocorticoid)
• Androgen

Answer 18

• Increase b.p by salt and water balance
• Stress hormone when low blood glucose (not during starvation)
• Precursor for sex hormone

Question 19

What is the stress response?

Answer 19

Stress is the state of percieved or real threat to homeostasis leading to behaviour and physiological adaptations

Question 20

How does the body respond to stress short term and long term?

Answer 20

• ACTH from hypothalamo-hypophysesal portal system
• ACTH binds to receptors on adrenal gland

Question 21

What is the anatomical positon of the pancreas?

Answer 21

• Lies behind stomach with head lying in curve of duodenum on right
• Pancreatic duct –> bile duct –> common bile duct
• Acinar glands

Question 22

What are some secretions from the exo and endocrine part of the pancreas?

Answer 22