Endocrine System

Question 1

What is a half-life?

Answer 1

The time it takes for a hormone to reach half of its original concentration

Question 2

What are the 3 locations of secretion?

Answer 2

Glands, Endocrine cells, Neurons

Question 3

What is local control?

Answer 3

Restricted to one tissue. Local change = local response

Question 4

What is reflex control?

Answer 4

Throughout body, by nervous or endocrine system. A change is counteracted by changes in the brain.

Question 5

Target cells are always ___ from secretion locations.

Answer 5

Far

Question 6

What do hormones regulate?

Answer 6

Metabolism, temperature, water balance, reproduction, growth

Question 7

Where are hormones secreted?

Answer 7

From almost all tissues of the body.

Question 8

What are pheromones?

Answer 8

Hormones secreted into external environment that change behaviour of others of the same species.

Question 9

What are the 3 receptor locations? And which are fast/slow?

Answer 9

Cell surface (fast), in the cytosol (slow), in the nucleus (slow)

Question 10

What are the 3 classifications of hormones?

Answer 10

Peptides, steroids and amines

Question 11

What are the characteristics of peptides?

Answer 11

• lots of amino acids
• lipoPHOBIC
• short half-life
• cell-surface receptors
  ex. insulin

Question 12

What are the characteristics of steroids?

Answer 12

• derived from cholesterol
• lipoPHILIC
• long half-life
• intracellular receptor (most change in gene expression and synthesis of proteins)
  ex. cortisol

Question 13

What are the 2 types of amine hormones? Which one is lipophobic/lipophilic?

Answer 13

Catecholamines (lipoPHOBIC), thyroid (lipPHILIC)

Question 14

Which endocrine reflex involves neurons?

Answer 14

Complex endocrine reflex

Question 15

Explain primary hyperthyroidism and what is its name?

Answer 15

Grave’s disease. Antibodies mimic TSH activate thyroid, causing too much TSH to be released.

Question 16

Explain secondary hyperthyroidism.

Answer 16

A tumour on thyroid or pituitary gland causes excess stimulation.

Question 17

Explain primary hypothyroidism.

Answer 17

Lack of iodine in diet, iodine is needed for the production of thyroxine.

Question 18

Explain secondary hypothyroidism and what is its name?

Answer 18

Hashimoto’s. Autoimmune destruction of thyroid.

Question 19

Explain primary hypercortisolism and what is its name?

Answer 19

Cushing’s syndrome. Tumour on adrenal gland.

Question 20

Explain secondary hypercortisolism and what is its name?

Answer 20

Cushing’s disease. Tumour on pituitary gland.

Question 21

What is the cortisol pathway?

Answer 21

CRH (hypothalamus) - ACTH (anterior pituitary) - CORTISOL (endocrine target) - TARGET CELLS (non-endocrine target)

Question 22

What is the thyroid hormone pathway?

Answer 22

TRH (hypothalamus) - TSH (anterior pituitary) - T4 (thyroid)

Question 23

What are 3 ways a goiter will form?

Answer 23

Iodine deficiency, Grave’s disease, Hashimoto’s

Question 24

How are goiters formed?

Answer 24

• Overstimulation of the thyroid gland (thyroid making too much thyroxine)
• Pituitary sending too much TSH
• Not enough iodine to form thyroxine

Question 25

Where is thyroxine secreted from in the thyroid gland?

Answer 25

Follicle cells

Question 26

What length of half-life does a steroid hormone have?

Answer 26

Long half-life, long action

Question 27

What length of half-life does a peptide hormone have?

Answer 27

Short half-life, short action

Question 28

Which hormone binds to the plasma membrane?

Answer 28

Peptide hormones

Question 29

Which hormones can pass through the plasma membrane and bind to intracellular receptors?

Answer 29

Steroid hormones, amine hormones

Question 30

What kind of hormone is thyroid hormone?

Answer 30

Amine hormone.

Question 31

If the hormone can pass through the plasma membrane, it is lipo___?

Answer 31

LipoPHILIC