Endocrinology

Question 1

In the stages of cell signalling, the signalling molecule (e.g. hormone or neurotransmitter) is directly involved in

a. amplification of the signal in the cell
b. producing the 2nd messenger in the cell
c. transduction
d. activation of the cellular response
e. reception

Answer 1

e. reception

Question 2

G-protein coupled receptors differ from insulin receptors in all of the following ways EXCEPT

a. The time required for an effect
b. The mechanism by which they produce a response in a cell
c. The role of phosphorylation in their cellular effects
d. D.The receptors are on the cell surface
e. The involvement of second messengers in their cellular effects

Answer 2

d. The receptors are on the cell surface

Question 3

Insulin is released from the pancreas after a meal and reduces plasma glucose levels. Which mechanism is NOT involved in the action of insulin?

a. phosphorylation of several targets inside liver cells
b. increased expression of glucose transporters in the pancreas
c. increased production of glycogen
d. increased expression of glucose transporters in the liver
e. stimulation of tyrosine kinase linked receptors

Answer 3

b. increased expression of glucose transporters in the pancreas

Question 4

Steroid hormone receptors

a. are found inside cells
b. have no effects on expression of genes
c. mediate fast actions similar to ligand-gated ion channels
d. require their ligands to be water soluble
e. are coupled to heterotrimeric G-proteins

Answer 4

a. are found inside cells

Question 5

Vasopressin is produced in the neurons of the hypothalamus and later secreted into the bloodstream before it finally reaches the kidneys. This is an example of

a. endocrine signalling
b. paracrine signalling
c. neuroendocrine signalling
d. autocrine signalling
e. synaptic signalling

Answer 5

c. neuroendocrine signalling

Question 6

Which of the following statements about hormones is CORRECT?

a. Polypeptide hormones require special transport proteins in the bloodstream
b. Steroid hormones have intracellular receptors in the cells from which they are released
c. All amine hormones are made from cholesterol
d. The receptors for polypeptide hormones are usually found on the cell surface of target cells
e. Water soluble amine hormones usually have their receptors in the nuclei of target cells

Answer 6

d. The receptors for polypeptide hormones are usually found on the cell surface of target cells

Question 7

Which of the following statements about homeostasis is INCORRECT? Homeostasis

a. results in an animal conforming to its external environment
b. depends on negative feedback mechanisms
c. refers to a steady-state balance of the internal environment
d. does not usually require positive feedback loops
e. allows fluctuation of the internal environment within a normal range

Answer 7

a. results in an animal conforming to its external environment

Question 8

Your friend’s mother has symptoms of losing weight and feeling hot and sweaty. It has been found that the symptoms are due to overactivity of her thyroid gland. Which one of these possibilities would NOT be the cause?

a. excess thyroid stimulating hormone release from the anterior pituitary
b. excessive growth of the thyroid gland due to a tumour
c. lack of function of a negative feedback mechanism
d. lack of function of a positive feedback mechanism
e. excess secretion of a tropic factor from the hypothalamus

Answer 8

d. lack of function of a positive feedback mechanism

Question 9

Your friend’s mother has symptoms of losing weight and feeling hot and sweaty. It has been found that the symptoms are due to overactivity of her thyroid gland. The thyroid hormone is an example of a

a. steroid hormone
b. water soluble peptide hormone
c. lipid soluble amine hormone
d. soluble amine hormone
e. neurotransmitter

Answer 9

c. lipid soluble amine hormone

Question 10

Your friend’s mother has symptoms of losing weight and feeling hot and sweaty. It has been found that the symptoms are due to overactivity of her thyroid gland. Why?

a. thyroid hormone receptors are found only on the hypothalamus
b. thyroid hormone stimulates metabolism
c. thyroid hormone is required for a tadpole to develop into a frog
d. thyroid hormone is released in response to stress
e. thyroid hormone is important in embryonic development

Answer 10

b. thyroid hormone stimulates metabolism

Question 11

What will NOT be likely to happen in response to this sudden stressful event?
A. increase in activity of the sympathetic nervous system
B. increase in heart rate
C. decrease in blood flow to the intestine
D. release of glucose from glycogen stores in the liver
E. increase in activity of the parasympathetic nervous system

Answer 11

E. increase in activity of the parasympathetic nervous system

Question 12

Matt’s response to the appearance of the shark event will involve
A.	only an endocrine response
B.	only a nervous system response
C.	only the central nervous system
D.	the nervous and endocrine systems
E.	only the peripheral nervous system

Answer 12

D. the nervous and endocrine systems

Question 13

Increased cardiac output in ‘fight or flight’ is mostly due to

a) α–adrenoceptors binding adrenaline
b) α–adrenoceptors binding noradrenaline
c) β–adrenoceptors binding glutamate
d) β–adrenoceptors binding adrenaline & noradrenaline
e) Corticosteroids affecting the right ventricle

Answer 13

d) β–adrenoceptors binding adrenaline & noradrenaline

Question 14

Which of the following is INCORRECT in relation to the adrenal glands?

a) they are found close to the kidney
b) they release catecholamines and corticosteroids from the same cell type
c) the immediate response to stress is mediated by catecholamines
d) corticosteroids mediate the long-term response to stress
e) they are stimulated by mechanisms involving the hypothalamus

Answer 14

b) they release catecholamines and corticosteroids from the same cell type

Question 15

Which of the following statements about the hypothalamus and pituitary gland is INCORRECT?

a. Neurons from the hypothalamus enter the posterior pituitary
b. The pituitary is not a single organ
c. Neural signals from the hypothalamus go to the adrenal medulla
d. Endocrine signals from the hypothalamus go to the anterior pituitary
e. Neurons from the hypothalamus enter the anterior pituitary

Answer 15

e. Neurons from the hypothalamus enter the anterior pituitary

Question 16

Adrenaline mediates a decrease in which of the following?

a. uptake of glucose into liver cells
b. heart rate
c. blood flow to the lungs
d. blood flow to the brain
e. diameter of the airways

Answer 16

a. uptake of glucose into liver cells

Question 17

Explain hypothyroidism and hyperthryroidism

Answer 17

Hypothyroidism – not enough, cant maintain homeostasis. underactive metabolism so gain weight, poor tolerance to cold weathers
Hyperthyroidism – too much – overactive metabolism, weight loss, poor tolerance to heat

Question 18

Which of the following statements is correct regarding the oxytocin pathway?

a) Oxytocin is produced by the anterior pituitary gland.
b) The oxytocin pathway is an example of a negative feedback system.
c) Oxytocin is considered a trophic hormone.
d) Increase in stimulus would trigger an excitatory response to release more oxytocin.
e) Oxytocin is produced by the pineal gland.

Answer 18

d) Increase in stimulus would trigger an excitatory response to release more oxytocin.

Question 19

Which of the following statements regarding hormonal release is FALSE?

a) Beta-cells of pancreas release insulin in response to high blood glucose levels
b) Alpha-cells of pancreas release glycogen in response to low blood glucose levels
c) Aldosterone is released by the adrenal gland in response to a drop in blood pressure or blood volume
d) Only the polypeptide hormones of oxytocin and ADH are released from the posterior pituitary

Answer 19

b) Alpha-cells of pancreas release glycogen in response to low blood glucose levels

Question 20

The thyroid hormone is an example of a

a) Neurotransmitter
b) Steroid hormone
c) Water-soluble peptide hormone
d) Lipid-soluble amine hormone

Answer 20

d) Lipid-soluble amine hormone

Question 21

How does overactivity of the thyroid gland relate to these symptoms? Thyroid hormone:

a) Stimulates metabolism
b) Is required for a tadpole to develop into a frog
c) Is released in response to stress
d) Receptors are found only on the hypothalamus
e) Is important in embryonic development

Answer 21

a) Stimulates metabolism

Question 22

The action of oxytocin is an example of:

a) Neuroendocrine signalling
b) Endocrine signalling
c) Synaptic signalling
d) Autocrine signalling
e) Paracrine signalling

Answer 22

a) Neuroendocrine signalling

Question 23

Name and describe the five types of chemical signalling.

Answer 23

Endocrine signalling – hormones secreted in blood to reach target cells anywhere in body
Synaptic signalling – neurotransmitters diffuse across synapse to trigger response in target tissue
Neuroendocrine signalling – neurohormones diffuse into bloodstream and reach target cells anywhere in body
Paracrine -local regulators diffuse through ECF to target neighbouring cells
Autocrine – local regulators diffuse locally to target the secreting cell itself.

Question 24

What hormones are released from the posterior pituitary? Where are they produced?

Answer 24

ADH (Anti Diureitic hormone) or Vasopressin and Oxytocin, produced by large body neurons of the hypothalamus

Question 25

What hormones are released from the anterior pituitary?

Answer 25

FSH, TSH, ACTH, Prolactin, MSH

Question 26

Explain the difference between tropic and non-tropic hormones. Give examples of each.

Answer 26

Tropic hormones that regulate the function of other endocrine cells or glands. E.g. TSH acts on thyroid to stimulate release of thyroid hormones
Non-tropic – hormones that target nonendocrine tissues e.g prolactin, MSH

Question 27

List the key differences between water-soluble and lipid-soluble hormones. Also provide some (2) examples of each.

Answer 27

Water soluble can easily enter the blood stream, the lipid will need a transport or carrier protein to attach to it to float through
Water soluble will need a receptor protein to get back through the membrane. Whereas lipid could move through membrane and then find its intracellular receptor and bind
Water soluble amine – adrenaline, water soluble polypeptide - insulin
Lipid soluble – oestradiol , steroid-cortisol amine, thyroid hormone

Question 28

Explain the long- and short-term responses to stress involving the adrenal glands.

Answer 28

Short term
Glycogen broken down to glucose, increased blood glucose
Increased blood pressure, heart rate, metabolic rate
Change in blood flow leading to increased alertness and decreased digestion
Long Term
Retention of Na+ and water by kidneys
Increased blood volume and blood preasure
Increased blood glucose
Possible suppression of immune system

Question 29

Receptors for nonsteroid hormones are located in

a) the extracellular fluid
b) the cytoplasm
c) the nucleus
d) the cytosol
e) association with a cell’s plasma membrane

Answer 29

e) association with a cell’s plasma membrane

Question 30

Which of these is a nonsteroid hormone?

a) estrogen
b) testosterone
c) both estrogen and testosterone
d) oxytocin
e) epinephrine and oxytocin

Answer 30

e) epinephrine and oxytocin

Question 31

How do nonsteroid hormones differ from steroid hormones?

a) nonsteroid hormones bind to a cell’s DNA; steroid hormones do not bind to a cell’s DNA
b) nonsteroid hormones act via signal transduction pathways; steroid hormones do not act via signal transduction pathways
c) the action of nonsteroid hormones never affects gene expression; the action of steroid hormones always affects gene expression
d) nonsteroid hormones bind to cytoplasmic receptors; steroid hormones bind to plasma membrane receptors
e) nonsteroid hormones are fat-soluble; steroid hormones are water-soluble

Answer 31

b) nonsteroid hormones act via signal transduction pathways; steroid hormones do not act via signal transduction pathways

Question 32

Which of the following does not represent a chemical signal?

a) movement of a signal from one nerve to the next
b) a chemical released that affects the cell that releases it
c) an immune cell releasing a cytokine
d) movement of a signal from one end of a nerve to the other end of the nerve
e) chemicals released into the bloodstream from nerve cells

Answer 32

d) movement of a signal from one end of a nerve to the other end of the nerve

Question 33

If the adrenal cortex were removed, which group of hormones would be most affected?

a) peptide
b) paracrine
c) steroid
d) amino acid-derived
e) tropic

Answer 33

c) steroid

Question 34

Which term describes a steady state in which the internal conditions of an organism are kept within a narrow range without regard to the external conditions?

a) Conformational homeostasis.
b) Negative feedback.
c) Regulatory homeostasis.
d) Thermoregulation.

Answer 34

c) Regulatory homeostasis.

Question 35

Which of these extracellular signal molecules could diffuse through a plasma membrane and bind to an intracellular receptor?

a) estrogen
b) epinephrine
c) cellulose
d) oxytocin
e) starch

Answer 35

a) estrogen

Question 36

The primary reason steroid hormones usually act slowly is that

a) they are produced at very low concentrations
b) acting via a signal transduction pathway makes for slower responses than does directly interacting with a cell’s DNA
c) they are too large to enter a cell and therefore must first bind to a plasma membrane receptor before having an effect on a cell
d) target cells tend to ignore steroid hormones in favor of nonsteroid hormones
e) they turn genes on or off and it takes time for gene products to build up or become depleted

Answer 36

e) they turn genes on or off and it takes time for gene products to build up or become depleted

Question 37

Steroid hormone-receptor complexes act in

a) the nucleus
b) lysosomes
c) vesicles
d) the cytoplasm
e) the plasma membrane

Answer 37

a) the nucleus

Question 38

Which type of hormone is lipid soluble?

a) Polypeptides.
b) DNA.
c) Amino acid derivatives.
d) Steroids.

Answer 38

d) Steroids.

Question 39

Which molecules determine the tissue specificity of hormones?

a) Second messengers.
b) Agonists.
c) Hormone-response elements.
d) Receptor

Answer 39

d) Receptor

Question 40

True or false? Lipid-insoluble hormones affect their target cells by binding to receptors inside the cell.

a) True
b) False

Answer 40

False

Question 41

Which of the following statements about lipid-soluble hormones is true?

a) They act by producing second messengers.
b) They bind to DNA as soon as they enter a cell.
c) They bind to receptors on the plasma membrane.
d) They act by affecting the transcription of genes.

Answer 41

d) They act by affecting the transcription of genes.

Question 42

True or false? For a signal transduction pathway to be activated, hormones must be present in the bloodstream at very high concentrations.

a) True
b) False

Answer 42

False

Question 43

Which of these glands secretes releasing hormones?

a) hypothalamus
b) adrenal cortex
c) thymus
d) ovaries
e) testes

Answer 43

a) hypothalamus

Question 44

Which of these hormones are responsible for the “fight or flight” response to danger?

a) insulin and glucagon
b) thyroxine and calcitonin
c) androgens and estrogens
d) antidiuretic hormone (ADH) and oxytocin
e) epinephrine and norepinephrine

Answer 44

e) epinephrine and norepinephrine

Question 45

A distinctive feature of the mechanism of action of thyroid hormones and steroid hormones is that

a) these hormones bind to receptors inside cells.
b) target cells react more rapidly to these hormones than to local regulators.
c) these hormones bind with specific receptor proteins on the plasma membrane of target cells.
d) these hormones are regulated by feedback loops.
e) these hormones affect metabolism.

Answer 45

a) these hormones bind to receptors inside cells.

Question 46

Consider the similarities and differences between the adrenal cortex and adrenal medulla and answer the following questions.

a) What are their cell types? [1 mark]
b) What hormones do they produce? [2 marks]
c) How are they regulated (i.e. how is hormone production from these parts of the adrenal gland controlled)? [2 marks]
d) Which of these parts of the adrenal gland trigger the ‘fight or flight’ response?

Answer 46

Cell types
Cortex - endocrine cells
medulla - modified neural/nerve cells

Hormones
Cortext - cortisol and aldosterone
Medulla - adrenaline, noradrenaline

How regulated
corext - controlled by ACTH
Medulla - controlled by hypothalamus