Physiology

Question 1

The endocrine system involves ducts. True/False?

Answer 1

False

It is a ductless system involving glands that secrete directly into blood

Question 2

How is specificity of signalling by endocrine glands achieved?

Answer 2

Chemically distinct hormones
Specific hormone receptors
Distinct distribution of receptors

Question 3

List the main endocrine glands of the body

Answer 3

Hypothalamus
Pituitary
Parathyroid
Thyroid
Adrenal gland
Pancreas
Placenta
Ovaries/testes

Question 4

What is meant by an autocrine gland?

Answer 4

Hormone released acts back on the structure that released it

Question 5

What is meant by a paracrine gland?

Answer 5

Hormone released acts on neighbouring structures

Question 6

List the 3 main classes of hormones

Answer 6

Glycoproteins + peptides
Steroids
Tyrosine derivatives

Question 7

Give an example of glycoprotein/peptide hormones

Answer 7

Insulin
Growth hormone
Oxytocin
Prolactin

Question 8

Give an example of a steroid hormone

Answer 8

Cortisol

Testosterone

Question 9

Give an example of a tyrosine-derivative hormone

Answer 9

Adrenaline
Thyroid hormone
Melatonin

Question 10

A whole protein is always required to achieve hormonal effect. True/False?

Answer 10

False

Protein can be cleaved into active hormonal units

Question 11

On a basic level, how are amines, peptides and proteins released from the endocrine cell?

Answer 11

Synthesised, packaged into vesicles and then released in response to stimuli via exocytosis

Question 12

On a basic level, how are steroid hormones released from the endocrine cell?

Answer 12

Synthesised upon demand, then stimuli increases cellular uptake and availability of cholesterol + rate of conversion into pregnenolone, which is then used to build steroid to be released

Question 13

Steroid hormones travel freely in blood. True/False?

Answer 13

False

Usually has carrier protein in inactive form

Question 14

Which carrier protein binds cortisol?

Answer 14

Cortisol-binding protein! FANCY THAT

Question 15

Which carrier protein binds thyroxine (T4)?

Answer 15

Thyroxine-binding globulin

Question 16

Which hormones normally bind to sex steroid-binding globulin?

Answer 16

Testosterone

Estradiol

Question 17

Free and bound lipophilic hormone are in equilibrium in the blood. True/False?

Answer 17

True

Question 18

What does “tropic” mean with regards to hormones?

Answer 18

Refers to a hormone that acts upon another endocrine gland to regulation secretion of hormone

Question 19

What are the biggest players in elimination of hormone?

Answer 19

Liver

Kidney

Question 20

Time taken to reach half life of amine hormones is achieved in seconds/minutes/hours

Answer 20

Seconds

Question 21

Time taken to reach half life of protein hormones is achieved in seconds/minutes/hours

Answer 21

Minutes

Question 22

Time taken to reach half life of steroid hormones is achieved in seconds/minutes/hours

Answer 22

Hours

Question 23

List the 3 main distinct types of hormone receptor

Answer 23

GPCR
Receptor kinases
Nuclear receptors

Question 24

Which of the 3 main types of hormone receptor are cell surface receptors?

Answer 24

GPCR

Receptor kinases

Question 25

Which of the 3 main types of hormone receptor are intracellular receptors?

Answer 25

Nuclear kinases

Question 26

Describe class 1 nuclear receptors

Answer 26

Activate by steroid hormones | Usually in cytoplasm bound to heat-shock-proteins

Question 27

Describe class 2 nuclear receptors

Answer 27

Activate by lipids | Present in nucleus

Question 28

Describe the hybrid class of nuclear receptors

Answer 28

``` Activated by T3 Similar function to class 1 ```

Question 29

Give an example of a hormone that utilises signalling via receptor kinases

Answer 29

Insulin

Question 30

What are the 3 main components of the hypothalamic pituitary axis?

Answer 30

HYPOTHALAMUS influences PITUITARY to secrete hormones to act on PERIPHERAL GLAND (thyroid, adrenal etc.)

Question 31

List the main hormones secreted by the anterior pituitary

Answer 31

``` GH LH/FSH ACTH TSH Prolactin ```

Question 32

List the main hormones secreted by the posterior pituitary

Answer 32

ADH | Oxytocin

Question 33

What is the effect of peripheral hormones secreted by target glands (thyroid, adrenals etc.) upon the pituitary and hypothalamus?

Answer 33

Negative feedback loop (inhibition)

Question 34

List the factors that influence our ability to measure hormone levels

Answer 34

``` Pattern of secretion Presence of carrier proteins Interfering agents Stability/half-life Absolute concn ```

Question 35

What is the major determination of hormone concentration?

Answer 35

Rate of secretion

Question 36

Outline the thyroid hormone axis

Answer 36

Hypothalamus secretes TRH which stimulates anterior pituitary to stimulate TSH which stimulates thyroid to produce thyroid hormones

Question 37

Thyroid hormones inhibit the thyroid, anterior pituitary and hypothalamus to reduce further thyroid hormone release. True/False?

Answer 37

False | They do not inhibit the thyroid gland!

Question 38

What test is done to evaluate thyroid hormone?

Answer 38

Highly-sensitive TSH assay

Question 39

Outline the hypothalamic-pituitary-adrenal axis (HPA axis)

Answer 39

HYPOTHALAMUS releases CRH to stimulate ANTERIOR PITUITARY to release ACTH which stimulates ADRENALS to release cortisol

Question 40

Which parts of the HPA axis does cortisol inhibit via negative feedback loop?

Answer 40

Anterior pituitary | Hypothalamus

Question 41

Random cortisol measurement is useful in determining cortisol levels. True/False?

Answer 41

False | Circadian rhythm means levels will vary widely throughout the day

Question 42

GH stimulates the liver to produce what hormone?

Answer 42

IGF-1

Question 43

Which cells secrete prolactin?

Answer 43

Lactotroph cells in the anterior pituitary

Question 44

Which hypothalamic hormone inhibits release of prolactin?

Answer 44

Dopamine

Question 45

What is the rate-limiting step in steroid hormone metabolism?

Answer 45

Cholesterol to pregnenolone