Endocrine

Question 1

Principles of hormone action – “Endocrine”

Answer 1

hormone carried by circulation to distant targets

Question 2

Principles of hormone action – “Paracrine “

Answer 2

target cell is an immediate neighbor

Question 3

Principles of hormone action – “Synaptic”

Answer 3

referring to neurotransmitters (communication of the nervous system)

Question 4

What do hormones do? 6

Answer 4

1. Regulates ion channels and transporters
2. Stimulates transcription and translation
3. Activates or deactivates enzymes
4. Induces secretory activities
5. Stimulates mitosis
6. Everything else

Question 5

Types of Hormones “Peptides”?????

Answer 5

Large, charged peptides that do not pass through the membrane (lipophobic)
Synthesized based on genetic code as prehormones
Cleaved to make active hormone
Short half-life
Circulate freely
Bind to membrane receptors

Question 6

Example of Peptides

Answer 6

Glucagon, insulin, growth hormone, parathyroid hormone, follicle stimulating hormone, etc.

Question 7

Types of Hormones Lipid Derivative

Answer 7

Small, lipid soluble molecules that can pass freely through membranes (lipophylic)
Synthesized from precursor molecules by cellular enzymes (ie. cholesteroltestosterone)
Longer lasting
Circulate bound to plasma proteins
Bind to nuclear receptors

Question 8

Example of Lipid Derivative

Answer 8

Cortisol, testosterone, estrogen, aldosterone

Question 9

Types of Hormones Amino acid derivative

Answer 9

Small molecules derived from amino acids
Synthesized from amino acid precursor (tyrosine)
Short lasting
Circulate freely or bound to plasma proteins
Bind to membrane or nuclear receptors

Question 10

Example of Amino acid Derivative

Answer 10

Thyroid hormone, epinephrine

Question 11

How a hormone is delivered depends????

Answer 11

largely on the type of hormone you are dealing with.

Question 12

What are G-protein coupled receptors? How do they transmit a hormonal signal?

Answer 12

constitute a large protein family of receptors that detect molecules outside the cell and activate internal signal transduction pathways and, ultimately, cellular responses

Question 13

What is cAMP made from?

Answer 13

Cyclic AMP is synthesized from ATP by adenylate cyclase located on the inner side of the plasma membrane and anchored at various locations in the interior of the cell.[1] Adenylate cyclase is activated by a range of signaling molecules through the activation of adenylate cyclase stimulatory G (Gs)-protein-coupled receptors

Question 14

What does cAMP do?

Answer 14

cAMP is a second messenger, used for intracellular signal transduction, such as transferring into cells the effects of hormones like glucagon and adrenaline, which cannot pass through the plasma membrane. It is also involved in the activation of protein kinases. In addition, cAMP binds to and regulates the function of ion channels such as the HCN channels

Question 15

What kinds of hormones bind to nuclear receptors?

Answer 15

Steroids: Testosterone, Estrogen, Cortisol

Thyroid hormone: Nuclear receptor not cytoplasmic

Question 16

What do nuclear hormone receptors commonly do?

Answer 16

Nuclear receptors do: Steroid hormone diffuses through membrane lipids → Binding of hormone to cytoplasmic or nuclear receptors → Binding of hormone-receptor complex to DNA → Gene Activation → Transcription and mRNA production → Translation and protein synthesis → Alteration of cellular structure or activity → Target cell response

Question 17

What factors determine hormone potency?

Answer 17

Blood levels of the hormone
Relative number of receptors on the target cell
The affinity of those receptors for the hormone

Question 18

Explain the process of hormone signal amplification and what benefit it has on the cell.

Answer 18

When a hormone binds to the receptor, it will affect a effector, but the command from the effector will activate many enzyms (2nd messenger) and spreading effect continues.
Benefit: efficient and sensitive. (If 1 hormone activates only 1 enzym, a lot of hormones needed, thus the increase in size of glands).

Question 19

Explain what receptor downregulation is?

Answer 19

Hormone actions lead to receptor desensitization, degradation

Question 20

What are three stimuli for hormone release?

Answer 20

Humoral Stimuli: Changing blood levels of ions and nutrients stimulate the release of hormone.
Neural Stimuli: Nerve fibers stimulate the release of hormone.
Hormonal stimuli: Other hormones (which are produced by other endocrine organs) stimulate the release of hormones.

Question 21

Example of three stimuli for hormone release

Answer 21

Humoral Stimuli: Na+ balance in body may stimulate adrenal glands to secrete aldosterone.
Neural Stimuli: PREganglionic sympathetic nervous system (SNS) fibers stimulate the adrenal medulla to secrete catecholamines.
Hormonal stimuli: Hypothalamic hormones stimulate Anterior pituitary à pituitary hormones stimulate targets to secrete still more hormones.

Question 22

What are the names of the pituitary lobes?

Answer 22

Anterior, Posterior, Intermediate

Question 23

What are the two methods by which the hypothalamus regulates pituitary secretions?

Answer 23

Negative feedback and Down-regulation

Question 24

What are 5 hormones of the anterior pituitary, what are their target organ actions and what hypothalamic hormones stimulate their release?

Answer 24

1, Prolactin (PRL): Mammary glands
2, Growth Hormone (somatotropin): Liver (IGF)
3, Gonadotropins (FSH & LH): Testes, ovaries
4, Thyroid Stimulating Hormone (TSH): thyroid
5, Adrenocorticotropic Hormone (ACTH): Adrenal cortex

Question 25

What are the two hormones secreted from the posterior pituitary?

Answer 25

1, Oxytocin—target: Uterus Breast ——Contraction Milk let-down
2, Vasopressin (ADH)—–target: Kidney——-Water reabsorption

Question 26

Name 9 endocrine glands.

Answer 26

Pineal gland
Hypothalamus
Pituitary gland
Thyroid gland
Parathyroid glands
Thymus gland
Adrenal gland
Pancreas
Ovary (female) or Testie (male)