Lecture 2- Endocrine system and Hormones

Question 1

Where do hormones come from?

Answer 1

Produced by glands and secreted into the blood.

Question 2

Where do hormones go?

Answer 2

Travel through the blood to target tissues with specific receptors.

Question 3

What do hormones do?

Answer 3

Interact with receptors to trigger biochemical changes and activate genes for biological responses.

Question 4

What are genomic effects of hormones

Answer 4

Hormones bind to receptors inside cells.
Change gene activity to produce long-term effects.

Question 5

Nongenomic effects

Answer 5

• Hormones act on receptors outside cells.
• Produce faster effects on behavior.
• Genes are still involved, despite the name.

Question 6

The type of chemical mediation where cells release products that act back on themselves

Answer 6

Autocrine mediation

Question 7

The type of chemical mediation where chemicals act within the same cell

Answer 7

Intracrine

Question 8

The type of chemical mediation where chemicals affect nearby cells

Answer 8

Paracrine

Question 9

The type of chemical mediation where hormones are secreted into the bloodstream and travel to distant targets

Answer 9

Endocrine

Question 10

The type of chemical mediation where substances are released externally and affect other individuals

Answer 10

Ectocrine mediation

Question 11

Give 2 examples of the overlap between nervous, endocrine and immune systems

Answer 11

• Immune cells have receptors for NT and hormones
• Neurons have receptors for hormones and cytokines

Question 12

Greek etymology of the words “endocrine” and “hormone”

Answer 12

Endon = “within”
Krinein = “to release.”
Hormon= “to excite” or “to set into motion”

Question 13

What are neurohormones?

Answer 13

Special hormones released into the blood by neurosecretory cells (nerve cells).

Question 14

What is the difference between endocrine and exocrine glands?

Answer 14

Endocrine glands: Release hormones directly into the blood
(e.g., thyroid, adrenal glands).
Exocrine glands: Use ducts to release products into internal
or external environments (e.g., sweat, salivary glands).
!! Dual-function glands have both fx

Question 15

What is leptin?

Answer 15

A hormone produced by adipose tissue and involved in energy balance

Question 16

What is ghrelin?

Answer 16

A hormone produced by the stomach and which regulates hunger

Question 17

Name the 2 types of hormones

Answer 17

Protein/peptide hormones (water[blood]-soluble)
- stored in vesicles
Steroid hormones (lipid-soluble [bind to carrier proteins in the blood])
- not stored; produced and released on demand

Question 18

Describe how protein/peptide hormones are released.

Answer 18

Released through exocytosis: Vesicles fuse with the cell membrane, releasing hormones into the extracellular space, then into the bloodstream

Question 19

How can receptor availability affect biological response?

Answer 19

Low receptor numbers: Can cause endocrine deficiency even with normal hormone levels.
* Example: Androgen receptor deficiency can prevent male traits despite normal testosterone.
High receptor numbers: Can lead to endocrine excess symptoms despite normal hormone levels

Question 19

Compare protein vs peptide hormones.

Answer 19

Protein hormones: Larger in size, composed of
long chains of amino acids (more than 50 amino acids).
–>ex: insulin, growth hormone, prolactin
Peptide hormones: Smaller, usually consist of
short chains of amino acids (fewer than 50 amino acids).
–>ex: oxytocin, ADH, glucagon