3.2 - Endocrine System

Question 1

What is the endocrine system?

Answer 1

A control system that coordinates long, slow, lasting responses to maintain homeostasis

Question 2

How does the endocrine system maintain homeostasis?

Answer 2

Releasing hormones from ductless glands

Question 3

What are the major roles of the endocrine system?

Answer 3

• Control and co-ordination of growth from infancy to childhood to adolescence to adulthood (including puberty and menopause/andropause)
• Regulation of the reproductive system and gamete production
• Circadian rhythm (sleep cycle)
• Long term stress response
• Monitoring and maintaining set points: Hunger, thirst, body temperature, energy levels…

Question 4

What kind of signal is generated by the endocrine system?

Answer 4

Chemical signals

Question 5

What is the primary chemical signal used by the endocrine system?

Answer 5

Hormones

Question 6

How long of a distance do messages travel in the endocrine system?

Answer 6

Long and short distances

Question 7

How fast is the response time in the endocrine system?

Answer 7

Slow and long lasting response times

Question 8

What environment is targeted by the endocrine system?

Answer 8

Internal environment (always inside the body)

Question 9

How do hormones move about the body?

Answer 9

The endocrine system achieves its mission by releasing hormones into the blood, through which they can travel throughout the body

Question 10

What kinds of cells do hormones bond to?

Answer 10

Hormones travel throughout the body, but act on specific target cells by binding to specific receptors. This allows them to move throughout the body but only affect certain locations

Question 11

Where are hormones released from?

Answer 11

Hormones are released from glands

Question 12

What controls the release of a hormone?

Answer 12

Typically, a hormone is released from a control centre (endocrine gland). This generally causes an effector to have some form of negative feedback.

Question 13

What effects do hormones have on the target cell?

Answer 13

• Hormones can influence which proteins are made by the body.
• Hormones can prompt the body to create a completely new protein.
• They can also adjust the amount of a specific protein produced.
• Hormones can modify proteins to turn them on or off.
• When a hormone does its job, it often signals the body to make less of that hormone, maintaining a balance. This is called negative feedback.

Question 14

What is the general pathway for a hormone?

Answer 14

• A signal or stimulus reaches an endocrine gland.
• In response, the endocrine gland releases a hormone.
• The hormone enters the bloodstream and travels to target cells.
• Receptors on or in target cells recognize the hormone.
• The target cell responds to the hormone.
• The response typically counters the original stimulus, creating a negative feedback loop to maintain balance.

Question 15

What are the 2 basic types of hormones?

Answer 15

• Peptide based (water soluble): receptors on outside of the cell (ex: insulin)
• Steroid based (water insoluble): receptors on outside of the cell (ex: testosterone)

Question 16

How does the hypothalamus support homeostasis?

Answer 16

• The hypothalamus is a very important anatomical and physiological section within the brain
• It is critical to homeostasis because it monitors and regulates many of our bodily SET POINTS
• It is also the regulator of the autonomic nervous system (ANS)

Question 17

What functions in the endocrine system does the hypothalamus control?

Answer 17

• It’s in the brain and manages the release of hormones from the Pituitary and Adrenal glands.
• It makes two hormones directly: ADH, which helps kidneys retain fluid, and Oxytocin, known as the “cuddle hormone,” promoting bonding, empathy, and childbirth.

Question 18

What is the anterior lobe and the posterior lobe?

Answer 18

2 parts of the pituitary gland
- Anterior is one ball, posterior is the other

Question 19

What are the 7 anterior lobe hormones?

Answer 19

ACTH (Adrenocorticotropic Hormone):
- Stimulates the adrenal glands to produce cortisol, which helps manage stress and regulate metabolism.

TSH (Thyroid-Stimulating Hormone):
- Prompts the thyroid gland to release thyroid hormones, regulating metabolism and energy levels.

GH (Growth Hormone):
- Stimulates growth, cell reproduction, and regeneration. Important for overall body development.

PRL (Prolactin):
- Promotes milk production in mammary glands, supporting breastfeeding in females.

FSH (Follicle-Stimulating Hormone):
- In females, it stimulates the growth of ovarian follicles. In males, it helps in sperm production.

LH (Luteinizing Hormone):
- In females, triggers ovulation and supports the formation of the corpus luteum. In males, it stimulates testosterone production.

MSH (Melanocyte-Stimulating Hormone):
- Regulates the production and release of melanin, influencing skin pigmentation.

Question 20

What are the roles of the 7 anterior lobe hormones?

Answer 20

• Adrenocorticotropic Hormone (ACTH): stimulates the adrenal glands to produce and release cortisol, a hormone involved in stress response and metabolism.
• Thyroid-Stimulating Hormone (TSH): stimulates the thyroid gland to produce and release thyroid hormones, which regulate metabolism and energy production.
• Follicle-Stimulating Hormone (FSH): in females, stimulates the development of ovarian follicles and the production of estrogen; in males, stimulates sperm production in the testes.
• Luteinizing Hormone (LH): in females, triggers ovulation and promotes the production of progesterone; in males, stimulates the production of testosterone in the testes.
• Prolactin (PRL): stimulates milk production in the mammary glands (breasts) during lactation.
• Growth Hormone (GH): stimulates growth, cell reproduction, and regeneration. It plays a crucial role in childhood growth and adult metabolism.
• Melanocyte-Stimulating Hormones (MSH): regulates pigmentation by stimulating melanocytes, the cells responsible for producing melanin.