Endocrine system

Question 1

What is the hypothalamus

Answer 1

control centre, functions include homeostasis, secretory activity of pituitary gland, makes ocytocin and ADH

Question 2

What is the Pituitary gland

Answer 2

Base of brain, posterior lobe releases ADH and oxytocin
ADH- antidiretic hormone, regulates the water and sodium levels, works on tubules of nephroms to increase water reabsorption
Oxytocin- helps the uterus to contract, helps females progress in labour.

Question 3

What is the endocrine system

Answer 3

-Responsible for indirect and directly on almost every cell, organ and function of the body
- maintain homeostasis
- Remove waste protects
- consists of glands, hormones and cluster ducts
- Hormones are chemical transmitters secreted by stimulation and released into the bloodstream
- Works closely with CNS however is slowly released and lasts longer than action potentials and neurotransmitters.

Question 4

What are the adrenal glands

Answer 4

Top of kidneys , produce hormones such as aldoesterone, cortisol and adrenaline. Released in fight or flight situations, regulate the general stress response, conversion of amino acids into carbs for storation of glucagon in the liver.

Question 5

What is the pancreas

Answer 5

Maintain blood sugar levels
Insulin and glucagon sent into blood stream to regulate blood sugar levels
Insulin decreases, glucagon increases, act in opposite to balance.

Question 6

What is the thyroid

Answer 6

Metabolism
Digestion
Heart rate
Temperature- through thyroxine
bone growth

Question 7

How are hormones secreted

Answer 7

1. Hormonal stimulation
2. Humeral stimulation
3. Neural stimulation

Question 8

What is hormonal stimulation

Answer 8

Where one gland that secretes hormone triggers another gland to release a hormone

Question 9

Humeral stimulation

Answer 9

Floating in the blood, for example glucose that is floating in the blood stream triggers the release of insulin

Question 10

Neural stimulation

Answer 10

Neurons stimulate a gland to release its hormone
Neurotransmitters bind to receptors
e.g. sympathetic NS, stimulates adrenal gland to release adrenaline

Question 11

How are hormones regulated?

Answer 11

Through feedback loops
Either positive or negative
Example of negative feedback loop: Sympathetic nervous system detects stimulus and sends signal to adrenal medulla to release adrenaline. If the stimulus is eliminated, signal to adrenal medulla to release less adrenaline.

Question 12

Explain the RAAS system in relation to endocrine system

Answer 12

It is activated when the blood volume/pressure drops.
Renin is released when there is a drop in blood volume/pressure, when chemoreceptors detect a drop in calcium and direct communication with the sympathetic nervous system in fight of flight as we need to increase our blood pressure to allow more blood to travel to our heart.
Angiotension 1 is released from the liver and travels in the blood stream and bumps into renin. Angiotension 1 goes to the lungs where ACE enzyme converts it to angiotensin 2.
Angiotensin 2 is a vasoconstrictor (increasing blood volume and pressure), it goes to the smooth muscles and makes it contract, goes to the hypothalamus and triggers the ADH to retain and reabsorb water, and it travels to the adrenal cortex to release aldosterone.
Aldosterone travels to the tubules to take present sodium back into the body increasing sodium and water levels in the kidneys.
Consequently increasing blood volume, blood pressure, filtration, and sodium concentrate.