Endocrine System Introduction

Question 1

Define the endocrine system

Answer 1

This is a system that integrates and controls organ function via the secretion of hormones form cells, tissues and glands

Question 2

What do hormones act on

Answer 2

They travel through the blood to a distant target organ

Question 3

Give an example of a fast response hormone

Answer 3

The release of adrenaline onto the sinoatrial node increasing heart rate

Question 4

Name 3 other classes of hormones which are NOT endocrine hormones and briefly describe them

Answer 4

Paracrine - act locally at the site of synthesis e.g. histamine
Autocrine - act on the same cell that it was synthesised within e.g. cytokines
Exocrine - released into the environment e.g. saliva and sweat

Question 5

Describe basic endocrine communication

Answer 5

Hormone is released, travels to distant site, leaves bloodstream, binds to target receptor and induces response

Question 6

Describe neural communication

Answer 6

Neurotransmitters are released from presynaptic neurones, travel across synaptic cleft to directly alter the activity of the postsynaptic cell

Question 7

Describe neuroendocrine communication

Answer 7

Neurotransmitter excited, sends an action potential, triggers the release of hormone which enters the bloodstream and travels to target organ. e.g. hypothalamus to anterior pituitary