Chapter 15 - Hormones & Endocrine Glands

HORMONES & ENDOCRINE GLANDS

OVERVIEW • What are hormones • What are endocrine/exocrine glands • Role of Insulin/glucagon in regulating blood glucose • Effects of Adrenaline in response to stress, fear and anger

I’m so angry that I feel like punching somebody now!

What are hormones? • • • • •

Chemical substances Produced by endocrine glands Transported by blood Alter activity of target organ e.g. regulate metabolism, growth, sexual development

Endocrine vs Exocrine Endocrine gland Exocrine gland Ductless

With Ducts

Secrete H into blood Carried H by duct e.g. Adrenal gland, Pituitary gland, pancreas

e.g. Salivary glands Sweat glands

“MASTER” GLAND

ADH THYROXINE

ADRENALINE

TESTOSTERONE

INSULIN / GLUCAGON OESTROGEN / PROGESTERONE

• GOITRE • Lack of iodine • Thyroxine controls rate of energy produced from nutrients BACK

TELL YOUR PARTNER 1. What is the difference between Endocrine & Exocrine glands? 3. NAME 1 endocrine gland and the hormone it produces

Regulating blood glucose Islets of Langerhan in pancreas secrete insulin and glucagon

High blood glucose

insulin

GLYCOGEN

GLUCOSE glucagon

low blood glucose

RE-CALL • What are hormones? • What are the 2 hormones produced for regulation of blood glucose? • Where are they produced/secreted? • What happens when there is high blood glucose? • What happens when blood glucose is low?

How does your body respond to STRESS?

STIMULUS Fear Anger Stress

RECEPTOR Brain receives stimulus, activates sensory neurons, transmit impulses to spinal cord

RESPONSE in various parts of body to prepare for “fight” or “flight” response

SPINAL CORD directs nerve impulses to Adrenal gland

ADRENAL GLAND (Effector) secretes Adrenaline (carried in blood)

“FIGHT or FLIGHT” • INCREASE HEART RATE • INCREASE Blood flow to muscles • PUPILS DILATE • INCREASE METABOLIC RATE - more energy

SUMMARY • • • • •

Define Hormones Differentiate Endo/Exocrine glands Examples Regulation of Blood glucose Effects of Adrenaline on stress