1. Control and Communication
National 5 Biology
Key Area 3:
Control and Communication
(b) Hormonal control
National 4 Biology
Key Area 6:
Biological actions in response to internal and external changes to maintain stable body conditions.

2. By the end of the lesson you will be able to …..
Describe how hormones work.
Describe how hormones control blood sugar.

3. Hormonal Control
Hormones released by the endocrine system coordinate with the actions of the nervous system to control the body.

4. Hormones Endocrine glands release hormones into the blood stream.
Hormones are chemical messengers.
Target tissues have cells with receptor proteins for hormones, so only some tissues are affected by specific hormones.
Liver cell
Insulin
National 4 – first 2 bullet points and the basic diagram (without any additions)
National 5 – everything!
Pancreatic cell
Specific receptor proteins on the membrane

5. Example:
Growth hormone is released from the pituitary gland and affects the liver as well as muscle and bone cells.

6. What effect can this have on an organism?
Too much: Gigantism
Too little: dwarfism

7. Muscle, bone and liver cells
Use the table on pg 89 of the text book to help you fill in the rest of the table
Endocrine gland where hormone is produced
Hormone
Target Tissue
Function/Effect of hormone
Growth Hormone
Oestrogen
Insulin
Stimulates growth during development
Muscle, bone and liver cells
Pituitary
Regulates the menstrual cycle
Uterus and Pituitary
Ovary
Controls the conversion of excess glucose into glycogen
Liver
Pancreas

8. Blood Glucose Regulation
Blood sugar levels change throughout the day
Blood sugar level must be kept below a certain concentration for your cells to work optimally
What organ is responsible for controlling blood sugar levels?

9. The liver is also involved in storing away the excess glucose (they did not learn about this in S3)

10. GCSE Science Revision - How Insulin and Glucagon control Blood Sugar Levels (~5 minutes)

11. High blood glucose level Pancreas produces insulin
National 4
Blood Sugar control
Eaten a big meal
Glucose stored in the liver.
Normal Blood glucose level
Normal Blood glucose level
National 4 basics – could be done with whole class as an intro to National 5. ASN version at end of powerpoint.
From National 4 support notes: If blood glucose levels are too high insulin (a hormone) is released. This tells the body to store the excess glucose in the liver. This brings the blood glucose levels back to normal. If blood levels are too low this excess glucose can be released again bringing them back to normal.
Not eaten in several hours
Glucose released from liver back into blood stream.
Low blood glucose levels

12. Pancreas produces more Insulin than glucagon
Glucose converted to glycogen
High blood glucose level
Eaten a big meal
Glycogen stored in the liver
Your pancreas releases glucagon when glucose is gone from your blood stream.
Normal Blood glucose level
Normal Blood glucose level
Glucose released from liver into blood stream
Not eaten in several hours
Pancreas produces more glucagon than insulin
Glycogen in liver converted back to glucose
Low blood glucose levels

13. WORD BANK Liver Insulin Glycogen Pancreas Glucose Glucagon WORD
MEANING
Organ that produces the hormone insulin (and glucagon)
Organ that stores excess glucose (as glycogen)
Sugar present in blood
Hormone that stimulates the liver to store excess glucose (as glycogen)
Store of glucose
Hormone that stimulates the liver to break down glycogen into glucose
Class can do this as a table or use this list to populate the blood sugar fold out (a master of the foldout is in the folder if you want to use it).
N4 – orange
N5 – everything!
WORD BANK
Liver
Insulin
Glycogen
Pancreas
Glucose
Glucagon