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.

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

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

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

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

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

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

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?

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

GCSE Science Revision - How Insulin and Glucagon control Blood Sugar Levels (~5 minutes) https://www.youtube.com/watch?v=e-3N7w2sWps

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

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

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