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Description
Flashcards by hannawin98, updated more than 1 year ago
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Created by hannawin98
over 8 years ago
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| Question | Answer |
| What is the Hormonal System? | The system in which information is sent via chemicals |
| What are endocrine glands? | Groups of cells that are specialised to secrete hormones directly in the blood |
| What are hormones? | 1. "Chemical messengers" 2. usually proteins, e.g insulin, or steroids, e.g progesterone |
| When are hormones secreted? | When an endocrine gland is stimulated, either by the change in concentration of a specific substance or by electrical impulses |
| Outline hormonal communication | 1. Hormones diffuse into the blood 2. They bind to specific receptors on target cells 3. This triggers a response in the target cells. |
| What are exocrine glands? | Groups of sepcialised cells that secrete chemicals through ducts into cavities or onto the surface of the body |
| What is a first messenger? | A chemical involved in cell signalling that binds to a receptor in a cell membrane and triggers activity inside the cell. |
| What is a second messenger? | A chemical produced inside a cell in response to a signal outside the cell. The chemical relays the signal to the inside of the cell |
| What happens when a hormone binds to a receptor on the target cell? | An enzyme is activated in the cell membrane. This enzyme catalyses the production of the second messenger which activates a cascade of reactions inside the cell. |
| What is adrenaline? | A hormone that is secreted from the adrenal glands. It is secreted when there's a low glucose concentration in your blood when you are stressed or exercising. |
| What does adrenaline do? | Makes your body ready for action by making more glucose available for muscles to respire, e.g by activating glycogenolysis |
| What happens when adrenaline binds to it's target cell? | An enzyme called Adenylate cyclase is activated. This catalyses the production of Cyclic AMP (cAMP) which causes a cascade of reactions that make glucose more available to the cell. |
| What are the adrenal glands? | Endocrine glands that are found above the kidney. They have an outer part called the cortex and the inner part called the medulla. |
| What does the cortex do? | Secretes steroid hormones when you're stressed e.g glucocorticoids |
| What does the medulla do? | Secretes catecholamine hormones (modified amino acids) when you're stressed e.g adrenaline |
| What is the Pancreas? | An endocrine and exocrine gland found below the stomach |
| What are Islets of Langerhans? | Endocrine tissue in the pancreas. They're found in clusters by blood capillaries and are made up of Alpha and beta cells. |
| What do alpha cells do? | They secrete glucagon to raise blood glucose concentration levels |
| What do beta cells do? | They secrete insulin to lower blood glucose concentration levels |
| What are acinar cells? | Exocrine cells in the pancreas. They're found in clusters by the pancreatic duct. They secrete digestive enzymes into the small intestine via the pancreatic duct. |
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