The Hormonal System and Glands
- Created by: Tashajanewinstone98
- Created on: 03-11-15 19:42
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- The Hormonal System
- What is the hormonal system?
- Sends information as chemical signals.
- Made up on endocrine glands and hormones.
- Endocrine glands are groups of cells that are specialised to secrete hormones e.g. the pancreas secretes insulin.
- Hormones are chemical messengers. Many are proteins or peptides e.g. insulin. or some are steroids e.g. progesterone.
- Hormones are secreted when an endocrine gland is stimulated.
- Glands can be by stimulated by a change in concentration of a specific substance or electrical impulses.
- Made up on endocrine glands and hormones.
- Hormonal Communication
- Hormones diffuse directly into the blood, then they're taken around the body by the circulatory system.
- They diffuse out of the blood all over the body but each hormone will only bind to specific receptors found on cell membranes- target cells.
- Tissues that contain target cells are called target tissue.
- The hormones trigger a response in the target cell (effectors)
- Tissues that contain target cells are called target tissue.
- They diffuse out of the blood all over the body but each hormone will only bind to specific receptors found on cell membranes- target cells.
- Hormones diffuse directly into the blood, then they're taken around the body by the circulatory system.
- Sends information as chemical signals.
- Glands
- There are 2 types of gland: endocrine and exocrine.
- Endocrine glands secrete hormones directly into the blood.
- Exocrine glands are groups of cells specialised to secrete chemicals through ducts into cavities or onto the surface of the body.
- They usually secrete enzymes. Some organs have exocrine tissue and endocrine tissue so act as both types of gland. e.g. pancreas.
- There are 2 types of gland: endocrine and exocrine.
- Action of Hormones
- A hormone is called a first messenger because it carries the chemical message the first part of the way, from the endocrine gland to the receptor on the target cell.
- When a hormone binds to its receptor it activates an enzyme in the cell membrane.
- The enzyme catalyses the production of a molecule inside the cell called a signalling molecule.
- The signalling molecule is called a second messenger because it carries the chemical message the second part of the way. from the receptor to other parts of the cell.
- Secondary messengers activate a cascade inside the cell.
- The signalling molecule is called a second messenger because it carries the chemical message the second part of the way. from the receptor to other parts of the cell.
- The enzyme catalyses the production of a molecule inside the cell called a signalling molecule.
- When a hormone binds to its receptor it activates an enzyme in the cell membrane.
- Adrenaline
- Adrenaline is a hormone secreted from your adrenal glands.
- Its secreted when there's a low concentration of glucose in your blood, when you're stressed or exercising.
- Adrenaline gets the body ready for action by making more glucose available for muscles to respire. e.g. by activating glycogenolysis (breakdown of glycogen to glucose.
- It is a first messenger. It binds to specific receptors in the cell membranes of many cells.
- When adrenaline binds it activates an enzyme in the membrane called adenylate cyclase.
- Activated adenylate cyclase catalyses the production of a second messenger called cyclic AMP.
- cAMP activates a cascade.
- Activated adenylate cyclase catalyses the production of a second messenger called cyclic AMP.
- When adrenaline binds it activates an enzyme in the membrane called adenylate cyclase.
- It is a first messenger. It binds to specific receptors in the cell membranes of many cells.
- Adrenaline gets the body ready for action by making more glucose available for muscles to respire. e.g. by activating glycogenolysis (breakdown of glycogen to glucose.
- Its secreted when there's a low concentration of glucose in your blood, when you're stressed or exercising.
- Adrenaline is a hormone secreted from your adrenal glands.
- A hormone is called a first messenger because it carries the chemical message the first part of the way, from the endocrine gland to the receptor on the target cell.
- Adrenal Glands
- The adrenal glands are endocrine glands that are found just above your kidneys.
- Each adrenal gland has an outer part called the cortex and an inner part called the medulla.
- The cortex secretes steroid hormones. e.g. it secretes glucocorticoids such as cortisol when stressed.
- The medulla secretes catecholamine hormones. e.g. it secretes adrenaline when stressed.
- Each adrenal gland has an outer part called the cortex and an inner part called the medulla.
- The adrenal glands are endocrine glands that are found just above your kidneys.
- The Pancreas
- The pancreas is an endocrine and exocrine gland that's found below the stomach.
- The areas of endocrine tissue are called the islets of Langerhans.
- They're found in clusters around blood capillaries and they secrete hormones directly into the blood.
- They're made up of two types of cells: alpha cells and beta cells. Alpha secrete glucagon. Beta secrete insulin. They both help to control blood glucose concentration.
- They're found in clusters around blood capillaries and they secrete hormones directly into the blood.
- Most of the pancreas is exocrine tissue. The exocrine cells are called acinar cells.
- They're found in clusters around the pancreatic duct- a duct that goes to the duodenum.
- The acinar cells secrete digestive enzymes into the pancreatic duct. The enzymes digest food in the duodenum.
- They're found in clusters around the pancreatic duct- a duct that goes to the duodenum.
- The areas of endocrine tissue are called the islets of Langerhans.
- The pancreas is an endocrine and exocrine gland that's found below the stomach.
- What is the hormonal system?
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