Chapter 20 - Hormones Flashcards
What are endocrine glands?
Glands which produce hormones.
Ductless, and releases hormones directly into the blood
Name the parts of the endocrine system (and make sure you know where they are situated)
- Pituitary gland (brain
- Thyroid gland (Larynx)
- Adrenal Glands (Kidneys)
- Islets of langerhans (Pancreas)
- Testes
- Ovaries
Explain the effects of adrenaline on the respiratory system
- Increases the rate and depth of breathing
- Increased uptake of oxygen in blood
- Bronchioles dilate
- More oxygen for faster respiration
- More carbon dioxide is excreted
- Conversion of glycogen to glucose happens faster
- More glucose = faster respiration
Explain the effects of adrenaline on the circulatory system
- Increased heartrate
- Increased blood pressure
- Faster transport of oxygen
- Increased respiration and metabolic rate
- More energy is released
- Increases skeletal muscle tone
Explain the effects of adrenaline on the rest of the body`
- Pupils dilate (better vision)
- Diverts blood from gut, causins inhibition
- Hair erector muscles contract, increasing size of organism
- Increased mental awareness and sensory perception
- More repid response is possible
Explain, in terms of hormones, what happens when blood glucose levels are too high
- The beta cells in the Islets of Langerhans in the pancreas secrete insulin
- Insulin is transported to the liver
- Insulin instructs the lier to convert excess glucose into glycogen
- Glycogen can be stored in the liver and muscles
- Insulin can increase the rate of respiration
Explain, in terms of hormones, what happens when blood glucose levels are too low
- Alpha cells in the Islets of Langerhans in the pancreas release glucagon
- Glucagon is transported to the liver
- Glucagon instructs the liver to convert glycogen into glucose
- Glycogen is stored in liver and muscles
- Glucagon can decrease rate of respiration
- Adrenaline can also be secreted from the adrenal glands to perform this function
- Controlled by homeostasis
State the normal concentration of glucose in the blood
90 - 100 mg/100 ml of blood (0.1%)
Define a hormone
Chemical messengers produced by endocrine glands, which is released directly into the bloodstream and transported to target organs.