Endocrine System Flashcards
What does the endocrine system do?
Consists of structures that secrete hormones, either at cellular or organ level.
What does endocrine mean?
Release hormones straight into surroundings
What forms the autonomic nervous system?
The sympathetic and parasympathetic; function together to maintain regular heartbeat, temp and etc
What is sympathetic stimulation?
Prepares body for stressful or exciting situations. Adrenal glands secrete adrenaline which can effect your heart, lungs, blood vessels and etc. Example- heart rate speeds up to increase oxygen flow around body and digestion system slows down to preserve energy.
What is parasympathetic stimulation?
Slows down cardiac and respiratory activity. Stimulates digestion and absorption of food.
What are glands?
Groups of epithelial cells that produce specialised secretions.
What is a hormone?
Chemical messengers secreted into the bloodstream to target tissues and organs that may be quite distant.
How do hormones work?
Hormones bind to receptors on the target cells that change their behaviour.
What is homeostasis?
A self-regulating process by which an organism can maintain internal stability while adjusting to changing external conditions.
What are the 5 stages of homeostatic control?
Stimulus
Receptor
Input
Output
Response
What is positive feedback mechanism?
Enhance original stimuli
What is negative feedback mechanism?
Inhibit original stimuli
What is the hypothalamus?
Tiny collection of nuclei at the base of the forebrain that controls an astonishing amount of human behaviour, including emotional and stress responses.
What is the Pituitary gland and where can it be found?
Makes hormones that control several other glands such as the thyroid gland, adrenal glands, ovaries and testicles. The pituitary gland is in charge of many different functions, including how your body grows. It’s located at the base of your brain.
What is your thyroid and where can it be found?
Butterfly shaped gland in front of neck. Responsible for metabolism
What is the Parathyroid gland?
Four small glands that control level of calcium in body
What is your adrenal gland and where can it be found?
There is one on top of each kidney (2). Controls metabolism, blood pressure, sexual development and response to stress
What does the pineal gland do?
Manages your sleep cycle by releasing melatonin, a hormone that causes you to feel sleepy.
What role does the pancreas have in the endocrine system?
Secretes insulin and glucagon which regulates blood glucose.
Exocrine: helps with digestion
What do the ovaries do?
Release sex hormones called oestrogen, progesterone and testosterone.
What do the testes do?
Make sperm and release the hormone testosterone. This hormone affects sperm production, muscle strength and sex drive.
What are steroid hormones?
Derived from cholesterol. Made in adrenal glands and gonads
What are non-steroid hormones?
Derived from peptides/proteins or single amino acids.
What are the 5 different cell types?
Alpha
Beta
Delta
Gamma
Epsilon
What hormones does the hypothalamus secrete?
Oxytocin
ADH
What hormones do the anterior pituitary gland secrete?
Growth hormone
What hormones does the thyroid gland secrete?
T3 and T4
Calcitonin
What hormones do the adrenal cortex secrete?
Sex hormones
What hormones do the adrenal medulla secrete?
Epinephrine
Norepinephrine
Which hormone do alpha cells secrete?
Glucagon
Which hormone do beta cells secrete?
Insulin
Structure of insulin
Polypeptide consisting of 50 amino acids. Responds not just to raised glucose levels, but fatty acids and amino acids.
How does glucagon work?
Increases blood glucose levels by stimulating the conversion of glycogen to glucose in the liver and skeletal muscles. Glucagon is stimulated by low blood glucose levels and exercise.
What does the thymus gland do?
Found in chest in between lungs. Makes white blood cells that are part of immune system.
