Whole content Flashcards
(25 cards)
Define Homeostasis
Maintaining a constant internal envionmeny despite external changes
Why is homeostasis important?
Maintains optimum conditions for enzymes and cell functions
List 3 things we need to control in the body
Blood glucose concentration
Body temperature
Water levels
What will a control system in the body always have?
A receptor
A co-ordination centre
An effector
Define receptor
A cell that detects stimuli (a change in the envionment)
List 3 co-ordination centres
Brain
Spinal cord
Pancreas
Define effector
A muscle or gland that brings about a response back to optimum
What is a cell fhat electrical impulses pass along called?
Neurones
List the order of the reflex arc
Stimulus Receptor Sensory Relay Motor Effector
What are examples of effectors and what do they do?
Muscles (which contract)
Glands (secrete substances)
What does the CNS do?
Control the response of the effectors
What does CNS stand for, what is it made up of?
Central Nervous System
Made up of the Brain and Spinal cord
Why are reflex actions important?
They enable survival
Why are reflex actions said to be automatic and rapid?
Do not go to/involve the conscious part if your brain
What is the endocrine system?
Composed of glands which secrete hormones directly into the bloodstream
How is the endocrine system different to the nervous system?
Its slower but the effect last longer
Name the “master” gland in the brain?
Pituitary gland
What organ monitors and controls blood glucose?
The pancreas
What happens if blood glucose concentration is too high?
Pancreas produces the hoone insulin that causes glucose to move from the blood into the cells
Where excess, glucose stored is and what is it stored as?
Liver and Muscle, stored as glucose
What’s the difference between diabetes type 1 and 2?
Type 1 : pancreas fails to produce sufficient insulin
Type 2 : body cells no longer respond to insulin produced by the pancreas
Is obesity a risk factor for type 1 or 2 diabetes?
Type 2
What occurs if blood glucose concentration is too low?
The pancreas produces glucagon, that causes glycogen to be converted into glucose and released into the blood
What are the effects of glucagon bringing glucose levels back to normal an example of?
Negative feedback
