Topic 5 - Homeostasis & Response Flashcards
(35 cards)
What is homeostasis?
Maintaining a stable internal environment despite changing conditions
Why does the body need to maintain optimal conditions?
For optimal enzyme action and cell function
What is the role of a receptor?
Detects changes in the internal or external environment (to detect a stimulus)
In what order are signals passed along the control system?
receptor
➔ coordination centre ➔
effector
What is the role of a coordination centre?
Interprets changes and organises a response
What is the role of effectors?
Carry out the response
Name the two types of effectors and state what they do.
The two types of effectors are muscles and glands.
Muscles contract when stimulated, whilst glands release hormones.
What passes along nerve cells?
Electrical impulses
What is the gap between two neurones called?
Synapse
What is released across a synapse?
Chemicals
What is the role of a sensory neurone?
To transfer a signal from a receptor to the CNS
What is the role of a motor neurone?
To transfer a signal from the CNS to an effector
What is the role of a relay neurone?
To transfer a signal from a sensory neurone to a motor neurone
What is a reflex?
An automatic response to a stimulus
The pathway of a reflex arc
stimulus ➔ receptor ➔ sensory neurone ➔ relay neurone ➔ motor neurone ➔ effector ➔ response
How the endocrine system works
Glands are organs that release small chemicals called hormones.
These chemicals are normally released into the bloodstream, allowing them to travel around the body.
They can then bind to specific cells that have the correct receptors.
This will bring about some change within the cells.
What is the role of adrenaline?
Stimulates fight or flight response (higher heart rate etc)
Thyroxine released from the thyroid glands cause what
Thyroxine regulates your metabolic rate.
What happens if blood glucose concentrations fall too low?
There won’t be enough glucose for tissue cells to respire
Which hormone decreases blood glucose levels?
Insulin
How glucagon works
When blood glucose levels fall too low, it’s detected by the pancreas.
This causes the pancreas to release the hormone glucagon into the blood stream.
This hormone then travels around the body, and binds mainly to cells in the liver.
This stimulates those liver cells to break down their stored glycogen into glucose and release it into the blood.
This extra glucose increases blood glucose levels back up to normal.
When glucose is absorbed by the liver for long term storage, what molecule is it converted to?
Glycogen
Glucose is a type of:
Carbohydrate
How is type 1 diabetes managed?
Inject insulin
Monitor diet
Exercise regularly
