Year 9 Biology Flashcards
Recall the role of the digestive system
Consists of glands and organ used for digestion.
Recall the role of the circulatory system
carries blood cells and nutrients around your body and to your heart to maintain health and body tempreture.
Recall the role of the excretory system or excretion
Remove’s waste from the body
Recall the role of the endocrine system? And what does it help with?
Secretes or releases hormones into the bloodstream to control bodily functions (sleeping, growing, blood glucose)
Why is it difficult to maintain internal balance?
because of disruptions in the negative feedback loop
Recall each stage of the ‘stimulus response model’
stimulus - receptor - control centre - effector - response
Explain the role of each stage of the stimulus response model
Stimulus- a change in environment
Receptor- the receptor cells in our sense organs detect the change in environment
Control Centre- makes a decision on how to react
Effector- organs control a response (usually the muscles)
Response- final response to three stimulus
What is the need for receptors inside and outside the body?
The nervous system is able to detect stimuli from the inside or outside of the body. The brain can respond to this to maintain homeostasis.
Why does a constant internal environment need to be maintained? (homeostasis)
Because it will prevent chemical reactions such as metabolism from occurring
How does the hypothalamus maintain homeostasis?
monitors and coordinates appropriate responses to return to body temp to set point
How does the brain maintain homeostasis
the brain receives messages from the sense organs and sends messages to form responses for a stimulus
What is negative feedback?
happens when the response to a stimulus leads to a decrease in that stimulus.
Define metabolism
chemical reactions that occur within the body
Match the receptor types with what their role is.
Thermoreceptor - detects temperature
Photoreceptor - detects light
Chemoreceptor - detects chemicals
Mechanoreceptor - detects pressure
Define the difference between ‘the central nervous system’ and ‘the peripheral nervous system’.
Central nervous system - consists of the brain and spinal cord
Peripheral nervous system - nerves (communicate between body and C.N.S)
What do neurons do?
Neurons carry ‘messages’ called nerve impulses through the body and the C.N.S (central nervous system)
What are dendrites?
convert information from nuclear receptor cells
What is an axon?
transmits nerve impulse’s from dendrites
What is a cell body?
contains nerve impluses
What is an axon terminal?
where nerve impulses can travel to another neuron, or stimulate a muscle gland
In what system do messages travel along neurons?
The nervous system
In what system do messages travel along the bloodstream?
The endocrine system
What form do messages take in the nervous system?
Nerve impuleses
What form do messages take in the endocrine system?
Hormones
Nerve impulses travel in…?
One direction
Hormones travel…?
All over the body, but only act on targeted cells
List the regions of the brain.
Cerebrum, cerebellum, Brain stem, hypothalamus
Define glucose.
Basic sugar in your blood
Define glycogen.
A form of stored sugar in the body which is released when needed.
What is Thermoregulation?
When the hypothalamus detects that the blood temperature is too high or too low, then maintains it.
What is hormone binding?
When a cell in the endocrine gland releases hormones into the bloodstream and then then the hormones attach themselves to their designated hormone receptor. This then changes the activity in the target cell.
What is the pituitary gland?
A gland which secretes many different hormones throughout the body
What is a reflex arc?
An involuntary, unplanned response to a stimulus. This response is instantaneous or fast to protect yourself from danger.
What is neurotransmission?
The passing of information from one place to another.
Where does neurotransmission occur?
In the synapse. A chemical signal is converted back into electrical signal in the dendrite of the next neuron.
What is a nerve cell?
A neuron
A nerve is a bundle of what?
Neurons
connect the hypothalamus, the brain, homeostasis, and negative feedback loop
What are motor neurons?
What are sensory neurons?
