Homeostasis and Response Flashcards
what is homeostasis?
maintaining a stable internal environment
why is homeostasis important?
because it stabilises your body or cells when an internal or external condition has changed.
2 kinds of communication systems in your body?
nervous and hormonal
what three components are your automatic control systems made up of?
cells called receptors, coordination centres and effectors
how do automatic control systems keep your internal environment stable?
negative feedback
what does a receptor do?
detects when a stimulus level is too high or low
What does a coordination centre do?
Receives information and processes it then organises a response
what does an effector do?
produces a response to counteract the change and restores the optimum level
do you think about the process of automatic control systems?
No, it happens on its own
What is stimuli?
A change in the environment
what do multicellular organisms do to communicate with each other to survive?
they form communication systems like the nervous and hormonal.
Name the different parts of the nervous system.
Central nervous system, sensory neurones, motor neurones, and effectors
What is the central nervous system?
In vertebrates (Animals with backbones) it consists of the brain and spinal cord only. It takes in sensory information, process is the information, and sends out motor signals
What are sensory neurons?
The neurones (communication cells) that carry information as electrical impulses from the receptors to the CNS
what are motor neurones?
The neurons that carry electrical impulses from the CNS to effectors
what are Effectors?
All your muscles and glands which respond to Nervous impulses
Give two examples of receptors.
taste receptors on the tongue and sound receptors in the ears
Receptors can form parts of larger complex organs, give an example.
The retina of the eye is covered in the light receptor cells
Muscles and glands are both effectors but do different things, what are they?
Muscles contract in response to nervous impulse whereas glands secrete hormones
What are synapses?
the connection between two neurones.
how are nerve systems transferred?
Chemicals diffuse (move) across the gap then set up a new electrical signals into the next neurone
What are reflexes?
Rapid automatic responses to certain stimuli that don’t involve the conscious part of the brain.
What is the name of the passage of information in a reflex (from receptor two a factor)?
The reflex arc.
Where does the reflex arc go through?
The central nervous system
What is the passage of a reflex arc?
stimulus is detected by receptors, impulses move along the sensory neurones to the CNS. Synapses cause the impulses to move from the sensory neurones to the relay neurones which move to the motoneurons which travel to the effector . 
What are hormones?
Chemical messengers sent in the blood.