Biology (homeostasis B5) Flashcards
What is homeostasis?
the regulation of internal conditions of a cell or organism to maintain optimum conditions for function.
What are the things the body controls during homeostasis? (6)
Carbon dioxide/ urea/ salt/ water/oxygen/ temperature
What are internal conditions in the body that need to be controlled? (3)
Body temperature, water content of the body, blood glucose concentration
What is negative feedback?
Negative feedback is when the body tries to undo the change
What does a receptor do?
Receptors detect changes in the internal and external environment
What is a stimulus?
A change in the environment of something
What is a coordination centre?
They send out signals and coordinate the response of the body
What is an effector?
A muscle or gland. This part changes the conditions
What is a response?
the action taken by a processing centre, as a reaction to a stimulus
What is a neurone?
Cells that can conduct electricity
What are the different types of neurons? (3)
Sensory neurone, motor neurone , relay neurone
What is a sensory neurone?
They carry impulses from receptors to the CNS
What is a motor neurone?
connects brain and spinal cord to the effector cells. Carries impulses from CNS to effectors
What is a relay neurone?
A relay neurone carries messages from one part of the CNS to another
What does the CNS do
The central nervous system is a coordination centre
Structure of a reaction pathway
Stimulus, receptor, sensory neurone, CNS, motor neurone, effector, response
What are some types of receptors (6)
Light receptors in the eyes.
Sound receptors in the ears.
Taste receptors in the tongue.(chemical
Smell receptors in the nose (chemical)
Touch,pressure and temperature receptors in the skin.
Changes of position receptors in the ears (balance)
Stimulus examples (5)
Light. Sound. Taste. Smell. Touch, pressure, temperature. Changes of position.
Effectors can be either a…(2)
Muscles or glands
The CNS consists of…
The brain and the spinal cord
What are synapses?
The connection between two neurons
The nerve signal is transferred by chemicals which diffuse across the gap.
What are reflexes?
Reflexes are rapid, automatic responses to certain stimuli that don’t involve the conscious part of the brain
