|a change in the environment of an organism
|The central nervous system is made up of....
|The brain and the spinal cord
|bundle of nerve cells
|any part of the body that produces a responce
|bundles of nerve cells that pass on electrical signal to the brain
|carry impulses from receptors to the spinal cord
|carry impulses to and from the spinal cord
|carry impulses from the brain to the effector
|is a junction between two neurons
|molecules that are released as a chemical to diffuse across a synape
|When your body needs to react to something very quickly and sends the impulse through before it reaches the brain
|In bright light eyes...
|1. radial muscles of the iris relax 2. circular muscles of the iris contract 3. recieve less light through contracted pupil
|In dim light our eyes..
|1. Radial muscles of iris contract 2. Circular muscles of iris relax 3. Receive more light through dilated pupil
|pull lens for focusing
|lets light into eye and focuses
|controls the amount of light entering eye
|focuses light onto the retina
|sends signals to the brain
|lets light through to lens
|light sensitiv layer that sends signals to the optic nerve
|hold lens in place
|Hormones (in people)
|are chemical messengers that co-ordinate systems in the body
|What are the two types of glands found in the body
|endocrine and exocrine glands
|is linked by nerves to the hypothalumos in the brain and produces many hormones
|is both an endocrine and an exocrine gland wich reguate blood
|What happens when adrenaline is released into the body?
|-pupil dilate -breathing becomes faster and deeper -heart beats faster -hair stands on end -glucose is released from liver -blood is directed away from gut towards liver
|is the maintenance of a constant internal environment
|What does the body do in response to a sudden increase in temperature?
|What does the body do in response to a sudden decrease in temperature?
|-Shivering -Hair stands on end -Vascoconstriction