Response and regulation Flashcards
The nervous system
- 5 organs which contain receptor cells
- they detect external - stimuli and send an electrical signal along neurons to the central nervous system.
- Made up from the brain and spinal cord to coordinate response.
name the stimulus for each organ
- eye
- ear
- nose
- tongue
- skin
- light
- sound
- chemical smells
- chemical tastes
- pain , pressure , temp
What is reflex response?
- Rapid
- Automatic
- Generally protective
what is a reflex arc?
- Path taken by an electrical impulse for a stimulus to response by an efector
- Withdrawal action reflex is shown here an automatic reaction from a hot pan causes a quick withdrawal.
What is Homeostasis?
- Homeostasis is the maintenance of a constant internal environmental
What is regulating glucose?
- amount of glucose in your blood is controlled by hormones
What does eating do to the glucose in your blood?
- increases glucose in the blood
- Pancreas detects increase and releases the hormone insulin into the blood
- insulin travels to liver turns insulin into insoluble glycogen for storage
-Glucose levels return to normal levels
what does exercise do to the glucose in your blood?
- decreases glucose in your blood
- Pancreas detects decreases and releases the hormone glucagon into the blood
- Glucagon tells the liver to turn stored glycogen into glucose and release into the blood
- Glucose levels return to normal
what is diabetes?
- ## condition where you’re unable to control your own glucose levels
what is type 1 diabetes?
- body doesn’t release insulin
what is type 2 diabetes?
- body cells do not respond from chemical signal to insulin.
symptoms for diabetes
- glucose detected in urine by a benedict’s test
treatment to diabetes
- injecting insulin
- pancreas transplants
- low sugar/carbohydrates diet
what are the two actions studied that occur in the eye?
- Blinking and pupil reflex
what is the iris?
-muscles that alter the size of the pupil
-control amount of light entering
what is the sclera?
- protective , tough withe outer coat
what is the choroid?
- pigment layer
-absorbs light - prevent reflection
- contains blood vessels
what is the retina?
- light sensitive layer
- image is formed here
- impulses sent to optic nerve
what is the optic nerve?
- carries impulses from retina to brain
what is the blind spot?
- where optic nerve leaves the eye
- no light sensitive cells
what is the lens
- changes shape to focus light onto retina
what is the cornea?
- clear part of sclera allows light to enter
- refracts light to entering the pupil
- hole in centre of iris
- allows light to enter
what happens if we get too hot?
- hairs lie flat
- sweating
- vasodilation
what happens if we get too cold?
- Hair stands on end to trap layer of insulating air over skin
- reducing heat loss
- Shivering
- Vasoconstriction
what happens when we sweat when were too hot?
- Layer of liquid sweat made by sweat glands
- carried up by sweat ducts
- released by sweat pores onto the skin and
- evaporates
- removing heat energy
what is vasodilation?
- Blood vessels in skin widen
- more heat from blood is lost to the environment
what is shivering?
- involuntary contraction of muscles
- increases respiration and release of heat energy
what is Vasoconstriction?
- blood vessels in skin get narrower
- less heat is lost from blood to the environment
What are the lifestyle factors?
- Diet- A diet high in sugars and carbohydrates can lead to obesity
and type II diabetes.
Drug and alcohol abuse - - lead to dependence and addiction
- people suffer withdrawal symptoms if they are unable to
consume it.
Alcohol -
- causes immediate slowing of reaction times
- long term can cause liver, circulatory and heart disease.
what is phototropism
- growth response in a plant to a one directional
stimulus. - caused by the release of the hormone auxin.
positive phototropism
- growth towards light
positive gravitropism
- root grown down into the ground with gravity
