Response and Regulation (NEW) Flashcards
What are sense organs?
They CONTAIN receptor cells, which detect specific stimuli and and then relay this information as electrical impulses along neurones to the central nervous system to coordinate a response
What does the Central Nervous System consist of?
Brain and spinal cord
What is in the CENTRAL NERVOUS SYSTEM?
brain and spinal cord
What is in the Nervous System?
the brain, spinal cord and nerves
What are properties of reflex actions?
Fast, automatic and protective
How does information move from the receptors to the effector in the nervous system?
Receptor ➟ Through sensory neurones ➟ Relay Neurones in spinal cord ➟ Through Motor Neurones ➟ Effector
What is a sclera?
Protective, tough white outer coat of the eye
What is a Cornea?
- Allows light into eye
- refracts light
What is an iris?
Coloured part of eye
Contains muscles that alter the size of the pupil to CONTROL the amount of light entering the eye
What is a pupil?
Hole in the centre of eye which lets light enter the eye
What is lens?
changes shape to focus light on retina
What is choroid?
- pigmented layer-
- which absorbs light to prevent reflection.
- prevents light being detected several times
- Also contains blood vessels
What is a retina?
Light sensitive layer (photoreceptor cells) that detect light.
What is a net blind spot?
Where the optic nerve leaves the eye. There are no light sensitive cells here
What is an optic nerve?
Carries electrical impulses from retina to brain
What factors does your body need to keep constant?
- temperature
- Ph
- water
- blood glucose conc
Why does your body need to regulate normal conditions?
- as our chemical reactions are controlled by catalysts called enzymes
- changes in conditions may slow down or even stop enzymes working and thus disrupting vital chemical reactions (metabolisms)
What are hormones?
a chemical messengers, carried by the blood, which control many body functions
( a protein)
Why do we need to keep blood glucose levels within a constant level?
- if present in high concentrations it can damage cells
- glucose is needed for cells for respiration
What does your body do when blood glucose RISES?
- pancreas produces the hormone, insulin into the blood
- insulin travels to LIVER
- liver turns glucose into INSOLUBLE glycogen for storage
- this reduces level of glucose in blood
What is diabetes?
a condition where you are unable to control your own blood glucose levels
What is TYPE 1 Diabetes?
the body does not produce insulin
What is TYPE 2 diabetes?
- the pancreas still produces some insulin
- the body cells do not respond to the chemical signal from insulin
What are some treatments for diabeties?
- Injecting insulin
- pancreas transplants
- low sugar/ carbohydrates diet
What it the CAUSE of type 1 diabetes?
damage to the beta cells in the pancreas which produce insulin
What is the cause of type 2 diabetes?
a person’s body becoming resistant to insulin
When your blood glucose level is low, what does your body do?
- pancreas releases the hormone glucagon into the blood
- travels into liver
- insoluble glycogen is converted back to glucose
How does alcohol affect the body?
, increases the body’s reaction time. This could have fatal consequences if a person is driving a car under the influence of alcohol.
- can cause liver, circulatory and heart disease
What can drugs do to the body?
lead to dependence and addiction where people suffer withdrawal symptoms if they are unable to consume it
How can you get type 2 diabetes from lifestyle choices?
Eating too much food over a long period can contribute to the development of type 2 diabetes
What hormone causes phototropism?
Auxin
What is tropism?
growth movement of a plant in response to a one sided stimulus
How does your boy react when you get to hot?
- sweat
- ERECTOR MUSCLES
- Vasodilation
- no shivering
What does your body do when it gets too cold?
- shivering, skin muscles contract and relax, rapidly generating heat, this warms up blood
- reduce sweating
- erector muscle CONTRACTS and the hair is pulled upright, more insulating air is trapped next to skin, more insulation
- vasoconstriction, - Blood vessels in the skin get narrower so less blood flows to the skin surface so less heat is lost by RADIATION (cooling rate decreases)
What is vasodilation?
blood vessel diameter widens, more blood flows to skin surface so more heat is lost to radiation (cooling rate increases)
How is sweat created when your hot?
- liquid sweat is made by sweat glands
- carried up by sweat ducts
- released by sweat pores onto the skin and evaporates removing heat energy
How do ERECTOR MUSCLES work when your HOT?
ERECTOR MUSCLES relaxes and hair lies flat, less insulating air is trapped next to skin so less insulation
How does shivering work?
skin muscles contract and relax, rapidly generating heat, this warms up blood
How do ERECTOR MUSCLES work when you are cold?
erector muscle CONTRACTS and the hair is pulled upright, more insulating air is trapped next to skin, more insulation
How does VASOCONSTRICTION work?
Blood vessels in the skin get narrower so less blood flows to the skin surface so less heat is lost by RADIATION (cooling rate decreases)
What does your skin detect?
Temperature and pressure
