5 Homeostasis and responce - Seperate Flashcards
Name the region in the brain that involves consciousness, intelligence, memory and language.
Cerebral cortex
Name the region in the brain that coordinates muscular activity and balance.
Cerebellum
Name the region in the brain that coordinates automatic, unconscious activities.
Medulla (oblongata)
Name a method scientists used to find out the functions of each part of the brain.
Studying brain damage patients/Electrically stimulating different parts of brain/MRI scans
State the function of the sclera.
White outer layer to protect the eyeball
State the function of the cornea.
Allows light into the eye; Refract/focus light
How is the size of the pupil controlled?
Muscular contraction and relaxation of the iris
State the function of the lens.
Refracts light to focus the image onto the retina
Name the two components that change the shape of the lens.
Suspensory ligaments + Ciliary muscles
Name the component that carries impulses from the retina to the brain.
Optic nerve
Describe the state of the ciliary muscles and the lens as the eye focuses on a distant object.
Ciliary muscles relax, Lens becomes thinner
Name the condition in which people can see close objects clearly but distant objects look blurred.
Myopia/Short sightedness
Name the condition in which people can see distant objects clearly but close objects are blurred.
Hyperopia
Give two possible reasons for myopia.
Lens too curved; Long eyeball
Describe the state of the lens if more refraction is to happen.
More convex/rounded
Name a treatment for myopia or hyperopia.
Contact lenses/Laser eye surgery/Replacement lenses
Define ‘phototropism’.
The response of a plant to light
Define ‘gravitropism/geotropism’.
The response of a plant to gravity
What are auxins?
A plant hormone that controls photo- and geotropism
How do auxins respond to one-sided light on a young shoot?
Auxins move to the unlit side (causing quicker growth, hence the shoot bends towards the light)
How do auxins respond to a young root placed sideways?
Auxins move to the lower side of the root
What is the effect of a high level of auxin on shoot growth?
Auxins promote shoot growth
What is the effect of a high level of auxin on root growth?
Auxins inhibit root growth
Name one use of auxins in agriculture and horticulture.
Weed killers/Rooting powders/Tissue culture
Name one use of ethene in agriculture.
Control fruit ripening
Name one use of gibberellins in agriculture.
Increase fruit size/Stimulate germination/Promote flowering
Name the part in the brain that controls your core body temperature.
Thermoregulatory centre in hypothalmus
Name the action where surface skin capillaries dilate to allow more blood flow to the surface.
Vasodilation
State one response of the body to high body temperature.
Sweating/Vasodilation/Hair lies flat
State one response of the body to low body temperature.
Vasoconstriction/Less sweating/Shivering
Briefly explain how shivering helps increase our body temperatre.
Contractions requires energy from respiration (exothermic)
Name the two main poisonous waste products in our body.
Carbon dioxide + Urea
How does high carbon dioxide level affect the body?
Dissolved CO2 makes acidic solution –> denature enzymes
How is carbon dioxide removed from the cells and out of the body?
Transported to alveoli –> exhaled into environment
How is urea produced?
Breakdown of excess amino acids
Name the organ that removes urea from the body.
Kidney
Name the process which removes the amine group from the amino acids.
Deamination
Name the product formed from deamination of excess amino acids, before it is converted into urea.
Ammonia
Name the organ that breaks down excess amino acids.
Liver
Name the organ that controls water and mineral ion content of the blood.
Kidney
Namefour substances that are filtered out of the blood into the kidney.
Glucose, mineral ions, urea, water
Why can’t blood cells and proteins leave the blood to enter the kidney?
Too big to pass through vessel wall
How is glucose reabsorbed back into the blood from the kidney?
Diffusion + Active transport
What is ‘selective reabsorption’?
The process in which the kidney reabsorbs certain useful substances back into the kidney
Name the hormone that regulates the amount of water reabsorbed back into the blood from the kidney.
ADH
Name the organ that secretes ADH.
Pituitary gland
If there is an increase in ADH release, does the amount of water reabsorbed increase or decrease?
Increase
Briefly describe the volume and concentration of urine produced if there is little ADH release.
High volume, low concentration
Name two treatments of kidney failure.
Dialysis, kidney transplant
What is ‘dialysis’?
A process where the machine acts as an artificial kidney - it filters the blood and restores normal urea/water/ion levels
Which component of the dialysis machine that we rely on to prevent the loss of useful substances from the blood?
Dialysis fluid
What should be the concentration of glucose and mineral ions of the dialysis fluid be like, in comparison to the blood of a healthy person?
Same as a healthy person’s blood
What is the concentration of urea in the dialysis fluid?
Zero/None
State one disadvantage of dialysis.
Carefully controlled diet/Long periods of time connected to machine (poor quality of life/immobile during dialysis/Inconvenient)
State a problem in kidney transplant.
Rejection/Lack of donor kidney
State a component on a donor kidney that causes rejection problems.
Foreign antigen on donor kidney
Name the component of the patient’s body that may attack the donor kidney.
Antibodies
State a method that reduces the risk of rejection.
Use close relative’s kidney for similar antigens/Immunosuppresant drugs
Name the type of drugs that is prescribed to a patient with a new organ.
Immunosuppresant drugs
State a disadvantage of taking immunosuppresant drugs.
Weakened immune system means harder to defend self against diseases effectively
