GSCE Homeostasis in Humans

COMPLETED

What are disadvantages of kidney transplant?

Immunosuppressant drugs, shortage of organs donors and operation carries risks

What are kidney stones?

Salt and minerals precipitating out causing stones that have to excreted through ureter and urethra

What is kidney failure?

Kidneys are no longer able to filter blood, substances are not reabsorbed and proteins and cells can fit through the tubules and nephrons.

What are advantages of kidney dialysis?

Available to all kidney patients and no need for immunosuppressant drugs

What are disadvantages of kidney dialysis?

Expensive for NHS, regular dialysis sessions and limits on salt and protein intake

What are advantages of kidney transplant?

Patients can lead a more normal life without having to watch what they eat and drink and cheaper for NHS

What are disadvantages of IVF?

Expensive, Not always successful, IVF drugs have health risks, premature babies and ethical problems.

What are advantages of IVF?

Eggs can be stored for long, Free on NHS and Emotional relief

What happens when the eggs have been fertilised?

A few are placed in the uterus of the women.

What happens after the sperm and egg are mixed?

They are checked to have been fertilised and early embryo is developing

What happens to the collected eggs?

They are placed in a Petri dish and mixed with a sample of sperm

What does the use of fertility drugs do?

Increase the amount of mature eggs for collection in IVF

How is LH used to help infertility?

Artificial LSH stimulates the release off an egg

How is FSH used to help infertility?

Artificial FSH can be used to let eggs mature.

What are male reasons for infertility?

Lack of sperm in the semen

What are female reasons for infertility?

Age,Obesity, Damaged oviducts, Lack of important hormones and Eating disorders

What are contraceptive patches?

Patches that release oestrogen and progesterone

What are disadvantages of contraceptive patches?

Last of week.

What are disadvantages of contraceptive injections?

Last for 12 weeks

What are contraceptive injections?

Injections of progesterone.

What are disadvantages of implants?

May prolong periods.

What are advantages of implants?

No pill needed, discrete and no pill needed.

What are disadvantages of IUD/IUS?

Stop periods or worsen them and increased of cancer.

What is an IUD?

Intrauterine device made of copper which is a spermicide

What is an IUS?

Intrauterine device which release progesterone into the uterus.

What is Tubal litigation?

Oviducts are tied to stop egg reaching the uterus

What is a vasectomy?

Sperm ducts are cut to prevent sperm in being in semen

What is abstinence?

No sex (around time of ovulation)

What are disadvantages of the contraceptive pill?

Can cause high blood pressure and cancer

What is homeostasis

maintenance of constant conditions inside the body

what are conditions that need to be controlled in our bodies

water levels

what are types of automatic control responses

nervous and chemical responses

what are nervous responses

electrical impulses using the nervous system

what are chemical responses

using hormones as chemical messengers

why do we have to control our internal temperature?

to avoid slowing enzymes action or denaturing

why do we have to control our water content

can affect the osmotic balance of cells and might affect the state of the cell

why do we have to control our blood glucose concentration

it can affect respiration and brain function if too low and can cause circulatory problems if high

how does information travel in nerves

travel from eye to brain along fast-moving impulses

What are neurons?

nerve cells

what is the central nervous system

brain

what is the release of hormones

secretion

responses to change

ears

What are receptors?

detect stimuli from the environment and send information to the CNS

what are effectors

an organ that does something in response to a stimulus

what are types of effectors

muscles and glands

Parts of a neuron

Dendrites

how is a neurone similar to a normal cell?

nucleus

what is the CNS order

stimulus

what is a motor neurone

carries nerve impulses from the relay neurone to the effector organs

what is sensory neurone

carries nerve impulses from the sense organs to the CNS

what is a receptor

cells which are clustered together in sense organs

what is a stimulus

changes in the environment around you e.g light and sound

What are effectors?

organs which respond to impulses sent by the motor neurone

what are reflexes

automatic responses to stimuli

Why are reflexes important?

avoid danger or harm because they are fast

what part of your body is bypassed during reflex arc

the brain and sensory neurone sends impulses straight to spinal cord

what are types of reflex responses

simple and conditional

what are simple responses

breathing and blinking

what are conditional reflexes

learned responses

What are synpases?

gap between two nerves

what is the order of a reflex arc

stimulus

What is the nervous system?

the body's control system

what is the role of spinal cord in NS

co-ordinates the responses of effectors to changes in the environment

what is the role of neurones in NS

carry electric cal impulses between receptors

what is the role of the brain in NS

co-ordinates the response of effectors

how do synapses arrive

electrical impulse reach the end of the neurone before the synapses and trigger the release of chemicals

how do synapses pass

they diffuse

what components of a reflex arc

stimulus

when is the brain formed

embryo is three weeks and stem cells start to differentiate to produce neurones

what is the cerebral cortex

outer layer of the brain

what does the cerebral cortex control

senses

how does the cerebral cortex function

the right communicates with the left side of the body

What is the cerebellum?

The cerebellum is the part of the brain associated with voluntary responses.

What does the cerebellum control?

Balance and coordination

What is the medulla oblongata?

brain stem

what does the medulla oblongata control

heart rate

What is the mass of medulla oblongata

mass of neurones that make up the medulla oblongata connect the brain to the spinal cord

What is the spinal cord?

carries information between the brain and the rest of the body

what are ways of studying human brains

studying people with brain damage

what is electrically stimulation of the brain

top of skull is removed and different areas are stimulated to see the effect

what are CT scans

shows the shapes of structures in the brain

What are MRIs?

uses magnetic fields and radio waves and signals produced are analyses by computers to produce an image

what are problems with the brain

easily damaged

what are parts of the eye

cornea

what is the cornea

light rays pass through focusing the light rays

what is the iris

Controls how much light enters the pupil

what are lenses

focus light rays onto the back of the eye

what are retina

contains receptors cells for light which allow us to detect light intensity and light colour

what are light receptors

rods and cones

what are rods

cells that detect light (rays)

what are cones

cells that detect colour

what is the optic nerve

Carries electrical impulses from the retina to the brain

what is the sclera

tough out structure protects the eye

what are ciliary muscles/suspensory ligaments

control how light is focused and works with the lens

what are the muscles in the iris

circular and radial

what happens when there is lots of light

contraction of circular muscles cause pupils to constrict and radial muscles to relax

what happens it is dim

contraction of radial muscles cause pupils to dilate and circular muscles to relax

what is accommodation

the process by which the eye's lens changes shape to focus near or far objects on the retina

how does accommodation work

light is refrecated at cornea and lens

what happens to the lens when focusing far

the lens becomes thinner