Bio paper 2

• Nervous system: Homeostasis is the regulation of internal conditions to maintain optimum conditions in response to changes.
• Stimulus: A change in the environment.
• Receptors: Cells that detect changes in the environment.
• Sensory neurone: Nerve cells taking impulse from the receptor to the brain.
• Motor neurone: Nerve cells taking impulse from the brain to the body’s effectors.
• Coordination centres: Receive and process information from receptors.
• Brain: The cerebral cortex is the outer part of the brain responsible for intelligence, language, memory and consciousness.
• Medulla: Controls unconscious activities such as heart rate and breathing rate.
• Cerebellum: Controls balance, co-ordination of movement and muscular activity.
• MRI: Brain scanning technique.
• Accommodation: The process of changing the shape of the lens to focus on near or distant objects.
• Myopia: Short-sightedness (can’t see far away - focal point short of retina).
• Hyperopia: Long-sightedness (can’t see close up - focal point after the retina).
• Optic nerve: Nerve going to the brain from the eye.
• Sclera: Tough white outer covering of the eye.
• Cornea: Clear section at the front of the eye that does most of the light bending.
• Iris: Pretty coloured muscles around the pupil controlling light levels.
• Pupil: Hole in the iris that can change shape.
• Ciliary muscles: Muscles that change the shape of the lens for focusing.
• Lens: Clear ball that can change shape and focus light on the retina.
• Suspensory ligaments: Connects the lens to the ciliary muscles and can tighten to flatten the lens to focus on far objects.
• Retina: Layer of light sensitive receptors at the back of the eye connected to the optic nerve.
• Laser eye surgery: Using a laser to change the shape of the cornea and correct vision.
• Endocrine system: Consists of glands that release hormones into the blood to get to a target organ to cause a response.
• Pituitary: Master gland that controls many other glands and organs.
• Pancreas: Small tree-shaped gland which produces digestive enzymes as well as the hormones to control blood sugar.
• Thyroid gland: Gland that produces thyroxine for control of the metabolism.
• Adrenal gland: Gland that produces adrenaline for ‘fight or flight’ response.
• Vasodilation is a process where blood vessels supplying blood to the skin open and allow more warm blood to flow near the surface of the skin, increasing heat loss.
• Barrier methods are contraception methods where egg and sperm are physically prevented from meeting, such as using a condom or diaphragm.
• Kidney tubules are long tubes in the kidney where the body quickly reabsorbs any water or nutrients it doesn’t want to end up in the urine.
• Kidney transplant is a process using a donor kidney to replace failing kidneys, as kidneys can be taken from a living donor as you can survive on one.
• Vasoconstriction is a process where blood vessels supplying blood to the skin narrow and allow less warm blood to flow near the surface of the skin, reducing heat loss.
• Gibberellins starts seeds germinating, ends seed dormancy, increases flower size, and increases fruit size.
• Filtrate is the liquid part of the blood that is pushed through the filter in the kidney with the useful solutes and the waste.
• A kidney is an organ that removes the toxin urea from the blood and keeps the water levels in the blood constant to avoid issues with osmosis.
• In vitro fertilisation (IVF) is a method where egg cells are fertilised outside of the body with sperm cells then implanted into the woman to grow the baby.
• Ethene promotes ripening of fruit, controls cell division, and is used in tissue culturing.
• Kidney dialysis is a process using a machine to replace the cleaning and water balancing functions of failing kidneys.
• Hormonal methods are contraception methods where hormones are used to interrupt the menstrual cycle and prevent egg release, such as the pill or implants.