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36 Cards in this Set
- Front
- Back
- 3rd side (hint)
Homeostasis |
The regulation of the conditions inside the body to maintain a stable environment |
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Negative feedback components |
Receptor (detects stimulus)—> coordination centre (organised a response) —> effector (counteracts change) |
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Central Nervous System |
Coordinates a response to a detected stimulus |
In vertebrates, it’s the spinal chord and brain |
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Sensory Neurone |
Carry info as electrical impulses from receptors to CNS |
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Relay neurone |
The neurone carrying electrical impulses inside the CNS |
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Motor Neurone |
Carry electrical impulses from CNS to effectors |
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Receptors and effectors |
R- cells that detect stimuli E- muscles or glands • respond to a nervous impulse to bring about change |
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Synapse |
Connection between two neurones Nerve signal is transferred by chemicals which diffuse across the gap These chemicals set off a new electrical signal in next neurone |
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Reflex |
Rapid immediate responses that don’t involve the conscious part of the brain |
Reflex Arc- go through spinal chord or unconscious part of brain Quicker than normal responses |
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Cerebral Cortex |
Memory, Language, Intelligence and consciousness |
Outer wrinkly part |
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Medulla |
Unconscious activities - breathing and heartbeat |
Long bit with a bulge? Next to spinal chord |
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Cerebellum |
Muscle coordination |
Looks like a cauliflower, at the back of the brain |
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Methods to Study the Brian |
Study patients with brain damage Electrically stimulating brain MRI scans |
Can have consequences - risks of physical damage or increased problems |
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Sclera, Cornea and Iris & Pupil |
S- tough supporting wall of eye C- transparent layer at front, refracts light into eye I + P- contains muscles, control s diameter of pupil and therefore how much light enters eye |
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Lens & Retina, ciliary muscles & suspenders ligaments and optic nerve |
L & R- lens focuses light onto retina (which contains receptor cells to light intensity & colour) CM & SL- control shape of lens ON- carry impulses from retina receptors to the brain |
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Iris Reflex |
Bright light - circular muscles contract and radial muscles relax - smaller pupil Dim light - radial muscles contract, circular muscles relax - wider pupil |
Adjusting to light |
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Focusing (a reflex) - accommodation is changing shape of lens |
Near objects - ciliary muscles contract, slackens suspending ligaments - fat lens, more refraction of light |
Distant objects- ciliary muscles relax, suspensory ligaments contact - thin lens, less refraction of light |
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Short sighted (myopia) |
Can’t focus on distant objects Light is refracted too much Eye ball too long |
Concave lens to prevent images being brought into focus in front of retina |
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Long sighted (hyperopia) |
Can’t focus on near objects Light isn’t refracted enough Eyeball too short |
Convex lens to prevent images being brought into focus behind retina |
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Treatments for vision defects |
Contact lenses Laser eye surgery Replacement lens surgery |
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Too hot |
Hairs stay flat Sweat glands produce sweat Vasodilation |
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Too cold |
Hairs erect Sweat gland produce no sweat Vasoconstriction Shiver (needs lots of respiration) |
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Endocrine System |
Pituitary Gland -master Thyroid -thyroxine; metabolism, heart rate, temperature Ovaries (oestrogen) and Testes (testosterone) Adrenal gland - adrenaline Pancreas - insulin; blood glucose level |
Hormones are chemical molecules released directly into the blood |
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Blood glucose level too high |
Pancreas produces insulin Glucose moves into liver muscle cells Insulin turns soluble glucose into insoluble glycogen |
Metabolism, exercise and eating affect glucose levels |
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Blood glucose level too low |
Pancreas produces glucagon Glucagon turns glycogen stored in liver into glucose Glucose released into blood by liver |
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Diabetes |
Type 1- pancreas produces little to no insulin • require insulin therapy |
Type 2- resistant to their own insulin • being overweight is a major risk factor • exercise and eat a carb controlled diet |
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Kidneys |
Make urine by taking waste products out of blood Filtration - selective reabsorption |
Water, Ions and Urea (deamination converts amino a into fats and carbs -storable- and ammonia is a waste product that’s converted to urea in the liver) |
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Concentration of Urine control |
Water content = too high - receptors in brain detects it, CNS makes pituitary gland release less ADH so less reabsorption from kidney tubules |
Water content = too low - receptor, CNS, pituitary gland releases more ADH so more water is reabsorbed from kidney tubules |
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Dialysis |
Blood flows between partially permeable membranes surrounded by constantly replaced dialysis fluid (lower conc of bad so diffuse, same conc of good) |
3 times a week, 4 hour sesh, expensive for NHS Donor- transplants are good |
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Hwh |
Hqa |
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Oof |
Hate biology |
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Adrenaline |
Released by adrenal gland Fight or flight - trigger machinists that increase supply of oxygen and glucose to cells in brain and muscles - increases heart rate |
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Thyroxine |
Released by thyroid gland Regulates metabolism Also protein synthesis and many other things Released in response to TSH |
Negative feedback with TSH- Thyroxine = too high- inhibit TSH which reduces the amount of thyroxine released so level falls |
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Auxins |
Stimulate cell elongation in the shoot and inhibits plant growth in the root Uses: killing weeds, rooting powder and in tissues cultures |
More auxin in shaded areas in tip, causes phototropism More auxin in lower side due to gravity, causes geotropism |
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Gibberellins |
Stimulates seed germination, stem growth and flowering |
Uses: controlling dormancy, inducing flowering and growing larger fruit |
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Ethene |
Stimulates fruit ripening - a gas produced by aging parts of plants |
Fruit can be picked unripe, transported whilst supplies with ethene, and then in shops ripe Can also delay ripening with ethene removing chemicals |