Not in GCSE Flashcards
Label the brain
A= cerebral cortex B=medulla C=Optic nerve D=cerebellum
Cereberal cortex function
Controls memory, intelligence, langugae and conciousness
Cerebelum function
Control muscular coordiation
Medulla function
Cotrol unconcious activities
How does the eye focus on far away objects
1) ciliory muscles relax 2)Suspensory ligaments tighten 3)Lens becomes thinner so light rays are refracted weakly
What is myopia
Short sightedness, when lens becomes too curved, light focused in front of the retina so images apper blury far away
Treatment for myopia
glasses with concave lens, which spreads light rays out, so can be focused on retina
what is hyperopia
Long-sightedness, lens is too flat, light focused behind retina so images appear out of focus when close
Treatment for hyperopia
lasses with convex, brings light rays together, so can focused on retina
2 types of contact lenses
hard- rigid material, lastslong and must always be kept sterile soft-flexible material that last for shorter time, but are more comfortable
What is laser eye surgery
Use of lasers to fix visual defects in adults
Laser eye surgery for myopia
lasers reduce tickness of cornea so light refacted less strongly
Laser eye surgery for hyperopia
lasers alter curvature of cornea so light is refracted correctly
Risks of lens replacement
retina damage, infection, cataracts
What is lens replacement
Treats hyperopia, natural lens removed ad artificial, clear, plastic is inserted
Function and structure of retina
light stimulates retina ells, impulses sent to brain, light sensitive layer at back of eye
Function and structure of sclera
Protects internal structures, tough outer layer of eye
Lable the eye
A= suspensory ligaments B= retina C=optic nerve D=sclera E=ciliary muscle F=lens G=pupil H=cornea I=iris
Function and structure of cornea
Lets light into eye and allows light to be focused onto retina cirved transparent layer at front of eye
Function and structure of iris
Controls size of pupil by contracting and relaxing, allows eye to adjust to bright and dim light, muscle
How iris alters pupil in bright light
Circular muscles contract, redial muscles relax, pupils smaller to avoid retinal damage
How iris alters pupil in dim light
Circular muscles relax, radial muscles contract, pupils get larger so more light can enter eye
What is accommodation
Alteration of lens’ shape to focus on near or distant object
How eye focuses on nearby object
Ciliary muscles contact, suspensory lgaments loosen, lens becomes thicker and more curved-light rays refracted strongly
How scientists determine brain function
Study patients with brain damage, electrical stimulation of he brain, MRI scans
Eye receptors stimuli
Ligh/colour change
Main fnctions of structures in the eye (2)
Focusing on near or distant objects-accomidation, adapting to bright and dim light
Function and structure of optic nerve
Carry impulses to the rain so images can be visualised, conects eys to brain
Label the kidney
A= medula B=renal artery C=renal vein D=Ureter E=Cortex F=Renal pelvis
Cortex function kidney
filter large molecules from blood
Renal artery function kidney
Bring blood to kidney
Reanal vein function kidney
Take blood away from kidney
Renal pelvis function kidney
Collects urine
Medulla function kidney
water, salt and urea removed from blood
Ureter function kidney
Takes urine from kidney to blader
What is cancer
Development of tumour as a result of uncontrolled and rapid cell division
Benign tumour
Tumous grow till no space so stays in one space - not cancer
Malignant tumour
Grows and spreads to other healthy tissues by blood to form secondary tumours - cancer
4 risk factors of tumours
- Fauly genetics
- Smoking
- Obesity
- ionising radiation
- Viral infection
<p>Job of platelets</p>
<p>Help clot blood and stop pathogens entering</p>
Job of platelets
Help clot blood and stop pathogens entering
why do you respire when doing exercise
Muscles contract more so ore energy needed
Why breathing rate and volume increase when exercising
To get more oxygen into the blood
why heart rate increases when exercising
To get more oxygenated blood around body faster and remove carbon dioxide faster
Nervous system function
Allows body to react to surroundings and coordinate a response
How does a stimulus lead to a reflex reaction
1)The receptors detect a change in environments 2) receptors pass electrical impulses along sensory neurons to the CNS 3)The CNS coordinates appropate response to relay neurons, which stimulate the motot neurons 4) impulses sent to effectors, which carry out function
Main 3 components of automatic control systems
Receptors, coordination cnter and effectors
what 3 components do all control systems have
Receptors, coordinator and effectors
Receptor function
Detect change in external/internal environment
Coordinator function
Obtain and process info rom receptors
How reflex actions occur via reflex arc
1) Stimulus detected by receptors and electrical ompulses sent along sensory neurone to spinal cord 2)Chemical diffuses across synapse and stimulates new impulse passed to relay neuron 3) same happens at synapse between relay and moto neurone 4) effectos carry out a response
What is a reflex action
Automatic rapid response to external stimulus that requires no concious input
Reflex actions importance
Aid survival and prevent bodily harm
Main male reproductive hormone
testosterone which contols sperm production
Main female reproductive hormone
oestrogen, which is involved in the menstral cycle
What is the mensural cycle
monthly cycle of physiological chnages that occur in females, involving the shedding of the uterus lining and ovulation
Describe the events of the menstural cycle (3)
1) uterus lining thivkens and eggs begin to mature in ovaries 2) An egg is released from one ovary (ovulation) 3) If the egg is fertilised, pregnancy occurs, if not, egg an uterus lining shed during menstration
What is ovulation
Te release of a mature egg from the ovaries, which ccurs approximately every 28 days
4 hormones involved in menstural cycle
oestrogen, progesterone, folicle stimulating hormone (FHS), luteinsing hormone (LH)
Role of FSH in menstral cycle
Secreted by pituitary gland, controls maturation of egs within ovaries and trigers the production of oestrogen in ovaries
Role of oestrogen in menstral cycle
Released because of FSH and causes the uterus lining to regrow, trigers production of LH and restricts the production of more FSH
Role of LH in menstral cycle
Produced by pituitary gland as a result of oestrogen, release trigers ovulation
Role of proesterone in menstral cycle
Secreted by follicle of ovary, sustains uterus lining and inhibites FSH and LH production
What is contraception
Any method that prevents pregnancy
What are 2 types of oral contraception
Comined contraceptive pill that contains oestrogen and progesterone, mini pill that only contains progesterone
How does contraceptive pill prevent pregnancy
Inhibits the production of FSH so eggs don’t mature, the lining of uterus is not developed so eg can’t implant there, cervical mucus is thickened so sperm is impbalised
What is a contraceptive patch
patch that is placed on skin for 7 days at a time containing oestrogen and progesterone
What is the contraceptive implant
Small rod inserted under skin which continuously releases progesterone for 3 years
What is the contraceptive injection
Injectio that lasts 3 months and contains progesterone
What is the IUS
Small plastic device inserted in the uterus, releases progesterone hich thickens cervical mucus and prevents the build up of uterine lining
What is the IUD
small copper-containing device inserted uterus which prevents implantation of embryos
What is a spermicide
A chemicl that kills or imobilises sperm- not very effective
What is a barier method of contraception
Physical separation of sperm and egg
2 barrier methods and what they do
condom: sheath on penis or in vagina that protects agains STI’s aswell Diaohragms: thin cap over cervix that prevents sperm entering
2 ypes of surgical contraception and what
Sterilisation- sperm ducts tied (vasectomy) Oviducts tied
How do fertility drugs help increase chance of pregnancy
Many contain FSH which stimulates oestrogen production and maturation of eggs in the ovary and also contain LH which triggers ovulation
What is IVF
Type of fertility where mother given FSH and LH, egggs fertilised using sperm in lab, once developed into embryo, 1/2 of the embryos are inserted into mothers womb
2 Adantages of IVF
Allows infertile couples to have children, can store womens eggs for later
4 disadvantages of IVF
Expensive, low success rate especialy fro older couple, increases chance of multiple pregnancies- dangerous fro mother and babies, side effects of fertility drugs
How is thyroxine controlled by negative feedback
Levels of blood thyroxine falls, detected by recetors in brain, pituitary gland releases more TSH, stimulating production of thyroxine in thyroid gland, blood thyroxine levels restored
4 effects of adrenaline
Increased heart and breathing rate, stored glycogen converted to glucose, pupils dilate, increased mental awareness, blood diverted way from digestive system to muscles
Circumstances in which malarial parasites reproduce sexually and asexually
Sexual in mosquitoAsexual in the human host
Circumstances in which fungi reproduce sexually and asexually
Asexual by spores Sexual to give variation
Circumstances in which plants reproduce sexually and asexually
Sexual to produce seeds Asexual by runners or bulb divisions
2 pieces of evidence for evolution
Fossils and antibiotic resistance in bacteria
3 ways fossils form
Parts of organisms that have not decayed due to conditions of decay being absent, part of organisms that have been replaced by minerals as they decayed, e.g. bones, traces of organsism covered in sediment and becoming rock
Why are there few traces of early life forms left behind
Mostly soft-bodied so destroyed by geological activities
How do fossil fuels act as evidence for evolution
Scientisits can identify the ages of fossils and use them to show how organisms have chnaged overtime
what do branches in evolutionary trees indicate
where speciation has occurred
What is speciation
When an organsims phenotype has chnaged so much from natural selection that a new species is formed
What is extinction
Where there are no indivifuals of a species alive
5 factors that cause extinction
New disease, predation, competition, changes in the environment, catastrophic event
What are the classes of organisms determined by Carl linnaeus
Kingdom, phylum, class, order, family, genus, species
How are living creatures classified
structure and characteristics
What is the binomilal name system of naming organisms
Genus name followed by species name
why are new classification models proposed
Developments in microscopy allow better examination of internal structures, improvements in understanding of biochemical processes
3 domains
Archaea, eurarya, bacteria
Which organisms belong in domain bacteria
Bacteria
Which kingdoms belong in domain eukarya
Plants, animals, fungi, protists
How are evolutionary trees created
Examining DNA of different species and analysing how similar the sequaences are
how temperature change an be bad for communities
too hot, evaporation increases so water becomes limited, to cold, Growth will be slower a organisms use more energy to stay warm
How changes in water levels affect ecosystems
too little, animals ave to migrate to find water, too much like metling ice caps, habitats are destroyed
Impacts of carbon monoxide in environment
Irreversibly binds to haemoglobi which prevents it from carrying oxygen, too much exposure can cause unconciousness and death
Why brain treatment and investigatio is dangerous (4)
Complex and delicate, easily damaged, certain membranes prevent drugs reaching brain, exact function of each part not all known
