+ Biology Revision B5 The Living Body. + 5a In good shape Skeletons No skeleton – e.g. worms...
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Transcript of + Biology Revision B5 The Living Body. + 5a In good shape Skeletons No skeleton – e.g. worms...
+5a In good shape Skeletons
No skeleton – e.g. worms
Exoskeleton – e.g. insect made of chitin
Endoskeleton – e.g. shark made of cartilage; human bone with some cartilage
Advantages of endoskeleton:
1. Framework of body
2. Can grow with body
3. Easy to attach muscles
4. Flexibility
Human skeleton starts as cartilage by is ossified by the addition of calcium & phosphorus. Amount of cartilage present determines growth stage
+5a In good shape Long bone structure:
Head covering of cartilage
Shaft, bone marrow with blood vessels
Cartilage & bone are living tissue
Bones are strong but easily broken
Types of fractures:
Simple
Compound
Green stick
+5a In good shape Joints
Where 2 or more bones meet
Joined by ligaments
Bones moved by muscles, attached by tendons
Synovial joints e.g. ball & socket, hinge
Advantages & disadvantages of joint replacement?
+5a In good shape The arm
Biceps & triceps are antagonistic muscles
Arm is like a lever:
Biceps contract, triceps relax -> arm raises
+5b The vital pump Circulatory Systems
None – e.g. amoeba
Open – e.g. insects
Closed – single e.g. fish , 2 chambered heart
Double e.g. mammals, 4 chambered heart
Historical contributions about circulatory system:
Galen – 200AD – believed blood flowed between heart & liver
Harvey – 1628 – discovered blood vessels, valves & high pressure blood flows away from heart in arteries
+5c Running repairs Heart Conditions/Diseases
Lifestyle risk factors– diet, alcohol smoking, stress, drugs
Condition Effect Treatment
Irregular heart beat Pacemaker
Hole in heart Surgery
Damaged or weak valves
Replacement with artificial valves
Blocked coronary artery
Bypass surgery
Heart attack Transplant – disadvantages?
+5c Running repairs Blood components
Blood groups: A, B, AB, O
Rhesus positive & negative
Agglutinins – markers on the surface
of red blood cells which make them Clump
if they contact the corresponding antigen:
Blood group Agglutinin on surface
Antibodies in blood
Can accept blood from
A A Anti-B A or O
B B Anti-A B or O
AB A & B None Any
O None Anti-A & Anti-B O
+5c Running repairs
Blood donation – cards for everyone? Religious objections?
Blood Clotting occurs:
1. When blood vessels are damaged
2. When blood comes into contact with air
3. To prevent too much blood being lost
4. To prevent pathogens entering through wounds
Vitamins K & C are needed for healthy blood clotting Alcohol & cranberries slow it down Anti-coagulant drugs e.g. warfarin, heparin & aspirin
reduce it Haemophilia is an inherited disease where a faulty protein
stops blood clotting
+5d Breath of life Gas Exchange
Simple organisms e.g. amoeba through skin
Complex organisms through specialist organs
Fish gills Respiratory System
+5d Breath of life Breathing
Volume of chest cavity increases, pressure in lungs falls
Volume in chest cavity decreases, pressure in lungs rises
+5d Breath of life Measuring Breathing
Tidal air/volume – volume of air in a normal breath
Vital capacity – maximum volume breathed in & out
Residual air/volume – air
that remains in lungs
Respiratory Diseases
Industrial e.g. asbestosis
Genetic e.g. cystic fibrosis
Lifestyle e.g. lung cancer
Pathogenic e.g. pneumonia
Asthma – irritated bronchioles narrow, muscles tighten, more mucus produced
+5e Waste Disposal Excretion – getting rid of waste e.g. CO2, urea, sweat
Defecation – getting rid of solid waste through the anus
Excretory organs: lungs, kidneys, liver, skin
Skin structure:
Excess water & salt are
excreted as sweat, which
evaporates
+5e Waste Disposal Kidneys
Ultrafiltration – at bowman’s capsule – small molecules squeezed out under pressure
Selective reabsorption – in tubules & loop of Henle – useful substances reabsorbed into blood
+5e Waste Disposal ADH – controls reabsorption of water in kidneys
Made in pituitary gland
Negative feedback:
Water content low -> ADH released -> nephron tubules more permeable -> normal water level
Dialysis Machine
Waste diffuses from blood into
dialysis fluid
Sodium & glucose in blood
replaced
+5f Life goes on
Menstrual Cycle
Day 1-5 – menstruation
Day 14 – ovulation
Hormone Where Made
Effect
FSH Pituitary
Stimulates egg to ripen & oestrogen release
Oestrogen Ovary Uterus lining thickens, LH released
LH Pituitary
Ovulation
Progesterone
Ovary/corpus luteum
Preserve uterus lining
+5f Life goes on Infertility
Fertility drugs – FSH injected to stimulate egg release
Artificial insemination
Egg donation – problem? Only has genes from one parent
Ovary transplant
Surrogacy – problem? Emotional attachment
IVF – problem? low success rate, twins/triplets more likely
Foetal Screening – for health of baby
Ultrasound
Anmiocentesis – tests cells from amniotic fluid using hypodermic needle, Ethical issues? Can cause miscarriage (1 in 200), termination?
+5g New for old Organ Donation
Biological replacement e.g. blood, cornea, heart, lungs, kidney & bone marrow
Organs must be: healthy, right size & age, tissue matched
Can be from living donors e.g. kidneys or dead donors if they cannot regain consciousness & breath unaided
Mechanical replacement e.g. Kidney, knee & hip joint, heart, eye lens Problems with
mechanicalProblems with Biological
Size Shortage of donors
Power supply Tissue match/ immunosuppresants
Material used (non wearing)
Rejection
Body reactions e.g. allergic
+5h Size matters Growth – animals grow in the early stages of life,
plants grow continually in areas called meristems e.g. shoot tips
New cells for growth made by mitosis
Human growth stages:
1. Infancy (up to 2)
2. Childhood (2 -11)
3. Puberty (11-15)
4. Adulthood (15 – 65)
5. Old age (over 65)
Problems of living longer?
Growth is measured as gain in height & mass
Determined by:GenesDietExerciseHormonesHealth/disease
Human growth hormone – made in pituitary gland – releases energy for growth from fat stores, stimulates growth of long bones