B5 : The Living Body
Qu / Skeletons / Ans / Skeletons1 / What is the insect exoskeleton made of? / 1 / Chitin
2 / Give 2 examples of animals with no skeleton / 2 / Jellyfish, worms
3 / Name the two types of living tissue found in the human skeleton. / 3 / bone and cartilage
4 / What are the advantages and disadvantages of a skeleton made of cartilage? / 4 / Advantages: light and flexible
Disadvantage: not rigid enough to support an animal’s weight on land
Why do some patients with serious bone fractures need a blood transfusion? / Bones are living tissue and have a blood supply, fractures can cause internal bleeding and sometimes this means that a person needs to have that blood replaced.
H5 / Which two minerals replace cartilage during ossification? / H5 / calcium and phosphorus
H6 / How can scientists determine the age of the person if they only have a skeleton to investigate? / H6 / The proportion of bone to cartilage can be used as a measure of growth. It is possible to produce a graph of the proportion bone to cartilage for different ages. You can then estimate the amount of cartilage in skeleton under investigation and estimate the age of the skeleton.
H7 / Why are elderly people more likely to fracture bones when they fall? / H7 / Elderly people are likely to suffer from osteoporosis which means that their bones are brittle and much easier to break.
8 / What type of joint is the elbow? / 8 / A hinge joint
9 / What is the role of the synovial fluid? / 9 / It lubricates and cushions the synovial joint, which reduces friction between the two bones that make the joint
10 / Which muscle contracts to raise the arm? / 10 / Biceps
11 / Where are ball and socket joints found in the human body? / 11 / shoulder and hip
Explain the difference between a tendon and a ligament / A tendon attaches the muscle to bone whereas a ligament holds two bones together
H12 / Many of the joints in the human body act as levers, in the arm, what is the fulcrum? / H12 / elbow joint
H13 / Give 2 disadvantages of replacement joints / H13 / · requires major surgery
· they cannot repair themselves if they are damaged
· can weaken the surrounding bones
Qu / Circulatory systems and the cardiac system / A
ns / Circulatory systems and the cardiac system
1 / Why do single celled organisms not need a circulatory system? / 1 / They are in contact with the environment directly and they can rely on diffusion to supply oxygen and nutrients.
2 / What is meant by an open circulatory system? / 2 / A body with no blood vessels, the blood fills up the body system. Special tubes deliver air directly to the respiring cells.
3 / What is meant by a closed circulatory system? / A body with blood vessels and a heart to pump blood around these blood vessels
4 / Name the blood vessels which deliver oxygen and glucose to the heart muscles / coronary arteries
H5 / Describe the heart structure of an animal with a single circulatory system? / H4 / The heart has just two chambers: one atrium and one ventricle.
H6 / What is the advantage of a double circulatory system? / 4 / Blood is under high pressure which moves materials around the body quickly.
H5 / Harvey was a British doctor who investigated the circulatory system, what did he discover about arteries and veins? / He discovered that arteries carry blood under high pressure away from the heart and that veins have valves to prevent back flow
6 / Name the blood vessel which delivers deoxygenated blood from the body / vena cava
7 / Which heart chamber accepts blood from the pulmonary vein? / right atrium
8 / Which side of the heart has a thicker muscle wall? / the left side
9 / Where are the semi-lunar valves found? / 9 / They separate the ventricles from the blood vessels which carry blood away from the heart (the pulmonary artery and the aorta)
10 / Summarise the cardiac cycle / 10 / The heart relaxes and blood fills the atria.
Both atria contract and blood enters the ventricles.
Ventricles contact from the bottom up, pushing blood upwards towards the arteries
Which method is used by doctors to investigate the electrical impulses in the cardiac cycle? / An ECG
Which method is used by doctors to investigate the structure of the heart? / An echocardiogram
Which hormone increases heart rate? / adrenaline
H11 / What is the pacemaker (SAN) and where is it found? / H11 / The pacemaker is a group of specialised cells found in the right atrium. It produces a small electrical charge impulse which spreads across the atrium causing it to contract and stimulate the AVN
H12 / What is the role of the AVN? / H12 / The AVN (atrio-ventricle node) causes the ventricles to contract
Qn / RUNNING REPAIRS / Ans / RUNNING REPAIRS
1 / Why do heart values sometimes need replacing? / 1 / The values become damaged and this allows blood to flow backwards and reduces blood pressure
2 / What is bypass surgery? / 2 / When the coronary arteries get blocked by cholesterol plaques, the amount of oxygen delivered to the heart muscles is reduced and this can cause cell death and a heart attack. Blood vessels from the leg can be used to replace the blocked coronary artery and restore blood flow to the heart muscle.
H13 / What is a hole in the heart? / H13 / All human foetuses, while in the uterus have a hole in the heart, between the atria. This is because the placenta delivers oxygenated blood and the hole in the heart by-passes the lungs. The hole usually closes after birth. If it does not close less oxygen is carried in the blood because oxygenated and deoxygenated blood mix.
What is the first step in the cascade reaction which results in a blood clot? / Platelets must be exposed to air
H14 / Which protein are blood clots made from / H14 / Fibrin
H15 / Which vitamin is essential for blood clotting? / H15 / Vitamin K
H16 / What is meant by the term anticoagulant and give the name of one anticoagulant drug / H16 / A drug which interferes with the clotting process. Heparin or warfarin or aspirin are all anticoagulants
Which genetic disease limits blood clotting? / Haemophilia
Name two factors that must be matched before blood can be given in a transfusion? / ABO blood group and the Rhesus factor
H17 / Which blood group is the Universal Donor? / H17 / Group 0
H18 / Which blood group is the Universal recipient? / H18 / Group AB
H19 / Which agglutinins (antigen) do the red blood cells of someone with Group AB blood? / H19 / Both A and B agglutinins
Which antibodies are found in the blood plasma of the blood of someone with group A blood? / Anti-B antibodies
Qns / RESPIRATORY SYSTEMS / ANS / RESPIRATORY SYSTEM
Define gas exchange / Process where oxygen enters an organism
and carbon dioxide is released
Name the gas exchange organ in amoeba / The cell membrane
Name the gas exchange organ in fish / Gills
Describe the movement of oxygen into the blood via the respiratory system / Air enters the mouth and down the trachea into the bronchi. The bronchi split into left and right side of the body. The air enters the bronchioles and then into the alveoli. Here oxygen diffuses into the blood capillaries which surround the alveoli and oxygen enters the blood supply.
What is ventilation? / Breathing
What is the difference between ventilation and respiration? / Ventilation is the process where air moves into and out of the lungs, whereas respiration is the process that occurs inside the cells and releases energy for cells to use.
Describe how inhalation occurs / The intercostal muscles contract causing the ribcage to move upwards and outwards. The diaphragm also contracts. Both of these processes increase the volume of the chest cavity. As the pressure inside the lungs is now below air pressure, air moves into the lungs
What is the vital capacity? / It is the maximum volume of air that can be used in gas exchange in the lungs
What is the residual air? / The volume of air that stays in the lungs at the end of the maximum breathe out.
By which process does oxygen enter the blood supply and carbon dioxide leave the blood supply? / diffusion
How are the alveoli adapted for gas exchange? / large surface area
moist, thin permeable surface
good blood supply
Why are alveoli easily damaged by dust and microorganisms? / Alveoli are ‘dead ends’ dust and bacteria can collect; there are no cilia to waft trapped bacteria from the alveoli. The alveoli are thin, so are easily damaged.
How do the trachea and bronchi protect the body from pathogens? / The goblet cells produce mucus which traps pathogens and dust. Ciliated cells waft and move the mucus up to the back of the throat, where it swallowed and the acid in the stomach is kills the microorganisms.
What is pneumonia? / A disease which is usually caused by a virus or bacteria; it causes inflammation where fluid builds up.
Explain what happens during an asthma attack? / Asthmatic airways are sensitive and can become swollen or inflamed.
Bronchioles narrow (constrict) and the muscles tighten and there is an increase in mucus produced. It makes it difficult to breathe and causes wheezing, coughing and chest tightness.
Qn / DIGESTION / An / DIGESTION
What is physical digestion and why is it important? / Chewing and squeezing of food in the stomach. Breaks down the food into smaller pieces so that it can pass through the digestive system easily. It increases the surface area which increases the rate of chemical digestion (enzymes)
How is food moved along the gut? / By peristalsis, the circular muscles in the gut wall squeeze the food along.
Where does chemical digestion take place? / In the mouth, the stomach and small intestine
Describe the breakdown of carbohydrates. / It begins in the mouth where starch is broken down to glucose. The pancreas produces carbohydrases which are released into the small intestine and carbohydrates are broken down into small soluble sugars
Which enzymes break down proteins? / Proteases
What are the breakdown products and lipids and the general name for enzymes which catalyse this reaction? / Lipids are broken down into glycerol and fatty acids. Lipases are the enzymes which speed up this reaction
How is the small intestine adapted for efficient absorption of food? / · Very long
· Large surface area because of the microvilli
· Thin lining that reduces diffusion distance for dissolved food molecules
· Good blood supply
Describe the breakdown of starch include the name of the enzymes involved / Starch is digested in a 2 step process
First amylase breaks down starch to maltose
Then maltase breaks down maltose to glucose
Amylase and maltase are the enzymes
Why is bile needed for the digestion of fat? / Fat is hard to digest because it does not mix well with water. Bile is an emulsifier which allows lipases to work.
Where is bile produced, stored and released? / Bile is made in the liver, it is stored in the gall bladder and it is released into the small intestine.
Why are the enzymes secreted in the mouth, denatured in the stomach? / The stomach secretes hydrochloric acid, which means the stomach has a pH around 2. This low pH denatures most enzymes including those produced in the mouth. (The proteases produced in the stomach have a low pH optimum)
QNS / WASTE DISPOSAL / ANS / WASTE DISPOSAL
What is the name of the process which produces faeces? / egestion
Name the 3 excretory products of the human body / urea, sweat and carbon dioxide
Where and how is urea produced? / Urea is produced in the liver by the breakdown of excess amino acids
State the function of the kidneys / To excrete urea, water and salt
Name the blood vessel which delivers blood to the kidney / renal artery
Which vessel carries urine from the kidney to the bladder? / ureter
Which useful chemicals are reabsorbed in the kidney? / glucose, water and amino acids
What influences the amount of urine someone produces? / temperature, amount of water drunk, amount of sweating
On a hot day, after exercising –how would you describe the urine a person produces / They would produce a low volume of concentrated urine
What happens when carbon dioxide levels are high in the blood? / Carbon dioxide levels are detected by the brain and breathing rate is increased, to increase gas exchange and removed from the blood
What is ultrafiltration? / It happens in the kidney tubules (nephrons) and small molecules such as glucose, water and urea move into the glomerulus and capsule because the blood in from the renal artery is under pressure. The large red blood cells stay in the blood and do not move into the glomerulus.
Why is selective reabsorption important? / Small useful molecules such as glucose and amino acids pass into the nephron and would be excreted in the urine. Both glucose and amino acids are reabsorbed into the blood leaving some water and urea in the kidney tubule, to be excreted.
What is ADH and where is it produced and where does it act? / ADH is antidiuretic hormone. It is produced by the pituitary gland in the brain; it acts on the collecting duct. It increases the permeability of the collecting duct, so more water is reabsorbed into the blood, so less volume of urine is produced. This means that the urine is more concentrated.
If a person’s kidneys fail what are the treatment options. / Initially dialysis is used to remove urea from the patients’ blood. The patient may be offered a kidney transplant if a suitable kidney is available.
What is the principal of dialysis? / It removes urea from the blood and maintains sodium and glucose levels in the blood, of someone with kidney failure