Further biology Flashcards
What are the functions of the skeleton?
Support; protection; blood production; movement
How does the skeleton keep us upright?
The bones are held together with joints and muscles.
How does the skeleton protect us?
The rigid bones can protect our soft tissues, eg the skull protects our brain.
How does the skeleton make blood?
The bone marrow inside the larger bones make blood.
How does the skeleton enable us to move?
The long bones can act as levers.
What makes our bones move?
We rely on muscles
How does a muscle make a bone move?
It contracts and pulls on the bone.
How can you move a bone back to the original position?
A second muscle has to pull is back into the original position.
How do muscles contract?
Proteins in their cells react together,
What happens to the muscle when it contracts?
It becomes shorter.
What has more force, a large muscle or a small muscle?
A large muscle.
What happens when an athlete trains?
The muscles can be increased in size, and therefore strength.
What do you call the two muscles involved in the movement of one bone?
An antagonistic pair.
What does antagonist mean?
Something that actively fights against or opposes something.
What happens when one muscle of the antagonistic pair contracts?
The other has to relax.
How much can muscles contract?
About 10% of their length
How is the movement of muscles magnified?
By using the bones as levers.
What can’t muscles do?
Push, muscles can only PULL
What is a joint?
The connection between two bones
What are most of our joints called?
Synovial joints
Give some examples of synovial joints
Shoulders, hips, elbows
What do synovial joints permit?
Relatively free movement.
What lines the inside of a synovial joint?
The synovial membrane.
What does the synovial membrane produce?
Synovial fluid.
What is between the two bones, acting like a cushion?
Articular cartilage
What stops the ends of the bones being worn away in the joint?
Articular cartilage
What does to articulate mean?
To introduce a joint (or to speak fluently)
What joins bone to bone?
Ligaments
What joins muscle to bone?
Tendons.
What are tendons like?
They are transmitting the pull of a muscle, so they are not stretchy.
What are ligaments like?
They need to allow the movement of the bones, so they are stretchy,
What could happen without ligaments?
The bones could come away from the joint
What can ligaments do when you jump?
They absorb some of the energy of the impact.
What sort of joint is the knee, or a finger?
A hinge joint.
What sort of movement does a hinge joint permit?
Movement in one plane, like a door hinge.
What sort of joint is the shoulder, or the hip?
Ball and socket joints
What sort of movement do ball and socket joints permit?
A wider range than hinge joints.
How can you assess the risk and the benefits of a sport?
The risks are what could happen, and how likely it is; the benefits are the know benefits to health of taking exercise.
Name some risks and benefits associated with the trampoline?
Risks - broken neck, broken leg, waffle face, sprains, cuts, bruises. Broken neck - unlikely, I have only heard of 2. Waffle face - almost inevitable. Health benefits - lower blood pressure, stronger heart, stronger bones etc
What can happen if you have problems with joints and still do sports?
You could injure the joint.
How severe are sports injuries?
They vary
Which sports are more likely to cause injury?
Contact sports (like rugby)
How can you get an idea of how healthy your weight is?
BMI
What BMI counts as seriously underweight?
17.5 or under
What BMI is underweight?
17.5 - 19
What BMI is ideal?
19 - 25
What BMI is overweight?
25 - 30
What BMI is obese?
30 +
Why is BMI by itself not enough to tell whether someone has a healthy weight?
Proportion of muscle and fat could be different in an individual. Sports people often have a BMI in the overweight range as they have so much muscle.
What do you need to do if your BMI, and your body fat percentage, are too high?
Lose weight.
How can you lose weight?
An exercise programme is one way.
What should you consider before starting an exercise programme?
Symptoms; medication; alcohol and tobacco consumption; current level of physical activity; family medical history; previous treatments.
If you consider all possible factors before starting an exercise programme, it would enable the exercise programme to be?
Effective.
If there are factors that could have an affect, what should you do?
Address them before starting to exercise.
Why should an exercise programme be started slowly?
To prevent excessive strain on heart, joints, muscles.
How could we see whether the exercise programme is working?
Take measurements of weight.
What does the accuracy of data depend on?
The accuracy of the monitoring technique.
What would you need in order to see whether there has been progress?
Multiple readings, as the individual reading will fluctuate.
How could you reduce the fluctuations if you wanted to show the data?
Present the data as averages.
How does exercise affect the heart and the blood pressure (at the time of the exercise)
An increase in heart rate, and an increase in blood pressure
What does the increased pulse rate, and the increased blood pressure, do?
More blood is supplied to muscles.
What is the blood going to the muscles needed for?
It delivers oxygen and glucose for respiration, and removes waste product such as carbon dioxide.
What does respiration do?
Converts glucose and oxygen to carbon dioxide and water, and gives out energy that the cells use.
What can muscle cells do with the energy?
Contract
What can happen if the heart rate is too high during exercise?
Muscles become strained, and blood pressure can increase.
What can happen if blood pressure goes too high?
Delicate blood vessels, eg in the eye or heart, can burst.
What is the safe heart rate for exercise?
About 70-90% of the maximum rate your heart can actually achieve.
What is the formula for the maximum safe heart rate?
220 - your age in years.
What is the time for the heart to return to normal after exercise called?
Recovery period.
When do injuries take place?
If you exercise more than your body can physically take
What happens when ligaments overstretch?
You get a sprain, and the joint can be more wobbly.
Torn ligaments or tendons are…
when ligaments or tendons become disconnected
What is a dislocation?
When a bone comes out of the socket
How do you treat a sprain?
Protect; Rest; Ice; Compression; Elevation
What must you do before treating a sprain?
Make sure that it is a sprain, and not something more serious.
What does a physiotherapist do?
Helps the injured person strengthen any damaged joints by providing a suitable exercise programme
How many chambers in the human heart?
Four
What does the heart do?
Collect deoxygenated blood at low pressure from the body; pump deoxygenated blood to the lungs; collect oxygenated blood at low pressure from the lungs; pump oxygenated blood at high pressure to the body
Humans have a …….. circulation system?
Double
What is meant by a double circulation system?
Blood is pumped twice for each entire trip around the body
Where does deoxygenated blood enter the heart?
On the right hand side. (So on the left as you look at a picture)
What vessel takes deoxygenated blood to the heart?
Vena cava
What is the route taken through the heart by deoxygenated blood?
Right atrium, right ventricle
What vessel take deoxygenated blood from the heart?
Pulmonary artery
Where does the pulmonary artery lead from the heart?
The lungs
What vessel leads back to the heart from the lungs?
Pulmonary vein
What route does oxygenated blood take through the heart?
Left atrium, left ventricle
What vessel takes the oxygenated blood to the body?
The aorta (at high pressure)
What does the blood do in the lungs that enables gas transfer?
Slows down.
What gas transfer takes place in the lungs?
Carbon dioxide leaves the blood and oxygen enters the blood.
By what process does the gas transfer take place?
Diffusion
What system is the heart part of?
Circulatory system
What forms the circulatory system?
heart; arteries; veins; capillaries
What is an artery wall like?
Thick, with layers of muscle and elastic fibres.
What is a capillary wall like?
Thin, a single cell
What is a vein wall like?
Thin, no muscles.
What is the direction of blood flow in an artery?
Away from the heart.
What is the direction of blood flow in capillaries?
Through tissues
What is the direction of blood flow in veins?
Back to the heart
What is the blood like in an artery?
Oxygenated - except pulmonary
What is the blood like in a vein?
Deoxygenated - except pulmonary
What is the blood like in capillaries?
Oxygenated at the start, deoxygenated by the end
Which blood vessels contain valves?
Veins; aorta; pulmonary artery
What do valves in the heart and veins prevent?
Backflow of blood.
How can the closing of the heart valve be detected?
There is an audible noise, which can be detected using a microphone.
What can a faulty heart valve cause?
The blood may not reach the lungs in sufficient quantities to pick up enough oxygen to enable the person to keep the body going.
What do valves in the vein do?
Stop gravity from allowing the blood to pool at the lower end of the body.
What are varicose veins?
When a valve in the leg veins fails and blood pools at the next valve down.
What is blood made of?
Red blood cells; white blood cells; platelets; plasma
What do red blood cells contain?
Haemoglobin, to bind with oxygen.
What is very unusual about red blood cells?
They have no nucleus, giving maximum space for haemoglobin
Why can’t red blood cells be used for DNA tests?
They have no nucleus, so no DNA
What is the function of red blood cells?
To carry oxygen around the blood.
Why does the body need oxygen?
For respiration
What is the shape of a red blood cell?
Smooth, to allow them to slide along narrow capillaries.
Are all white blood cells alike?
No
What do white blood cells do?
Some recognise invading organisms and swallow them, others produce antibodies.
What do platelets do?
Help blood to form a clot at the site of an injury.
What is plasma?
The liquid part of blood, containing nutrients, antibodies, proteins, waste, salt.
What is 90% of plasma?
Water
What is 10% of plasma?
Glucose; proteins; salts; hormones; waste substances.
What is the glucose in the plasma for?
To provide energy in body cells through respiration.
What are the proteins in the plasma?
Some are antibodies that help protect the body.
Why is there salt in the plasma?
To keep the osmotic pressure of the blood equal to the body cells - otherwise cells will expand or shrink due to water crossing the semi-permeable membrane.
What are the hormones in the plasma for?
To help control a range of functions in the body, eg growth
What wastes are found in the plasma?
Carbon dioxide, on the way to the lungs;urea, going to the kidney.
How do platelets react to an injury?
They start a series of reactions that ends up producing a protein called fibrin, which helps to produce the clot.
What happens to plasma in the capillaries?
Some leaks out.
What is the name for the spaces between the capillaries and the cells?
The capillary bed.
How does dissolved oxygen, and glucose, move into the cells?
By diffusion.
What can white cells also do through the walls of capillaries?
Escape into the tissues.
What happens to most of the fluid?
It passes into tubes called lymph vessels.
What red chemical is found in red blood cells?
haemoglobin
What metal is part of the haemoglobin molecule?
Iron (Fe)
What is the job of haemoglobin?
To carry oxygen
What compound is formed with haemoglobin and oxygen?
Oxyhaemoglobin
How does the oxygen get into the blood?
It diffuses.
What happens when the red blood cell containing oxyhaemoglobin passes through an area of low oxygen?
The oxygen detaches from the haemoglobin and diffuses into the cells.
What happens to the carbon dioxide in the tissues?
It passes into the plasma by diffusion
What other waste enters the blood plasma?
Urea
How is the carbon dioxide removed from the blood?
It diffuses out of the blood plasma in the lungs, and can be breathed out.
What else does blood transport, other than gases?
eg white blood cells, glucose, hormones, salt, urea, red blood cells, platelets
Why do some white blood cells travel in the blood?
To protect against infection.
What can some white blood cells do to remove micro-organisms?
Engulf them
What do some white blood cells release to “mark” micro-organisms as foreign for other cells to destroy?
Antibodies.
Why is glucose transported in the blood plasma?
It is needed for respiration
How are waste products transported around the body?
In the blood plasma
Where is urea made?
In the liver
What is urea made from?
Waste amino acids
What removes urea from the blood?
The kidneys
Where do the kidneys move the urea to?
Into the urine.
What are hormones?
Chemical messengers, chemicals that affect the functions of cells in the body.
What is insulin?
A hormone that controls blood sugar
Where is insulin made?
In the pancreas
How is insulin transported?
In the blood plasma.
What does insulin do?
It influences the take up of blood glucose by the bodies cells.
What is adrenaline?
A hormone that prepares the body for vigorous exercise, the “fight or flight” hormone.
Where is adrenaline made?
By the adrenal glands, which are near the kidneys
What is special about red blood cells as compared to all other body cells?
They don’t have a nucleus.
Why does the red blood cell not have a nucleus?
It gives extra space for haemoglobin.
What shape are red blood cells?
Biconcave - both sides are dish shaped.
Why do red blood cells have such an odd shape?
It gives extra surface area without having any parts that could catch in the capillaries. The large surface area gives the best chance for oxygen take up.
What does the disorder sickle cell anemia lead to?
Sickle shaped (new moon shaped) red blood cells. One sickle gene gives and advantage against malaria, two gives disadvantage as sickle blood cells are more likely to clump together and block blood vessels.
What is normal human body temperature?
Around 36.9C
What does an increase in temperature cause?
Body reaction could go faster - or stop, as enzymes are denatured. This could cause death
Why would it be hard to keep cool if you are working hard in hot temperatures?
Muscles produce heat when they do work.
How do we cool down?
Blood is diverted to the skin surface, to enable heat to be lost; sweat is produced which cools the body as it evaporates.
What is the disadvantage of sweating?
The body loses water and salts (and urea, which is not a problem)
What would happen if you don’t replace water and salts lost by sweating?
You would become dehydrated.
What happens to sweating as you become dehydrated?
The body stops sweating as it tries to conserve water.
What is the implication of the body not sweating due to dehydration?
The body cannot cool itself.