Applied anatomy and physiology

Question 1

Long bones

Answer 1

The humerus and femur are examples of long bones.
Long bones are found in limbs (arms or legs). They are used for movement, shape, blood cell production and mineral storage.

Question 2

Short bones

Answer 2

The carpals and tarsals are examples of short bones.
Short bones are found in the hands and the feet. They are used for shape and small movements.

Question 3

Flat bones

Answer 3

The scapula, sternum and cranium are examples of flat bones.
Flat bones are found near vital (important) organs. They are mainly needed for protection.

Question 4

Irregular bones

Answer 4

The vertebrae are examples of irregular bones.
They are used for small movements and protection.

Question 5

Tendons

Answer 5

Lengths of strong connective tissue are called tendons connect muscle to bone. they are tough an inelastic meaning the can’t stretch when a muscle is contracting and pulling the bone.

Question 6

Ligaments

Answer 6

A ligament is a tough band of connective tissue that connects bones to other bones. ligaments are made up of collagen fibres, which are strong and flexible. ligaments help to stabilise joints and to prevent dislocation.

Question 7

Joint types

Answer 7

A joint is a point where 2 or more bones meet.
Immovable joints are found in the cranium (skull).
Immovable joints provide protection.
Slightly movable joints are found in the vertebrae (back).
Slightly movable joints let us make small movements and also provide some protection.
Synovial joints are the most common type of joint in the body.
Synovial joints let the body move freely.

Question 8

Function of the skeleton

Answer 8

Support - the bones are solid and rigid. They keep us upright and hold the rest of the body - the muscles and organs - in place.
Protection - certain parts of the skeleton enclose and protect the body’s organs from external forces, e.g. the brain is inside the cranium, the ribs protect the heart and lungs.
Movement - the skeleton helps the body move by providing anchor points for the muscles to pull against. The long bones in the arms and legs work as levers to allow certain movements.
Structural shape and points for attachment - the skeleton gives us our general shape such as height and build. Tall people have long leg bones and larger vertebrae. People with a heavy build have larger clavicles and scapula as well as bigger pelvises. The skeleton also provides anchorage points for the muscles to attach, so when they contract we move.
Mineral storage - bone stores several minerals, including calcium and phosphorus, which can be released into the blood when needed.
Blood cell production - the inner marrow of the long bones and ribs produces red and white blood cells. Red blood cells are important in activities because they carry oxygen to the working muscles. White blood cells are important to fight off infections in order to keep healthy.

Question 9

Synovial joint

Answer 9

Synovial joints are the most common type of joint in the human body.
They are characterised by a joint cavity filled with a lubricating synovial fluid which reduces friction.
The fluid is produced by the synovial membrane, which surrounds the joint.
The joint capsule surrounds the membrane, sealing the joint space and providing stability to the joint. It is made from tough fibrous tissue.
Synovial joints are capable of a variety of different movements which depends on the structure within the joint including the joint type and the ligaments.

Question 10

Cartilage

Answer 10

Smooth cartilage (tissue) is a protective layer that covers the end of each bone to stop them from rubbing together.

Question 11

Joint capsule

Answer 11

The joint is surrounded by a joint capsule that is very tough and fibrous.
The joint capsule is lined with a synovial membrane. This produces an oily substance called synovial fluid.
Synovial fluid keeps joints well lubricated (greased to prevent friction) to stop them wearing down and rubbing together.

Question 12

Bursae

Answer 12

Synovial joints are also protected by bursae. Bursae are small bags of synovial fluid (oily substance) that help to reduce friction in a joint.
Bursae act like an airbag in a car. They cushion the joint from any external impacts, stopping the bones from coming together.

Question 13

Hinge joint

Answer 13

Hinge joints are an important type of freely movable joint. Hinge joints have a limited range of movement, involving flexion (bending) and extension (straightening).

Question 14

Ball and socket joint

Answer 14

Ball and socket joints are an important type of freely movable joint. A ball and socket joint looks exactly like a ball fitting into a cup. It can move freely in all directions. This type of joint is located in the shoulder and the hip.

Question 15

Flexion and extension

Answer 15

Flexion - This is a movement where the angle of the joint decreases.
Extension - This is a movement where the angle of the joint increases.

Question 16

Plantar and dorsiflexion

Answer 16

Plantar flexion is the term used for the movement that describes the pointing of the foot towards the ground, as in standing on tiptoes.
Dorsiflexion is the opposite movement, and involves the movement of the foot away from the ground, as in pulling the toes up and walking on one’s heels.

Question 17

Adduction and abduction

Answer 17

Abduction - movement where limbs are moved away from the body.
Adduction - movement where limbs are moved back towards the body.

Question 18

Rotation and circumduction

Answer 18

Rotation - turning a limb along its axis.
Circumduction - the movement of the limb, hand, or fingers in a circular pattern, using the sequential combination of flexion, adduction, extension, and abduction motions.

Question 19

Antagonistic muscle movement

Answer 19

For all movements, the prime mover (or agonist) is the main muscle that causes movement. The antagonist then acts to produce the opposite action to the agonist. they work in antagonistic pairs.

Question 20

Isotonic contractions

Answer 20

When a muscle contracts and changes length. There are 2 types of isotonic contraction:
Eccentric → when a muscle extends.
Concentric → when a muscle shortens.

Question 21

Isometric contractions

Answer 21

When a muscle contracts, but stays the same length.
During isometric contractions, we are always stationary.

Question 22

Location of bones

Answer 22

Cranium, vertebrate, clavicle, scapula, sternum, humerus, ribs, radius, ulna, carpels, femur, patela, fibula, tibia, talus, tarsals.

Question 23

Location of muscles

Answer 23

Rotator cuffs, pectorals, bicep, tricep, deltoids, abdominals, latissimus dorsi, hip flexor, gluteals, quadriceps group, hamstring group, gastrocnemius, tibialis anterior.

Question 24

Adaptations of the lungs for gaseous exchange

Answer 24

There are millions of alveoli (air sacs) in each lung (approximately 150 million in each).
The alveoli have the following adaptations for gaseous exchange:
They are only 1 cell thick, meaning that there’s a short distance for the oxygen to travel.
They are moist.
There is a very good blood supply to the lungs. This means that there are plenty of capillaries (blood vessels) surrounding the alveoli for diffusion to take place.
Because each bronchiole contains a cluster of alveoli, there is a large surface area for diffusion to happen over. This lets the blood absorb more oxygen.
The capillaries are only 1 cell thick and wrap tightly around the alveoli, so the distance for diffusion remains small.

Question 25

Gaseous exchange in the lungs

Answer 25

For diffusion to happen, there must be a difference in the concentration of a gas in the alveoli and in the blood. The gas will diffuse from the area of higher concentration (more particles) to the area of lower concentration (fewer particles).
Oxygen travels from the alveoli into the blood because:
There is a high concentration of oxygen in the alveoli.
There is a low concentration of oxygen in the blood.
Carbon dioxide travels from the blood into the alveoli because:
There is a high concentration of carbon dioxide in the blood.
There is a low concentration of carbon dioxide in the alveoli.

Question 26

Hemoglobin

Answer 26

Red blood cells carry haemoglobin, which transports gases around the body.
Haemoglobin carries carbon dioxide from the body to the alveoli in the lungs.
Oxygen binds with haemoglobin to make oxyhaemoglobin. This is transported through the blood to the tissues around the body.

Question 27

Arteries

Answer 27

Arteries are the largest in external (outer) diameter and have the thickest walls of all blood vessels.
Because they have such thick walls, they have a slightly smaller lumen (internal diameter).
During exercise, the body can vasoconstrict (make the lumen smaller) or vasodilate (make the lumen larger) to distribute blood efficiently.
Arteries are elasticated and thick. This lets them cope with the high pressures at which blood is pumped away from the thick, muscular ventricles of the heart.

Question 28

Veins

Answer 28

Veins have a large internal diameter (lumen) but thin walls as the pressure inside them is low.
Veins have valves to prevent the backflow of blood, which is a possibility due to the lower pressures. This means that they do not have a pulse.
Veins carry blood towards the heart (mostly deoxygenated blood).

Question 29

Capillaries

Answer 29

Arteries branch into much smaller vessels, called capillaries. Capillaries have thin walls and pass very close to the body cells. Capillaries are the smallest blood vessel at around 7-10um (micrometres) in diameter. This means that red blood cells must pass through the capillaries 1 at a time. They are also 1 cell thick which means oxygen can diffuse into the system faster. Their function is gas exchange.

Question 30

The main blood vessels

Answer 30

The pulmonary vein transports oxygenated blood from the lungs to the left atrium.
The aorta (main artery) transports oxygenated blood from the left ventricle to the body.
The veena carva (main vein) transports deoxygenated blood from the body to the right atrium.

Question 31

Atria

Answer 31

The atria are the top 2 chambers of the heart. They fill up with blood received from the veins.
The atria are small because the body only needs them to pump blood into the next chamber of the heart (ventricle).
The right atrium receives deoxygenated blood from the rest of the body through the superior vena cava.
It then pumps blood through to the right ventricle.
The left atrium receives oxygenated blood from the lungs through the pulmonary vein.
It then pumps the blood into the left ventricle.

Question 32

Ventricle

Answer 32

These are the bottom 2 chambers of the heart. They pump blood out through the arteries.
The right ventricle has thinner walls and is less muscular.
This is because less pressure is needed to pump the deoxygenated blood into the lungs via the pulmonary artery.
The left ventricle has a thick, strong wall.
This is because it needs to pump oxygenated blood to the entire body at a high pressure to make sure it gets there.

Question 33

Systole and diastole

Answer 33

Systole is the process of contracting and pumping out blood. Diastole is the process of relaxing and filling up with blood. The heart beats in 2 phases, both of which involve systole and diastole:
Firstly, the atria contract together and pump out blood (atrial systole) into the ventricles.
While this happens, the ventricles relax and fill with blood (ventricular diastole).
Secondly, the ventricles contract to pump blood out of the heart (ventricular systole).
While this happens, the atria relax and fill with blood (atrial diastole).

Question 34

Heart performance

Answer 34

Heart rate (HR) is the number of times the heart beats (usually measured in beats per minute or bpm).
Stroke volume (SV) is the volume of blood that the left ventricle ejects (pumps out) with each beat.
Cardiac output (Q) is the volume of blood that the heart can pump out per minute (usually measured in litres per minute or L/min).

Question 35

Effects of exercise on the heart

Answer 35

Exercise increases the body’s oxygen demands. The following changes happen in the heart to help more oxygen to be distributed throughout the body:
Heart rate increases. This results in an increase in cardiac output because more oxygenated blood is leaving the heart each minute.
An anticipatory rise is where the heart rate increases just before physical activity. This happens because the body releases adrenaline when it expects physical activity.
Stroke volume increases. This causes an increase in cardiac output because more oxygenated blood is being ejected from the left ventricle with each beat.
Cardiac output increases.
This is because any increase in stroke volume or heart rate causes an increase in cardiac output.

Question 36

Inhaling

Answer 36

Inhaling is the process of breathing in air by increasing the volume (amount of space within) of the chest cavity. The following changes happen to help increase the chest cavity volume:
When we inhale, the intercostals (muscles between the ribs) contract. This causes the rib cage to rise up and outwards.
When we inhale, the diaphragm (the dome-shaped muscle at the base of the chest cavity) also contracts and flattens out.
In inspiration, the pectoral (chest) and sternocleidomastoid (neck) muscles contract to expand the lungs to allow more air in (increases chest cavity volume).

Question 37

Exhaling

Answer 37

Exhaling is the process of breathing out by reducing the volume of the chest cavity. Exhalation is passive because the muscles just relax.
When we exhale, the intercostal muscles relax. This causes the rib cage to fall and decreases the volume of the chest cavity.
When we exhale, the diaphragm (the dome-shaped muscle at the base of the chest cavity) relaxes.
In expiration, the abdominal muscles contract to force air out of the chest cavity to speed up expiration, letting us breathe more quickly.

Question 38

Flow of air

Answer 38

Air will always flow from an area of high pressure to an area of low pressure to create an equilibrium (balance).
During inhalation, the volume of the chest cavity is increased, so a low pressure is created inside the chest.
This causes air to rush into and fill the lungs.
During exhalation, the volume of the chest cavity is decreased, so a high pressure is created inside the chest.
This causes air to rush out of the lungs.