B3 Form and Function : Organisms Flashcards
gas exchange, transport, muscle mobility
double circulatory system
To go around the body once, blood has to pass through the heart twice.
antagonistic muscles
Opposing pairs of muscles that work in opposite directions or have opposing effects.
thoracic cavity
The volume or space within your chest.
total lung capacity
The total volume of air in your lungs after inhaling the maximum possible volume of air.
forced vital capacity
The volume of air you can exhale with maxiumum effort after inhaling the maximum possible volume of air.
residual volume
The volume of air remaining in the lungs that cannot be exhaled even after maximum expiration.
tidal volume
The volume of air that moves into and out of your lungs with every normal breath.
inspiratory reserve
The extra volume of air that can be inhaled with maximum effort beyond the volume of air inhaled in a normal inspiration.
expiratory reserve
The extra volume of air that can be exhaled with maximum effort beyond the volume of air exhaled after a normal exhalation.
transpiration
Transpiration is the loss of water vapour from plant leaves. Water vapour is lost by evaporation at the surface of the mesophyll cells; this water vapour then diffuses through the stomata and out of the plant.
allosteric
A site other than the main binding site.
multinucleate
A cell containing more than one nucleus.
myofibrils
Thread-like structures found in muscle fibres composed of repeating sarcomeres.
myosin
A fibrous contractile protein, forms the thick protein filaments in a sarcomere.
actin
A fibrous contractile protein, forms the thin protein filaments in a sarcomere.
Z discs
A region that organises and anchors the actin, as well as defining the boundaries of a sarcomere.
M line
A region in the centre of a sarcomere that organises and anchors the myosin.
I bands
The region on a sarcomere where only actin is present.
A band
The region on a sarcomere where myosin is present.
H band
The region in the middle of the sarcomere containing only myosin.
Tropomyosin
A protein subunit that runs alongside actin, blocking the myosin binding sites when the sarcomere is relaxed.
troponin
A protein subunit that, when calcium binds to it, undergoes a conformational change, moving tropomyosin away from the myosin binding sites on actin.
sarcoplasm reticulum
A specialised endoplasmic reticulum that surrounds a myofibril and contains and releases calcium ions.
cross-bridge
A structure formed when a myosin head binds to a myosin binding site on actin.
power stroke
A movement of the myosin head that pulls the actin filament towards the centre of the sarcomere.
titin
skeletal muscle unit
A muscle fibre and the motor neuron that innervates it.
ligaments
Strong, flexible bands of connective tissue that connect bones to bones.
tendons
Fibrous structures that attach muscle to bones.
flexion
Bending of a joint that decreases the angle between the bones involved.
extention
Straightening of a joint that increases the angle between the bones involved.
abduction
Movement of a bone away from the midline of the body.
adduction
Movement of a bone towards the midline of the body.
rotation
Movement of a bone around its axis.
circumduction
Circular movement of a limb that involves flexion, abduction, extension and adduction in sequence.
external intercostal muscles
A group of muscles between the ribs that contract during inspiration and relax during expiration.
internal intercostal muscles
A group of muscles between the ribs that relax during inspiration and contract during expiration.
