IB Exams

axial skeleton

central points that the body rotates around

cranium, sternum, ribs, vertebrae, sacrum, coccyx

appendicular skeleton

attaches to support

clavicle, scapula, humerus, radius, ulna, pelvis, carpals, metacarpals, phalanges, femur, patella, fibula, tibia, tarsals, metatarsals

four types of bones

flat bones, long bones, short bones, irregular bones

structure of a long bone

superior

abovein

inferior

below

lateral

towards the outside

medial

towards the middle

proximal

close to joint

distal

farther from joint

anterior

to the front

posterior

to the back

cartilage

acts as a shock absorber and prevents friction where bones articulate

tendons

attach muscle to bone

ligaments

hold bone to bone, secure articulating bones to a stable joint

joint

where two or more bones articulate

fibrous joints

allow no movement

cartilaginous joints

allow little movement

synovial joints

freely moveable

structure of a synovial joint

types of synovial joints

hinge, ball and socket, gliding, saddle, pivot, condyloid

contractility

ability to contract

elasticity

ability to return to resting length after contracting

extensibility

ability to extend beyond normal length

hypertrophy

ability to build muscle and increase in size due to training

atrophy

ability to lose mass, size, and strength due to lack of training

how muscles are fed

capillaries provide nutrients like oxygen and glucose and remove carbon dioxide

how muscles are controlled

based on stimulation from the CNS, controlled by nerve stimuli

smooth muscle

involuntary muscles located on the walls of arteries and organs

narrow, non-striated, uninucleated fibers

cardiac muscle

involuntary muscle located on the walls of the heart

striated, branched, nucleated fibers

skeletal muscle

voluntary muscle attached to skeleton via tendons

striated, multi-nucleated fibers

structure of skeletal muscle

origin of muscle

stabilizes the movement, where the muscle attaches to the stationary bone

insertion of muscle

where the muscle attaches to the moving bone

structure of a motor unit

role of acetylcholine in muscle contraction

stimulates muscle contraction by binding to nicotinic receptors on the skeletal muscle

role of acetylcholinesterase in muscle contraction

consumes the excess ACh, leading to muscle relaxation

type 1 slow twitch fibers

high response to fatigue, low force production

type 2a fast twitch fibers

medium resistance to fatigue, high force production

type 2b fast twitch fibers

low resistance to fatigue, very high force production

abduction

movement away from the midline of the body

adduction

movement toward the midline of the body

flexion

bending movement that decreases the angle between the bones of the limb at the joint

extension

straightening movement that returns the body part to the zero position

supination

rotation of the hands and forearms so the palm faces up

pronation

movement of the forearm so the palm is turned down

elevation

movement that raises a body part vertically in the front plane

depression

movement that lowers a body part vertically in the front plane

dorsi flexion

bending the foot in the direction of the upper surface (flexing)

plantar flexion

bending the foot in the direction of the sole (pointing)

circumduction

distal end of the bone moves in a circle while the proximal end remains relatively stable

rotation

moving a bone around its longitudinal axis

inversion

tips the soles medially to face each other

eversion

tips the soles laterally away from each other

isotonic

result in a change in muscle length

isometric

involve no change in muscle length

isokinetic

occur at a constant velocity, typically with specialized machines

concentric

shorten the muscle

eccentric

lengthen the muscle

agonist

muscle that contracts concentrically

antagonist

muscle that contracts eccentrically

delayed onset muscle soreness (DOMS)

most often caused by eccentric exercises, large forces and breaking actin-myosin bonds result in lactic acid build up and microtears in muscles

results in pain, restricted movement, stiffness, and reduced muscle force capacity

principal structures of ventilatory system

nose, mouth, pharynx, larynx, trachea, bronchi, bronchioles, lungs, and alveoli

functions of the conducting airways

low resistance pathway to airflow, defense against chemicals and other harmful substances that are inhaled, and warming/moistening air

pulmonary ventilation

inflow and outflow of air between atmosphere and lungs

total lung capacity

vital capacity + residual volume

vital capacity

tidal volume + inspiratory reserve volume + expiratory reserve volume

tidal volume

normal volume of air breathed

expiratory reserve volume

air in excess of tidal volume that can be forcibly exhaled

inspiratory reserve volume

additional inspired air over tidal volume

residual volume

air still in lungs after a maximum exhale

mechanics of inhalation

diaphragm contracts, external intercostals contract, internal intercostals relax, thoric cavity volume increases and pressure decreases

mechanics of exhalation

diaphragm and external intercostals relax, internal intercostals contract, thoracic cavity volume decreases and pressure increases

chemoreceptors

detect chemical changes in blood (pH)

more CO2 = increased breathing rate/depth

proprioceptors

detect angle movement at joints

increased movement = increased breathing rate/depth

stretch receptors

inhibit inspiration and stimulate expiration after a large inhalation to prevent over-stretching in the lungs

hemoglobin in O2 transport

O2 enters red blood cells and binds with the heme group, O2 disassociates into body cells where the partical pressure is lower

gas exchange at th ealveoli

passive diffusion between alveoli and capillaries with O2 and CO2

composition of blood

erythrocytes, leucocytes, platelets, and plasma

erythrocytes

red blood cells, transport O2 and CO2

leucocytes

white blood cells, identify and eliminate pathogens

thrombocytes

platelets, form clots to prevent bleeding

structure of the heart

pulmonary circulation

blood that circulates to the lungs

systemic circulation

blood that circulates to the body systems

regulation of heart rate

SA node → AV node → Bundle of His → purkinje fibers

how the sympathetic nervous system regulates heart rate

secretes adrenaline to increase alertness

how the parasympathetic nervous system regulates heart rate

releases ACh to decrease alertness and calm the body

heart rate

the number of times your heart beats per minute

stroke volume

the amount of blood ejected from the heart per beat

cardiac output

heart rate * stroke volume

stroke volume, heart rate, and cardiac output in males vs females

SV: slightly higher for men

HR: slightly higher for women

CQ: slightly higher for men

stroke volume, heart rate, and cardiac output in trained vs untrained

SV: significantly higher in trained

HR: significantly higher in untrained

CQ: higher in trained

stroke volume, heart rate, and cardiac output in young vs old

resting HR: slightly higher in old

exercise HR: slightly higher in young

SV: higher in young

CQ: slightly higher in young

cardiovascular drift

an increase of body temperature results in lower venous return to the heart and a small decrease in blood volume from sweating → a reduction in stroke volume causes the HR to increase to maintain CQ

systolic

force exerted on the arterial walls as blood is ejected from the ventricles (contracted)

diastolic

force exerted on arterial walls as blood fills the ventricles (relaxation)

systolic BP vs diastolic BP during exercise

systolic BP increases and diastolic BP stays the same or slightly decreases

dynamic - systolic BP increases and diastolic BP decreases

static - systolic BP increases and diastolic BP decreases

distribution of blood at rest

most blood goes to digestive organs, kidneys, muscles, and the brain

distribution of blood during exercise

most blood goes to the muscles