composed to multinucleated muscle cells= fibers

uses ATP through cell respiration

uses contractile proteins to generate force

Thin filaments

made of two strands

O2 & CO2 both dissolve in plasma

solubility of O2< CO2

in red blood cells of vertebrates

in hemoglpyh of invertebrates

sigmodal like a hill

blood flows through connected blood vessels pumped by muscular hearts

to supply tissues wiuth nutrients

blood flows through a vessel with muscular thickenings that act like a pump

empties into an open body cavity to supply nutrients

returned to the circulation

carry blood towards the heart

carries blood away from heart

more efficient gas exchange

increased 02 delivery

higher metabolic rates

greater activity

deoxygenated blood enters the right atrium from the inferior/ superior venae cavae

deoxygenated blood passes through the right AV vale

enters through the right ventricle

deoxygenated blood is pumped into the pulmonary arteries through the pulmonary valve

oxygenated blood wooohooo!!!

retuerns from the lungs to the left atrium

oxygenated blood enters the left ventricle through the left AV valve

oxygenated blood is pumped by the left ventricle

pumped through the aortic valve

finally into the systemic circulation

biggest in the skeletal muscle

muscle bundle

muscle cell

most inner layer

contains hundreds of fascicle

repeating structural unit along the myofibrils

breaks up Z discs

sliding of actin past myosin generates muscle tension

when they slide against each other with pressure they create what we know as contracting muscles

when they start to stop sliding against each other so much, that's when we get relaxation of the muscles

Thick filaments

made of two intertwined subunits with a head and tail

head of myosin is facing away from the centre

head of myosin is facing towards the centre

large diameter

long protein

extends over many actin molecules

when at rest it blocks the myosin-binding site

overall rate of energy used

C6H1202+ 6O2 -> 6H20+ CO2+ ATP

oxygen consumption rises and then levels off at the beginning of exercise

oxygen consumption falls gradually to resting levels when exercise ends

a cat is gonna weigh more than a fly

chemicals speed up or slow down with changing temps

behavioural, biochemical, physiological response to ensure body temp is within an acceptable limit

TB (body temp)

generate internal heat to maintain body temp

Environment determines body temp

stable body temp

variable body temp

a mix (hibernators)

constriction of arterioles reduces blood flow to skin surface

decrease constriction of arterioles

vessels dilate

blood directed to skin surface

skeletal muscles pull against one another

ATP converted into ADP

occurs in mammals

brown adipose tissue (BAT)

large body size

reduced extremities

fur and feathers

trap air

requires grooming