Ch 1 Structure and Function of Body Systems Flashcards
axial skeleton
skull, backbone, ribs and sternum
appendicular skeleton
shoulder girdle, arms, wrists, hands, pelvic girdle, legs, ankles, and feet
fibrous joints
non moving bone structures
cartilaginous joints
joints w/ limited movement
synovial joints
joints w/ considerable movement
hyaline cartilage
covers articulating bone ends
synovial fluid
capsule that encloses the joint
uniaxial joints
act like hinges by rotating on 1 axis
biaxial joints
allow movement on 2 perpendicular planes
multiaxial joints
allow movement in al 3 perpendicular axes of space
vertebral column
made up of vertebrae separated by flexible discs
epimysium
fibrous connective tissue that covers the skeletal muscles
tendon
pulls on the bone when the muscle contracts
proximal
closer to the trunk of the body
distal
farther from the trunk of the body
superior
closer to the head of the body
inferior
closer to the feet of the body
muscle fibers
muscle cells
fasciculi
bundles of muscle fibers
perimysium
connective tissue that surrounds the fasciculi
endomysium
connective tissue that surrounds each muscle fiber
sarcolemma
muscle fiber’s membrane
motor neuron
nerve cell
neuromuscular junction
junction between a motor neuron and the muscle fiber it innervates
sarcoplasm
cytoplasm of a muscle fiber
myofibrils
located in the sarcoplasm of the muscle fiber and contains the apparatus that contracts the muscle cell
myofilament
next smallest unit of a muscle fiber
myosin
thick myofilament
actin
thin myofilament
crossbridge
where a pair of myosin filaments interact w/ actin
sarcomere
smallest contractile unit of skeletal muscle
A-band
dark part of myofilament that corresponds w/ the alignment of the myosin
I-band
light part of myofilament that corresponds w/ the area in 2 adjacent sarcomeres that contain only actin filaments
Z-line
the middle of the I-band that appears as a thin dark line running longitudinally
H-zone
area in the center of the sarcomere where only myosin filaments are present
sarcoplasmic reticulum
an intricate system of tubules that is parallel to and surrounds each myofibril and terminates at the vesicles in the vicinity of the Z-lines
T-tubules
transverse tubules that run perpendicular to the sarcoplasmic reticulum and terminate in the vicinity of the Z-line between 2 vesicles
action potential
electrical nerve impulse
sliding-filament theory
states that the actin filaments at each end of the sarcomere slide inward on myosin filaments pulling the Z-line toward the center of the sarcomere thus shortening the muscle fiber
troponin
a protein that is situated at regular intervals along the actin filament and has a high affinity for calcium ions
tropomyosin
protein molecule that runs along the length of the actin filament in the grove of the double helix
power stroke
pulling action of z-line toward the center of the muscle fiber due to actin sliding inward on myosin
acetylcholine
neurotransmitter released due to AP that diffuses across the neuromuscular junction an excited the sarcolemma causing the muscle fiber to contract
all or none principle
states that a motor neuron stimulus can’t cause only some of the fibers to contract and a stronger AP can’t produce a stronger contractions
twitch
a brief contaction
tetanus
when twitches begin to merge and eventually fuse
slow twitch fiber
develops force and release slowly producing a long twitch time
fast twitch fiber
develops force and relaxes quickly producing a short twitch time
type I fiber
slow-twitch fiber
type IIa fiber
fast-twitch fiber
type IIx fiber
fast-twitch fibers
proprioceptors
specialized sensory receptors located within joints, muscles and tendons
muscle spindles
proprioceptors made of several modified muscle fibers enclosed in a sheath of connective tissue
intrafusal fibers
the modified fibers in muscle spindles
extrafusal fibers
the normal fibers in muscle spindles
golgi tendon organs
proprioceptors located in tendons near the myotendinous junction and are in series w/ extrafusal muscle fibers; they inhibit muscle activation
atria
upper chambers of heart that deliver blood to the ventricles
ventricles
lower chambers of heart that pump blood through the body
tricuspid valve
1 of the AV valves
mitral valve
1 of the AV valves
atrioventricular valves
prevent flow of blood from ventricles to atria during systole
systole
ventricular contraction
aortic valve
one of the semilunar valves
pulmonary valve
one of the semilunar valves
semilunar valves
prevents back flow from aorta and pulmonary arteries into ventricles during diastole
diastole
ventricular relaxation
sinoatrial node node
intrinsic pacemaker of heart
atrioventricular node
slightly delayed impulse that signals for blood to be passed into the ventricles
AV bundle
conducts impulses to ventricles
LBB, RBB, and Purkinje fibers
conducts impulses to ventricles
myocardium
heart muscle
sympathetic nervous system
accelerates depolarization of the SA node making the heart beat faster
parasympathetic nervous system
slows rate of SA d/c slowing HR
bradycardia
<60 BPM
tachycardia
> 100 BPM
ECG
graph of electrical activity of heart
P-wave
records electrical depolarization of atria
QRS complex
records electrical depolarization of ventricles
depolarization
reversal of membrane electrical potential
T-wave
caused by electrical potential generated as ventricles recover from depolarization
repolarization
represented in ventricles by T-waves
arterial system
carries blood away from the heart
venous system
returns blood toward heart
arteries
transports pumped blood from heart to body
arterioles
small branches of arteries where blood enters capillaries from
capillaries
facilitates exchanges of O2, fluid, nutrients, electrolytes, hormones and other substances between the blood and interstitial fluid in the body tissue
venules
collect blood from capillaries and gradually converge into progressively larger veins
veins
transport blood from body back to heart
hemoglobin
iron protein molecule that transports O2 and acts as an acid-base buffer which helps regulate rate of chemical rxn in cells
red blood cells
helps remove O2 from body and blood
trachea
1st generation respiratory passage
bronchi
2nd generation respiratory passage
bronchioles
3rd generation respiratory passage
pleural pressure
the pressure in the narrow space between the lung pleura and the chest wall pleura
pleura
membranes enveloping the lungs and lining of the chest
alveolar pressure
pressure inside the alveoli when the glottis is open and no air is flowing into or out of the lungs
diffusion
random motion of molecules moving in opposite directions through the alveolar capillary membrane
