Chapter 6.2 Flashcards
cell membrane in muscles
sarcolemma
cytoplasm of cell
sarcoplasm
long structures in sarcoplasm
myofibrils
arrangement of filaments in myofibrils produces
striations
the basic contractile unit of muscle fiber.
sarcomere
sarcomere is composed of two main protein filaments—[ ]
and [ ]—which are active structures responsible for muscle contraction
actin and myosin
the most popular model that describes muscular
contraction is called the [ ]
sliding filament theory
- muscle fibers respond to the neurotransmitter [ ]
- causes skeletal muscle to contract
acetylcholine
- following contraction, muscles release the enzyme [ ]
- breaks down acetylcholine
- allows muscle to relax
acetylcholinesterase
- in the iris of the eye and walls of blood vessels
- responds to neurotransmitters and hormones
multiunit smooth muscle
- In walls of hollow organs
- Responds to neurotransmitters AND
- Stimulate each other to contract so that muscle fibers
contract and relax together in a rhythmic motion –
peristalsis
visceral smooth muscle
rhythmic contraction that pushes substances through
tubes of the body
peristalsis
- connect groups of cardiac muscle
- allow the fibers in the groups to contract and relax together
- allows heart to work as a pump
intercalated disks
sends out an electrical impulse to make the upper heart chambers contract
SinoAtrial node
sends out an electrical impulse to make the lower heart chambers contract
AtrioVentricular node
the source of energy in working muscles
adenosine triphosphate
the three biochemical systems for producing ATP are, in order:
using creatine phosphate
using glycogen
aerobic respiration
a movement that decreases the angle between two bones at the joint.
flexion
a movement that increases the angle between two bones at the joint.
extension
a movement that results in movement of one bone around
its longitudinal axis.
rotation
a movement that results in the part moving away from the midline.
abduction
a movement that results in the part moving toward the midline.
adduction
permitting movement in all directions, the [ ] features the rounded head of one bone sitting in the cup of another bone. examples include your shoulder joint and your hip joint.
ball and socket joint
the [ ] is like a door, opening and closing in one
direction, along one plane. examples include your elbow joint and your knee joint.
hinge joint
the [ ] allows movement, but no rotation.
examples include your finger joints and your jaw.
condyloid joint
also called the rotary joint or trochoid joint,
is characterized by one bone that can swivel in a ring formed from a second bone. examples are the joints between your ulna and radius bones that rotate your forearm, and the joint between the first and second
vertebrae in your neck.
pivot joint
also called the plane joint. although it only permits limited movement, it’s characterized by smooth surfaces that can slip over one another. an example is the joint in your wrist.
gliding joint
although the [ ] does not allow rotation, it does
enable movement back and forth and side to side. an example is the joint at the base of your thumb.
saddle joint
when the foot is raised as when you dig in your heels.
dorsiflexion
when you lower your foot as when you lift yourself onto the balls of your feet.
plantar flexion
when you turn your feet inward so that your soles are facing one another.
inversion
when you turn your feet outward so that your soles are facing laterally.
eversion
is rotation of the radius across the ulna that results is your palms facing backwards.
pronation
movement in the opposite direction that uncrosses the
radius from the ulna to cause the palms to face forward.
supination
this movement enables us to be skillful tool
users. [ ] is the movement of the tip of the thumb
that enables it to touch the tips of the other fingers.
opposition
