Lab Final Study Guide Flashcards
Skeletal muscle is _______ and ________.
voluntary; striated
Cardiac muscle is _______ , _______, and has _______ _________.
striated, involuntary, intercalated discs
Smooth muscle has _______ and ________.
no striations, involuntary control
Where is skeletal muscle found?
skeletal muscle attached to bone
Where is cardiac muscle located?
walls of the heart
Where is smooth muscle located?
walls of hollow organs
What is the sarcolemma?
plasma membrane of a muscle cell
muscle fiber = ?
muscle cell
muscle cell = ?
muscle fiber
What is a sarcomere?
the functional unit of muscle fibers; is the contractile unit; space between the two z lines
What is the banding pattern?
light and dark bands are created by the arrangement of myofilaments
What are myofilaments?
thick(myosin) filaments and thin(actin) filaments in the sarcomeres
What is the endomysium?
thin connective tissue covering each muscle fiber
What is the perimysium?
fibrous membrane covering bundles of muscle fibers creating a fascicle; bundle of muscle fibers bound together by connective tissue
What is the epimysium?
fibrous connective tissue surrounding many fascicles creating a skeletal muscle; basically the outer covering of the entire skeletal muscle; blend into strong cordlike tendons or into sheetlike aponeurosis
What is aponeurosis?
fibrous or membranous sheet connecting a muscle and the part is moves
What is a tendon?
cord of dense fibrous tissue attaching a muscle to a bone
What is fascia?
layers of fibrous tissue covering and separating muscles
What is the neuromuscular junction(aka myoneural junction)
where the neuron and the muscle fiber interact; the motor axons of the neurons branch into axon terminals
What is a neuron?
a nerve cell
What is a muscle fiber?
muscle cell
What is an axon?
part of the neuron that goes away from the cell body
What is a motor unit, and what does it consist of?
a neuron and all of the muscle fibers it stimulates; consists of synaptic cleft gap between the axon terminal of the neuron and the sarcolemma; axon terminals contain vesicles which have ACh
What is a prime mover or agonist?
muscles that are responsible for producing a particular movement
What is the antagonist?
muscles that oppose or reserve a movement
ex: tricep would be the antagonist when flexing bicep
What is a synergist?
muscles that aid the action of the agonists by reducing undesirable movement
What are fixators or fixation muscles?
specialized synergists that immobilize the origin of the prime mover so that all tension is exerted at the insertion
Ex: the rotator cuff is a fixator in a bicep curl
What are myofibrils?
long parallel muscle fibers that run parallel to each other
What is actin?
thin contractile protein; is bound by myosin to contract muscle
What is myosin?
thick contractile protein; binds to actin to contract muscle
What is a transverse tubule?
an indentation of the sarcolemma into the muscle cell at each junction of the A and I bands
What is the sarcoplasmic reticulum?
the endoplasmic reticulum of the muscle cells
What are the terminal cisterns?
cross channels of the sarcoplasmic reticulum
What is the neuromuscular junction?
the junction between the axon of a motor neuron and a muscle fiber
What is the synaptic cleft?
a small fluid filled gap that separates the neuron and muscle fiber
What is an axon terminal?
a region at the end of each axon branch that is specialized to release packets of chemical neurotransmitters from synaptic vesicles
What are synaptic vesicles?
small intracellular membrane bound vesicles
Describe acetylcholine.
ACh is a neurotransmitter that is released via exocytosis when Ca channels open. ACh diffuses across the synaptic cleft and combines with the receptors on the sarcolemma
What are the two principal cell populations of the nervous system?
neurons and neuroglia/glial cells
Describe neurons
structural units that are highly specialized to transmit nerve impulses from one part of the body to another
Describe neuroglia/glial cells
they branch and protect neurons
List the neuroglia found in the CNS
astrocytes, oligodendrocytes, microglia, & ependymal cells
List the neuroglia found in the PNS
Schwann and satellite cells
Define neurofibrils
cytoskeletal elements
Define chromatoophilic substances
aka the nissil bodies; are rough ER involved in metabolic activities of the cell
What are the two cell body clusters?
nuclei and ganglia
Define nuclei
a cluster of neuron cell bodies found within the CNS
Define ganglia
a cluster of neuron cell bodies found outside the CNS; both the nuclei and ganglia make up gray matter
What are tracts
neuron fibers running through the CNS
What are nerves
neuron fibers running through the PNS
What are the two types of neuron processes?
dendrites and axons
Define dendrites
the receptive regions that bear neurotransmitter receptors
Define axons
generate and conduct impulses
What are collaterals?
branches of axons
What is the axon hillock?
initial axon segment found beside the cell body
What are axon terminals?
the ends of axons which form synaptic clefts with other neurons or effector cells