Muscle Tissue Flashcards
What is motor unit recruitment?
Is the process whereby the number of active motor units is increased according to need.
The more neurons that are activated (in the spinal cord) the more motor units will be?
Stimulated and the more muscle tension will be produced.
The larger the motor units recruits, the more?
muscle tension will be produced
Are all motor units recruited simultaneously?
No, only the number of motor units needed are recruited
Which motor unit is recruited first?
The smallest, weakest motor units.
Larger, stronger motor units are recruited if?
They are required by the task.
In response to AP, what contracts longer, Cardiac muscle or skeletal muscle?
Cardiac muscle
It contracts 10-15 times longer than skeletal muscle and must continue to do so, without rest, for the life of the individual.
What does cardiac muscle use to respond to each AP?
The rich supply of O2 delivered by the extensive coronary circulation to generate ATP through aerobic respiration,
Muscle fibers of cardiac muscle exhibit
Autorhythmicity
What of the cardiac muscle tissue fibers results in synchronous contraction?
The interconnectedness of fibers
What alters the autorhythmicity of the cardiac muscle tissue?
Autonomic nervous system
Endocrine system
Why is the mitochondria larger and more numerous in the cardiac muscle compared to the skeletal muscle?
In accordance with a greater dependency on aerobic respiration to generate ATP.
True or False
Smooth Muscle is autorhythmic
True
How does smooth muscle generate ATP?
Through anaerobic respiration (glycolysis)
True or False
Smooth Muscle has a high capacity for generating ATP.
False
Has a low capacity
In addition to thick and thin filaments, which filaments are also present in smooth muscle?
Intermediate Filaments
Where do intermediate filaments attach?
Intermediate filaments,
which are functionally similar to Z discs found in striated muscle and found in both the sarcoplasm and the sarcolemma
What generates tension on the intermediate filaments?
Contraction of the thick and thin filaments.
It pulls the dense bodies and causes shortening of muscle fiber.
What are the two types of smooth muscle?
Single-unit smooth muscle tissue (AKA Visceral smooth muscle tissue)
Multiunit smooth muscle tissue
Which type of smooth muscle- fibers connect to one another by gap junctions and contract as a single unit?
Single-Unit (Visceral smooth muscle)
Which type of smooth muscle- fibers lack gap junctions and contract independently?
Multiunit smooth muscle
Electron microscopy has show that _____ can cause damage, including torn sarcolemma’s, damaged myofibrils, and disrupted Z discs.
Intense Exercise
Chemical analysis after exercise has also shown increases in blood levels of?
Myoglobin and creatine kinase, both of which are normally confined within muscle.
What is DOMS?
Delayed onset muscle soreness that follows strenuous exercise by about 12-48 hours
Functions of Muscular Tissue
What are some characteristics of muscular tissue?
Muscles are excitable
Contractible
Extensible
Elastic
Functions of Muscular Tissue
What are the main functions of muscular tissue?
Create Motion
Stabilize body positions and maintain posture
Store substances within the body using sphincters
Move substances by peristaltic contractions
Generate heat through thermogenesis
What are the three types of muscular tissue?
Skeletal
Cardiac
Visceral (smooth muscle)
What is the function of skeletal muscle?
Movement, heat, posture
Where is visceral (smooth muscle) located?
G.I. tract, uterus, eye, blood vessels
What is the function of visceral (smooth muscle) ?
Peristalsis
Blood pressure
Pupil size
Erects hairs
What is the appearance of skeletal muscle?
Striated, multi-nucleated (eccentric)
Fibers parallel
What is the appearance of cardiac muscle?
Striated, one central nucleus
What is the appearance of visceral (smooth muscle)?
No striations, one central nucleus
Which of the three muscular types are voluntary?
Skeletal
Skeletal muscle
A single muscle cell
Fiber
Skeletal muscle
A bundle of muscle fibers (bundle of muscle cells)
Fascicle