Muscular System Flashcards
Skeletal muscle
- Moves skeleton
- voluntary control
- Striated
- Multinucleated
- Long, cylindrical fibers
Cardiac muscle
- Heart wall
- Involuntary
- Striated
- Uninucleated
- Short, branched fibers
Smooth muscle
- Walls of hollow organs
- Involuntary
- NO striations
- Uninucleated
- Small, spindle shaped cells
Structure of muscle smallest to largest
sarcomere, myofibril, muscle fiber, fascicle, skeletal muscle
What CT surrounds the whole muscle?
- Epimysium
- Dense irregular CT
What CT surrounds the fascicles?
- Perimysium
- Fibrous CT
CT surrounding individual muscle fibers?
- Endomysium
- Loose CT
Identify the levels of organization of a skeletal muscle from whole muscle to myofilament.
-muscle
-bundles of fibers (fascicles)
-individual muscle fibers (cells)
-myofibrils
-myofilaments (actin & myosin)
What protein makes up the thick filament?
myosin
what proteins are in thin filaments?
actin
What are the correct terms for the following found in muscle fibers?
- Smooth endoplasmic reticulum
- Plasma membrane
- Cytoplasm
- Sarcoplasmic reticulum
- Sarcolema
- Sarcoplasm
What is a primary function of the T-tubules?
Carries electrical stimulus for myofibrils
Define “motor unit”
A motor neuron and all of the muscle fibers it innervates
What is the neuromuscular junction? What occurs here and how is it related to muscle contraction?
Junction where neurons connects to fibers; neuron tells fiber to contract
List, in order from strongest to weakest, the following shapes of muscles:
- Convergent
- Parallel
- Pennate
Pennate, convergent, parallel
List, in order from the most able to shorten to the least able to shorten, the following muscles:
- Convergent
- Parallel
- Pennate
Parallel, convergent, pennate
Parallel muscle
parallel to axis
Unipennate muscle
connected at angle to one side to ligament
Bipennate muscle
connected at angel to both sides
Multipennate muscle
connected to many sides at an angle
Differentiate between direct and indirect muscle attachments
Direct short, indirect long
Differentiate between tendon and aponeurosis. Can you give an example for each?
- tendon is ropelike (arms)
- aponeurosis is like a flat sheet (abs)
What is the significance of the bumps, ridges, and raised markings on bones?
Attachment marks for tendons/muscle
Origin of a muscle
- Moves less
- Has more mass
- Proximal end of attachment
Insertion of a muscle
- Moves more
- Has less mass
- Distal end of attachment
- Moves closer to origin during contraction
What does it mean that cardiac muscle cells have autorhythmicity? Do they function completely
without nervous input?
- Does not need nervous input to contract
- No, they need the brain to contain homeostasis to still act
What anchors actin and myosin in smooth muscle cells?
Intermediate filaments
Smooth muscle is often found in layers with cells oriented at angles to each other. What is the significance of this?
To make it stronger
Elbow flexion and extension requires the coordinated action of a number of muscles. Please
give an example of a muscle for the following functional types of muscles involved in elbow
flexion and extension:
• Synergist
• Antagonist
• Prime mover
• Fixator
- Synergist: Brachial and brachialis
- Antagonist: Triceps
- Prime mover: Brachialis
- Fixator: Scapula
What is the neurotransmitter released at the neuromuscular junction?
Acetylcholine
