Lecture Week 9 Flashcards
What are the types of muscle?
Skeletal, Smooth, Cardiac
Skeletal Muscle Info
Attached to skeleton, cylinder shape, many nuclei/cell, striations present, voluntary control
Smooth Muscle Info
Walls of hollow internal organs, spindle cell shape (wide in middle, taper at the ends), one nuclei/cell, striations absent, involuntary control
Cardiac Muscle Info
Location - heart, branched cylinder shape, one nuclei/cell, striations present, involuntary control
Multinucleate
More than one nucleus per fiber
Uninucleate
Fiber has single nucleus
What does skeletal muscle refer to?
Tissue and organs
What are functions of skeletal muscle tissue?
Produce skeletal movement, maintain posture and position, support soft tissues, guard body entrances and exits, maintain body temp, provide nutrient reserves
Origin
Point of attachment that does not move when the muscle contracts
Insertion
Point of attachment that moves when the muscle contracts
Action
Type of movement that occurs when a muscle contracts
Agonist (aka prime mover)
Primary muscle responsible for an action
Antagonist
Muscle responsible for the action that opposes the prime mover
Synergist
Muscle assisting a prime mover
What does each skeletal muscle consist of?
Organ consists of muscle, nervous, and connective tissues
Tendon/Aponeurosis
Anchors muscle to bone, dense connective tissue
Fascia
Separates muscle from surrounding organs, dense connective tissue
Epimysium
Surrounds skeletal muscle, dense connective tissue
Perimysium
Surrounds fascicle, dense connective tissue
Endomysium
Surrounds fiber, areolar tissue
Sarcolemma
Plasma membrane
Sarcoplasm
Cytoplasm
Mitochondria
Sites for cellular respiration
Myofibrils
Structures that contract
Myofilaments (filaments)
Thick - myosin
Thin - actin
Sarcoplasmic Reticulum
ER, sotres calcium
Transverse (t-) tubules
Run between cisternae of the SR, open to the outside of the cell, contain extracellular fluid
Organization of thick and thin myofilaments within a myofibril is responsible for?
Striations in skeletal and cardiac muscle tissue
What is the A band?
Dark, correspond to the length of the thick myofilaments
What is the I band?
Light, contain only thin myofilaments
What is the Z band?
Center of an I band, thin myofilaments are anchored to this
Sarcomere
Segment of myofibril from one Z line to the next, contractile unit of muscle tissue
What is the H zone?
Center region of A band
