Ch. 11 Muscular System Flashcards
Aponeurosis
A thin, flat sheet of connective tissue that attaches to bones; helps with movement and posture
Atrophy
The progressive decline or wasting away of a body part, organ, tissue, or cell. decrease in muscle size
Fatigue
A physical or mental state of weariness that can be cause by exertion or other factors (health conditions, medications, habits, etc.)
Hypertrophy
The process by which cells enlarge, causing an organ or tissue to increase in size. increase in muscle size
Insertion
The point where the muscle attaches to a bone, tendon, or connective tissue that moves when the muscle contracts
Origin
The point where a muscle attaches to a bone that remains fixed during muscle contraction
Paralysis
The loss of muscle function in part or all of the body, caused by an issue with the messages sent between the brain and muscles
Posture
The position of the body in space, and how the body is held while sitting, standing, or moving
Tendon
Tough, fibrous, cord-like tissue that connects a muscle to a bone or other structure
Tone
The amount of tension a muscle had at rest, or its resistance to passive stretching
What are the 3 types of muscular tissue?
-skeletal
-cardiac
-smooth
Skeletal muscle location
Muscles of body
Skeletal muscle function
Movement of bones
Skeletal muscle appearance
-Straited (regular)
-multinucleated
Skeletal muscle control
Voluntary
Cardiac muscle location
Heart
Cardiac muscle function
Pumping of blood
Cardiac muscle appearance
-striated (irregular)
-single nucleus
Cardiac muscle control
Involuntary
Smooth muscle location
-viscera (organs)
-Ex: blood vessels, bladder, stomach
Smooth muscle function
-movement
-change in size, depends on structure
Smooth muscle appearance
-no striations
-single nucleus
Smooth muscle control
Involuntary
Functions of skeletal muscles
-movement
-heat production
-posture
Characteristics of muscle tissue
-contractility
-extensibility
-excitability (irritability)
Innervation
The distribution of nerves to a body part or structure to regulate its function
Prime mover (agonist)
Main muscle that causes the action
Antagonist
Opposite action of prime mover. (Ex. Bicep curls—> biceps = prime mover, triceps = antagonist)
Synergist
Muscle that works with another muscle to help it perform a function more effectively (works with agonist)
Fixator
A muscle that stabilizes a body part while another part moves
Endomysium
Connective tissue around muscle cells
Fascicle
Group of muscle or nerve fibers
Perimysium
Connective tissue around muscle fascicles
Epimysium
Connective tissue surrounding entire muscle
Fascia
Sheet or thin band of fibrous tissue that covers muscles and some organs of the body
What is the nervous system responsible for?
-muscle tone
-regulation
-coordination
Muscles exert a continual pull on bones in….
The opposite direction from gravity
Neuromuscular junction
-Where nerve and muscle come together
-electrical impulses to cause muscle contraction
Neurons release a neurotransmitter called what?
Acetylcholine
What does acetylcholine do?
Causes changes in sarcolemma
Incomplete tetanus
Muscle fibers partially relax between contraction
Complete tetanus
No relaxation between contractions
Isometric muscle contraction
No change in length but tension increases
Isotonic muscle contraction
Change in length but tension is constant
Muscle tone
Sustained partial contraction over time
What is rigor mortis?
Hardening of muscles and stiffening of the body after death
How long after death does rigor mortis start to occur?
3-4 hours after death
When does rigor mortis peak?
About 12 hours after death
When does rigor mortis start to diminish?
After peaking 12 hours after death, diminishes over the next 48-60 hours
