Muscles Flashcards
What is a muscle?
A connective tissue that supports the function of your organs & organ systems
Muscles are made of which two fibers?
Myosin (thicker)
Actin (thin)
The two _____ types work together to produce ______ ___________ (all _______ force)
The two FIBER types work together to produce MUSCLE CONTRACTIONS (all PULLING force)
How do muscles produce opposing forces?
Antagonistic muscle groups
Extension vs. Flexion
What is the model of Muscle Function?
The Sliding Filament model
Step one in Muscle Contraction
Impulse (from nervous system) arrives at the sarcomere “tells muscle to contract”
Step two in Muscle Contraction
Ca2+ ions flood the sarcomere
Step three in Muscle Contraction
Tropomyosin moves off the myosin binding sites on the actin, so the myosin heads grab actin & pull
Step four in Muscle Contraction
ATP is used to get myosin to “let go” so it can bind & pull again
When does muscle contractions stop?
When desired contraction is reached
What dictatates the strength of muscle contraction?
The number of impulses
Few impulses, far apart=
Weak contraction
Many Impulses, close together=
Strong contraction
What are the three muscle types?
Skeletal
Smooth
Cardiac
Characteristics of Skeletal muscle
Striated Muscle
Voluntary movement
Attached to bones/ ligaments etc.
Characteristics of Smooth muscle
Flat appearance Lines vessels & tubes of the body Bronchioles Intestines Arteries Pushes material through rhythmic contraction (peristalsis)
Characteristics of Cardiac Muscle
Branched
In the heart ONLY
Pumps blood to lungs and body
What are the two sub-types of skeletal muscle?
Fast twitch
Slow twitch
Fast Twitch Muscle
Type II myosin Thicker Better able to grab and pull actin More vascularized (blood vessels) to resource delivery Uses ATP quickly
Used during sprinting
Slow Twitch Muscle
Type I myosin
Doesn’t grab actin as much or as quickly
Uses ATP slowly & efficiently
Used during endurance
What is Myoglobin?
A dark red pigment
Protein with an iron group (heme)
Retains O2 (g)