Intro to Muscles Flashcards
Muscles actively _____ and passively _____.
Actively contract
Passively relax
In movement, bones create an _____ at the joints, forming an _____.
Angle
Apex
To produce movement, the muscles make the angle of the joint either narrower (_____) or wider (_____)
Narrower = flexion Wider = extension
When muscles contract, it makes the joint _____ (_____)
Narrower (flexion)
_____ makes the joint wider.
Extension
If the shape of the joint allows, muscles may also move the bones sideways, either toward the body (_____) or away from it (_____).
Toward = adduction Away = abduction
_____ makes the joint narrower.
Flexion
Muscles that have prime function of closing angle of a joint are called:
Flexors
Muscles pass over the apex of the joint and are called:
Extensors
Drawing a limb towards the body =
Adduction (muscles = adductors)
Leading a limb away from the body =
Abduction (muscles = abductors)
3 Types of muscle (List whether they are voluntary/involuntary and examples)
Smooth muscle (involuntary) - bladder, intestinal wall lining Cardiac muscle (involuntary) - heart Skeletal or striated muscle (voluntary) - attached to skeleton
4 Functions of skeletal muscle
Support skeleton
Move skeleton
Maintain joint stability, preventing excessive movement
Produce heat by shivering
Skeletal muscle consists of a central fleshy and contractile “_____” and 2 _____, one at each end.
Muscle belly and 2 tendons
The muscles and tendons of skeletal muscle are arranged so that they _____ in one bone and _____ on a different bone while spanning at least one joint.
Originate; insert
As muscles contract, the bones move in relation to….
Each other
When activated by a motor nerve, a skeletal muscle can only _____.
Shorten
Each muscle belly is made up of _____
Muscle fibers
Each muscle fiber is innervated by _____
Only ONE motor neuron
One motor neuron can innervated _____
Many muscle fibers
Each muscle fiber contains hundreds to thousands of _____
Myofibrils
Each myofibril is made up of repeating _____, which has a disk at each end called a _____.
Sarcomeres with Z disks
Thin proteins called _____ are attached to Z disks
Actin
Thicker proteins that are suspended between Z disks
Myosin
“H” zone only contains
Myosin
Muscles need _____ and _____ to contract.
Oxygen and glycogen
_____ keep limbs from splaying out
Adductors
Oxygen is stored in the muscle pigment and protein _____. Gives meat its pigment
Myoglobin
When oxygen is the main fuel, work is called _____
Aerobic
When glycogen is the main fuel, work is called _____
Anaerobic
Glycogen is produced in the…
Liver
3 types of skeletal muscle fibers
Type I
Type II A
Type II B
8 Characterisitics of Type I fibers
Slow-twitch fibers Red endurance muscle ^ Myoglobin = Highly oxidative 1 motor neuron/ 20-30 musle fibers Slow to fatigue Narrow Less power Type of work: Endurance
8 Characteristics of Type II B fibers
Fast-twitch fibers White sprint muscle Low-oxidative = high glycolytic capacity Rapidly fatigued Power Larger in diameter 1 motor neuron/2,000 muscle fibers Type of work: Sprinters
5 Characteristics of Type II A fibers
Fast-twitch fibers High oxidative IN BETWEEN other two types ^ Myoglobin Type of work: Racing horses
Usually a muscle belly contains a _____ of the 3 types of fiber, proportion varying according to muscle’s use.
Blend
The muscle belly blend of fibers depends on _____, _____, and _____.
Gender, breed and training
During exercise _____ of fiber are used, with _____ recruited first, followed by _____ then _____
All the types used
Type I first
Type IIA
Type IIB
When anaerobic pathways are used during exercise, _____ results within the muscle fiber.
Lactic acid production
Lactate reaches the blood and then _____
Needs to be removied via urination
The rate of lactate removal from blood depends on _____ taken during the recovery period following an exercise bout.
Depends on the level of activity taken
Lactate is removed from the blood faster at _____ > _____ > _____.
Trot
Walk
Stand
If muscle could not produce any lactate, exercise would be limited to low and moderate intensities only. Lactice acid production is essential for _____, _____ and _____.
Acceleration, speed and explosive efforts
_____ immediately after exercise bout is caused, in part, by lactate.
Muscle soreness
