Chapter 7 The Muscular System Flashcards
What is the function of the muscular system?
The muscular system allows for movement
External
motion of the arms and legs
Internal
motion including the movement of the digestive system
and the respiratory system
T/F: Different types of muscles allow for both external and internal movement.
True
general term for all skeletal muscle tissue
Muscle
Contraction
muscle tissue becomes short and thick because of a
nerve impulse
Relaxation
occurs when impulse ends - returning to the initial state
Cause of movement
Alternating contraction and relaxation
Muscle tissue
is constructed of bundles of fascicles
fascicles
is made
of myofibrils
myofibrils
made up of myofilaments which is the smallest subunit
Myofilaments
made of 3 protein structures called: actin , myosin, and the
nonfunctional unit titin
What are skeletal muscles
Attached to tendons which attach to bone; provide movement for the
body
Striated
means they look striped
Voluntary
movement is controlled by conscious thought
Contraction
shortening of muscle
All movement is a result of what?
contraction of primary movers and
extension/relaxation of opposing muscles
flexor
The muscle shortening the angle
the muscle
lengthening the angle is called the
extensor
Circular movement that occurs
around an axis
Rotation / circumduction
Movement away from the
midline
Abduction
Movement toward the midline
Adduction
Increasing the angle between
bones connected at a joint
Extension
Decreasing the angle between
two bones connected at a joint
Flexion
What is a muscle?
a collection of cells, is a tissue
Sarcomeres
are the functional contractile units of each fiber. They
contract but do not shorten
Each sarcomere consists of what?
two types of threadlike structures called thick
and thin myofilaments
Thick myofilaments
are made up of the protein myosin
Thin myofilaments
are made up of the protein actin
Acetylcholine
a neurotransmitter, is released from the nervous system
Releasing acetylcholine causes what?
This causes contraction by causing myosin heads to bind to actin
filaments (crossbridge formation)
What form of energy is needed for contraction and relaxation?
ATP
(adenosine triphosphate)
What are needed to make ATP?
Oxygen and glucose
What can be converted to glucose?
Glycogen stored in muscle
What does increased blood supply to muscles do?
Gives them a darker colour. Allows them to carry much-needed oxygen.
T/F: Muscles produce heat
True
Why is important for muscles to produce heat?
Producing heat is important in maintaining homeostasis when it is too cold, like shivering.
What happens during Rigor Mortis?
When a body dies, all the stored calcium is unable to be pumped back out of the muscles.
Excess calcium remains in the muscles throughout the body and causes muscle fibers to shorten and contract the whole body.
Shortage of ATP also contributes.
Smooth Muscle is also called
visceral muscle
Smooth muscle can be found in?
Found in hollow organs (except heart) and tubes, such as blood
vessels
Smooth muscles; slower…
slower than skeletal muscles and uncontrolled
vasodilation
Increasing the diameter of a blood vessel
vasoconstriction
Decreasing the diameter of a blood vessel
close and open tubes
Sphincters
Cardiac Muscles an be found where?
Found in the wall of the heart
Cardiac muscles are uncontrolled therefore they are?
involuntary
Cardiac muscle fibers are?
Fibers are shorter and receive a richer supply of blood than any
other muscle in the body
Intercalated disks
connective fibers; causing one fiber to contract
and then pull the next one into a contraction, creating a domino effect
T/F: Cardiac muscles do not regenerate themselves, leading to scarring.
True
Tonus (muscle tone)
partial contraction of a muscle with resistance
to stretching
Hypertrophy
increased muscle size
atrophy
muscle wasting from disuse
myalgia
pain or tenderness in a muscle
fibromyalgia
a disease that mainly affects women under 40 but is not fully
understood
fibromyalgia symptoms?
include aches, pains, and muscle stiffness with specific tender points; cause is unknown but is linked with chronic fatigue syndrome.
Paralysis
partial or total loss of function in skeletal muscles; can be
either flaccid or rigid paralysis
spasms or cramps
involuntary sudden and violent contraction of a
muscle for a prolonged period of time
Sprains
tears or breaks in ligaments
Strains
actual tears in tendons or muscles
Shin splints
inflammatory condition of the extensor muscles and
surrounding tissues of the lower leg; often found in runners
Hernia
tear in the muscle wall through which an organ of the body
protrudes
Tendinitis
inflammation of tendon
electromyography
a diagnostic test in which a muscle or group of
muscles are stimulated with an electrical impulse, causing contraction, allowing the strength of the contraction to be measured
Myasthenia gravis
- Gradually increasing profound muscle weakness
- Drooping eyelids frequently the first symptom
Guillain-Barré syndrome
- Disorder of the peripheral nervous system that causes flaccid paralysis and the loss of reflexes
- Ascends from the feet and progressing to the head
- Paralysis peaks in 10 to 14 days and then subsides gradually
Tetanus
Creates rigid paralysis, and any minor stimulus causes muscles to go into a major spasm
Tetanus is caused by?
Caused by toxins produced by bacteria found in the ground and can be spread by any type of puncture, not just a rusty nail
Botulism
is a potentially deadly disease resulting from bacterial
poisoning with the Clostridium botulinum bacteria.
Botox
- Science can utilize botulinum toxins for medical and cosmetic treatment.
- Small amounts of botulinus toxin are injected into facial muscles to stop previously untreatable facial twitching by paralyzing the muscles.
- Toxin also is used to treat wrinkles without surgery; known as botox injections
Muscular dystrophy
- Degenerative muscular diseases
- Muscle fibers degenerate
