Muscular System

Question 1

What are the functions of muscles

Answer 1

movement
stability 
control of body openings and passages 
heat production 
glycemic control

Question 2

movement

Answer 2

move from place to place; move body contents

Question 3

stability

Answer 3

maintain posture

Question 4

control of body openings and passages

Answer 4

mouth; internal sphincters

Question 5

heat production

Answer 5

85% of body heat produced by skeletal muscles

Question 6

glycemic control

Answer 6

regulation of blood glucose concentration within its normal range; skeletal muscles absorb, store, and use a large share of
one’s glucose, and play a highly significant role in stabilizing it’s blood concentration

Question 7

what are the characteristics of muscles

Answer 7

responsiveness (excitability)
conductivity
contractility
extensibility
elasticity

Question 8

responsiveness (excitability)

Answer 8

when stimulated by chemical signals, stretch, and other stimuli, muscle cells respond with electrical changes across the cell membrane

Question 9

conductivity

Answer 9

stimulation of a muscle cell produces more than a local effect; the local electrical change triggers a wave of excitation that travels rapidly all the cell and initiates processes leading to contraction

Question 10

contractility

Answer 10

muscle cells are unique in their ability to shorten substantially When stimulated; enables them to create movement

Question 11

extensibility

Answer 11

ability to stretch again between contractions

Question 12

elasticity

Answer 12

ability to stretch, release, and recoil to a shorter length

Question 13

Epimysium

Answer 13

covers entire muscle; attachment to tendon

Question 14

perimysium

Answer 14

surrounds fascicle or bundle of skeletal muscle

Question 15

endomysium

Answer 15

surrounds individual skeletal muscle cell

Question 16

parallel

Answer 16

fibers run parallel and can be arranged with or without body/gaster (biceps brachii – with body/gaster); (rectus abdominis – without body/gaster)

Question 17

convergent

Answer 17

fibers meet at a common attachment site (mylohyoid)

Question 18

pennate

Answer 18

fibers arranged at an angle;

Question 19

unipennate

Answer 19

fibers on one side of tendon (extensor digitorum longus)

Question 20

bipennate

Answer 20

fibers on both sides of tendon (rectus femoris)

Question 21

multipennate

Answer 21

fibers branch within tendon (deltoid)

Question 22

circular

Answer 22

fibers arranged in circular pattern (orbicularis oris or oculi); sphincters

Question 23

tetanus (lock jaw)

Answer 23

caused by bacterium Clostridium tetani; toxins released cause the involuntary contraction of skeletal muscle; jaw muscles affected first

caused by a deep dirty wound

Question 24

botulism (food poisoning)

Answer 24

caused by bacterium Clostridium botulinum; toxins released prevent the release of Ach (acetylcholine); causes paralysis of respiratory muscles

treated with oxygen, acetylcholine and pump the stomach

Question 25

hernias

Answer 25

due to weakness in a muscle; organ can protrude through the muscle

Question 26

inguinal hernia

Answer 26

most common; groin region; small intestine pushes through groin muscles, and can twist and strangulate

Question 27

clostridium

Answer 27

doesn’t require oxygen

Question 28

hiatal hernia

Answer 28

most painful; weakness in diaphragm; stomach and liver push up into thoracic cavity; difficulty in breathing

Question 29

Muscular Dystrophy (MD)

Answer 29

group of genetic diseases characterized by progressive weakness and degeneration of the skeletal muscles. Some forms of muscular dystrophy are seen in infancy, or childhood, while other forms may not appear until middle age or later.

Question 30

Duchenne’s Muscular Dystrophy

Answer 30

sex linked disease
females can be carriers
*is the most common form of MD
it primarily affects boys, since the recessive mutation in the p21 gene on the X chromosome; since males have one X they usually have the disease, whereas, females are carriers of the disease
the p21 gene codes for the protein dystrophin, which is involved with maintaining the integrity of the muscle; therefore, dystrophin is absent in people with Duchenne’s MD
onset is between 3 and 5 years, and progresses rapidly; most boys are unable to walk by age 12
**symptoms include: progressive difficulty walking; frequent falls; fatigue; and muscle deformities
diagnosis; a CPK test is performed to measure creatine phosphokinase to determine if the muscles are damaged; in Duchenne’s MD, CPK leaks out of the muscle cell and into the blood, so a higher level of CPK would confirm that the muscle is damaged
some boys die in infancy, while others have a pro-longed life span into adulthood; depending on the rate of progression of the disease
NO CURE

Question 31

Becker Muscular Dystrophy

Answer 31

**is a less severe form of Duchenne’s MD
have faulty or not enough dystrophin
onset is at about age 12 years; most men are unable to walk by age 25 to 30 years
***symptoms include: progressive muscle weakness of legs and pelvis; muscle weakness also occurs in arms, neck, and other areas of the body, but not as severely as in the lower half of the body; fatigue
diagnosis; CPK test

Question 32

Facioscapulohumeral Muscular Dystrophy:

Answer 32

**usually begins in the teenage years
**progressive weakness in muscles of the face, arms, legs, and around the shoulders and chest
it progresses slowly, and can vary in symptoms from mild to disabling

Question 33

Myotonic Muscular Dystrophy:

Answer 33

**most common adult form MD
**symptoms include; prolonged muscle spasms; cataracts; cardiac disturbances; and endocrine disturbances
individuals with Myotonic MD have long, thin faces, drooping eyelids, and a swan-like neck

Question 34

Myasthenia Gravis:

Answer 34

“ grave muscle weakness “; progressive muscle weakness
**chronic, autoimmune neuromuscular disease
is caused by a defect in the transmission of nerve impulses to muscles
**antibodies block, alter, or destroy the receptors for acetylcholine at the neuromuscular junction; prevents muscle contraction from occurring
usually affects any skeletal muscles, and muscles that control eye and eyelid movement, facial expression, and swallowing
**occurs in both genders; most commonly affects young adult women (under 40 years), and older men (over 60 years), but can occur at any age
diagnosis with a blood test to measure presence of acetylcholine receptor antibodies
can use medications to help reduce and improve muscle weakness; acetylcholinesterase agents such as neostigmine, which help improve neuromuscular transmission, and increase muscle strength
patients can periodically go into remission and no symptoms occur