6.1 The Muscular System Flashcards
CLASSIFICATION OF MUSCLES BY LOCATION
- Skeletal muscles
- Visceral muscles
- Cardiac muscles
usually attached to bones
Skeletal muscles
in the walls of some organs
Visceral muscles
in the heart, myocardium
Cardiac muscles
striated, voluntary
Skeletal
nonstriated, involuntary
Visceral
striated, involuntary
Cardiac
the red lean meat of the body, make up almost half of the body weight
Skeletal muscles
Skeletal muscle usually controlled by the
cerebrum
muscle cells
Muscle fibers
many fine threadlike structure
Fibrils or myofibrils
a layer of connective tissue
Fascia
are usually attached at each to a bone, but some are attached to a cartilage, a ligament, another muscle or to the skin
Skeletal muscles
The attachment to bone is by ______, usually a ______, but sometimes directly to a bone
connective tissue,
tendon or aponeurosis
of a muscle is its more fixed, less movable attachment, usually its proximal end
Origin
of a muscle is its more movable end, usually its distal end
Insertion
is a cordlike fibrous connective structure that extends from the end of a muscle to a bony attachment
Tendon
Tendon sometimes called a
sinew cord, or leader
is a sheet of fibrous connective tissue that is often attached at one end to a muscle, often flat muscle and by the other end to a bone, cartilage, ligament or other muscle
Aponeurosis
is a tunnel-like channel that surrounds a tendon
A tendon sheath
is an inflammation of a tendon sheath
Tenosynovitis
is a saclike structure lying between a muscle or tendon and an adjacent bony prominence over which the muscle tendon moves
Bursa
is an inflammation of a bursa and it is frequently very painful
Bursitis
the deposition of calcium, may occur in a bursa or tendon sheath
Calcification
muscles do not completely relax when at rest, but remain partly contracted
Muscle Tone
the main function of all muscles is to _____ and cause movement of the body or a part of it
contract (Contraction)
Muscle that cross a joint to insert into a bone and cause movement are located ______ to that joint
proximal
are muscles that initiate and carry out some movement
Prime Movers
are muscles that perform some movement opposite to that caused by the prime movers
Antagonists
are muscles that act with the prime movers to accomplish some movement but prevent unwanted movement
Synergists
are those that hold the adjacent bones in a fixed position so that the prime movers may accomplish some certain movement
Fixation muscles
the maintenance of the upright position of the body consists of a balanced contraction of some muscle groups and the partial relaxation of opposing groups
Posture
is a contraction of muscles that may persist for a long period of time, without relaxation
Muscle spasm
follows injury to, or destruction of, the nerves supplying that muscle
Paralysis of muscles
may attack cells in the spinal cord that supply motor nerves to skeletal muscles
Poliomyelitis (infantile paralysis)
is the property of being able to respond to stimuli
Irritability
is the ability to conduct impulses from nerves, from electrical stimuli
Conductivity
is the facility or stretching. This occurs by a lengthening of the fibrils of each muscle fibers
Extensibility
the ability to return to the original length following stretching
Elasticity
is the ability to become shorter, and is dues to a shortening with thickening of each fibril of each muscle fiber
Contractility
FUNCTIONS OF MUSCLES
- Skeletal muscles contract and cause movement
- They maintain position (posture) in the upright and other positions of the body
- They give support to joints by maintaining a partial state contraction
HOW MUSCLES ARE NAMED
- By Location – Pectoralis major
- By Shape – Quadratus, deltoid
- By Direction of Fibers – Transversus, oblique
- By Action – Flexor digitorum
- Number of Parts – Biceps, triceps, quadriceps
a partition
(G) Diaphragma
diaphragm
(G) Phren
Dome-shaped muscular partition that separates the thorax and abdomen
Diaphragm
Diaphragm 3 large openings
- Aortic hiatus
- Esophageal hiatus
- Opening of the inferior vena cave
thick fan-shaped muscle that covers the upper anterior chest wall
Pectoralis Major Muscle
costodiaphragmatic recess
Costophrenic Sinus
muscle lies lateral to the lumbar vertebrae in the posterior wall of the abdomen
Psoas Major Muscle
fill in the spaces between adjacent ribs, and their costal catilages
Intercostal Muscles
The tops of the dome lie well above the costal margins and may reach the ____ ribs
4th
Following inspiration, they lie at a lower level that the following expiration
Diaphragm
With the subject lying down the ____ lies at a higher level than when upright
Diaphragm
Air escaping from a hole in the wall of the stomach or intestine will rise to the _____ possible level in the abdomen
highest
The _____ must be included in both chest and abdomen radiography
Diaphragm
EXAMPLE OF LIGAMENTS AND TENDONS
- Inguinal ligament
- Patellar ligament
- Ligamentum teres
- Calcaneal tendon
WEAK ABDOMINAL AREAS
- Umbilical Area
- Inguinal Area
- Femoral Area
