Muscular System Flashcards
Muscular System- Movement Function
muscles act as motors by shortening or lengthening under the control of the nervous system
Excitability
or IRRITABILITY is the capacity of the muscles to respond to a stimulus (chemical , electrical or mechanical) or nerve impulses from the brain and spinal cord
Muscular System- Heat Production Function
the use of muscles can cause chemical changes that release heat or energy
Muscular System- Posture Function
The partial contraction of skeletal muscles helps to maintain posture and body position
Muscular System- Protection Function
the partial contraction of skeletal muscles form a wall that protects the viscera of the abdominopelvic cavities
Contractility
The capacity of the muscle fiber to shorten and tighten;
Smooth Muscle
Involuntary, not under conscious control, controlled by ANS, action is slow, visceral organs
Skeletal Muscle
Voluntary, action is fast, attached to skeleton, act as opposing groups or teams-each performing the opposite function
Cardiac Muscle
Involuntary, not under conscious control, under the control of ANS, variable speed, heart only, capable of beating on its own without nervous system stimulation
Muscle Fibers
The cells of the muscle tissue are long and thread-like, hence their name muscle fibers. Muscle fibers form bundles called FASCICLES
Connective Tissue
Muscle fibers are arranged in bundles and are held together with connective tissue. Connective tissue that covers individual muscle fibers is called the ENDOMYSIUM and connective tissue that covers each *fascicle is called the PERIMYSIUM
Epimysium
A tough connective tissue sheath which encloses the entire muscle
Tendons
White glistening cords or bands of fibrous tissue that help to hold the muscles to the bone of the skeleton.
Aponeurosis
A broad sheet of fibrous connective tissue that attaches muscle to bone or to other muscles; examples abdominal muscles or muscles of the skull.
Muscle body (belly)
Part of a muscle that is the main part, usually in the center where it bellies out when contracted
Muscle origin
The part of a muscle that is attached to the stationary bone, end closer to the trunk
Muscle insertion
Part of the muscle that is attached to the moveable bone
Prime Mover
Muscle that performs a given movement
Antagonist
Muscle that performs opposite movement
Muscle Tone
A normal state of slight continuous tension in the muscle tissue that is maintained by reflexing activity and which facilitates its response to stimulation; Poor muscle tone due to lack of exercise, poor health, old age and lost during sleep.
Muscle hypertrophy
The over development of muscle fibers or an increase in the size of muscles fibers due to heavy usage
Muscle atrophy
The wasting away and shrinkage of muscle tissue due to inability such as paralysis
Muscle fatigue
Possibly due to oxygen debt in the muscles due to strenuous activity. Lactic acid is produced and is store in the muscle until adequate amount of oxygen can be supplied. Lactic acid is the byproduct of incomplete metabolism, must be broken down to carbon dioxide, energy and water
Rigor mortis
Stiffness in corpses or cadavers; no energy is available to relax the muscles. Once decomposition starts to occur (days) rigor mortis disappears.
Muscle spasm and colic (cramp)
Involuntary muscle contraction, usually sudden, persistent and painful, can be intermitted or continuous; due to stress, strain, electrolyte or pH imbalance (sodium, calcium, etc.) as well as injury or over stretching. SPASM in skeletal muscle and COLIC in smooth muscle (stomach).
Muscle sprain
Excessive strain on a muscle which will cause the detachment of the muscle from the bones or involve damage to the ligaments, blood vessels or nerves that support the muscle
Tendinitis
Inflammation of the muscle tendons and/or their attachments. Caused by repeat trauma, strain or excessive exercise. Common sites are the shoulder, hip, hamstrings and Achilles (heel) tendon.
Carpal Tunnel Syndrome
Involves the tendons of the muscle of the fingers and the nerves of the fingers. Repetition of an activity is the cause.
Nerve Fiber
Carry impulses to the muscles. A bundle of axons within the PNS is a nerve.
Nerve branches
The nerve fiber extends from the cell body and often gives rise to many smaller nerve branches before ending at nerve terminals. A single axon can have multiple branches.
Neurotransmitter
A chemical substance that is released at the end of a nerve fiber by the arrival of a nerve impulse and, by diffusing across the synapse or junction, causes the transfer of the impulse to another nerve fiber, a muscle fiber, or some other structure
Neurotransmitter vesicles
In a neuron, synaptic vesicles (or neurotransmitter vesicles) store various neurotransmitters that are released at the synapse.
Muscle receptor
Muscle spindles are stretch receptors within the body of a skeletal muscle that primarily detect changes in the length of the muscle.
Biceps brachii
A muscle on the front of the arm that flexes the elbow and supinates the hand
Orbicularis oculi
A muscle that closes the eyelid
Orbicularis oris
Also known as musculus orbicularis oris is a complex, multi-layered muscle which attaches through a thin, superficial musculoaponeurotic system to the dermis of the upper lip and lower lip and serves as an attachment site for many other facial muscles around the oral region
Masseter
A muscle which runs through the rear part of the cheek from the temporal bone to the lower jaw on each side and closes the jaw in chewing
Sternocleidomastoid
A muscle on the side of the neck that flexes the head
Tapezius
A triangular muscle on the back of the neck and the upper back that extends the head
Deltoid
The muscle capping the shoulder and upper arm
Pectoralis major
The superior most and largest muscle of the anterior chest wall
Intercostals
Muscles between the ribs that can enlarge the thoracic cavity
External oblique
One of the outermost abdominal muscles, extending from the lower half of the ribs around and down to the pelvis
Internal oblique
A muscle found on the lateral side of the abdomen
Rectus abdominis
Makes up the top layer of your abdominal muscles, commonly referred to as your “six-pack.”
Abdominal aponeurosis
Encloses the long muscles located in the stomach area, from the bottom of the chest to the top of the pubic area
Quadriceps femoris
The muscle that flexes the thigh and extends the lower leg.
Gastrocnemius
The chief muscle of the calf of the leg and the muscle that causes plantar flexion of the foot.
Tibialis anterior
Also known as the tibialis anticus, is the largest of four muscles in the anterior compartment of the leg
Triceps brachii
The large muscle on the back of the arm that extends the elbow
Gluteus maximus
The main extensor muscle of the hip. It is the largest and outermost of the three gluteal muscles and makes up a large part of the shape and appearance of each side of the hips. It is the single largest muscle in the human body.
Cranial aponeurosis
A tough fibrous sheet of connective tissue that extends over the cranium, forming the middle (third) layer of the scalp
Hamstring Group
The semitendinosus, semimembranosus, and biceps femoris muscles comprise the hamstring muscle group. Beginning at the pelvis and running posteriorly along the length of the femur, the majority of muscles within the hamstring complex cross both the femoroacetabular and tibiofemoral joints
Buccinator
Plays an active role along with the orbicularis oris and superior constrictor muscle during swallowing, mastication, blowing, and sucking
Fascicle
A bundle of muscle fibers
