Muscular System Tiffany Silvas p.4 (Body Movement Terminology (opposition-…
Muscular System Tiffany Silvas p.4
Major Functions of the Muscular System
Digestion- (smooth muscles in the gastrointestinal or GI tract control digestion)
Urination- (urinary system compromise both smooth & skeletal muscle)
Respiration- (breathing involves using the diaphragm muscle)
Childbirth- (smooth muscles are in the uterus & contract/expand during childbirth)
Circulation- (the heart is a muscle that pumps blood throughout the body)
Vision- (there are skeletal muscles around the eye and they control movement)
Posture- (skeletal muscles help keep the body in the correct position when someone is sitting or standing.)
Organ Protection- (muscle in the torso protect the internal organs)
Stability- (muscle tendons stretch over joints & contribute to joint stability)
Temperature Regulation- (the muscle system is responsible for maintaining a normal body temperature)
Mobility- (allows movement. when muscles contract, they contribute to gross movement)
Types of Muscle Tissue
Cardiac: function- contracts the heart & pumps blood. main characteristics- involuntary & striated/branched.
Smooth: function- forms organs like the stomach & bladder. main characteristics- involuntary & nonstriated.
Skeletal: function- moves bones & other structures.
main characteristics- voluntary & striated
Head and Face Category
Orbicularis Oculi- closes the eyelid, and to help in the passing and draining of tears through the punctum, canaliculi, and lacrimal sac, all parts of the tear drainage system.
Zygomaticus- muscle that controls facial expression, drawing the mouth's angle upward and outward.
Orbicular Oris- controls movements of the mouth and lips.
Frontalis- raises the eyebrows which also causes the skin of the forehead to wrinkle.
Masseter- helps a person bite down or chew.
Temporalis- chewing muscle
Neck and Torso Category
Pectoralis major- primarily responsible for movement of the shoulder joint.
Deltoid- contraction of the anterior fibers flexes and medially rotates the arm by pulling the humerus towards the clavicle. also. abduction of the arm results in the arm moving away from the body, as in reaching out to the side.
Sternocleidomastoid- flexes the neck and helps with movement of the head.
Biceps brachii- helps control the motion of two different joints, the shoulder and the elbow.
Rectus Abdominis- flexion of the trunk (flexion of thoracic and lumber spine)
Transverse Abdominus- maintains tone of the abdominal organs
External Oblique- helps pull the chest, as a whole, downwards, which compresses the abdominal cavity.
Sartorius- moves the hip joint and the knee joint,
Gracilis- responsible for hip adduction and assists knee flexion.
Adductor Longus- to adduct the thigh and it is innervated by the obturator nerve.
Tensor Fascia Latae- works in synergy with the gluteus medius and gluteus minimus muscles to abduct and medially rotate the femur.
Rectus Femoris- helps to extend or raise the knee.
Semitendinosus- works to flex the knee and extend the hip.
Triceps Brachii- responsible for extension of the elbow joint (straightening of the arm).
Trapezius- elevates, depresses, rotates, and retracts the scapula (shoulder blade)
Latissimus dorsi- responsible for extension, adduction, transverse extension, flexion from an extended position, and (medial) internal rotation of the shoulder joint.
Biceps Femoris- extends the thigh, bending the knee, and rotating the knee
Gluteus Medius- works to provide rotation of the thigh outward from the center of the body.
Vastus Medialis- involved in knee extension, along with the other muscles which make up the quadriceps muscle.
Gastrocnemius- plantar flexing the foot at the ankle joint and flexing the leg at the knee joint.
Vastus Lateralis- extends the lower leg and allow the body to rise up from a squatting position.
Adductor Magnus- contracts and pulls the hip towards the body's midline.
Gluteus Maximus- responsible for movement of the hip and thigh.
Tibialis Anterior- acts to dorsiflex and invert the foot
Peroneus Longus- acts to evert and plantarflex the ankle.
Structure & Organizational Levels of Skeletal Muscle
LARGEST TO SMALLEST: Sarcolemma, Myofibril, Sarcomere, Myofilament. (sarcolemma is the specialized plasma membrane of skeletal muscle cells)
Body Movement Terminology
extension- straightening movement that increases the angle.
abduction- movement of the body part away from sag. plane.
flexion- bending movement that decreases the angle.
adduction- movement of body part toward sag plane.
circumduction- combo of abduction & adduction.
rotation- motion that occurs as one body part turns on an axis.
opposition- motion in which body parts are brought together.
pronation- rotary motion of the forearm that turns the palm from anteriorly facing to posteriorly facing.
supination- rotary motion of the forearm that returns the palm to a position in which the thumb is lateral.
dorsiflexion- flexion of the entire foot away from the ground.
plantarflexion- flexing of the entire foot inferiorly, toward the ground at the ankle.
eversion-turning the sole of the foot outward, facing away from the midline.
inversion- turning the sole of the foot inward, facing towards the midline.
Physiology of Muscle Contraction
2) Actin and myosin cross-bridge formation
1) Depolarisation and calcium ion release
3) Sliding mechanism of actin and myosin filaments
4) Lastly, Sarcomere shortening (muscle contraction)
Amyotrophic lateral sclerosis (ALS) - fatal type of motor neuron disease
Muscular dystrophy- group of genetic diseases that cause progressive weakness of the body's muscles.
Multiple sclerosis- a long-lasting (chronic) disease of the central nervous system.
Myasthenia gravis- a chronic autoimmune disorder in which the body attacks its own neuromuscular connections.
Charcot-Marie-Tooth disease- inherited nerve problem. (causes abnormalities in the nerves that supply your feet, legs, hands, and arms)
Myopathy- general term referring to any disease that affects the muscles that control voluntary movement in the body.
Myositis - rare group of diseases characterized by inflamed muscles, which can cause prolonged muscle fatigue and weakness.
Peripheral Neuropathy- refers to the conditions that result when nerves that carry messages to and from the brain and spinal cord from and to the rest of the body are damaged or diseased.