Chapter 9 terms Flashcards
Definition: calat-
Something inserted
Definition: erg-
Work
Definition: fasc-
Bundle
Definition: -gram
Something written
Definition: hyper-
Over, more
Definition: inert-
Between
Definition: iso-
Equal
Definition: laten-
Hidden
Definition: myo-
Muscle
Definition: reticul-
A net (network)
Definition: sarco-
Flesh
Definition: syn-
Together
Definition: tetan-
Stiff
Definition: -tonic
Stretched
Definition: -troph
Well fed
Definition: voluntar-
Of one’s free will
Fascia
Layers of dense connective tissue; surrounds each muscle and may project beyond the ends of its muscle fibers, forming cordlike tendon.
Tendon
A flexible but inelastic cord of strong fibrous collagen tissue attaching a muscle to a bone.
Aponeurosis (plural: aponeuroses)
A sheet of pearly-white fibrous tissue that takes the place of a tendon in sheetlike muscles having a wide area of attachment.
Myofibrils
Any of the elongated contractile threads found in striated muscle cells.
Myosin
A fibrous protein that forms (together with actin) the contractile filaments of muscle cells and is also involved in motion in other types of cells.
Actin
A protein that forms (together with myosin) the contractile filaments of muscle cells, and is also involved in motion in other types of cells.
Sarcomere
A structural unit of a myofibril in striated muscle, consisting of a dark band and the nearer half of each adjacent pale band
Titin
A protein important in the contraction of striated muscle tissues
Troponin
A globular protein complex involved in muscle contraction. It occurs with tropomyosin in the thin filaments of muscle tissue
Tropomyosin
A protein involved in muscle contraction. It is related to myosin and occurs together with troponin in the thin filaments of muscle tissue
Sarcoplasmic reticulum
A specialized form of endoplasmic reticulum surrounding myofibers. A membrane system responsible for storing, releasing, and resequestering calcium in response to an action potential.
Transverse tubule
a deep invagination of the sarcolemma, which is the plasma membrane, only found in skeletal and cardiac muscle cells
Cisternae
a sac or cavity containing fluid.
Triad
The structure formed by a T tubule with a sarcoplasmic reticulum (SR) known as the terminal cisterna on either side.
Synapse
A junction between two nerve cells, consisting of a minute gap across which impulses pass by diffusion of a neurotransmitter
Neurotransmitters
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
Motor neurons
A nerve cell forming part of a pathway along which impulses pass from the brain or spinal cord to a muscle or gland
Neuromuscular junction
A neuromuscular junction (NMJ) is the synapse or junction of the axon terminal of a motoneuron with the motor end plate
Motor end plate
the flattened end of a motor neuron that transmits neural impulses to a muscle
Synaptic cleft
The space between a presynaptic and postsynaptic membrane, containing extracellular fluid (ECF). Neurotransmitters must diffuse across this cleft to activate postsynaptic receptors.
Acetylcholine (ACh)
A compound that occurs throughout the nervous system, in which it functions as a neurotransmitter.
ATPase
ATPases are a class of enzymes that catalyze the decomposition of adenosine triphosphate (ATP) into adenosine diphosphate (ADP) and a free phosphate ion.
Sliding filament model
When sarcomeres shorten, the thick and thin filaments do not change length. They slide past one another, with the thin filaments moving toward the center of the sarcomere from both ends.
Acetylcholinesterase
An enzyme that causes rapid hydrolysis of acetylcholine. Its action serves to stop excitation of a nerve after transmission of an impulse
Creatine phosphate
A compound produced in the body, stored in the muscle fibers, and broken down by enzymes to quickly replenish the adenosine-triphosphate stores.
Myoglobin
A red protein containing heme that carries and stores oxygen in muscle cells. It is structurally similar to a subunit of hemoglobin
Lactic acid threshold
amount of effort it takes before the body switches from aerobic exercise to anaerobic.
Oxygen debt
a cumulative deficit of oxygen resulting from intense exercise; the deficit must be made up when the body returns to rest
Twitch
The contractile response of a single muscle fiber to a muscle impulse.
Threshold stimulus
The weakest stimulus capable of producing an action potential in an excitable cell.
Summation
Summation is a method of achieving or inhibiting action potential in the postsynaptic neuron, when one presynaptic neuron does not generate enough neurotransmitter.
Tetanic contraction
Occurs when a motor unit has been maximally stimulated by its motor neuron.
Recruitment (multiple motor unit summation)
The combined effect of a number of motor units acting within a muscle at any given time.
Muscle tone
The tension present in resting muscles.
Isotonic contraction
The force of the muscle fibers remains constant but the speed may vary.
Concentric contraction
Shortening
Eccentric contraction
Lengthening; occurs when the force a muscle generates is less than that required to move or lift an object.
Isometric contraction
When a muscle strains against a resistance but does not change in length; the length stays the same but the force changes.
Multiunit smooth muscle
Smooth muscle containing few tight junctions, but richly innervated; responds as individual motor units, not as a single unit.
Visceral smooth muscle (single-unit smooth muscle)
Smooth muscle containing many tight junctions that contracts as a unit and responds to stretch.
Peristalsis
The involuntary constriction and relaxation of the muscles of the intestine or another canal, creating wavelike movements that push the contents of the canal forward
Levers
Simple mechanical devices
Origin of skeletal muscle
The less movable end of a joint.
Insertion of skeletal muscle
The more movable end.
Agonist
A muscle whose contraction moves a part of the body directly
Synergist
Synergist is a kind of muscle which performs, or assist in performing, the same set of joint motion as the agonists.
Prime mover
An agonist may be called a prime mover if it is doing most of the work.
Antagonist
A muscle that relaxes while another contracts
Pectoralis major
A muscle of large size (major) in the pectoral region (chest).
Deltoid
Shaped like a delta or triangle
Extensor digitorum
Extends the digits
Biceps brachii
A muscle with two heads (biceps), or points of origin, in the brachium (arm).
Sternocleidomastoid
Attached to the sternum, clavicle, and mastoid process.
External oblique
Located near the outside, with fibers that run obliquely or in a slanting direction.
Epicranius
Covers the upper part of the cranium and consists of two muscular parts– the frontalis and the occipitalis.
Orbicularis oculi
A ring-like band of muscle, called a sphincter muscle, that surrounds the eye.
Orbicularis oris
A sphincter muscle that encircles the mouth.
Buccinator
Located in the wall of the cheek. When its fibers contract, the cheek is compressed inward.
Zygomaticus major and minor
Extend from the zygomatic arch downward to the corner of the mouth. When they contract, the corner of the mouth is drawn upward.
Platysma
A thin, sheetlike muscle whose fibers extend from the cheek upward over the neck to the face. It pulls the angle of the mouth downward, as in pouting.
Masseter
A thick, flattened muscle in front of the ear. Its fibers extend downward from the zygomatic arch to the mandible. The masseter raises the jaw, controls the rate at which the jaw falls open in response to gravity.
Temporalis
A fan-shaped muscle that runs from the side of the skull to the back of the lower jaw and is involved in closing the mouth and chewing
Medial pterygoid
Closes the jaw and moves it from side to side.
Later pterygoid
Can open the mouth, pull the mandible forward, and move the mandible from side to side.
Sternocleidomastoid
Each of a pair of long muscles that connect the sternum, clavicle, and mastoid process of the temporal bone and serve to turn and nod the head
Splenius capitis
Deep back muscles that control the veretebral column, acting in concert with many other muscles. The splenius capitis and splenius cervicis, working together, retract the head. Singly, they turn it to the side, working with the sternocleidomastoid muscle.
Semispinalis capitis
Extends the head, bends it to one side, or rotates it.
Quadratus lumborum
Muscle in the back which attaches to the top of the pelvis and the spine in the upper lumbar area. Its function is to hike the hip.
Erector spinae
Muscles of the spine that lie posteriorly. These are commonly known as the “anti-gravity” muscles.
Trapezius
Either of a pair of large triangular muscles extending over the back of the neck and shoulders and moving the head and shoulder blade
Rhomboid major
The rhomboid major is a major muscle on the back that connects the scapula with the vertebrae of the spinal column.
Levator scapulae
Upper back muscles that elevate the shoulders.
Serratus anterior
Muscles that rotate the scapula and elevate the rib cage.
Pectoralis minor
A skeletal muscle that draws down the scapula or raises the ribs
Coracobrachialis
Flexor; Muscle with its origin on the scapula and insertion on the inner side of the humerus and functions by flexing and adducting the arm and shoulder.
Pectoralis major
Flexor; a skeletal muscle that adducts and rotates the arm
Teres major
Extensor; Flat muscle of the shoulder which functions to adduct, extend, and rotate the arm medially.
Latissimus dorsi
Extensor; Large muscle on the back which attaches to the upper arm and is used to pull the arm to the side.
Supraspinatus
Abductors; A small muscle at the top of the shoulder blade, abducts the arm
Deltoid
Abductor; a thick triangular muscle covering the shoulder joint and used for raising the arm away from the body
Subscapularis
Rotator; it connects the scapula to the humerus and rotates the arm medially.
Infraspinatus
Rotator; a muscle below the spine, rotates the arm laterally
Teres minor
Rotator; teres muscle that adducts the arm and rotates it laterally
Flexor; connects the scapula to the radius and flexes the elbow and rotates the hand laterally.
Biceps brachii
Brachialis
Flexor; a large muscle beneath the biceps brachii, is the strongest flexor of the elbow.
Brachioradialis
Flexor; connects the humerus to the radius; aids in flexing the elbow
Triceps brachii
Extensor; has three heads, is the only muscle on the back of the arm; primary extensor of the elbow.
Supinator
Rotator; assists the biceps brachii in rotating the forearm laterally.
Pronator teres
Rotator; rotates the arm medially
Pronator quadratus
Rotator; assists the pronator teres in rotating the arm medially
Flexor carpi radialis
Flexor; flexes the wrist and abducts the hand
Flexor carpi ulnaris
Flexor; flexes the wrist and adducts the hand
Palmaris longus
Flexor; connects the distal end of the humerus to fascia of the palm and flexes the wrist
Flexor digitorum profundus
Flexor; flexes the distal joints of the fingers, such as when making a fist.
Flexor digitorum superficialis
Flexor; flexes the wrist
Extensor carpi radialis longus
Extensor; extends the wrist and assists in abducting the hand
Extensor carpi radialis brevis
Extensor; assists in abducting the hand
Extensor carpi ulnaris
Extensor; extends the wrist and assists in adducting the hand
Extensor digitorum
Extensor; extends the fingers
Linea alba
A narrow, longitudinal, whitish band of tendonous tissue found along the mid-ventral line.
External oblique
Abdominal muscle primarily responsible for lateral flexion of the spine.
Internal oblique
Abdominal muscle primarily responsible for lateral flexion of the spine.
Transverse abdominis
Deepest layer of the abdominal wall. Responsible for abdominal compression.
Rectus abdominis
Abdominal wall muscle primarily responsible for forward flexion.
Levator ani
Main muscle group supporting the pelvic floor
Coccygeus
A fan shaped muscle; aids the levator ani
Superficial transversus perinei
Assists other muscles in supporting the pelvis viscera.
Bulbospongiosus
In a female, these muscles constrict the vaginal opening; can also retard the flow of blood in veins, which helps maintain an erection of the penis in men and the clitoris in the female.
Sphincter urethrae
Closes the urethra by compression and opens it by relaxation, helping control the flow of urine.
Psoas major
Anterior thigh muscle; flexes the thigh
Iliacus
Anterior thigh muscle; a primary flexor of the thigh along with psoas major, advances the lower limb in walking movements
Gluteus maximus
Posterior thigh muscle; largest muscle of the body; helps straighten the lower limb at the hip when a person walks, runs, or climbs.
Gluteus medius
Posterior thigh muscle; abduct the thigh and rotate it medially.
Piriformis
Posterior thigh muscle; lies beneath the gluteus medius and is its companion in attachments and functions
Tensor fasciae latae
Posterior thigh muscle; abducts and flexes the thigh and rotates it medially
Pectineus
Thigh adductor; flexes and adducts the thigh
Adductor brevis
Thigh adductor; adducts and assists in flexing the thigh
Adductor longus
Thigh adductor; adducts the thigh and assists in flexing and rotating it laterally
Adductor magnus
Thigh adductor; largest adductor of the thigh; adducts the thigh and portions assists in flexing and extending the thigh
Gracilis
Thigh adductor; adducts the thigh and flexes the leg at the knee.
Biceps femoris
Leg flexor; hamstring muscle; flexes and rotates the leg laterally and extends the thigh
Semitendinosus
Leg flexor; hamstring muscle; flexes and rotates the leg medially and extends the thigh
Sartorius
Leg flexor; connects the ilium to the tibia and flexes the leg and the thigh. It can also abduct the thigh and rotate it laterally.
Quadriceps femoris
Leg extensor; the primary extensor of the knee
Tibialis anterior
Dorsal flexor; contraction causes dorsiflexion and inversion of the foot.
Fibularis tertius
Dorsal flexor; it functions in dorsiflexion and eversion of the foot
Extensor digitorum longus
Dorsal flexor; actions include dorsiflexion of the foot, eversion of the foot, and extension of the toes
Extensor hallucis longus
Dorsal flexor; contraction extends the great toe, dorsiflexes and inverts the foot.
Gastrocnemius
Plantar flexor; the chief muscle of the calf of the leg, which flexes the knee and foot.
Soleus
Plantar flexor; A broad muscle in the lower calf, below the gastrocnemius, that flexes the foot to point the toes downward
Plantaris
Plantar flexor; when it contracts it flexes the foot, and because it crosses the knee joint it, it also flexes the knee.
Flexor digitorum longus
Plantar flexion; serves to curl the second, third, fourth, and fifth toes
Tibialis posterior
Assists in inversion and plantar flexion of the foot.
Fibularis longus
Everts the foot, assists in plantar flexion, and helps support the arch of the foot.
Plantaris
Plantar flexor; when it contracts it flexes the foot, and because it crosses the knee joint it, it also flexes the knee.
