BackAnatomy & Physiology Lab Exam 2 Review
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Terms in this set (30)
Orbicularis oris is a circular muscle surrounding the mouth that closes, puckers, and protrudes the lips, often called the "kissing muscle".
Orbicularis oculi is a circular muscle around the eye that closes the eyelids during blinking, winking, and squinting.
Zygomaticus major extends from the zygomatic bone to the mouth corner and elevates and retracts the mouth corners to produce a smile.
Risorius is a slender muscle running horizontally across the cheek that draws the mouth corner laterally, producing a smirk or smile.
Epicranius is a bipartite muscle covering the skull top, with frontal and occipital bellies connected by an aponeurosis; it raises eyebrows and wrinkles the forehead.
Platysma is a broad superficial muscle on the anterior neck that tenses neck skin and depresses the lower jaw.
SCM is a two-headed neck muscle; bilateral contraction flexes the neck forward, unilateral contraction rotates the head toward the opposite shoulder.
Temporalis is a fan-shaped muscle over the temporal bone that elevates and retracts the mandible to close the jaw.
Masseter is a powerful muscle at the jaw angle; it is the prime mover of jaw closure, elevating the mandible during chewing.
Buccinator is the principal cheek muscle that compresses cheeks inward, enabling whistling, blowing, sucking, and keeping food between teeth while chewing.
Erector spinae is a large muscle group running vertically along the spine; it is the prime mover of back extension and helps maintain erect posture.
External intercostals are superficial muscles between ribs that elevate the rib cage during inhalation to expand the chest cavity.
Internal intercostals are deeper muscles between ribs that depress the rib cage during forced expiration (exhalation).
Diaphragm is a large dome-shaped muscle separating thoracic and abdominal cavities; its contraction flattens the dome, drawing air into the lungs (prime mover of inspiration).
Deltoid is the thick, triangular shoulder muscle responsible for arm abduction.
The rotator cuff group includes supraspinatus, infraspinatus, teres minor, and subscapularis; they stabilize the shoulder joint and assist arm rotation.
Biceps brachii is a two-headed muscle on the anterior arm that flexes the elbow and supinates the forearm.
Triceps brachii is the three-headed muscle on the posterior arm that extends the elbow.
The quadriceps group includes rectus femoris, vastus lateralis, vastus medialis, and vastus intermedius; they extend the knee.
The hamstrings include biceps femoris, semitendinosus, and semimembranosus; they flex the knee and extend the hip.
Gastrocnemius is a large calf muscle that plantarflexes the foot and flexes the knee.
Soleus lies beneath the gastrocnemius and also plantarflexes the foot.
Tibialis anterior is a muscle on the anterior leg that dorsiflexes and inverts the foot.
Fibularis longus is a lateral leg muscle that everts and plantarflexes the foot.
Dendrites are branched extensions of a neuron that receive signals from other neurons.
Axon is a long projection that transmits electrical impulses away from the neuron's cell body.
Myelin sheath is a fatty layer that insulates axons to speed up nerve impulse conduction.
Node of Ranvier is a gap in the myelin sheath where ion exchange occurs to propagate nerve impulses.
Olfactory nerve (I) is responsible for the sense of smell.
Optic nerve (II) transmits visual information from the retina to the brain.