Which muscle is the prime mover of extension of the forearm at the elbow?
Triceps brachii
✓
Brachialis
Anconeus
Coracobrachialis
Correct Answer
Triceps brachii
The triceps brachii, on the back of the arm, inserts on the olecranon of the ulna and is the prime mover of elbow extension. Brachialis flexes the forearm at the elbow, the opposite action. Anconeus is a small muscle that only assists the triceps in extension. Coracobrachialis acts at the shoulder, flexing and adducting the arm.
Category: Upper Limb
Question 2
The pectoralis major arises from a broad area of the chest, and its fascicles come together at a single tendon on the humerus. Which fascicle arrangement does this describe?
Parallel
Convergent
✓
Circular
Unipennate
Correct Answer
Convergent
A convergent muscle has a wide origin whose fascicles fan inward toward one attachment point, which lets it pull in several directions. Parallel muscles have fascicles running along the length of the muscle. Circular muscles form rings around openings. Unipennate muscles have fascicles attached to only one side of a central tendon.
Category: Fascicle Arrangement
Question 3
The deltoid has fascicles that attach to several tendons running through the muscle, so different parts can pull the arm in different directions. What is this arrangement called?
Unipennate
Bipennate
Multipennate
✓
Fusiform
Correct Answer
Multipennate
A multipennate muscle has fascicles attached obliquely to multiple tendons, and the deltoid is the classic example. Unipennate muscles have fascicles on one side of a single tendon. Bipennate muscles have fascicles on both sides of a single central tendon. Fusiform muscles are parallel muscles with a spindle-shaped belly.
Category: Fascicle Arrangement
Question 4
The adductor longus is named for its action and for which other feature?
Its shape
Its location
Its number of heads
Its length
✓
Correct Answer
Its length
Longus means long, so the name describes the relative length of the muscle, while adductor describes its action. Its shape would be described by terms such as deltoid or rhomboid. Its location would be described by terms such as femoris or abdominis. Its number of heads would be described by terms such as biceps or triceps.
Category: Naming Muscles
Question 5
The suffix -ceps, as in biceps and quadriceps, describes which feature of a muscle?
Number of origins
✓
Fascicle direction
Relative size
Overall shape
Correct Answer
Number of origins
The suffix -ceps means head, and the prefix tells how many heads, or origins, the muscle has. Fascicle direction is described by terms such as rectus, oblique and transversus. Relative size is described by terms such as maximus and minimus. Overall shape is described by terms such as deltoid and trapezius.
Category: Naming Muscles
Question 6
What does the word rectus tell you about a muscle such as the rectus abdominis?
Its fascicles run diagonally to the midline
Its fascicles run parallel to the midline
✓
Its fascicles run across the midline
Its fascicles encircle an opening
Correct Answer
Its fascicles run parallel to the midline
Rectus means straight, so a rectus muscle has fascicles running parallel to the body midline or to the long axis of a bone. Fascicles that run diagonally to the midline are described as oblique. Fascicles that run across the body are described as transverse. Fascicles that encircle an opening belong to sphincter, or orbicularis, muscles.
Category: Naming Muscles
Question 7
Which muscle, lying over the ramus and angle of the mandible, is the main muscle used to elevate the mandible during chewing?
Temporalis
Buccinator
Masseter
✓
Orbicularis oris
Correct Answer
Masseter
The masseter runs from the zygomatic arch to the ramus and angle of the mandible and is the primary muscle for closing the jaw during chewing. Temporalis also elevates the mandible but lies on the side of the skull and assists the masseter. Buccinator compresses the cheek. Orbicularis oris closes and purses the lips.
Category: Head and Neck
Question 8
Which facial muscle compresses the cheek against the teeth, helping keep food between the molars and allowing you to blow out air forcefully?
Zygomaticus major
Platysma
Orbicularis oculi
Buccinator
✓
Correct Answer
Buccinator
The buccinator forms the muscular wall of the cheek and presses it inward against the teeth during chewing, whistling and blowing. Zygomaticus major pulls the corner of the mouth upward in a smile. Platysma tenses the skin of the neck and depresses the mandible. Orbicularis oculi closes the eyelids.
Category: Head and Neck
Question 9
Contracting one side of which neck muscle rotates the head toward the opposite side?
Sternocleidomastoid
✓
Splenius capitis
Platysma
Digastric
Correct Answer
Sternocleidomastoid
Acting on one side, the sternocleidomastoid turns the face toward the opposite side, and acting together the two sides flex the neck. Splenius capitis rotates the head toward the same side and extends it. Platysma tenses the skin of the anterior neck. Digastric elevates the hyoid and helps depress the mandible.
Category: Head and Neck
Question 10
Which extrinsic tongue muscle pulls the tongue forward so that it protrudes from the mouth?
Styloglossus
Genioglossus
✓
Hyoglossus
Palatoglossus
Correct Answer
Genioglossus
The genioglossus arises from the inner surface of the mandible near the chin and draws the tongue forward and down, protruding it. Styloglossus elevates and retracts the tongue. Hyoglossus depresses and flattens the tongue. Palatoglossus elevates the back of the tongue.
Category: Head and Neck
Question 11
Which group of the erector spinae lies most laterally along the back?
Spinalis
Longissimus
Iliocostalis
✓
Semispinalis
Correct Answer
Iliocostalis
The erector spinae has three columns, and from lateral to medial they are the iliocostalis, longissimus and spinalis. Spinalis is the most medial column, lying next to the spinous processes. Longissimus is the intermediate column. Semispinalis is not part of the erector spinae; it belongs to the deeper transversospinales group.
Category: Back and Trunk
Question 12
Which nerve supplies the diaphragm?
Vagus nerve
Intercostal nerves
Accessory nerve
Phrenic nerve
✓
Correct Answer
Phrenic nerve
The phrenic nerve, arising from cervical spinal nerves, innervates the diaphragm, so injury to it can paralyze that side of the diaphragm. Vagus nerve supplies thoracic and abdominal organs but not the diaphragm muscle. Intercostal nerves supply the intercostal muscles between the ribs. Accessory nerve supplies the trapezius and sternocleidomastoid.
Category: Abdomen and Thorax
Question 13
Which is the deepest of the anterolateral abdominal wall muscles, with fascicles running horizontally across the abdomen?
Transversus abdominis
✓
External oblique
Internal oblique
Rectus abdominis
Correct Answer
Transversus abdominis
The transversus abdominis is the innermost lateral abdominal muscle, and its horizontal fascicles compress the abdomen like a belt. External oblique is the most superficial layer, with fascicles running inferomedially. Internal oblique lies between them, with fascicles at right angles to the external oblique. Rectus abdominis is the vertical strap muscle on either side of the midline.
Category: Abdomen and Thorax
Question 14
Working with the diaphragm during inhalation, which muscles lift the ribs to expand the thoracic cavity?
Internal intercostals
External intercostals
✓
Transversus thoracis
Rectus abdominis
Correct Answer
External intercostals
The external intercostals elevate the ribs, increasing the width of the thoracic cavity during inspiration. Internal intercostals depress the ribs and assist forced expiration. Transversus thoracis also depresses the ribs. Rectus abdominis flexes the trunk and can assist forced expiration by compressing the abdomen.
Category: Abdomen and Thorax
Question 15
Which rotator cuff muscle, lying on the anterior surface of the scapula, medially rotates the humerus?
Supraspinatus
Infraspinatus
Subscapularis
✓
Teres minor
Correct Answer
Subscapularis
The subscapularis fills the subscapular fossa on the anterior scapula and is the rotator cuff muscle that medially rotates the arm. Supraspinatus initiates abduction of the arm. Infraspinatus laterally rotates the arm. Teres minor also laterally rotates the arm.
Category: Upper Limb
Question 16
Which muscle arises from the upper ribs and pulls the scapula forward around the chest wall, as when throwing a punch?
Trapezius
Rhomboid major
Levator scapulae
Serratus anterior
✓
Correct Answer
Serratus anterior
The serratus anterior runs from the lateral surfaces of the upper ribs to the medial border of the scapula and is the main protractor of the scapula. Trapezius elevates, retracts and depresses the scapula. Rhomboid major retracts the scapula toward the vertebral column. Levator scapulae elevates the scapula.
Category: Upper Limb
Question 17
The thenar muscles of the hand form a fleshy mound and move which digit?
Thumb
✓
Little finger
Index finger
Middle finger
Correct Answer
Thumb
The thenar muscles form the thenar eminence at the base of the thumb and produce its fine movements, including opposition. Little finger is moved by the hypothenar muscles on the medial side of the palm. Index finger and middle finger are moved mainly by forearm muscles and by small intrinsic hand muscles such as the lumbricals and interossei, not the thenar group.
Category: Upper Limb
Question 18
Which muscle belongs to the quadriceps femoris group?
Biceps femoris
Vastus lateralis
✓
Semitendinosus
Sartorius
Correct Answer
Vastus lateralis
The quadriceps femoris consists of the rectus femoris, vastus lateralis, vastus medialis and vastus intermedius, which together extend the leg at the knee. Biceps femoris is a hamstring muscle. Semitendinosus is also a hamstring muscle. Sartorius is a strap-like muscle of the anterior thigh but is not part of the quadriceps.
Category: Lower Limb
Question 19
Which muscle is the main extensor of the thigh at the hip, used forcefully when climbing stairs or rising from a squat?
Gluteus medius
Iliopsoas
Gluteus maximus
✓
Piriformis
Correct Answer
Gluteus maximus
The gluteus maximus is the largest gluteal muscle and the prime mover of hip extension during powerful movements. Gluteus medius mainly abducts the thigh and steadies the pelvis during walking. Iliopsoas is the prime mover of hip flexion, the opposite action. Piriformis laterally rotates the thigh.
Category: Lower Limb
Question 20
Which muscle running along the front of the shin is the prime mover of dorsiflexion of the foot?
Gastrocnemius
Soleus
Fibularis longus
Tibialis anterior
✓
Correct Answer
Tibialis anterior
The tibialis anterior lies along the lateral side of the tibia in the anterior compartment and dorsiflexes and inverts the foot. Gastrocnemius is a posterior calf muscle that plantar flexes the foot. Soleus also plantar flexes the foot. Fibularis longus plantar flexes and everts the foot.
Category: Lower Limb