Human Anatomy and Physiology : Gross Anatomy

Study concepts, example questions & explanations for Human Anatomy and Physiology

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Example Questions

Example Question #111 : Gross Anatomy

A spike in the concentration of which of the following hormones stimulates ovulation in females?

Possible Answers:

Progesterone

Estrogen

Follicle-stimulating hormone

Luteinizing hormone

Testosterone

Correct answer:

Luteinizing hormone

Explanation:

A spike in the concentration of luteinizing hormone (LH) leads to ovulation on day 14 of the menstrual cycle. This spike is known as the "LH surge" and is initiated by a positive feedback mechanism involving estrogen.

Follicle-stimulating hormone (FSH) is involved in the maturation of the follicle, but not ovulation. Progesterone functions in maintaining the endometrial tissue after implantation has occurred. Testosterone is not involved in the female reproductive cycle.

Example Question #112 : Gross Anatomy

What is the name of the muscle that surrounds the opening of the mouth?

Possible Answers:

Buccinator

Glossus

Masseter

Obicularis Oculi

Obicularis Oris

Correct answer:

Obicularis Oris

Explanation:

The muscle that surrounds the opening of the mouth is known as the Obicularis Oris. The Obicularis Oclui surrounds the eye. The Masseter is connected to the mandible and responsible for chewing.The Glossus muscles are found inside the mouth and responsible for tongue movement. The Buccinator is found deep to the Masseter located on the cheek.

Example Question #113 : Gross Anatomy

Which of the following is not considered part of the quadriceps muscle group?

Possible Answers:

Vastus intermedius

Biceps femoris

Vastus lateralis

Vastus medialis

Rectus femoris

Correct answer:

Biceps femoris

Explanation:

The quadriceps muscle group consists of four different regions, each with a different origin. The rectus femoris originates on the anterior inferior iliac spine (AIIS). The vastus lateralis originates from the greater trochanter of the femur. The vastus medialis originates from the intertrochanteric line. The vastus intermedius originates from the shaft of the femur. Together, the muscles of the quadriceps work to extend the leg by straightening the knee.

The biceps femoris is located posterior to the femur, and is a part of the hamstring muscle group. The primary action of the biceps femoris is flexion of the leg by bending the knee.

Example Question #114 : Gross Anatomy

What is the primary action of the sartorius?

Possible Answers:

Lateral rotation of the thigh

All of these are actions of the sartorius

Abduction of the thigh

Flexion of the thigh

Flexion of the leg

Correct answer:

All of these are actions of the sartorius

Explanation:

The sartorius originates from the anterior superior iliac spine (ASIS) and inserts near the tibial tuberocity, running laterally to medially along the anterior thigh. Because the sartorius crosses both the hip and the knee, contraction of the muscle is capable of flexing both the leg and thigh. By running laterally to medially, shortening of the muscle also causes lateral rotation and abduction of the thigh.

Example Question #115 : Gross Anatomy

Which muscle is responsible for the plantar flexion of the foot?

Possible Answers:

Biceps femoris

Gastrocnemius

Tibialis anterior

Rectus femoris

Correct answer:

Gastrocnemius

Explanation:

Plantar flexion involves increasing the angle between the foot and the leg (pointing the toe). The gastrocnemius is found on the posterior portion of the leg, and is contracted in order to cause plantar flexion of the foot. The other muscle to contribute to this action is the soleus, also located in the posterior portion of the leg.

The tibialis anterior is located in the anterior portion of the leg and is involved in dorsiflexion, the opposite of plantar flexion. The biceps femoris and rectus femoris are located in the thigh, and do not act on the position of the foot. The biceps femoris is involved in flexion of the knee and the rectus femoris is involved in extension of the knee.

Example Question #116 : Gross Anatomy

Which muscle does NOT extend the knee?

Possible Answers:

Biceps femoris

Rectus femoris

Vastus medialis

Vastus lateralis

Correct answer:

Biceps femoris

Explanation:

The quadriceps muscle group is primarily responsible for the extension of the knee. This group includes the rectus femoris, vastus lateralis, vastus medialis, and vastus intermedius. The biceps femoris part of the hamstring muscle group and is responsible for the flexion of the knee.

Example Question #117 : Gross Anatomy

Located laterally to the abductor hallucis, what muscle is located in the center of the sole of the foot and is fed by the medial plantar nerve?

Possible Answers:

Flexor digitorum brevis

Flexor hallucis brevis

Abductor digiti minimi

Quadratus plantae

Flexor digiti minimi brevis

Correct answer:

Flexor digitorum brevis

Explanation:

The flexor digitorum brevis is sandwiched between the plantar aponeurosis and the tendons of the flexor digitorum longus. It flexes the lateral four digits at the proximal interphalangeal joints.

Example Question #118 : Gross Anatomy

Which of the following innervates the gluteus maximus?

Possible Answers:

Superior and inferior gluteal nerves

Inferior gluteal nerve

Superior gluteal nerve

Femoral nerve

Obturator nerve

Correct answer:

Inferior gluteal nerve

Explanation:

The gluteus maximus is innervated by the inferior gluteal nerve. The gluteus medius and minimus are innervated by the superior gluteal nerve. The femoral nerve does not innervate the glutes, and the obturator nerve innervates muscles in the medial thigh. 

Example Question #5 : Identifying Muscles Of The Lower Extremities

Which of the following is considered a muscle of the posterior thigh, but not a part of the hamstring muscle group?

Possible Answers:

Long head of the biceps femoris

Semitendinous

Semimembranous

All of these are part of the hamstring muscle group

Short head of the biceps femoris

Correct answer:

Short head of the biceps femoris

Explanation:

The short head of the biceps femoris is the only muscle of the posterior thigh that is not part of the "hamstring" muscle group. It is not cosnidered a hamstring muscle because it only crosses the knee joint; it does not act on the hip joint. 

Example Question #119 : Gross Anatomy

Which of these muscles is innervated by the common fibular divison of the sciatic nerve?

Possible Answers:

Semitendinous

Short head of the biceps femoris

Long head of the biceps femoris

Semimembranous

Gluteus maximus

Correct answer:

Short head of the biceps femoris

Explanation:

Only the short head of the biceps femoris is innervatd by the common fibular division of the sciatic nerve. The long head of the biceps femoris, the semimembranous, and the semitendinous are innervated by the tibial division of the sciatic nerve. The gluteus maximus is innervated by the inferior gluteal nerve.

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