The stomach contains hydrochloric acid and digestive enzymes.

Why doesn’t the stomach digest itself?.

 

This muscle is one of the four muscles that make up the quadriceps femoris group and it lies on the lateral side of the thigh. It originates from the greater trochanter and lateral lip of the linea aspera of the femur and inserts into the patella and tibial tuberosity via the quadriceps tendon. It acts to extend the knee and stabilize the patella.

Choice A. Gastrocnemius is wrong because this muscle is not part of the quadriceps femoris group. It is located in the posterior compartment of the leg and it acts to flex the knee and plantarflex the ankle.

Choice C. Anterior tibialis is wrong because this muscle is not part of the quadriceps femoris group. It is located in the anterior compartment of the leg and it acts to dorsiflex and invert the foot.

Choice D. Rectus femoris is wrong because this muscle does not lie on the side surface of the lower extremity.

It is part of the quadriceps femoris group and it lies on the anterior surface of the thigh. It originates from the anterior inferior iliac spine and acetabular rim of the pelvis and inserts into the patella and tibial tuberosity via the quadriceps tendon. It acts to extend the knee and flex the hip.

When the sympathetic nervous system is stimulated, it prepares the body for a fight-or-flight response by increasing the heart rate and blood pressure, which results in increased cardiac output.

Cardiac output is the amount of blood pumped by the heart per minute.

Choice B is wrong because increased pancreatic activity is not a result of sympathetic stimulation. The sympathetic nervous system inhibits digestion and reduces blood flow to the gastrointestinal tract.

Choice C is wrong because increased uterine activity is not a result of sympathetic stimulation. The sympathetic nervous system relaxes the smooth muscles of the uterus and other reproductive organs.

Choice D is wrong because increased gastrointestinal activity is not a result of sympathetic stimulation. The sympathetic nervous system inhibits digestion and reduces blood flow to the gastrointestinal tract.

The correct answer is choice C. Melanoma. Melanoma is a type of skin cancer that can be recognized by the lesion’s character based on the ABCD rule.

The ABCD rule stands for Asymmetry, Border irregularity, Color and Dermoscopic structure. Melanomas tend to have asymmetrical shapes, irregular borders, multiple colors and different structures.

Choice A is wrong because sarcoma is a cancer of the connective tissues, not the skin. Choice B is wrong because basal cell carcinoma is a type of skin cancer that usually has a pearly or waxy appearance, not the features of the ABCD rule. Choice D is wrong because squamous cell carcinoma is a type of skin cancer that usually has a scaly or crusty appearance, not the features of the ABCD rule.

Normal ranges for skin lesions vary depending on the type and location of the lesion, but generally they should be symmetrical, have smooth borders, be uniform in color and have a consistent structure. Any changes in size, shape, color or texture of a skin lesion should be checked by a doctor.

The correct answer is choice B. Ear. The malleus, incus, and stapes are the three smallest bones in the body and they are located in the middle ear.

They are also called the auditory ossicles or ear bones. They transmit vibrations of the tympanic membrane (eardrum) to the oval window of the inner ear, where they are converted into electrical signals by the cochlea.

Choice A. Mouth is wrong because the mouth does not contain any bones, only teeth and soft tissues.

Choice C. Skull is wrong because the skull is a large bony structure that encloses the brain and the ear, but it does not house the malleus, incus, and stapes. The auditory ossicles are located inside a small cavity in the temporal bone called the tympanic cavity.

Choice D. Lungs is wrong because the lungs are organs of respiration that do not have any bones or connection to the ear.