Biology Human Anatomy & Physiology Flashcards

Which layer of the skin contains melanocytes that produce melanin?

Answer: Stratum basale

Melanocytes in the stratum basale produce melanin, which protects deeper cells from UV radiation.

The bicuspid (mitral) valve controls blood flow between which two chambers?

Answer: Left atrium and left ventricle

The bicuspid valve prevents backflow of blood from the left ventricle into the left atrium during systole.

Which region of the brain regulates body temperature, hunger, and the release of pituitary hormones?

Answer: Hypothalamus

The hypothalamus integrates autonomic functions and controls the pituitary gland through releasing and inhibiting hormones.

Surfactant, which reduces surface tension in alveoli, is produced by which cell type?

Answer: Type II pneumocytes

Type II pneumocytes secrete pulmonary surfactant, preventing alveolar collapse during expiration.

What term describes the movement of a limb away from the midline of the body?

Answer: Abduction

Abduction moves a limb laterally away from the body's midline, such as raising an arm to the side.

Which enzyme in saliva begins the chemical digestion of carbohydrates?

Answer: Amylase

Salivary amylase (ptyalin) begins breaking down starch into maltose in the mouth.

The trachea bifurcates at the carina to form the two primary bronchi at approximately which vertebral level?

Answer: T4-T5

The trachea divides into left and right primary bronchi at the carina, located at the level of T4-T5.