You’re Reading a Preview Become a Clinical Tree membership for Full access and enjoy Unlimited articles Become membership If you are a member. Log in here
20.1 Overview Sense organs include the ear, olfactory mucosa, taste buds, cutaneous receptors, interoceptors (monitor the internal environment), proprioceptors in muscles, tendons, and joints, and eye. Specialized receptor organs in ears sense hearing and balance. The ear has three parts:…
19.1 Overview Eyes are complex, paired photoreceptor organs. Each is roughly spherical, about 2.5 cm in diameter. Eyes communicate with the brain via the optic (II) cranial nerve. They develop as an outgrowth of the brain, mostly from neuroectoderm, and from…
18.1 Overview The female reproductive system consists of paired ovaries and the genital tract, including fallopian tubes ( oviducts, or uterine tubes ), uterus, cervix, and vagina, located in the pelvis—the internal genitalia. External genitalia consist of labia majora, labia…
17.1 Overview The male reproductive system includes the paired primary sex organs, the testes , which have both exocrine and endocrine functions, and several secondary sex organs consisting of excretory ducts and accessory glands. The scrotum and penis , an…
16.1 Overview The urinary system comprises two kidneys , two ureters , a urinary bladder , and a urethra . Kidneys filter blood and produce urine, by which waste products and foreign substances leave the body. Urine formation involves filtration,…
15.1 Overview The respiratory system is divided functionally into a conducting portion that conveys air from outside the body to the lungs and a respiratory portion where exchange of gases between the air and blood occurs. The conducting airways moisten,…
14.1 Overview of the Liver The wedge-shaped liver, the largest and heaviest internal organ (weighs about 1.5 kg in an adult), is essential to life and is the most versatile and vascular organ. It sits just below the diaphragm in the…
13.1 Development of the Foregut, Midgut, and Hindgut The early embryo starts as a flattened, trilaminar disc with three primary germ layers: ectoderm, mesoderm, and endoderm. Its ventral surface, covered by endoderm, communicates with the yolk sac. Later, lateral and…
12.1 Overview The digestive system—a long, tortuous, hollow tube—comprises the mouth (or oral cavity ), pharynx, and digestive tube or tract (also called the alimentary canal ). Associated with this tract are accessory glands of digestion: salivary glands, liver, gallbladder,…