Plate 6-1 Open full size image EXTERNAL GENITALIA The vulva includes those portions of the female genital tract that are externally visible in the perineal region. The mons veneris, overlying the symphysis pubis, is a fatty prominence, covered by terminal…
Plate 5-1 Open full size image ANATOMY OF A SPERM The mature spermatozoon is an elaborate, specialized cell produced in massive quantity, up to 1200 per second. Spermatogenesis begins when Type B spermatogonia divide mitotically to produce diploid primary spermatocytes…
PROSTATE AND SEMINAL VESICLES The prostate, seminal vesicles, and bulbourethral glands of Cowper are the accessory glands of male reproduction and contribute to the makeup of seminal fluid. Prostatic secretions are acidic and comprise the first and minor portion (10%…
Plate 3-1 Open full size image SCROTAL WALL The testicles are maintained in position within the scrotal cavity by the structures of the spermatic cord. Each testicle and spermatic cord is invested in six distinct tissue layers that are acquired…
PELVIC STRUCTURES The relationships of male pelvic structures are illustrated in these complementary sagittal views—a paramedian and a median section. In the lower median view, the complete course of the urethra from the bladder to the meatus at the end…
Plate 1-1 Open full size image GENETICS AND BIOLOGY OF EARLY REPRODUCTIVE TRACT DEVELOPMENT Most living species have some form of sex-determination system that drives the development and expression of sexual characteristics in that organism. Sex determination can be genetic…
Muscle Fiber Anatomy: Basic Sarcomere Subdivisions The basic function of skeletal muscle is to move various parts of the body via muscle contraction. Muscle structure is specifically related to its function. Muscles are composed of numerous multinucleated muscle cells called…
Neuromuscular Junction The outflow of nearly all behavior depends upon the neuromuscular system, where nerves emanating from the spinal cord and brainstem make connections with skeletal muscles that allow us to move, stand, and express ourselves. The numbers of skeletal…
Peripheral Nervous System: Overview The major function of the nervous system is the transmission and processing of information. This relies on propagation of electrical signals between the peripheral nervous system and the central nervous system. The somatic peripheral nervous system…
Neonatal Hypotonia Neonatal hypotonia, often referred to as the “floppy infant,” is the main presenting clinical feature of most neuromuscular diseases of early life. However, disorders of the central nervous system may also manifest with hypotonia. Two types of muscle…