Physical Address

304 North Cardinal St.
Dorchester Center, MA 02124

URINARY TRACT INFECTIONS

CYSTITIS Urinary tract infections (UTIs) can involve the bladder alone (lower UTI, also known as acute cystitis) or extend to the renal pelvis and parenchyma (upper UTI, also known as acute pyelonephritis). If untreated, such infections can progress in vulnerable hosts to systemic bacterial disease, known as urosepsis. Although “cystitis” refers, in the strictest sense, to inflammation of the bladder, by far the most common cause…

RENAL DISEASES

OVERVIEW OF ACUTE KIDNEY INJURY Acute kidney injury (AKI) consists of any precipitous decline in renal filtration function, which can occur secondary to disease affecting the renal vasculature, renal parenchyma, or urine collecting system. Such a decline is often first evidenced as an increase in serum creatinine concentration, which may be accompanied by normal urine output, oliguria, or anuria. DEFINITION Over time, various criteria have been…

PHYSIOLOGY

BASIC FUNCTIONS AND HOMEOSTASIS Blood enters the kidneys in a series of branching vessels that give rise to afferent arterioles. Each afferent arteriole leads to a tuft of glomerular capillaries. Plasma and small, non–protein bound solutes are filtered across the walls of the glomerular capillaries into Bowman's space, the initial portion of the nephron. From there, the filtrate is conveyed through the remaining segments of the…

NORMAL AND ABNORMAL DEVELOPMENT

DEVELOPMENT OF KIDNEY The kidneys develop from the intermediate mesoderm, which is located on each side of the embryo between the paraxial (somitic) and lateral plate mesoderm. After the fourth week, during which the embryo undergoes a complex folding process, the intermediate mesoderm forms a lateral nephrogenic cord and a medial genital (gonadal) ridge. The nephrogenic cord gives rise to three successive kidney precursors, while the…

ANATOMY OF THE URINARY TRACT

KIDNEY: POSITION AND RELATIONS POSITION AND SHAPE The kidneys are paired retroperitoneal organs that lie lateral to the upper lumbar vertebrae. In the relaxed, supine position, their superior poles are level with the twelfth thoracic vertebra, while their inferior poles are level with the third lumbar vertebra and about 2.5 cm superior to the iliac crest. On deep inspiration in the erect position, however, both kidneys may…

THE BREAST

Plate 13-1 Open full size image POSITION AND STRUCTURE The breast is shown in its partially dissected state in the upper part of the plate and below in sagittal section. The size of the breast is variable, but in most instances it extends from the second through the sixth rib, and from the sternum to the anterior axillary line, with an axillary tail in the outer…

PREGNANCY

Plate 12-1 Open full size image IMPLANTATION AND EARLY DEVELOPMENT OF OVUM Fertilization of the human ovum usually occurs in the ampullary portion of the oviduct, although in rare instances it may take place elsewhere in the genital tract or even in the ovary. Soon after the spermatozoon enters the ovum, the male and female pronuclei fuse to form the segmentation nucleus, which rapidly divides and…

THE OVUM AND REPRODUCTION

Plate 11-1 Open full size image THE OOCYTE AND OVULATION The completion of the final steps of meiosis I and the release of the oocyte from the parenchyma of the ovary constitute the process of ovulation. Through a process that takes approximately 375 days (13 menstrual cycles) a number of dormant, undeveloped primordial follicles begin to grow. These develop in a complex process of bidirectional hormonal…

THE OVARIES

Plate 10-1 Open full size image OVARIAN STRUCTURES AND DEVELOPMENT The ovaries develop from a thickening of cells that form ridges medial to the müllerian and wolffian bodies. These germinal ridges appear at the sixth week. Primary oocytes, arising in the umbilical vesicle (yolk sac) and migrating along the mesentery of the hindgut, arrive in the embryonic gonads and are thought to provide the countless thousands…

THE FALLOPIAN TUBES

Plate 9-1 Open full size image FALLOPIAN TUBES The fallopian tubes are musculomembranous structures, each about 12 cm in length, commonly divided into the intramural, isthmic, and ampullary sections. The intramural (interstitial) portion traverses the uterine wall in a more or less straight fashion. It has an ampulla-like dilation just before it communicates with the uterine cavity. On hysterosalpingography, this tiny tubal antrum either is connected…

THE UTERUS AND CERVIX

Plate 8-1 Open full size image PELVIC VISCERA The interrelationships between the uterus and the surrounding muscles, nerves, vessels, and organs determine both the pathophysiology of uterine function and dysfunction in addition to the therapeutic modalities available when pathologies exist. The viscera contained within the female pelvis minor include the pelvic colon, urinary bladder and urethra, uterus, uterine tubes, ovaries, and vagina. As with the pictures…

THE VAGINA

Plate 7-1 Open full size image THE VAGINA The vagina (from Latin, literally “sheath” or “scabbard”) serves as the portal to the internal female reproductive tract and a route of egress for the fetus during delivery. The viscera contained within the female pelvis minor include the pelvic colon, urinary bladder and urethra, uterus, uterine tubes, ovaries, and vagina. These structures surround the vagina and interact with…

THE VULVA

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 sexual (pubic) hair that functions as a dry lubricant during intercourse. From the mons, two longitudinal folds of skin, the labia majora, extend in elliptical fashion…

SPERM AND EJACULATION

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 (2 n ), which then duplicate their DNA during interphase. After a meiotic division, each daughter cell contains one partner of the homologous chromosome pair, and…

THE SEMINAL VESICLES AND PROSTATE

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% to 20%) of the ejaculate. The seminal vesicles contribute fluid of basic pH and constitute the majority of seminal fluid (80% to 90%). The adult prostate,…

THE SCROTUM AND TESTIS

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 as a result of the descent of the gonads from the retroperitoneum into the scrotum during fetal life. From superficial to deep, the first layer is…

THE PENIS AND MALE PERINEUM

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 of the penis , its passage through the prostate gland and the urogenital diaphragm , is shown. In the upper paramedian view, part of the pelvic…

DEVELOPMENT OF THE GENITAL TRACTS AND FUNCTIONAL RELATIONSHIPS OF THE GONADS

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 or can be a consequence of environmental or social variables. In humans, sex determination is genetic and is governed by specific genes and chromosomes. It is…

Muscle and Its Disorders

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 muscle fibers, or myofibers. Muscle fibers insert into tendons at their ends, at what on the microscopic level is referred to as the myotendinous junction. The…

Neuromuscular Junction and Its Disorders

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 muscles in the human body is daunting: somewhere between 500 and 1000. The face alone has enormous numbers of muscles that allow us to express our…