Urinary System And Male Genital System

Urinary System & Male Genital System

Dezhi Wang Department of Anatomy, Medical School of Wuhan University

Manneken Pis, a small bronze statue of a little boy peeing, is one of Brussels most famous landmarks.

Q:

1. Which organ produces urine? 2. To transport urine to the environment, how many organs serve as passageway?

URINARY SYSTEM Composing and functions: Kidney 肾 produce urine Urinary tract

Ureter 输尿管

carry urine to the bladder

Urinary bladder 膀胱 stores urine temporarily Urethra 尿道 carry urine to the outside genital functions (male) Other functions : Regulating blood volume and blood pressure by adjusting the volume of water lost in urine… Regulating ions in blood by controlling the quantities lost in urine… Helping to stabilize blood pH Helping the liver to detoxify poisons such as urea and uric acid…

Features of kidneys bean-shaped, the size : 10cm x 5cm x 4cm Two extremities: Superior extremity (broader) Inferior extremity (thicker)

Two surfaces: Anterior surface (convex) Posterior surface (plane)

Two borders: Lateral border (convex) Medial border (concave) Renal hilum 肾门 nerves

a slit where vessels and ant. post. V A sup. A V

enter and leave the kidney Renal pedicle 肾蒂 the structures Main structures which pass through the renal hilum and the connective tissue Renal sinus 肾窦 an internal cavity within the kidney, containing the

P inf. P

Coverings of kidney Three layers (from inside to outside)

Maintaining the kidney’s shape and forming a barrier from the surrounding region

Fibrous capsule: a layer of fibers that covers the outer surface of kidney closely Adipose capsule: a thick layer of adipose tissue

act as a soft cushion

Renal fascia: a dense, fibrous outer layer which enclose the kidneys and suprarenal gland, can be divided into anterior and posterior layers Fibers from the renal fascia cross the adipose capsule to the fibrous capsule to fix the kidney

Location of kidneys

The kidneys are located on the posterior abdominal wall, either side of the vertibral column. The kidneys extend from the level of the 11th or 12th thoracic vertebra superiorly to the third lumbar vertebra inferiorly. The 12th ribs are behind the posterior surface of the kidneys The right kidney Lies slightly inferior to the left kidney

Structure of kidney

Renal cortex Renal column Renal medulla

The superficial area Inward extensions of the renal cortex The deep darker area

Structure of kidney urine Renal papillae Papillary foramina Minor renal calices Major renal calices Renal pelvis Becomes narrow

Ureter 输尿管

ureter Junction of ureter and the renal pelvis Abdominal part

Three parts

Pelvic part Intramural part

terminal part of left common iiliac A. beginning of right external iiliac A. Junction of ureter and the wall of bladder Ureteric orifice

ureter

Junction of ureter and the renal pelvis

Abdominal part

Three parts

Pelvic part Intramural part

The first narrowed place

terminal part of left common iiliac A. beginning of right external iiliac A. Junction of ureter and the wall of bladder Ureteric orifice

The narrowest place Kidney stones tend to lodge in the three narrowed places

A radiographic view of the urinary system (Posterior view. Obtained by taking an x-ray of the kidneys after a radiopaque compound has been administered.)

The second narrowed place

location of urinary bladder Empty bladder Lies entirely within the pelvis Posterior to the pubic symphysis Anterior to the rectum (male) or the vagina and uterus (female)

Full bladder roughly spherical and expands superiorly into the abdominal cavity

Features of empty bladder Empty bladder has the shape of an upside-down pyramid with four parts

Apex, fundus, body and neck

four triangular surfaces four angles

and

Structure of urinary bladder Trigone of bladder A triangular smooth area at the base of the bladder between the openings of the two ureters and that of the urethra Each year in the US, approximately 52,000 new cases of bladder cancer are diagnosed, and millions of new cases in India and China. The bladder cancer rate is highest among cigarette smokers and employees of chemical and rubber companies.

Interureteric fold

A fold of mucous membrane between the ureteric orifices It is the landmark to find the ureteric orifices when the urinary bladder is examined with cystoscope in the living body

The trigone is of special clinical importance because infections and cancers tend to persist in this region

Urethra Extends from the neck of the urinary bladder to the exterior, between internal and external urethral orifice.

Male urethra has three parts Female urethra

short and straight

Urinary tract infections occur in about 40% of women. Most urinary tract infections occur in sexually active young women, because intercourse drives bacteria from the vagina and the external genital region (and from the anus as well) through the nearby opening---the short urethra and toward the bladder. The infection of the bladder, can spread superiorly to infect the ureters and kidneys.

Urethral sphincter Internal urethral sphincter: A thickening of the smooth muscle around the internal urethral orifice

External urethral sphincter: A circular band of skeletal muscle in the urogenital diaphragm, which can be used voluntarily to inhibit urination until the proper time.

Male genital organs Internal genital organs Gonad

Testes 睾丸 Produce sperms and sex hormones

Epididymis 附睾 (store Reproductive sperms) Ductus deferens 输精管 duct Ejaculatory duct 射精管 尿道 of sperms; stores sperms Serve asUrethra passageway Seminal vesicles 精囊 Accessory Prostate gland 前列腺 glands Bubourethral glands 尿道球腺 Secrete the fluid to maintain the nutrition and activity of the sperms

External genital organs Scrotum

House the testes

Penis

Sexual intercourse

Testes and epididymis testes

shape: flattened egg with two extremities, two surfaces and two borders Size: 4cm x 3cm x 2cm

Tunica albuginea Septa testis 　 Lobules of testis Seminiferous tubules sperms

Testes and epididymis

sperms Rete testis Efferent ductules of testis Head of epididymis Body of epididymis

epididymis

Tail of epididymis

Ductus deferens

Ductus deferens The level of tail of epididymis Testicular part

The shortest part The level of head of epididymis

Four parts

Funicular part

Can be palpated easily The superficial inguinal ring

Inguinal part

Lies in the inguinal canal The deep inguinal ring

Pelvic part

The longest part The junction of the semianl vesical and ductus deferens

Spermatic cord and scrotum Spermatic cord

Contents

Deep inguinal ring

Ductus deferens Testicular artery Pampiniform plexus of vein Nervous plexus Lymphatic Vessels

upper extremity of testis

Spermatic cord and scrotum Covering of testis

Skin Scrotum Dartos External spermatic fascia Cremaster Internal spermatic fascia

Covering of Spermatic cord

Sperm cannot be produced at the core body temperature of 37℃, the scrotum’s superficial position provides an environment that is about 3 ℃ cooler, an essential adaptation. Furthermore, the scrotum responds to changes in external temperature. If the external temperature is too high…

Seminal vesicles and ejaculatory duct Seminal vesicle

location

Posterior to the fundus of urinary bladder The yellow secretion constitutes 60% of the volume of semen

The end of ductus deferents

Excretory duct of seminal vesicle

Ejaculatory duct Open into Prostatic urethra

Prostate gland

location

Inferior to the neck of urinary bladder Superior to the urogenital diaphragm Posterior to the pubic symphysis Anterior to the ampulla of rectum

Three parts

Apex of prostate Base of prostate Corpus glandulae

The milky secretion constitutes about 1/3 of the volume of semen

Prostate enlargement occurs in about 50% of men at age 50 and 80% of men at age 70. It often begins with the hesitation to urinate, a weak stream and increased urinary urgency and frequency and may cause urinary obstruction finally. A digital rectal exam can help diagnose the disease, because there is a shallow sulcus lies in the midline of the posterior wall of prostate, the shallow sulcus disappears when the prostate enlarges.

Bulbourethral gland Pea-sized glands (round and with the diameters approaching 10 mm inferior to the prostate, within the urogenital diaphragm The bulbourethral glands produce a thin, clear fluid, some of which enter the spongy urethra when a male becomes sexually excited prior to ejaculation. which constitutes less than 5% of the volume of semen.

magnify

penis

Three parts:

Glans of penis: thickened distal end Body of penis: the movable portion

Neck of penis

Root of penis: the posterior portion

Covering Prepuce

skin and fascia the folded skin upon the neck and glans

Orifice The free border of of the prepuce prepuce Cavernous bodies Long cylindrical erectile bodies Covered with albuginea Two cavernous body of penis The proximal end

crus penis

One cavernous body of urethra The enlarged distal end The enlarged proximal end

glans penis bulb of penis

male urethra Prostatic portion

Anterior urethra

Urethral crest: a longitudinal mucosal fold on the posterior wall Seminal colliculus: a prominence on the urethral crest Openings of ejaculatory duct, prostate Membranous portion

Posterior urethra

pierces the prostate

Cavernous portion

pierces the urogenital diaphragm pierces the Cavernous body of urethra

Two curves the prepubic curve the subpubic curve Three constriction the internal orifice the membranous portion the external orifice Three dilated places

the prostatic portion the bulbous portion of urethra the navicular fossa