Gross Anatomy of the Male External Genitalia C

Gross Anatomy of the Male External Genitalia C. A. L. I. O. N Ozoemena 21/July/2017

Lecture Outline �Introduction �Gross Anatomy of ◦ Penis ◦ Scrotum ◦ Testis �How much can I remember? 2

Introduction �The male genitalia is divided for descriptive purposes into; ◦ External genitalia ◦ Internal genitalia �Male external genitalia consists of ◦ Penis ◦ Scrotum ◦ Scrotal contents 3

Introduction - 2 �The penis is a cylindrical, spongy and pendulous organ located between the thighs. �The scrotum is a pouch that lies below the root of the penis and the pubic symphysis. �The contents of the scrotum includes; ◦ Testis ◦ Epidydimis �These are referred to as the MALE EXTERNAL GENITALIA. 4

Gross Anatomy of the Penis �The penis is the male organ of copulation. �It is located between the thighs in male, in front of the scrotum. �The penis has ◦ Root ◦ Shaft (body) ◦ Glans penis �The penis has NO BONES, but ◦ is largely a spongy tissue ◦ filled with �nerves, �blood vessels and �some fibrous tissues. 5

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GA of Penis - 2 �Root; ◦ ◦ is the part that extends into the pelvic cavity. is the attached portion at the pubic arch. is located in the superficial perineal space. consists of ; �A bulb �Two crura (right and left) �Body; ◦ is the part that extends from the root to the glans ◦ is the free pendulous part. ◦ is cylindrical in shape and the longest part. 7

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GA of Penis - 3 �The body has dorsal and ventral surfaces. �The dorsum of the penis; ◦ Faces anteriorly when the penis is in a flaccid state ◦ Faces upwards and posteriorly when it is erect �The body has erectile tissues and is engorged with blood when erect. �Erectile tissues include; ◦ Right and left corpus cavernosum ◦ Centrally placed corpus spongiosum 9

GA of Penis - 4 �Corpus cavernosum and corpus spongiosum are continuations of the crura and bulb respectively. �Corpus spongiosum lies in the median groove and is close to the urethral surface. �It is smaller than the corpus cavernosum. �Spongy/penile urethra traverses the entire length of the body of the penis in the corpus spongiosum. 10

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GA of Penis - 5 �Corpus spongiosum forms the glans penis. �The glans is filled with numerous nerve endings and is covered with prepuce. �The base of the glans penis has a margin called corona glandis (crown of penis). �The prepuce or fore skin is removed during circumcision. �The deep fascia of the penis is called the bucks fascia and it encloses the corpora carvenosa and the corpus spongiosum. 12

GA of Penis - 6 �The penis is suspended by the fundiform and suspensory ligaments. �Fundiform ligament arises from the lower part of the linea alba and splits into left and right portions before uniting with the septum of the penis. �Suspensory ligament arises from the anterior portion of the pubic symphysis, triangular in shape and is deep to the fundiform ligament. 13

GA of Penis - 7 Blood Supply �Arterial supply is from three paired branches of internal pudendal artery. ◦ Artery to the bulb supplies corpus spongiosum and glans. ◦ Deep artery supplies corpus carvenosum only. ◦ Dorsal artery supplies the skin, fascia and glans. �Anastomosis between artery of bulb and dorsal artery; corpus spongiosum and glans. 14

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GA of Penis - 8 Venous Drainage �Superficial dorsal vein drains the skin and subcutaneous tissue, then empties into great saphenous vein and superficial external pudendal vein. �Deep dorsal vein drains the corpora carvenosum, corpus spongiosum and the glans, then it empties into the internal pudendal vein. 16

GA of Penis - 9 Lymphatic Drainage �Lymphatic vessels from skin and prepuce drain to superficial inguinal lymph nodes. �Lymph vessel from glans penis drains to deep inguinal lymph nodes and external iliac lymph nodes. 17

GA of Penis - 10 Nerve Supply �Nerve supply includes anterior scrotal branches, perineal and dorsal nerves , autonomics from hypogastric and pelvic nerves. �Erection is parasympathetic. �Emission, Ejaculation and Remission are sympathetic. 18

GA of Penis - 11 Applied Anatomy �Circumcision �Copulation �Priapism �Penile fracture 19

Gross Anatomy of Scrotum �The scrotum is containing the; a pouch of skin ◦ Vas deferens ◦ Epidydimis ◦ Testis �AKA scrotal sac is covered by skin �It has a fat deficient subcutaneous tissue containing dartos muscle. �Dartos muscle sends a sheet into the midline septum of the scrotum. 20

GA of Scrotum - 2 �The skin is affected by cold or exercise and the heat or elderly which makes the dartos muscle to contract or relax. �When it contracts, the skin becomes wrinkled and the scrotum is closely attached to the testis. �When it relaxes, it becomes elongated and flaccid. �The scrotum hangs freely from the front of the body wall (with the left slightly lower). 21

GA of Scrotum - 3 �Layers S D E C I T T of scrotum – Skin – Dartos muscle and fascia – External spermatic fascia – Cremasteric fascia – Internal spermatic fascia – Tunica Albuginea – Tunica Vaginalis 22

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GA of Scrotum - 4 �The skin ◦ wrinkled and covered with hair ◦ more pigmented than the rest of the body �Dartos muscle ◦ smooth muscle type ◦ causes the rugosity of the scrotum when the muscle is contracted �Cremasteric muscle ◦ skeletal muscle ◦ controls the proximity of the testes to the body 24

GA of Scrotum - 5 �Scrotum contains the testis and epidydimis. �The scrotum is divided into left and right portions by a septum ridge or raphae. �The left portion of the scrotum usually hangs lower than the right because the left spermatic cord is usually longer than the right. 25

GA of Scrotum - 6 Blood Supply �Superficial and Deep external Pudendal arteries (from the Femoral artery) �Scrotal branch of Perineal artery (from the internal Pudendal artery) �There are contributions from testicular arteries from aorta and cremasteric arteries from the inferior epigastric arteries. 26

GA of Scrotum - 7 Venous Drainage �Superficial and Deep external Pudendal veins (which drains into the great saphenous vein) Lymphatic Drainage �Superficial inguinal lymphnodes. 27

GA of Scrotum - 8 Nerve Supply �Genital branch of genitofemoral nerve from femoral plexus of nerves; ◦ supplies the anterolateral aspect �Anterior nerve; Scrotal nerve from the ilioinguinal ◦ supplies anterior aspect �Posterior nerve; Scrotal nerve from perineal ◦ supplies posterior aspect �Perineal branch of posterior femoral cutaneous nerve from sacral plexus ◦ supplies the inferior aspect 28

GA of Scrotum - 9 Applied Anatomy �Inguino-scrotal hernia �Cremasteric reflex 29

Gross Anatomy of Testes �They are paired ovoid organs located in the scrotum. �It is located below the abdomen in each hemiscrotum to allow for lower temp. �Anchored by the spermatic cord, each weighs about 10 to 14 g and measures about 5 cm in length , 3 cm thick and 2. 5 cm wide. �Has superior and inferior poles. �Has medial and lateral convex surfaces. 30

GA of testes - 2 �Has anterior and posterior margins. �Has a thick fibrous connective tissue coat called tunica albuginea(white coat or capsule). �It is invested into a double layer serous smooth surfaced covering called tunica vaginalis. �Tunica vaginalis consits of; ◦ outer parietal and ◦ inner visceral layers. 31

GA of testes - 3 �Morphology of testes ◦ Epididymis �is the site for sperm maturation �is attached to the posterolateral surface �is highly coiled tubes ◦ Vas deferens �is the sperm carrying tube �it enters the spermatic cord from the epididymis �it opens into the ejaculatory duct of the prostatic urethra 32

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GA of testes - 4 �The testes is lobulated and contains over 250 lobules. �Each lobule has 1 -4 seminiferous tubules. �They converge to form straight tubule which leads to the rete testis. �Seminiferous tubules contains the interstitial cells which produce androgens. 34

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GA of Testes - 5 �Blood supply ◦ Testicular arteries (branches of the abdominal aorta). �Venous drainage ◦ pampiniform plexus of veins draining into the testicular veins (Right drains into the IVC while Left drains into the Left renal vein). �Lymphatic drainage ◦ para-aortic nodes 36

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GA of Testes - 6 Nerve Supply �Sympathetic fibers from T 10 segment of the cord �It follows lesser splanchnic nerves and coeliac plexus �Fibers get to the testis through the part of the testicular artery 38

GA of Testes - 7 Applied Anatomy ◦ Cryptorchidism (undescended testes) ◦ Vasectomy ◦ Testicular cancer ◦ Hydrocele ◦ Hematocoele of testis �Hydrocoele is the excessive accumulation of fluid in the parietal and visceral layers of the tunica vaginalis. �Extravasation of urine tend to spread forwards into the scrotum between the dartos muscle and other coverings of the testis 39

How much can I remember? 40