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Scrotum & Contents (anterior view; anatomical position of penis).
What is the Spermatic Cord? (3; TPD)
Name the 5 parts and give their functions.
*All emerge from the Abdomen.
- 1) Testicular artery
- 2) Pampiniform plexus: epididymis & spermatic veins emerge.
- 3) Ductus deferens: behind testis
- 1) Superficial inguinal ring
- 2) Cremaster muscle: derived from internal abdominal oblique (outer: external spermatic fascia/internal: internal spermatic fascia).Regulates testes temperature (3 degrees below body core temperature; cooler is better for sperm cells).
- 3) Dartos muscle: causing contractions of scrotum.
- 4) Scrotum
- 5) Raphe: separates (middle of scrotum; anterior view)
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Scrotum & Contents.
What is the Superficial Inguinal Canal (ring)?
What happens if the canal doesn't seal completely?
*SI can travel through the scrotum, called a torsion (benign).
In men conveys the spermatic cord and in women the round ligament.
Passageway/canal doesn't seal fully, is called an inguinal hernia.
*Intestine pushes through the canal.
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Gonalda arteries & veins (see slide)
What are Vericocele's two affects?
-affects what percent of men?
-When does it occur during a boy's life?
Variocele: Defective valves, or compression of the varacosa veins by a nearby structure, can cause dilatation of the veins near the testis, leading to the formation of a varicocele.
- (Found in 15% of men) "bag of worms"
- -affects cooling
- -sperm production in left teste to infertility.
-Occurs during puberty
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Decent of Gonads (testes derived from: to testify; witness; see slide)
What does the Mesonepheric duct (to pelvis) become?
What is the Gubernaculum? Lined with?
What does the Vaginal Process become? (what is significant about this "pocket"?)
Becomes the Vas Deferens.
- Gubernaculum: rim of connective tissue (not a duct) down to the scrotum.
- -Lined w/ Peritenium.
Vaginal process: becomes tunica vaginalis (pocket within a pocket)
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What is the Tunica Vaginalis visceral & parietal?
What are Septae?
(see slide)
Visceral covers testes, parietal covers visceral.
Septae: (lobules) 250 lobules in each teste: tubules called "seminiferous tubules" = SPERM CELL development.
*Driven by Puberty.
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How long can sperm cells be stored in the Epidydmis?
Where are they then transported?
About 2 weeks before they're transported to the Efferent ductile to the Ductus Deferens.
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What is the Male Primary sex organ?
What are the Secondary sex organs?
(remember mnemonic)
Primary: testis
Secondary: Seminal vesicles, Epididymis, Vas deferens, Prostate, Penis, Bulbourethral glands.
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Scrotumn & Inguinal Region.
What is the function of the Scrotum?
*Contains layers corresponding to the abdominal wall.
Scrotum: sac that holds tests & epididymis outside of the body.
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The anatomy of the Scrotum & Inguinal region are the result of testicular descent during development, from the _____, to the _____, and then out of the body.
abdomen, pelvis
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Layers of the scrotum.
What are the layers of the scrotum, external to internal, give their functions.
#1
Skin: thin & permeable compared to other skin of body.
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Layers of the Scrotum #2.
Dartos fascia/muscle
-What is its function?
Contains muscle fibers that wrinkle the scrotal skin (contraction)
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Layers of the Scrotum #3.
External Spermatic Fascia (no function, but derived from..)
Derived from external oblique.
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Layers of Scrotum #4.
Cremesteric muscle/fascia (cremaster)
-What is it derived from, internal/external oblique?
-function?
Derived from internal oblique; contains muscle fibers that elevate the testis for heat regulation.
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Layers of Scrotum #5.
Internal spermatic fascia (no function, derived from..)
Derived from the Transversalis fascia.
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Layers of Scrotum #6.
Tunica Vaginalis (derived from..)
Derived from the Peritoneum; has parietal & visceral layers; fluid accumulation between layers is a hydrocele.
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Layers of Scrotum #7.
Tunica Albuginea.
-hint: what does "albu" mean?
Thick capsule covering testis (means 'white covering')
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Testicular Vaculature.
The blood supply to the Testis & Epididymis is from the _____ and _____, via how many arteries including the testicular artery?
abdomen, pelvis.
3 arteries, including the testicular artery.
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What do the testicular veins form?
the Pampiniform Plexus.
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Innervation of the Scrotum & Testis.
The _____ and ____ have autonmic innervation and the entire region has extensive pain ______ innervation.
testis, epididymis, afferent.
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What two nerves travels in the spermatic cord and is sensory to the scrotum?
ilioinguinal nerve, genital branch of the genitofemoral nerve.
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Temperature Regulation of the Scrotum.
-What temp. must testis be kept at a cool temperature for normal conditions. (Celsius-Fehrenheit)
Name the 3 mechanisms for cooling the testis.
(hint: relaxation of..& counter-current heat exchange..)
(~32 C/98.6 F)
- 1) Relaxation of Cremasteric muscle: allows testis to fall away from body wall.
- 1) Relaxation of Dartos fascia: to increase surface area of scrotal skin.
- 3) Counter-current heat exchange: testicular arterial blood --> venous blood in the pampiniform plexus.
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What are the nerves responsible for achieving erections? (para/symp?)
- Parasympathetic Nerves.
- -Travel outside of prostate gland, floor of pelvis, outward to erectile tissues.
- Penile dysfunction/implant
- -inability of blood vessels to receive blood
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Common Clinical Problems in the Inguinal Region.
Hernias. What are they?
Direct inguinal hernia vs Indirect inguinal hernia.
-Which occurs medial? Which occurs lateral?
- Which is most common? Which is usually congenital?
Hernia: Extrusion of abdominal or pelvic contents through the body wall.
- Direct IH: extrusion directly via the body wall in the inguinal region.
- -Occurs medial to the epigastric vessels
- -These hernias are common in men & are usually acquired
- Indirect IH: extrusion down the inguinal canal to scrotum.
- -Occur lateral to the epigastric vessels.
- -These hernias are almost always congenital.
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Testis.
What are the 2 functions of the Testis.
1) Produces the male gametes, spermatozoa (sperm), by spermatogenesis.
2) Synthesizes & secretes androgens (testosterone), the male sex steroid hormone.
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Testis.
Spermatogenesis, what is it?
What two hormones is this under the control of?
What is spermiogenesis?
Process of producing male germ cells (spermatozoa)
- Under control of
- 1) testosterone
- 2) FSH
Spermiogenesis: morphogenesisof round spermatid to elongated spermatid.
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Explain the 4 steps of Spermatogenesis involved with mitosis/meiosis (chromosome #, etc.)
Steps 1) What is spermatogonia? What happens after mitosis?
Step 2) Where does first meiotic division occur? What does it create?
Step 3) What does the Second meiotic division produce?
Step 4) What does the process of spermiogenesis result in?
- 1) germ cells that are the origin of sperm cells are diploid (2n - 46)
- -Mitotic divisions produce new germ cells and a committed cell, called a "primary spermatocyte".
2) primary spermatocyte diploid: first meiotic division occurs. The first division creates haploid (n - 23) cells called, "secondary spermatocytes".
3) Second meiotic division originates w/ the secondary spermatocytes and produces "spermatids".
4) Process of spermiogenesis results in morphological change needed to form "motile" sperm cells.
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Structure of the Testis.
The testis is made up of a series of what tubules?
What do these tubules connect to? ( _____ testis)
-Where is this ______ testis located?
- Seminiferous tubules: where spermatogenesis takes place.
- -seminiferous tubules connects to the "rete testis".
- Rete testis: collects spermatozoa.
- -located in mediastinum of the testis.
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Cell types of the Seminferous Tubule.
3 basic cell types.
#1: Sertoli cells.
-Name 3 functions of the Sertoli cells.
1) Creates Seminferous tubule fluid (contains proteins required by germ cells.
2) Form tight junctional complexes which isolates germ cells from the immune system (germ cells would be attacked).
3) Secrete androgen binding protein (ABP) which binds testosterone.
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Cell types of the Seminiferous Tubules.
#2 Germ cells (3 types of germ cells); DEFINE each.
-Spermatogonia (mitotic or meiotic? location?
-Spermatocytes (mitotic or meiotic? location?
-Spermatids (Define acrsome; has nucleus? undergoes??
- Spermatogonia:
- -2n cells (diploid)
- -Mitotic cells that proliferate & serve as stem cells for spermatoggenesis
- -Located in BASAL compartment of semeniferous tubule.
- Spermatocytes
- -4n (2n x 2) cells (tetraploid)
- -Undergo Meiotic cell divisions
- -located in LUMINAL compartment of seminiferous tubule
- Spermatids (acrosome - flagellum - midpiece)
- -1n cells (haploid)
- -Undergo morhogenesis into flagellar cells
- -Have compact nucleus
- -Acrosome: vesicle filled w/ enzymes for penetrating the zona pellucida of the egg.
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Cell types of the Seminiferous Tubule (see p. 370 LG)
#3 Peritubular cells (myoid)
-What do they surround?
-How do they move Spermatids through the seminferous tubule?
Surrounds the "tubule".
Movement by peristalsis.
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Where is the site of androgen synthesis in males?
The Testis.
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What cells produce Testosterone and controlled by what hormone?
(hint: pathway of Sperm is: FSH --> Sertoli cells --> Spermatogenesis, how is Testosterone produced?)
- Leydig cells under control of LH from the pituitary.
- LH --> Leydig cells --> Testosterone.
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Inhibin.
What are the 2 functions? (produced by what cells in response to what hormone from pituitary?)
1) Produced by Sertoli cells in response to FSH from pituitary.
2) Inhibits FSH production by pituitary.
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Common Clinical Problems w/ the Testis.
Varicocele.
-What is it?
-Leading cause of?
*1 in 6 men w/ varicocele present w/ infertility.
Varicocele: dilation of testicular veins in spermatic cord (1 in 6 males have one)
Leading cause of male INFERTILITY.
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Common Clinical Problems with the Testis (card 2)
Testicular Cancer
*Most common in what age group?
Is this curable?
1) Most common cancer in young men (college age)
2) Curable if detected early!
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Differentiate between Genotypic vs Phenotypic Sex characteristics
Genotypic (what are the chromosomes for females, males?; when is sex determined?)
Phenotypic (when do internal/external genetalia appear?)
- Geno:
- 1) Sex based on sex chromosomes
- 2) XX: females
- 3) XY: male
- 4) Determined at fertilization
- Pheno:
- 1) Appearance of internal/external genetalia
- 2) Tests: male; Ovaries: female
- 3) Appears after 7th week of development (no earlier)
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What weeks are the "sexually indifferent stages"?
What can you see @ week 6? (3)
Sexually indifferent stages (weeks 5-7; 6)
Week 6: Urogenital bulb, labioscrotal swelling, genital tubercle
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What can you see @ week 12 of the development stage?
..in males?
..in females?
What week can you see the "external genetalia"? (differentiation)
Males: Urogenital bulb begins to fuse (developing glans of penis)
Females: Developing clitoris & labia minor/major.
By week 20, external genetalia well differentiated.
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What is Peyronie's Disease?
Development of fibrous scar tissue in penis causing curved, painful erections.
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