Male Reproductive Anatomy Flashcards
Function of the scrotum
thermoregulation/radiation
protection and support of testis
What is in the thermoregulation mechanism of the scrotum
sweat glands
thermosensitive nerves
First layer of the scrotum
skin
second layer of the scrotum
tunica dartos
third layer of the scrotum
scrotal fascia
fourth layer of the scrotum
parietal vaginal tunic
fifth layer of the scrotum
visceral vaginal tunic
6th layer of the scrotum
tunica albuginea
what are the characteristics of the tunica albuginea?
dense connective tissue
secretory tissues of the testicle
What are the three parts of the tunica vaginalis?
parietal, visceral, albuginea
Order of descent into the testis?
Inguinal canal Gubernaculum Inguinal hernia Tunica vaginalis form Timing
Timing of testes descent in sheep/cattle
mid gestation
timing of testes descent in swine
1/3 of gestation
timing of testes descent in humans/horses
just before or after birth
function of the spermatic cord
suspends the testis in the scrotum Provides pathway to and from the body for the testicular vasculature, lymphatics, and nerves thermoregulation houses the cremaster muscle houses the ductus/vas deferens
paminiform plexus
provides a concurrent heat exchange mechanism and act as a pulse pressure eliminator in spermatic cord
cremaster muscle
- primary muscle supporting the testis
- coursing the length of the spermatic cords
- involves with testicular temperature regulation
- striated muscle, short-term elevation of testes (unable to contract)
ductus/vas deferens
responsible for sperm transport from epidiymis to the urethra
functions of the testis
- Produce male germ cells (spermatozoa)
- Produce male steroid hormone (testosterone)
- Produce inhibin and estrogen, and other proteins
what are the two layers of the testicular capsule
tunica vaginalis
tunica albuginea
functions of the tunica vaginalis
thin membrane
provides support
from peritoneum
functions of the tunica albuginea
connective tissue
provides structure
mediastinum
a membranous partition between two body cavities or two parts of an organ.
ex: bull testis
connective tissue
provides internal support
seminiferous tubule
site of sperm production
consists of two cell types
what are the two cell types within the seminiferous tubule
germ cells
sertoli/nurse cells
what are germ cells
eventual cells
a cell containing half the number of chromosomes of a somatic cell and able to unite with one from the opposite sex to form a new individual; a gamete. undergo meiosis
sertoli cells
-Produce variety of substances including androgen binding
protein, sulfated glycoprotein,
transferrin, and inhibin
- Surround developing germ cells
- Providing structural and metabolic
support to the developing spermatogenic cells
what is the blood-testis barrier
- cells surrounding the seminiferous tubules
- prevent autoimmune reaction from destroying the developing germ cells
what is a hormone produced by sertoli cells
androgen binding protein
-transports testosterone across blood testis barrier
interstitium
contiguous fluid-filled space existing between a structural barrier, such as a cell wall or the skin, and internal structures
ex: Leydig cells
functions of leydig cells
a. Located between seminiferous tubules
b. Produce androgens (testosterone)
c. Rete testis
d. Collect sperm from seminiferous tubules
e. Vasa efferentia (efferent ductules)
f. Collect sperm from rete testis
g. Carry sperm out of testis proper
morphology of the epididymis
three parts:
- head (caput)
- body (corpus)
- tail (cauda)
functions of the epididymis
In the epididymis spermatozoa gain the ability to fertilize an oocyte.
- Sperm transport:
a. Transport time varies with species
(1) boars: 9-14 days
(2) rams: 12 days
(3) bulls: 14 days - Sperm maturation
- Sperm motility
- Sperm concentration
- Storage (Bull = 50-75 billion sperm)
- Production of compounds (e.g. Glycerol phosphocholine (GPC))
vas deferens/ductus deferens
paired ducts
turns into ampullae (NOT PRESENT IN BOARS)
ampullae
wide end of the vas deferens
function of vas deferens
sperm transport from epididymis to pelvic urethra
ligation of vas deferens
vasectomy
vesicular glands (seminal vesicles)
- Paired glands
- Located at junction of urethra & vas deferens
- Have rough structure
- Contribute largest volume of seminal fluid
- Add the following
a. Fructose & sorbitol – energy sources
b. Phosphate & bicarbonate – buffers
prostate gland functions
- Located caudal to seminal vesicles and close proximity to pelvic urethra
a. Bi-lobulated in bull & boar
b. Diffuse in ram (scattered around pelvic urethra)
c. Surrounds urethra in dogs &humans - Only accessory gland found in dogs*
- Functions to cleanse & lubricate
- Secretes just prior to & during ejaculation
bulbourethral glands (cowpers gland)
- Paired glands
- Usually buried under bulbospongiosus muscle
- Small & round in bull, ram, stallion, and man
- Larger & longer in boar
- Function:
a. Bull: cleanse urethra prior to ejaculation
b. Boar: produces gel fraction and adds considerable volume to ejaculate
colliculus seminalis
- Region of urethra where sperm mixes with seminal vesicle secretions
- Mixing incomplete in stallion, boar
a. 2 different fractions: Sperm-free fraction & Sperm-rich fraction
penis definition
male copulatory organ consists of a base, a shaft, the glans penis, and crus penis
what are the two erectile tissues of the penis
corpus spongiosum
corpus cavernosum
corpus spongiosum
surrounds urethra and involves in erection by allowing rushing of blood into it
corpus cavernosum
involves in erection by allowing rushing of blood into it
what is the retractor penis muscle
Pair of smooth muscles
- Dorsally attached to tail vertebrae and it holds the penis inside the sheath in the
what species is the retractor penis in?
bull, boar, ram, buck, stallion
what are the three parts of the penis
base/root
shaft
glans penis
what is a glans penis
specialized distal end
contains sensory nerves
what is the crus penis
posterior portion of
what is the sheath
covers the penis
what are the two classifications of the penis
fibroelastic
musculovascular
what is the fibroelastic penis
a. Tunica albuginea – dense connective tissue
b. Sigmoid flexure – S-shaped configuration along shaft of penis that allows penis to be
retracted inside sheath until erection occurs
c. Relies on muscle contractions/sigmoid flexure for erection
what species have a fibroeleastic penis
bull, boar, ram, buck
musculovascular penis
a. Erection relies on blood engorgement within corpus spongiosum and cavernosum
species that has a musculovascular penis
stallions, humans
penis modification: bull
none
penis modification: ram/buck
filform appendage/urethral process
penis modification: stallion
bell
penis modification: boar
corkscrew
penis modification: dog
bulbus glandis
penis modification: tomcat
spines
