Anatomy of the Pelvis and Perineum Flashcards
what is the pelvis made of?
dorsal, ventral and lateral walls of the pelvic cavity
what is the perineum made of?
caudal walls of pelvic cavity
what is the boney pelvis?
2 coxal bones + sacrum + 3-7 caudal vertebrae
what is the pelvic girdle?
2 coxal bones
what is the coxal bone?
ilium + pubis + ischium
the boney pelvis results from the contribution of what 4 joints?
1) sacro-iliac joint
2) pelvic symphysis
3) acetabulum
4) intervertebral joints (sacral and caudal vertebrae)
what type of joint is the SI joint?
diarthrosis –> has all the elements of a true joint (movement, ligaments, articular surface, synovia)
what type of joint is the pelvic symphysis?
amphiarthrosis –> semi-mobile joints –> limited
in large animals, what is the most lateral layer of the pelvic wall, medial to the gluteal muscles?
sacrotuberous ligament
what is a synarthrosis joint?
a joint that has no movement + no elements (ie: no cartilage)
what muscle consists of the pelvic roof?
sacrocaudalis ventralis
what muscles consists of the lateral walls (pelvic diaphragm)?
levator ani
coccygeus
what muscle consists of the pelvic floor (ungulates)?
obturator internus
what is the N and A of the sacrocaudalis ventralis?
caudal spinal nerves
flexion and lateral movements of the tail
what is the N and A of the coccygeus (ungulates)?
N: caudal rectal and pudendal nerves
A: flexion and lateral movements of the tail
what is the N and A of the levator ani (ungulates)?
N: caudal rectal and pudendal nerves
A: reduces partial prolapse of anus at defecation
what is the N and A of the obturator internus?
N: sciatic nerve
A: rotates the femur laterally
what is the N and A of the levator ani (dogs)?
N: caudal rectal and pudendal nerves
A: flex tail laterally and ventrally and reduce partial prolapse of anus at defecation
what is the N and A of the coccygeus (dogs)?
N: caudal rectal and pudendal nerves
A: flex tail laterally and ventrally
what makes up the peritoneal ligaments?
1) mesorectum
2) broad ligaments of uterus (female)
3) lateral ligaments of bladder
4) middle ligaments of bladder
5) genital fold (male)
6) ligaments of ductus deferens (males)
what is the parietal supply of the pelvis in the dog?
dorsally: caudal gluteal artery and median sacral artery
ventrally: internal pudendal artery
what is the visceral supply of the pelvis in the dog?
internal pudendal artery
what do the kidneys do?
-filter the plasma in a 2 step process to reabsorb useful products and concentrate waste products for elimination
-produce and release renin and erythropoietin
describe the structure of the kidneys
1) capsule/parenchyma —> 2) cortex/medulla –> 3) outer zone/inner zone
what makes up the blood supply to the kidneys
1) renal artery
2) renal vein
3) ureter
4) renal pelvis
what is the renal pelvis?
enlargement that results from the union of the calices and provides the origin for the ureter
what do the ureters do?
convey urine from the kidneys to the bladder
describe the urinary bladder
a muscular and distensible sac that collects urine for its later convenient disposal
no constant size or position
describe the urethra
discharges urine (and semen in males)
what do the ovaries do?
produce hormones (estrogen and progesterone)
mature and release oocytes
what do the uterine tubes do?
-collect oocytes after ovulation
-transport gametes and store sperm
-provide suitable conditions for fertilization and early embryo development
-transport embryos to the tuerus
what does the uterus do?
-transports and stores sperm
-nurtures embryos and fetuses
-particpates in birth
what type of uterus do domestic mammals have?
bicornis
what does the cervix do?
-functions as a tight barrier (except during estrus)
-stores sperm
describe the cervix of the bitch and mare
muscular –> smooth muscle
describe the cervix of the cow and sow
fibrous –> cartilage
what does the ductus deferens do?
convey sperm to the pelvic urethra
what does the male pelvic urethra do?
-receive and mix secretions of sex accessory glands with sperm to form semen
-convey semen and urine to the penile urethra
what do the male accessory sex glands do?
produce the non-spermatic component of the semen and clean the urethra
what accessory sex glands does the horse and bull have?
ampullary glands
vesicular glands
prostate
bulbourethral glands
what accessory sex glands does the boar have
vesicular glands
prostate
bulbourethral glands
what accessory sex glands does the dog have
ampullary glands
prostate
what accessary sex glands does the cat have
ampullary glands
prostate
bulbourethral glands
what is the ejaculatory duct
duct that results from the union of ductus deferens and excretory duct of the vesicular glands
what is the perineal region made of?
perineum + external genitalia
what is the anal canal
terminal region of the rectum
what is the anus
caudal opening of the anal canal, includes the zona cutanea, zona hemorrhagica and the sphincters that close them
what makes up the zona cutanea
stratified squamous keratinized
what makes up the zona hemorrhagica
stratified squamous non-keratinized
what makes up the zona columnaris
simple columnar epithelium
what do the testes do?
-produce sperm (spermatogenesis)
-produce hormones (steroidogenesis - androgens)
how is testis size correlated in cattle?
INVERSELY correlated to age at first calving and length of calving intervals in female offspring
name the 3 locations of testes and what species they can be found in
1) inguinal –> bull
2) intermediate –> horse and dog
3) perineal –> pig and cat
name the blood supply and innervation of the testes
-testicular artery/vein
-caudal mesenteric plexus
what does the epididymis do?
matures (head and body) and stores sperm (tail)
because sperm is stored in the tail, palpation of this region help determine the extent of spermatogenesis and sperm reserves
where is the body of the epididymis located in compared to the ductus deferens?
located at the LATERAL SIDE of the ductus deferens
what is the N and A of the cremaster?
N: genital branch of urogenital nerve
A: raise the testes during cold weather, arousal, copulation and fighting
what supplies the scrotum?
external pudendal artery
what innervates the scrotum?
-lumbar nerves (ventral branches)
-iliohypogastric nerve
-ilioinguinal nerve
-genitofemoral nerve
describe what makes up the cooling and warming components for the thermoregulation of the testis
cooling: pampiniform plexus, thin scrotal skin
warming: dartos, cremaster
blood in vein gains heart + blood in artery loses heat
