09: Pelvis and Repro

Boundaries of the pelvic canal

• Dorsal: sacrum

• Ventral: pubis

• Lateral: os coxae

Pelvic cavity

The space within the pelvic canal that holds the organs

Caudal most point of the pelvic bones

Ischiatic tuberosity

Boundaries of the pelvic inlet

• Dorsal: sacral promontory

• Ventral: cranial aspect of the pubic bone

• Lateral: os coxae

Bony landmark when palpating to find the cervix and uterine body

Brim of the pubis

Boundaries of the pelvic outlet

• Dorsal: caudal vertebrae

• Ventral: ischiatic arch and tuberosity

• Lateral: free edge of the sacrosciatic ligament

In which large animal species does the pelvic canal narrow and why

Cow; dorsal slant of the pelvic symphysis

Locations of organ systems within the pelvic cavity

• Dorsal: GIT and mesorectum

• Middle: repro

• Ventral: urinary bladder

Repro structures palpable in the pelvic cavity of the male

Genital fold

Repro structures palpable in the pelvic cavity of the female

Uterus and other things

Genital fold

Double layered serous membrane between the R and L ductus deferens

Peritoneal pouches in the pelvic cavity

• Rectogenital pouch

• Vesicogenital pouch

• Pubovesical pouch

Orientation of testes in the stallion

Horizontal, with the head of the epididymis cranially and the body of the epididymis dorsolaterally

Ampulla

Dilated terminal portion of the ductus deferens

Orientation of testes in the bull

Vertical, with the head of the epididymis dorsally and the body of the epididymis medially

Orientation of testes in the boar

The testes are very caudal, ventral to the anus, and oriented with the head of the epididymis in a cranioventral direction

How is the boar ductus deferens different than that of the bull/stallion

The ampulla are not developed

T/F: the ampulla is an ASG

False, but it does produce some seminal fluid

ASG function

Provides fluid and nutrients for spermatozoa

ASGs in large animals

• Vesicular gland

• Prostate gland

• Bulbourethral gland

Vesicular gland morphology in the stallion

Paired, hollow glands just caudal to the genital fold

Vesicular gland morphology in the bull

Multilobed, solid glands just caudal to the genital fold

Vesicular gland morphology in the boar

Large, multilobed glands just caudal to the genital fold

Prostate morphology in the stallion

Bilobed body caudal to the vesicular glands

Prostate morphology in the bull

One continuous structure made of the body, around the proximal urethra, and the disseminate part around the pelvic urethra deep to the urethralis muscle

Prostate morphology in the boar

Body and disseminate parts

Bulbourethral gland morphology in the stallion

Large, paired gland

Bulbourethral gland morphology in the bull

Small, paired glands

Bulbourethral gland morphology in the boar

LARGE, paired glands

Where are the bulbourethral glands found

At the ischiatic arch

Type of penis in the stallion

Musculocavernosus, comprised of a lot of very vascular erectile tissue

Parts of the glans in the stallion that has the external urethral orifice

Urethral process

Depression around the urethral process in the stallion

Fossa glandis

Dorsal diverticulum of the fossa glandis in the stallion

Urethral sinus

What does it mean when a stallion has a “bean”

There is a collection of smegma that collects in the dorsal diverticulum, and it often needs to be removed

Layers of the prepuce in the stallion

• External lamina of the prepuce

• Internal lamina of the prepuce

• Outer layer of the preputial fold

• Inner layer of the preputial fold

Exit for the penis

Preputial orifice

Preputial ring

Transition between the inner and outer layers of the preputial fold

Type of penis in the bull

Fibroelastic, with less erectile tissue

Muscle that controls erection in the bull

Retractor penis muscle; maintains sigmoid flexure

Which type of penis is flaccid when non-erect

Musculocavernosus (stallion!)

CT that surrounds the erectile tissue

Tunica albuginea

Urethral process morphology in bulls

Small

What species has a corkscrew-shaped urethral process

Small ruminants

Type of penis in the boar

Fibroelastic

Extra structure in the prepuce of the boar that is also a site of smegma accumulation

Preputial diverticulum

Function of the preputial diverticulum

Produces lubricant

Ovary morphology in the mare

Inverted with medulla on the outside and cortex with follicles is deep

Part of the ovary that mares ovulate into

Ovulation fossa; on the medial aspect of the ovary

What catches the ovulated ova

Fimbriae of the infundibulum

Ovary morphology in the cow

Small ovaries with cortex and follicles superficially, producing palpable protrusions

Ovary morphology in the sow

Sow ovaries produce LOTS of follicles, and can take on a cobblestone appearance

Uterus morphology in the mare

• Long body

• Short horns

• T shaped

Uterus morphology in the cow

• Short body

• Long horns

• U/Y shaped

Structure between the cranial/medial aspects of the uterine horns in the cow

Dorsal/ventral intercornual ligaments

From the outside, why does it look like the cow uterus has a long uterine body

The uterine horns stay very close together, sharing a muscular septum called the uterine velum, before they split

Maternal contribution to the placenta in cows

Caruncles

What do caruncles join with from the fetus

Cotyledons

Uterus morphology in the sow

• Short uterine body

• LONG uterine horns

Cervix morphology of the mare

Short, with inner folds

Cervix morphology of the cow

Long, with circular and longitudinal folds

Cervix morphology of the sow

Long, with interdigitating ridges and longitudinal folds

Landmark for the termination of the vagina

Urethral tubercle

Where does the urethra open to

Ventral to the urethral tubercle

Fornix of the vagina

Recesses of the vagina around the cervix

Vestibule

Combined exit for the repro and urinary tracts

Structure that needs to be avoided in cows and sows when placing a urinary catheter

Suburethral diverticulum

Location of the clitoris

Just inside the ventral commissure

Which large animal species have a large clitoris

Mare

What does it mean when a mare “winks” the clitoris

Exposes the clitoris during heat

Major blood supply to the uterus in the mare

Uterine artery

Additional blood supply to the uterus in the mare

Vaginal and ovarian arteries

Opening between the labia

Rima pudenda

Female repro structures that can be palpated rectally

• Pelvic bones

• Cervix, uterine body, uterine horns

• Broad ligament

• Intercornual ligament (cows)

• Ovaries

Number of teats per mammary gland

1

Number of mammary glands in the cow

4

Functional secretory unit of the mammary gland

Alveolus

Alveolus structure

Specialized sweat gland with secretory cells that produce proteins, Igs, and fats. Surrounded by myoepithelium

Stimulus that causes the myoepithelium of the alveoli to contract

Oxytocin

How do the alveoli drain

Alveoli → lactiferous ducts → lactiferous sinus

Parts of the lactiferous sinus

Gland sinus/cisterns and teat sinus/cistern

Drainage from the teat sinus

Teat sinus → teat canal (aka streak canal/papillary duct) → teat orifice

Supranumerary teat

Any teats beyond the expected number, may or may not be associated with a gland

Support apparatus of the bovine udder

• Lateral laminae: collagenous

• Medial laminae: elastic, separates L and R mammae

Major blood supply to the bovine udder

External pudendal artery

Minor blood supply to the bovine udder

Ventral perineal artery

Blood drainage from the bovine udder

Venous ring → subcutaneous abdominal vein (milk vein) → internal thoracic vein → cranial vena cava

Lymphatic drainage of the udder

Superficial and deep inguinal LNs

Major innervation to the udder

Genitofemoral nerve

Mammary morphology in the mare

Only two mammae (2 glands, teats) and each gland has two alveolar duct systems → two teat orifices per teat