Carnivore Anatomy Lab 19 Introduction

CONTENTS:

Lab Objectives
Anatomical Terms
Instructor Commentary
Dissection Steps
Dissection Videos
Dissection Images

Lab Objectives:

• Identify visceral branches of the internal iliac a.:
      - umbilical a. (to urinary bladder)
      - internal pudendal a. (supplies pelvic viscera)
            -- vaginal or prostatic a. (to cranial viscera)
            -- caudal rectal a. (to anal canal)
            -- artery of penis/clitoris (branches to three erectile bodies)

• Examine pelvic viscera:
      - urinary bladder and urethra
      - rectum and anal canal
      - pelvic genitalia . . .

• Dissect male genitalia:
      - prostate and pelvic urethra (cat: bulbourethral glands)
      - penis (root, body, free part)
            -- three erectile bodies and three muscles

• Dissect female genitalia:
- vulva and clitoris
- vestibule, vagina, and cervix of the uterus

Corrections to Guide to Dissection of the Dog:

• On page 180 (bottom), change "preprostatic and prostatic components" to "preprostatic (cat only) and prostatic components"

• On page 184 (left bottom line), "bulbs of the penis" should be "bulb of the penis"

CONTENTS

Anatomical Terms:

Pelvic vessels
Terminal branches of aorta:
        median sacral artery
        external iliac artery (enters vascular lacuna)
        internal iliac artery
                umbilical artery
                internal pudendal artery
                        vaginal a. / prostatic a.
                                uterine a. / a. of ductus deferens
                                caudal vesical a.
                                middle rectal a.
                        ventral perineal a.
                        caudal rectal a.
                        artery of the penis (clitoris)
                                artery of the bulb of the penis
                                deep artery of the penis
                                dorsal artery of the penis

Pelvic Viscera
        urinary bladder
                trigone of the bladder
                median ligament of the bladder
                lateral ligaments of the bladder
        urethral muscle (urethralis m.)
        rectum
        anal canal
                columnar zone (has anal columns)
                anocutaneous line (intermediate zone)
                cutaneous zone [palpate]
                        anal sac (paranal sinus) [palpate opening]
                anus
                internal anal sphincter m. (smooth m.; not evident grossly)
                external anal sphincter m. (striated)
        rectococcygeus muscle

Male Genitalia
        prostate gland
        urethra
                pelvic part
                        pre-prostatic part (cat only)
                        prostatic part
                                urethral crest with colliculus seminalis
                        post-prostatic part -- (covered by urethralis m.)
                penile part
        prepuce [palpate]
                preputial orifice [palpate]
                fornix of the prepuce
        retractor penis muscle
        penis (root, body, & free part) [palpate]
                corpus cavernosum penis (paired)
                        tunica albuginea
                        crus (at root of penis)
                                ischiocavernosus m. (covers crus)
                corpus spongiosum penis
                        bulb of the penis [palpate]
                                bulbospongiosus muscle (covers bulb)
                glans
                        pars bulbus glandis
                        pars longa glandis
                os penis [palpate] (see bone box)
                        urethral groove
        bulbourethral glands (cat)

Female Genitalia
        cervix of uterus
                cervical canal
                        internal uterine ostium (uterine body opening)
                        external uterine ostium (vaginal opening)
        vagina
                fornix
        vestibule
                urethral tubercle (dog) groove (cat)
                        urethral opening
                vestibular bulbs (do not need to identyify)
                fossa clitoridis [palpate]
        clitoris
        vulva [palpate]
                labia [palpate]
                        vulval cleft
                dorsal & ventral commissures [palpate]

        Note:
             genitalia is from the Latin: genitalis = pertaining to birth
             vulva is from the Latin: vulva = vulva
             pudendal -- pertains to external genitalia,
                    from the Latin: pudere = to be ashamed

CONTENTS

Instructor Commentary:

Although the internal iliac artery supplies the pelvis with branches that are named the same in the dog and cat, the branching pattern is different in the two species. Identify branches of the internal iliac artery according to the region being supplied, but learn only the branching pattern seen in the dog:

After giving off the umbilical artery, the canine internal iliac artery divides into a branch that supplies the wall and a branch that supplies pelvic viscera. The visceral branch, internal pudendal artery, sends a branch to cranial viscera (prostatic/vaginal artery) and terminates in caudal viscera (caudal rectal artery and artery to the penis/clitoris). The wall branch, caudal gluteal artery, ends in the rump after giving off two branches that loop around the ilium.

In human anatomy, the term vulva (female external genitalia) includes the vestibule (which is quite compressed in women). In veterinary anatomy, the term vulva is restricted to just the labia because the vestibule is elongate and internal.

CONTENTS

Dissection Steps:

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Dissection Videos:

CONTENTS

Dissection Images:

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