pelvis

what is the pelvic girdle formed by

the 2 hip bones (ossa coxae) each consisting of ilium, ischium and pubisfued at the acetabulum

the hip bones are fused in the ventral median plan at the pubic symphisis

how is the pelvis formed

• 2 hip bones (ossa coxae)

• sacrum (fused vertevrae)

• the first 2 caudal vertebrae

• the sacrum articulates with the left and right ilium

where is the pelvic cavity continuous with

the abdominal cavity at the pelvic inlet and contains the pelvic organs

digestive, urinary and reproductive tract

boundaries of the pelvic cavity- what are these structures defined by

• pelvic inlet

• roof

• floor

• pelvic outlet

• perineum

• pelvic inlet is defined by the terminal line formed by the sacrum and cranial edges of the hip bones

• the roof formed by the sacrum and first caudal vertebrae

• the floor formed by hip bones (pubis)

• the pelvic outlet is continuous with the perineum

• the perineum is the region of body wall around the anus and urogenital openings

what are problems associates with the pelvic cavity

• fixed diamter as a result of its bondy borders (hip bones and sacrum)

• this can give rise to problems in partrition as aresult of foestal size and conformation eg braciocephaic dog

horse

• pelvic inlet

• ischial spine

• floor of pelvis

• canal

• pelvic inlet is relatively wide

• ischial spine and tubers are small

• floor of pelvis is flat and the canal is straight

ruminant

• pelvic inlet

• ischial spine and tubers

• floor of pelvis

• pevic inlet is relatively narrow

• ischial spine and tubers are larger than in the mare

• floor of pelvis is concave

boundaries of the pelvic cavity

• what forms the lateral walls

• lateral walls are formed by hip bones and broad sacrotuberal ligaments

• in the dog the sacrotuberal ligament is reduced to a cord

• the ligament is absent in cat

dysotcia

• which species is predisposed

• the maternal conformation predisposes to dystocia more commonly in ruminants than in the mare which has a striaghter canal and flatter floor

• other dfferent factors eg oversized foetus or ling legs of the foal

pelvic diaphragm

• what muscles

• formed by levator ani and coccygeus muscles

• arranged as a cradle around the anus and retains the organs in the pelvis

• levator ani and coccygeus muscle

perineum

• is the region of the body wall around the alimentary and uorogenital openings

• anus

• vulva

male perineum

• what does it contain

• region of body wall around the alimentary and urogenital openings

• contains the root (crura and bulb) of the penis

• in some species the scrotum (tomcat and boar)

which arteries supply

• hindlimb and body wall

• pelvic region

• midline structures and tauk

• pelvic organ (including the artery it branches into)

• wall of the pelvic caviy

• paired iliac arteries supply the hindlimb and body wall

• paired iliac arteries supply the pelvic region

• median sacral arteries supply the midline structures and tail

• internal iliac artery branches into internal pudendal artery supplying pelvic organs and caudal gluteal artery supplying the wall of the pelvic cavity

nerves

• which nerve (of which origin) is sensory to the skin of the perineum and motor to striated perineum muscle

• which is the autonomic

  • which one is parasympathetic

  • which one is sympathetic

• pudendal nerve of the sacral spinal cord origin

  • sensory to skin of perineum

  • motor to striated msucle in perineum eg urethralis

  • somatic

• pelvic plexus

  • autonomic

  • parasymptatheic pelvic nerves

  • sympathetic hypogastric nerve

what do the os coxae consist of

ilium, ischium and pubis

what are the deep bondy borders of the pelvic wall

• dorsally

• laterally

• ventrally

• 1st caudal (or coccygeal) vertebra dorsally

• the ischiadic tuberosity laterally

• ischiadic arch ventrally

what is

• the space lateral to the anus

• what is this bordered by (ligament and muscle)

• ischiorectal fossa

• sacrotuberal ligament and the superficial gluteal muscle

where is each half of the diaphragm directed and where is its origin

• each half of the diaphragm is directed caudomedially from its origin on the medial aspect of the spine of the ischium

causes of perineal hernias

• weakening or failure of the pelvic diaphragm

• may contain herniated abdominal and pelvic canal viscera

• animals with perineal hernias will demonstrate a swelling adjacent to the rectum on one or more sides coupled typically with difficulty defaecating and altered tail carriage

sacrotuberal ligament

• where is is the point of origin for

• shape in large animals

• where does it contribute to

• what is the space between the ligament and the shaft of the ileum called

• what is the space between the ligament and the lesser ischiatic notch called

• what species is it absent in

• superficial gluteal muscle

• broad

• lateral wall of the pelvic cavity

• greater sciatic foramen

• lesser sciatic foramen

• cat

Q Describe the path of the ischiadic n. and its relationship to the gluteal and hamstring mm. and the os coxae

• origin

• where does it leave

• originates from the sacral plexus

• leaves pelvis through the greater sciatic foramen

• passes through the gluteal but does not innervate

• innervates the hamstring

sphincter ani externus

• arrangement

• where does it have insertions in dog

• what does it cover

• where does the duct of each anal sac open

• circularly around the anus

• coccygeal vertebrae

• anal sacs (sinus paranalis)

• the cutaneous zone of the anus

what is the clinical relevance of the anal sac glands

• can becone inflamed, infected or impacted

• tumours (most commonly apocrine gland adenocarcinoma) can invade surrounding tissues and metastasise

• tumours sometimes cause hypercalcaemia

where do the internal and external obturator muscle originate and insert

the dorsal and ventral rims of the obturator foramen

and insert on the proximal femur

innervation of the internal obturator muscle and function

• obturator internus

• rotate the thigh laterally and stability to hip joint

innervation and function of the external obturator

• obturator nerve

• lateral rotation of the thigh, abduction of the thigh and the stability of the hip joint

clinical relevance of the obturator nerve

• potential for it to be damaged during parturition as it can be crushed against the ilium by the foetus during delivery

• abductor muscles will be affected

what are the

• autonomic motor innervation of thee

• pelvic viscera

• striated muscle of the perineum

• sensory innervation of the skin surrounding the anus and urogential openings

in dogs and cats what is a common consequence of spinal and pelvic injury

bladder dysfunction and faecal incontinence

what structures in the reproductive system take origin on the ischium

• crura of the penis

• clitora in female

• ischiocavernous and ischiurethral

what surrounds the pelvic urethra

• what muscle

• what is it the homologue of (2)

• what muscle is this a continuation of

• the bulbospongiosus muscle is the homologue of the constrictor vestibuli and constictor vulvae muscle of the female

• this is the continuatiopn of the urethral muscle which surrounds the pekvic urethra

1. coxal tuber

2. shaft of ileum

3. sacral tuber

4. sacrosciatic ligament

5. greater sciatic foramen

6. ischial spine

7. lesser sciatic foramen

8. right and left obturator foramina

9. ischial tuber

10. sacrum

11. greater trochanter