Dog · Bone · Pelvis
Sacrum
Os sacrum
Three fused vertebrae, with wings that meet the ilium at the sacroiliac joint and dorsal and ventral foramina for the sacral nerves.
- System
- Bone
- Region
- Pelvis
- Sides
- Single, on the midline
- Named parts
- 12
Where it runs from and to
A muscle is told apart from its neighbours by what it takes hold of at each end, which is also what decides what it does when it shortens.
- Action
- Three fused vertebrae, with wings that meet the ilium at the sacroiliac joint and dorsal and ventral foramina for the sacral nerves.
Written for Vetomica in its own words from the standard reference anatomy of the dog; the books it was checked against are listed below.
Named parts
What to look for on the bone, and what each part is called in the Nomina Anatomica Veterinaria.
- SacrumOs sacrum
- The three sacral vertebrae, fused into one bone in the adult dog.Miller 2020, p. 284
- Wing of the sacrumAla ossis sacri
- The broad side of the first segment, which meets the ilium.Miller 2020, p. 286
- Auricular surfaceFacies auricularis
- The rough ear-shaped face on that wing that forms the sacroiliac joint.Miller 2020, p. 286
- Median sacral crestCrista sacralis mediana
- The ridge along the midline of the dorsal surface, the fused spinous processes.Miller 2020, p. 286
- Intermediate sacral crestCrista sacralis intermedia
- The line of fused articular processes to either side of it.Miller 2020, p. 286
- Lateral sacral crestCrista sacralis lateralis
- The thin outer ridge of the dorsal surface.Miller 2020, p. 286
- Dorsal sacral foraminaForamina sacralia dorsalia
- The two pairs of openings on the dorsal surface for the dorsal branches of the sacral nerves.Miller 2020, p. 286
- Pelvic sacral foraminaForamina sacralia pelvina
- The matching pairs on the pelvic surface.Miller 2020, p. 286
- Sacral canalCanalis sacralis
- The continuation of the vertebral canal through the bone.Miller 2020, p. 286
- Base of the sacrumBasis ossis sacri
- The cranial end, facing the last lumbar vertebra.Miller 2020, p. 286
- PromontoryPromontorium
- The forward edge of that end, the landmark for measuring the pelvic inlet.Miller 2020, p. 286
- Apex of the sacrumApex ossis sacri
- The caudal end, meeting the first caudal vertebra.Miller 2020, p. 286
What it meets
Fused sacral vertebrae; sacroiliac joints with the ilia.
Bones it articulates with
- Lumbar vertebrae
- Ilium
- Caudal vertebrae
Joints it forms
- Sacroiliac joint
- Lumbosacral joint
Muscles and ligaments that take hold of it
- Sacrotuberous ligament
Measured on the specimen
What the sacrum is in contact with in the model itself, with the share of the other structure’s surface it covers. A contact is not always a joint: bones that simply lie against one another are in this list too.
- Sacrum14%
- Discus intervertebralis S1-Cd147%
- Os coxae6%
- Discus intervertebralis caudalis I39%
- Caudal vertebra II9%
Measured on the left side.
Terminology
- English
- Sacrum
- Latin (NAV)
- Os sacrum
- Status
- A valid term in the Nomina Anatomica Veterinaria
References
Where to read this structure in full, and where the named parts above were read.
- Miller 2020Miller 2020, ch. 4 The Skeleton, Sacral Vertebrae, PDF p. 284
- König & Liebich 2020skeleton of the pelvic limb, p. 243
- Dyce 2017ch. 15 Pelvis of the Dog and Cat, p. 442
- NAV 2017Osteologia