Veterinary Gross Anatomy

BONY PELVIS / BONE OF HIP (PELVIC) REGION 

• Bony pelvis consist of sacrum, 1^st three coccygeal vertebrae and two Os-coxae. Each formed by the ilium, ischium and pubis.

1. Sacrum

S. No.	Mare	Cow
1	It consist of 5 sacral segments, base and apex.	It consist of 5 sacral segments.
2	It is shorter than the cow.	It is longer than the mare.
3	It is triangular in shape.	It is roughly triangular in shape.
4	Dorsal surface presents 5 sacral spines which have tuberous summits and 4 pairs of dorsal sacral foramina.	Dorsal surface presents spines fuse to form median sacral crest. Articular processes fuse to form lateral sacral crest and 4 pairs of dorsal sacral foramina.
5	Ventral surface lodges 4 transverse lines.	Ventral surface presents 4 transverse groove and 4 pairs of foramina.
6	Pelvic surface presents transverse lines.	pelvic surface is concave in both directions and presents groove for middle sacral artery.
7	Smooth notches are present on either side of the body of 1st sacral segment.	No notches on either side of the body of 1st sacral segment.
8	Articular surface directed dorso-laterally which is slightly concave in its length. It is rough, irregular and articulates with ilium. Portion lateral to the foramina is formed by the fusion of the transverse processes.	Articular surfaces are concave and semicylindrical in curvature medially and process are large and widely separated.
9	Alae are the lateral part of the base (wing). Ventral margin of the base projects & form sacral promontory.

S. No.	Buffalo	Sheep
1	I consist of 5 sacral segments.	It consist of 4 sacral segments.
2	No vascular groove on the ventral aspect.	No vascular groove on the ventral aspect.
3	Spines are fused.	Spines are not fused except 1st and 2nd which may be partially united.
4	Sacral promontory flattened dorso-ventrally more than the cow.	Sacral promontory is not much flattened dorso-ventrally.
5	4th and 5th sacral vertebrae are not fused but laterally attached.	The last segment may remain separate or undergo partial fusion.
6	Transverse processes of last segment are not distinct.	Transverse processes of last segment are distinct and outstanding.

S. No.	Sow	Bitch
1	It consist of 4 sacral segments.	It consist of 3 sacral segments.
2	Pelvic surface is less curved as compared to cow.	It is short, wide and quadrangular in shape.
3	Fusion of vertebrae is less complete.	Fusion of vertebrae is complete.
4	Spines are less developed & commonly absent.	Spines are fused to form median crest which is notched. On either side 2 tubercles are the vestiges of the fused articular processes.
5	Middle of the dorsal surface is flattened, smooth and presents opening.	Pelvic surface is deeply concave and has two pairs of foramina.
6	Anterior processes are very large.	Anterior processes are large and have extensive, slightly concave facets. Wings are prismatic and bear laterally, auricular surface on its lower part.
7	Transverse lines are distinct	Sacral canal is compressed dorso-ventrally
8	-	Transverse processes of last vertebrae project backward.

2. Coccygeal vertebrae : Each vertebra consist of body, spinous and transverse processes.

S. No.	Mare	Cow
1	These (Cy) are 15 to 21 (18) in number.	These (Cy) are 18 to 20 in number.
2	Spinous processes are short and have double summit.	-
3	1st vertebra presents groove on postero-medial aspect of the body.	It is longer and better developed than horse.
4	Ventral surface has a groove for coccygeal artery.	Ventrally, median sacral groove for median coccygeal artery.
5	These are ill developed.	First 5 to 6 vertebrae have complete arches and spinous processes.
6	Bodies of first 3 vertebrae are flattened dorso-ventrally and constricted in the middle.	In anterior part of series, anterior articulating processes do not articulate and ventral spines form a groove for middle coccygeal artery.

S. No.	Sheep	Sow
1	These (Cy) are 16 to 18 (3 - 24) in number.	These (Cy) are 20 to 23 in number.
2	Transverse processes are long and thin.	First 3 or 4 vertebrae are specially characterized by the presence of functional articular processes.
3	No haemal processes on the ventral surface of the body.	-

A. Diameters of Pelvic inlet

1. Sacro-pubic (Conjugate) diameter :- It is measured from sacral promontory to the anterior margin of pubis symphysis.
2. Transverse (Bis-iliac) diameter :- Measured at its greatest width just above psoas tubercle.
• Superior bis-iliac diameter :- It is measured at upper 3^rd of pelvic inlet and receives greatest width of the fetus at shoulder in anterior presentation and hip in the posterior presentation.
• Inferior bis-iliac :- It is measured at the lower 4^th of pelvic inlet at elbow of fetus in anterior presentation and stifle in posterior presentation.
3. Vertical diameter of inlet :- It is measured between anterior end of symphysis pubis and articulation of sacral 3^rd and 4^th vertebra.
4. Oblique / sacro-iliac / ilio-sacral diameter of inlet :- It is measured from sacro-iliac joint of one side through the center of pelvic cavity to the psoas tubercle of opposite side. It is intermediate between sacro-pubic and superior bis-iliac diameter.

B. Diameter of Pelvic outlet

• Superio-inferior (Vertical) diameter :- It is measured between the summit of ischial arch and articular of coccygeal 1^st and 2^nd vertebrae.
• Transverse diameter :- It is measured between two ischiatic spines (Chauveau).