The Skeletal System-Vertebral Column PDF

V Anat 1 Identify the similarities and differences, parts, and other structures related to the different vertebra, ribs and sternum of a dog Identify the proper orientation of the vertebra, ribs and sternum in the dog  Vertebra (plural)  Vertebrae (singular)  Foramina (plural)  Foram...

V Anat 1 Identify the similarities and differences, parts, and other structures related to the different vertebra, ribs and sternum of a dog Identify the proper orientation of the vertebra, ribs and sternum in the dog  Vertebra (plural)  Vertebrae (singular)  Foramina (plural)  Foramen (singular)  Sternebrae (plural)  Sternebra (singular)  Neuro- pertaining to the nerves or the nervous system  Protects, supports, and acts as a flexible, slightly compressible rod through which the propelling force generated by the pelvic limbs is transmitted to the rest of the body  Basic movements: ◦ Flexion or dorsal arching of the spine ◦ Extension, straightening, or ventral arching of the spine ◦ Lateral flexion and extension ◦ Rotation  Approximately 50 irregular bones  CERVICAL  THORACIC  LUMBAR  SACRAL  CAUDAL / COCCYGEAL  C7 T13 L7 S3 Cd20 1. Protect the spinal cord and roots of the spinal nerves 2. Aid in the support of the head and the internal organs 3. Furnish attachment for the muscles governing body movements 1. Body / centrum 2. Vertebral arch / neural arch -consists of R and L pedicles and laminae 3. Processes for muscular or articular connections (transverse, spinous, and articular)  Constricted centrally  Has convex cranial articular surface  Has centrally depressed caudal articular surface  Intervertebral fibrocartilage / disc ◦ Center: pulpy nucleus – bulges freely when the confining pressure of the outer portion, or fibrous ring, is released  Has 2 pedicles and 2 laminae  Arch + body = vertebral foramen  Concurring vertebral foramina forms vertebral canal  R and L intervertebral foramina ◦ Through these pass the spinal nerves, arteries and veins  Spinous process  Transverse process ◦ In the cervical region, there is the presence of transverse foramen  Articular process ◦ Cranial process / prezygapophysis  Faces craniodorsally ◦ Caudal process / postzygapophysis  Faces cranioventrally  Cranial articular surface ◦ Articulates with the occipital condyles of the skull ◦ Joint movement is flexion and extension ◦ “yes joint”  Caudal articular surface ◦ Joint movement is rotation ◦ “no joint”  Vertebral foramen ◦ The spinal cord passes through this foramen: the collective vertebral foramina are referred to as the vertebral canal, or spinal canal.  Intervertebral foramina ◦ also called the neural foramen, is the opening between the vertebrae through which spinal nerve roots travel and exit to other parts of the body.  Transverse foramina ◦ The transverse foramen (foramen transversarium) of cervical vertebrae is an opening that is occupied by the vertebral artery and vein in the first six vertebrae and only the vertebral vein in the seventh. Atlas  Atlas ◦ 1st cervical vertebra, atypical ◦ Modified articular process ◦ Lack of spinous process ◦ Reduction of its body ◦ Lateral parts are thick and strong, forming lateral masses  Axis ◦ 2nd cervical vertebra ◦ Has elongated, bladelike, dorsal spinous process ◦ Has a cranioventral peglike eminence called dens or odontoid process  3rd, 4th,5th cervical vertebrae ◦ Differ slightly from each other ◦ Transverse processes of the 5th cervical vertebra are the shortest  6th cervical vertebra ◦ Possesses a higher spine than the 3rd, 4th, and 5th ◦ Expanded plate-like transverse processes  7th cervical vertebra ◦ Lacks transverse foramina ◦ Its spine is highest among all cervical vertebrae  13 thoracic vertebrae  The bodies of the thoracic vertebrae are shorter than those of the cervical or lumbar region  Possesses a cranial and caudal costal fovea or demifacet up to 11th thoracic vertebra ◦ 11th thoracic vertebra lacks caudal demifacets  Spinous process – most conspicuous feature of the first 9 thoracic vertebrae  The spine of the 1st thoracic vertebra is more massive than the others, but is about the same length  Anticlinal vertebra =11th thoracic vertebra  Transverse processes are short, blunt, and irregular with fovea for articulation with the tubercles of the ribs  Mammillary processes / metapophyses ◦ small, knoblike eminences which project dorsally from the transverse processes  Accessory processes / anapophyses ◦ Appears mid-thoracic up to the 5th or 6th lumbar vertebra  Articular processes  Anticlinal vertebra =11th thoracic vertebra  Have longer bodies than thoracic vertebrae  Body of 7th lumbar vertebra is as approximately long as the 1st  The spinous processes are highest and most massive in the mid-lumbar region.  The transverse processes are longest in the mid-lumbar region. ◦ Can be palpated in emaciated animals  Accessory processes are well developed on the 1st 3 or 4 lumbar vertebrae, and absent on the 5th or 6th.  Body of the 1st segment is larger than the bodies of the other 2 segments combined  Dorsal surface presents the median sacral crest – fused 3 spinous processes  The body of the 1st vertebra is as wide as it is long  Vertebral arch is best developed in the 1st coccygeal segment  Hemal arches are V or Y-shaped separate bones that protect the median coccygeal artery ◦ Articulate with 4th-6th coccygeal vertebrae ◦ Hemal processes The blood supply to the tail is also of interest because 20% of heat loss in the rat occurs via the tail.  13 pairs of ribs in the dog  Each rib is divided into: ◦ Os costale – convex dorsal bony part ◦ Costal cartilage - ventral cartilaginous part  The first 9 ribs articulate with the sternum, thus called true ribs.  The last four are called false ribs.  The costal cartilages of the10th,11th, and 12th ribs unite with the cartilage of the rib above to form the costal arch on each side.  Floating ribs – 13th rib; cartilage of this rib ends freely  9th rib and its cartilage are the longest.  Intercostal space – space between adjacent ribs  Vertebral extremity ◦ Head, neck, tubercle  Sternal extremity ◦ Costal cartilage  The 8th and 9th costal cartilages articulate with the cartilage between the 7th sternebra and the last sternebra,  Body / intermediate shaft ◦ Cylindrical in small breeds, flatter in large breeds  An unpaired segmental series of 8 bones which forms the floor of the thorax  Intersternebral cartilages – short blocks of cartilages connecting consecutive sternebrae  Manubrium – 1st sternebra; longer than others  Xiphoid process – last sternebra ◦ Possesses a cartilaginous plate caudally prolonging it called xiphoid cartilage