LAB 7 – Review Lab

Lab instructions:

Use this lab to review the axial skeleton, neck, back, thoracic wall and abdominal wall content.  Plan to be prepared for the lab and to focus on topics or specific structures that you/your dissection team, wish to gain more understanding of, particularly with the assistance of instructors.  Below, we have provided the list of links to lab review videos and a compilation of the terms lists, for Sections 2 and 3.

Review Videos

Carnivore skull osteology – 38 min, ignore details on foramina for now

Ungulate skull osteology – 17 min, ignore details on foramina for now

Cow cervical vertebrae osteology – Watch until 2:40

Horse nuchal ligament in motion – 15 sec

Ungulate thoracic osteology – 5 min

Terms

Print optimized terms list (Missing Lab 6 Terms, will try to update)

Lab 1

Regions and spaces of the Skull
Osteology
Comments Species Differences
Cranium Part of skull that encloses the brain.
cranial cavity Created by the bones of the cranium, brain resides in this cavity
calvaria Roof of the cranium.
Face (facies) Part of skull that encloses respiratory and alimentary tracts
Bones of the Skull
Osteology

Features
Species Differences/identify in
Bones of the cranium
Frontal bone Cornual process Ruminant
Parietal bone External sagittal crest Carnivore, horse
Temporal lines Horse, ruminant
Interparietal bone
Occipital bone External occipital protuberance
Occipital condyles
Paracondylar processes
Nuchal crest
Foramen magnum – where brainstem exits cranial cavity to continue as spinal cord
Basisphenoid bone
Presphenoid bone
Pterygoid bone
Temporal bone Squamous part Zygomatic process
Mandibular fossa
Retroarticular process
Tympanic part Tympanic bulla Contains tympanic cavity that is subdivided in cat by septum bulla
External acoustic meatus
Petrous part Mastoid process
Ethmoid bone Cribriform plate
Vomer Singular bone of skull on ventral midline, supports nasal septum
Bones of the face
Maxilla Facial crest Horse
Facial tuberosity Ruminant, pig
Nasal bone
Nasoincisive notch between nasal and incisive bones
Incisive bone
Lacrimal bone
Palatine bone
Zygomatic bone Forms zygomatic arch along with portions from temporal and frontal bones In carnivore, pig: connects to orbital ligament.
Mandible Body
Ramus
Coronoid process
Condylar process
Angular process Carnivore
Os rostrale (rostral bone) supports the snout Pig
Additional features and joints of the Skull
Feature Description/Species Difference
Nasal aperture bony opening to nasal cavity
Nasoincisive notch created by nasal and incisive bones, prominent in ungulates.
Orbit Orbital margin – consists of multiple bones combining to form rim.
Orbital ligament – carnivore, pig; bridges frontal to zygomatic bone, usually fibrous, may ossify in mature cats to form a complete bony rim.
Zygomatic arch Formed by zygomatic, temporal and sometimes frontal bones; species variation
Pterygopalatine fossa caudoventral to orbit, skull region between maxilla and pterygoid process of basisphenoid bone
Temporomandibular joint synovial joint
Intermandibular articulation (= mandibular symphysis),

Hyoid apparatus

Bone Species Difference/comments
Tympanohyoid (not seen) joins stylohyoid to temporal bone
Stylohyoid Divides guttural pouch compartments in horse
Epihyoid Carnivore, ox (vestigial in horse)
Ceratohyoid Surgical removal to treat temporohyoid osteoarthropathy in horse
Basihyoid
Lingual process Horse and ox
Thyrohyoid
Vertebral formula
Cervical (C) Thoracic (T) Lumbar (L) Sacral (S) Caudal (Ca)
Carnivore 7 13 7 3 20
Horse 7 18 6 5 variable
Ruminant 7 13 6 5 variable
Pig 7 14/15 6 4 variable
 Osteology of the vertebral column
Osteology Features and comments
All vertebrae
Body (except C1, which has a ventral arch instead)
(Dorsal) Spinous process
Transverse process
Articular process
Vertebral foramen
Arch (consists of two pedicles and a lamina)
Vertebral canal
Intervertebral foramen – for spinal nerves to exit vertebral canal.
Cervical vertebrae
C1 = Atlas Wings of atlas (= transverse processes)
Transverse foramen – for pathway of vertebral vessels and nerve.
Lateral vertebral foramen – for exit of C1 spinal nerve
C2 = Axis Dens
Transverse foramen
C3-C7 Transverse foramen (except  C7)
Ventral lamina of C6 (sled runners)
Thoracic vertebrae
Costal fovea
Anticlinal vertebra
Lumbar vertebrae
As above for all vertebra
Sacral vertebrae (sacrum)
Sacral foramina – for exiting of branches of sacral spinal nerves.
Auricular face – articulates with ilium (to form sacroiliac joint)
Promontory – ventral border of cranial base of sacrum
Caudal (coccygeal) vertebrae
Hemal arches (V shaped fusion of processes on ventral aspect of caudal vertebra, bovine and carnivore.

 

Features of the vertebral column

Feature Landmark Species Difference

Atlanto-occipital joint

the ‘yes’ joint
Dorsal atlanto-occipital ligament (membrane)
Atlantoaxial joint the ‘no’ joint
Dorsal atlantoaxial ligament
Transverse ligament of atlas Examine in carnivore models. Present in carnivore and pig.
Intervertebral disc Anulus fibrosus
Nucleus pulposus
Supraspinous ligament Between consecutive tips of spinous processes of thoracic and lumbar vertebrae.
Yellow ligament between adjacent vertebral arches, dorsal margin.
Intercapital ligament between paired rib heads for ribs 2-10 in the dog.

 

Lab 4

Muscles/structures

Epaxial mm. Iliocostalis system
Longissimus system
Transversospinalis system
Semispinalis capitis m. Carnivore, horse, ruminant
Splenius all; has 2 parts in ungulates
Hypaxial mm. Longus capitis m.
Longus colli m.
Nuchal ligament Funiculus nuchae Dog, horse, ruminant
Lamina nuchae (paired) Horse, ruminant
Lamina nuchae (un-paired) Ruminant – identify in calf
Bursa Supraspinous bursa Horse – often hard to specifically identify but let’s have a good crack at it.
Cranial (and caudal if present) nuchal bursa Horse – don’t look for these but be aware of location
Rectus capitis dorsalis mm. Horse, ruminant
Obliquus capitis caudalis m. Horse, ruminant

Muscle attachments and actions

Muscle/structure  Attachments Action
Iliocostalis system Overlapping fascicles from ilium to rib 1 Extension and lateral movement of vertebral column
Longissimus system Overlapping fascicles from ilium to skull Extension and lateral movement of vertebral column
Transversospinalis system Overlapping fascicles from sacrum to skull Extension and lateral movement of vertebral column
Semispinalis capitis Thoracic vertebrae to skull Extend head and neck, lateral flexion of neck
Splenius Spinous processes T1‐3 and median raphe to skull Extend and raise head and neck, lateral flexion of neck
Longus colli Ventral vertebral bodies and transverse processes T6 to C1 Flex neck
Longus capitis Transverse processes cervical vertebrae to skull Flex atlanto‐occipital joint and draw neck ventrally

 

Lab 5

Thorax osteology and arthrology
Thoracic vertebrae
 
 
 
 
 
 
 
 
Canine 13, Ruminant 13, Pig 14-15, Horse 18
(Dorsal) spinous process
transverse process
cranial/caudal articular processes
body
arch (consisting of two pedicles and the lamina)
costal fovea
anticlinal vertebra (T11) in canine
Ribs – paired. Same number as thoracic vertebrae Head
Neck
Tubercle
Body
Costochondral junction
Costal cartilage
Costal arch
Intercostal space
 
Sternum – sternebrae and number
carnivore 8, horse and ruminant 7, pig 6
Manubrium
Xiphoid process
Thoracic inlet  define boundaries
Thoracic outlet define boundaries
Thoracocentesis
define typical location as described
Thoracic wall myology and comments
Serratus dorsalis mm. cranial and caudal divisions
Scalenus m. multiple slips or divisions
External intercostal mm.
Internal intercostal mm.
Rectus thoracis m.
Transversus thoracis m. Learn on a model at this time

Lab 6

Abdominal Muscles
External abdominal oblique m.
Internal abdominal oblique m.
Transversus abdominus m. or Transverse abdominal m.
Rectus abdominis m.
Abdominal wall/muscle structures
Linea alba
External rectus sheath
Internal rectus sheath
Superficial inguinal ring
Inguinal canal define (dissected later)
Deep inguinal ring not identified yet, understand as part of inguinal canal anatomy
Flank Ruminant, horse
Paralumbar fossa Ruminant, horse
Lumbar vertebrae All, note number and that L1, L6 in live ox are typically not palpable.
Subiliac lymph nodes Ungulates only
Elastic abdominal tunic Horse, ruminant – yellowish appearance
Deep circumflex iliac vessels Horse flank

 

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Unit 2: Musculoskeletal System Copyright © by Mathew Gerard and Lindsey Cobb. All Rights Reserved.

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