The Neck - Horse and Ox Flashcards
Median Pectoral Groove (Sulcus)
Located in the midline, has the two Descending Pectorals on either side, deep to this groove is the Sternum
Lateral Pectoral Groove (Sulcus)
Between Descending Pectoral M and Cleidobrachialis M.
Name two blood vessels that run in the Lateral Pectoral Groove:
- Cephalic Vein
2. Deltoid branch of superficial cervical artery
Cephalic Vein
Runs along Lateral Pectoral Groove.
Carries blood from distal parts of the limb and drains into External Jugular V.
The Cephalic V is superficial at the distal part of the groove.
Deltoid branch of Superficial Cervical A
Runs along the Lateral Pectoral Groove. At the proximal part of the groove, the artery is superficial.
Superficial Cervical A is a branch of the……
Subclavian Artery
The Jugular Groove contains what vessel?
List its boundaries
Contains External Jugular V.
Dorsal boundary: Brachiocephalicus M, more specifically Cleidocephalicus M (in Horse more specifically Cleidomastoideus M)
Ventral boundary: Sternocephalicus (Sternomandubularis + Sternomastoideus in cow)
(Sternomandibularis in horse)
(Sternomastoideus + Sternooccipitalis in dog)
In the horse, Sternocephalicus M. consists of:
Only one part that attaches to the mandible, called Sternomandibularis M
In bovine, Sternocephalicus M. consists of:
Two parts, Sternomandubularis M. and Sternomastoideus M.
In the horse, the Brachiocephalicus M. consists of:
Cleidomastoideus M. and Cleidobrachialis M.
In the cow, the Brachiocephalicus M. consists of:
Cleidomastoideus M. and Cleidooccipitalis M. and Cleidobrachialis M.
How many pairs of cervical spinal nerves are there?
8 pairs for seven cervical vertebrae
List four main nerves of the neck:
- Cutaneous branches of spinal nerves
- Great auricular and transverse cervial nerves
- Cervical branch of the facial nerve
- Accessory Nerve (Cranial nerve XI)
Cutaneous branches of spinal nerves
consist of dorsal and ventral parts; ventral branches of C6-8 contribute to the brachial plexus
Ventral cutaneous branch of C2
Divides into two sensory nerves: Great Auricular N and the Transverse Cervical N.
Great Auricular N.
sensory branch of the ventral cutaneous branch of C2, runs along the caudal edge of parotid gland.
Supplies sensation to the lateral parts of the auricle
Transverse Cervical N.
sensory branch of the ventral cutaneous branch of C2; runs ventrally over the throat; innervates cutaneous muscles on the head and neck
Cervical branch of the facial nerve:
Small nerve that is not seen in cattle. Passes and emerges through parotid gland, and innervates parotidooricularis M. that lies over the parotid gland
Runs along external jugular V. to innervate cutaneous colli M. (motor)
Accessory Nerve (CN XI)
Applies to both cattle and horses. Emerges from the jugular foramen. Dorsal branch innervates: Cleidocephalicus M. Omotransversarius M Trapezius M. Ventral branch innervates: Sternocephalicus (COTS)
The brachiocephalicus M. splits into:
Cleidocephalicus M.
Cleidobrachialius M.
Cleidocephalicus M. splits into what regarding the dog, ox, and horse:
- Cleidomastoideus muscle in all domestic mammals. It is the only part in horses and sheep.
- Cleidooccipitalis muscle only in ruminants and pigs.
- Cleidocervicalis M. only in the dog and cat
Cleidomastoideus M.: O, I, N, A
Origin: Clavicular intersection
Inserts: mastoid process of temporal bone
Innervation: Dorsal branch of accessory nerve
Action: Protractor of limb; draws head ventrally or lateraly
Cleidooccipitalis M: O, I, N, A
Origin: Claivuclar intersection
Inserts: Occipital bone
Innervation: Dorsal branch of accessory nerve
Action: protractor of limb, raises head
Cleidocephalicus muscle is mainly innervated by:
dorsal branch of accessory nerve
Cleidobrachialis muscle is mainly innervated by:
Axillary N. (from the brachial plexus, which also innervates deltoideus M, teres major M, teres minor M
Sternocephalicus Muscle can split into what in regards to different domestic animals?
- Sternomandibularis M. (horse, ox, and goat); only part in the horse
- Sternomastoideus muslce (all domestic animals EXCEPT horse)
- Sternooccipitalis muslce (dog and cat)
Sternocephalicus M. can also be called what in the horse?
Sternomandibularis
Sternocephalicus M. is mainly innervated by:
Ventral branch of accessory N. (XI)
Hyoid muscles
Originate as a common mass from the manubrium of the sternum and attach cranially along the trachea and deviate close to the head.
- Sternohyoideus M.
- Sternothyroideus M.
- Omohyoideus M.
Sternohyoideus M.: O, I, N, A
Origin: manubrium sterni
Inserts: Basihyoid bone
N: Medial branch of the ventral branch of C1
A: Retractor of hyoid apparatus and tongue (pulls tongue caudally)
Sternothyroideus M.: O I, N, A
Origin: Manubrium sterni
Inserts: thyroid cartilage of the larynx
N: Medial branch of the ventral branch of C1
A: Synergist of sternohyoideus and retracts thyroid cartilage
Omohyoideus M.: O, I, N, A in the ox
O: thin band of fascia at cervical vertebrae 2 or 3
I: basihyoid bone
N: Medial branch of the ventral branch of C1
A: Synergist of sternohyoideus
Omohyoideus M: O and I in horse
O: subscapular fascia
I: basihyoid bone
Nuchal ligament i found in all domestic mammals except:
Cat and Pig
Nuchal ligament contineuous caudally as….. and consists of…… connetive tissue.
Nuchal ligament continues caudally as supraspinous ligament, and consists of very dense irregular collagenous conective tissue
List the two parts of the nuhal ligament:
Funiculus nuchae (funicular part) Lamina nuchae (laminar part)
Funiculus Nuchae
Funicular part of the nuchal ligament. Goes to externl occital protuberence of the skull.
Lamina nuchae
Laminar part of the nuchal ligament. Attaches onto te spinous processes of other cervical vertebrae.
List three associated bursae with the nuchal ligament:
- Cranial nuchal (atlantal) bursa
- Cuadal nuchal bursa
- Supraspinous bursa
Cranial nuchal (atlantal) bursa is between:
Between funiculus nuchae and dosral arch of the atlas/rectus capitis dorsalis major M because this muscle essentially lies ontop of this arch
Caudal nuchal bursa is between:
Funiculus nuchae and spine of axis
Supraspinous bursa is between:
Nuchal ligament and 3/4 cervices
Atlantal bursitis (poll evil)
Draining wound at the caudal end of the head/back of the neck
Supraspinous bursitis (fistulous withers)
Withers is the interscapular region where spinous processes of thoracic vertebrae T2-T7 are elevated. Supraspinous bursitis is an infection of this bursa - it is the area typically where the saddle presses up against the horse’s side.
The location of the thymus in the horse, dog and cat:
Cranial Mediastinum
The location of the thymus in ruminants and the pig:
There is a large amount of thymus, elongated within the neck, and goes up to the skull. This elongated portion of the thymus is known as the cervical lobe.
Topography of the esophagus at the cranial part of the neck.
The esophagus is a continuation of the laryngeal pharynx.
Topography of the esophagus at the middle of the neck.
Deviated to the left of the trachea, and is close to the external jugular vein.
Topography of the esophagus in the thoracic inlet.
Esophagus becomes dorsal to the trachea.
What is cervical fascia?
Layers of dense connective tissue in the neck, NOT superficial fascia that is subcutaneous.
What are the three layers of cervical fascia?
- Superficial lamina - outer most layer, expands entire neck, surrounds sternocephalicus, cleidocephalicus, and trapezius.
- Petracheal lamina (middle cervical fascia): it is continuous with the carotid sheath, surrounds visceral structures of the ncek, sternohyoideus M, sternomyoideus M
- Prevertebral lamina (deep cervical fascia): covers longus colli M., and attaches to transverse processes of vertebrae
The external jugular V. drains blood from the _____.
Head
Where is the internal jugular vein located in cattle and what does it drain, and do horses have this structure?
Beneath the common carotid A, and rains blood from the larynx, thyroid gland, trachea, etc…
Horses usually don’t have an internal jugular V
Superficial cervical artery is a branch of what?
Subclavian A.
Deep cervical artery arises from _____.
Arises from a branch of subclavian artery known as costocervical trunk seen on the deep surface of the semispinatus capitis muscle.
At what part of the jugular groove are the external jugular V. and common carotid A. very close together?
The caudal part of the jugular groove.
In the ox, the A. and V. are very close together because there is no cutaneous colli M present inbetween them, like there is in the horse.
Where does the longus colli M. start?
It starts in the thorax and extends cranially through the neck
Dorsal longitudinal ligament
Made up of collagenous connective tissue, lies on the dorsal surface within the vertebral canal.
Blends with annulus fibrosis of the disc.
Ventral longitudinal ligament
Made up of collagenous connective tissue.
Lies on the ventral surfaces of the vertebral bodies, beginning at the middle of the thorax. It is not present cranially because longus colli M. runs from the atlas to the middle of the thorax.
Yellow ligaments (ligamenta flava)
Made up of elastic connective tissue.
Span interarcuate spaces (dorsal).
Where are epaxial muscles located?
Above the axis - meaning above the transverse processes of the vertebra
Function of epaxial muscles
To straighten the spine/vertebral column and aid in sudden movements of the vertebral column.
Innervation of epaxial muscles
Dorsal branch of the spinal nerve: the motor part goes to the epaxial Mm., and the sensory part goes through and perforates the muscles to the skin.
What are the four groups of epaxial muscles?
- Erector spinae - “elevating the spine”
- Transversospinalis Mm.
- Intertransversarii Mm.
- Interspinalis Mm.
Muscles included in erector spinae
- Iliocostalis Mm - most lateral
- Longissimus Mm - medial to iliocostalis
- Spinalis Mm - medial to longissimus
Muscles included in Transversospinalis Mm.
- Semispinalis Mm.: sempispinalis capitis M. consists of two parts, the biventor cervices and complexus
- Multifidus Mm.: span 2-3 vertebrae from where thy originate, attach to spinous processes of 2-3 vertebrae cranially
Describe the location of interspinalis Mm.
Between individual spinous processes, span from caudal cervical vertebrae to lumbar vertebra.
Describe origin and insertion of transversoospinalis Mm.
From transverse processes of vertebrae to spinous processes of vertebrae
