Anatomy Flashcards
How many thoracic vertebrae and lumbars do dogs and horses have?
Horse 18 Thoracic 6 lumbar
Dogs 13 Thoracics, 7 Lumbar
What surfaces form the spinal canal?
How is the cord suspended in canal?
The vertebral canal contains the spinal cord until what level on horse and dog
Lamina, pedicle and dorsal surafce of vertebral body.
The dentate ligaments
Horse - L3
Dog- L4/5
Articular processes - how many in thoracolumbar region on each vert
Each vertebrae has 2 cranial and 2 caudal facets.
Chiro adjustments move along line of facets
What are the boundaries of the intervertebral Foramen?
Pedicles, intevertebral disc, ligamentum flavum, joint capsule of articular facet.
Problems with any of these structures can interfere with the size of the foramen and therefore crowd the contents.
What are the contents of the inteverteral foramen
Nerves:
- Soinal Nerve
- Dorsal root ganglia
- Recurrent meningeal nerve (ie branch of the spinal nerve that supplies disc, dorsal longitudinal ligaments and meninges.
Dural Extension
-Dura mater that followspinal nerve through the IVF
Cerebral spinal fluid - CSF circulates between dural extension and radicular nerve
Intervertebral veins -Carry blood supply from V venous sinus Spinal artery Connnective tissue- tissue folling in spaces between already mentioned structures. Adipose tissue Lymphatic vessels Intraforaminal ligaments
Lumbar Vertebrae Equine Bovine Canine Feline How many do each have
and what about typical lumbars?
Which was day SP point?
Equine: 5
Bovine: 6
Canine 6
feline 7
Typical Lumbars
Equine 2-4
Canine 2-6
SP point cranially
how many joint surfaces do a typical L vert have? What are they?
Facet joints Disc joint Intertransverse joints (only horse, hippo and rhino) always between L6 and sacrum. sometimes also between L4, L5 and L6
Typical lumbar vert has 6 joint surfaces.
Which way does the caudal articular processes face?
Cranial Articular processes?
Mammillary process
Caudal: face lateral and ventral
Cranial: facets face medial with concave dish
Facets are in sagitall plane.
Mammillary: Projects lateral
Thoracic Vertebrae
How many in Equine and Canine?
Which of those are typical?
Equine: 18, arabian 17 sometimes, or 19
Canine and Feline: 13, sometimes 12
Typical Thoracics
Equine 2-14
Canine 2-8
How many joint surfaces are on typical thoracic vertebrae
12 joint surfaces: Facets =4 Disc joints 2 Costovertebral Joints 4 Costotransverse = 2
Tell me which SP point in which direction for thoracics in Equine patient
T1-15- caudally
T16- anticlinal straight
T17-T18 points cranially
At T16 the shape and position of the facet joints changes
Thoracic Vertebrae Canine, which way do they point
SP of T1-10 point caudally
SP of T11 straight- anticlinal region
T12-T13 point cranially
Cranial joint surfaces pf T10 are coronal, then the caudal joint surfaces are sagittal
Cranial area of T spine (equine is T2-T12), Canine is T2- T10.
Which way is facet joints facing.
Cranial joint surfaces are located on the roof of the vertebral canal at the base of the SP and face dorsal and lateral
Caudal joint surfaces face ventral and medial
Equine Ribs, how many pairs?
18 pairs
8 of them articulate directly with sternum, canine 9 of them do.
TOPOGRAPHY Equine
The first palpable T vert is?
The withers ends at?
the lumbar spine begins at the end of the?
The last well palpable SP in the Lspine is
The which joint is located right in front of PSIS
In between the PSIS is?
The first bony prominence behind PSIS is S2,
■ The first palpable thoracic vertebra is T3
■ The withers ends at T8 (T9 / T10)
■ The lumbar spine begins at the end of the saddle area
■ The last well palpable spinous process is the one of L5
■ L6 is in most horses very difficult to palpate
■ The lumbosacral joint is right in front of the PSIS
■ In between the PSISs is S1
■ The first boney prominence behind the PSISs is S2, the second tubercle of the sacrum
TOPOGRAPHY Canine
■ The first palpable thoracic vertebra is
■ The anticlinal vertebra lies in an indentation of the TL spine
■ The lumbosacral joint lies in between the ?
■ The mammilary processes are to the side of the cranial edge of the respective dorsal spinous process
■ The first palpable thoracic vertebra is T2
■ The anticlinal vertebra lies in an indentation of the TL spine
■ The lumbosacral joint lies in between the tuber sacrale
■ The mammilary processes are to the side of the cranial edge of the respective dorsal spinous process T11 –L7
IVD
has a concave convex relationship, which side is which?
Intervertebral Disc
■ A disc is a powerful ligament that binds and stabilizes vertebral column
■ Relatively thin in the quadruped
■ Discs are thinnest in areas of decreased movement and thickest in areas of greatest movement
■ Joint is only partially movable, so it is classified as amphiarthrodial
Anatomy
Equine variation
■ Disc joint has concave-convex relationship; concave caudal body, convex cranial body
Imbibition
Nutrition of the disc
Anatomy
■ Movement of nutrients is mediated by spinal movement
■ Compression squeezes water out of nucleus through pores in annular fibers
■ Water content of disc returns to normal during rest
■ Water in nucleus allows nucleus to handle stress
■ Function, Water Content and Capacity of the disc to bind water decreases with age of disc
NEUROANATOMY
Ascending and descending tracts of motor and sensory
Ie how far down does the spinal cord run?
■ Equine: foramen magnum to L5/ L6
■ Canine: foramen magnum To L 6/ L7
■ Feline: foramen magnum to sacrum
Is this actually correct?
How many pairs of Spinal nerves are there?
In Equine and Canine?
Where is the cervical enlargement and lumbar enlargement for each species
Equine: 42 pairs 8 Cervical 18 Thoracic 6 Lumbar 5 Sacral 5 Coccygeal
Canine: 36 Pairs
8 Cervical 13 Thoracic 7 Lumbar
3 Sacral
5 Coccygeal
Cervical enlargement C6/C7
Lumbar enlargemsnt L3/L4 -canine
What is the conus medullaris?
The spinal segment of L3 is the last spinal segment that nominally corresponds with its vertebra (L3)
Caudal to L3 spinal nerves are elongated und spinal segments are shortened and displaced cranially, relative to their nominally corresponding vertebra.
The spinal cord ends in the conus medullaris and turns into the cauda equina
Neuroanatomy
Spinal Nerves pass through the intervertebral foramen and divide into three major branches
Dorsal Branch
■ Motor and sensory fibers to dorsal musculature
Ventral Branch
■ Motor and sensory fibers to ventral and lateral muscles of trunk and muscles of extremities
Visceral Branch
■ Autonomic N.S supplying thoracic and abdominal organs
■ Motor and sensory fibers
Sympathetic NS
what is their function??
■ Sympathetic neurons are found specifically in thoracolumbar region Thoracic 1 to Lumbar 4
■ Generally fibers from T1 to T5 are distributed cranially to head and neck
■ Generally fibers from T6 to L4 extend caudally
■ Nerve fibers from these cells accompany spinal nerves along ventral
branches
These nerve fibers join sympathetic trunk ganglia ventro- lateral to the spine
■ These ganglia contain neurons that send nerve fibers to : Viscera such as heart, Arteries in the head
Smooth Muscles Glands
Their function:
Sympathetic function:
■ Vasomotor:
Contraction of arterial wall muscles (vasoconstriction)
with increase in blood pressure
■ Sudomotor:
Contraction of smooth muscles in gland causing secretions
■ Pilomotor:
Contraction of erector pili muscles causing hair movement
■ Fibers to smooth muscles to hollow organs such as the heart
