Back and vertebral column and all that stuff Flashcards
- Back + vertebral column - Back, nerves + vessels
How many bones are in the vertebral column?
33
What is the trend in the size of vertebrae along the spine
Increase from superior to inferior
What are the functions of the vertebral column
Weight bearing
Protection
Movement
Site of muscle attachment
What are lordoses and kyphoses?
Spinal curvatures
Lordoses
- inward curvatures
- Cervical & lumbar
- Develop during infancy
Kyphoses
- outward curvatures
- Thoracic & sacral
- Already present in fetus
What is the name given to the condition, where there is abnormal spinal curvature, that is lateral?
Scoliosis
Describe the structure of a typical vertebra
Vertebral body \+ Vertebral arch: - Pedicle - Transverse process - Spinous process - Lamina - Superior & inferior articular processes
Describe the components of an intervertebral disc
Nucleus pulposus - high water content
Annulus fibrosus - lamellae (layers) of fibrocartilage surrounding the NP
What does the vertebral column protect?
Spinal chord
Spinal nerves
Arteries & veins
What encases the spinal chord?
The meninges + CSF
What are the 3 membranes of the meninges
Pia matter (inner-most)
Arachnoid matter
Dura matter (outer-most)
What movements are permitted by the spine?
Extension & flexion
Lateral flexion & Lateral extension
Rotation of upper trunk
Rotation of head & neck
What are the joints of the vertebral column?
What type of joint is each?
Intervertebral discs - 2nd cartilaginous
Facet joints - Synovial plane
Rib joints - Synovial plane
Skull & atlas joints - Synovial ellipsoid
Atlas & axis joints - Synovial pivot
What are the ligaments of the vertebral column
Posterior longitudinal
Anterior longitudinal
Ligamentum flavum
Interspinous
Supraspinous
Describe the muscle attachments of the vertebral column
Head Upper limbs Thorax Abdomen Hips Lower limbs
What are the erector spinae
Intrinsic back muscles (only act on the back)
Extension, controlled flexion and lateral flexion
What is the largest vertebrae type?
Sacral
Rib joints are found on what type of vertebrae?
Thoracic
Where do spinal nerves pass to the spinal chord?
Intervertebral foramen
What is the vertebral canal
Space in the vertebral column through which the spinal cord passes
The canal is made up by the vertebral foramen of each vertebrae
What is the conus medullaris?
The inferior end of the spinal cord
Where is the conus medullaris?
L1 - adults
L3 - children
What is the Causa equina?
Bundle of spinal nerves & spinal nerve rootlets
Begins at the conus medullaris
Has the appearance of a horse’s tail
Made of lumbar & sacral nerves
What is the Filum terminale
Strand of pia mater
Proceeding downwards from the apex of the Conus Medullaris to the coccyx
What are the meninges?
3 layers of protective tissue
Surround the brain and spinal cord
What are the 3 layers of the meninges?
Dura mater (outermost)
Arachnoid mater
Pia mater (innermost)
Describe the full composition of the meninges
Dura mater
Sub-dural space - this isn’t an actual ‘space’ however
Arachnoid mater
Sub-arachnoid space
Pia mater
Where is CSF located?
Sub-arachnoid space
What is the difference between the sub-dural space and extra-dural space?
Extra-dural space is the space between dura and bone of the vertebral column
Sub-dural is the space in between the dura and arachnoid mater
How far down the spinal cord do the dura & arachnoid mater extend?
S3 vertebra
The spinal cord is thickest in the cervical & lumbar region, and thinner in the thoracic region.
Why is this?
Cervical & lumbar regions supply the limbs
Enlargements for brachial & lumbar plexus nerves
What is the lateral horn?
Horn on the grey matter of the spinal cord, (along with the dorsal & ventral horn)
Contains the neuronal cell bodies of the sympathetic or parasympathetic NS
What levels of the spinal column are lateral horns present at?
Sympathetic: T1 - L2/3
Parasympathetic: S2 - S4
Why is white matter white and grey matter grey?
White matter is myelinated
Grey matter isn’t
What are the ramus communicans?
Short nerve trunks connecting the ganglia of the sympathetic chain to the spinal nerves
What 2 types of ramus communicans are there, and what do they do?
White RC: Pre-ganglionic fibres from spinal nerve to sympathetic trunk
Grey RC: Post-ganglionic fibres from sympathetic trunk back into the spinal nerve
If sympathetic fibres only exist between T1 - L2/3, how do other levels of the body receive sympathetic innervation?
Because of the sympathetic trunk
Distribution mechanism for the sympathetic supply to all parts of the body
A pre-ganglionic fibre can enter at 1 level, T2 for eg, and travel up the sympathetic trunk before synapsing in the cervical region
What are the 3 options for the route taken by a sympathetic motor fibre, emerging from lateral horn cells, in terms of the sympathetic trunk
1) Synapse in the chain/trunk, at the same level
2) Run up or down the trunk and synapse at a different level
3) Pass straight through the chain and synapse elsewhere
What are splanchnic nerves?
Paired visceral nerves carrying fibres of the autonomic nervous system (visceral efferent fibres) as well as sensory fibres from the organs (visceral afferent fibres)
True / False
The sympathetic motor fibres that supply the abdominal viscera are the only type of splanchnic nerves in the body
False
Abdominal & thoracic
Splanchnic to thoracic: synapse in sympathetic trunk then go to the organ supplied, via nerve plexus
Abdominal: Pass through symp. trunk without synapsing.
Sympathetic splanchnic nerves to the abdominal viscera synapse at prevertebral ganglia
Describe how sympathetic motor supply to the face and head is permitted
Sympathetic fibres synapse at 1 of 3 different cervical ganglia in the symp. trunk
Post ganglionic fibres wrap around arteries going into and around the head and neck
From what 3 ganglia do post ganglionic sympathetic fibres travel into the head from?
Superior cervical ganglion
Middle cervical ganglion
Inferior cervical ganglion
What are the main features of the sensory fibres of the autonomic nervous system
Afferent fibres of the ANS are not classified as Sympathetic or Parasympathetic
All afferent ANS fibres are General visceral afferent fibres (GVA)
What 2 regions of the body contain general visceral afferent fibres?
Abdomen & pelvis
Describe the pathways taken by general visceral afferent fibres
GVA’s for:
General sensory impulses run with parasympathetic efferent fibres
Pain impulses run mainly with sympathetic efferent fibres (in pelvis, run also with parasymp. fibres)
Where do parasympathetic nerve fibres arise from?
Cranial: 3rd, 7th, 9th, 10th
Spinal: S2, S3, S4
What is the vagus nerve?
10th cranial nerve
Parasympathetic control of the heart, lungs, and digestive tract
What are the 2 lymphatic ducts
Thoracic duct - drains whole body except upper right quadrant
Right lymphatic duct - drains the upper right quadrant
What is the Cisterna Chyli?
The most inferior part of the thoracic duct
What structures travel through the intervertebral foramen?
Spinal nerve roots
Arteries & veins
Ligaments
What types of joints are found on the vertebral column?
Secondary cartilaginous - intervertebral discs between vertebral bodies
Synovial plane joints - articular facet joints between adjacent vertebrae
Pivot joint - only between some vertebrae
What are the names for the C1 & C2 vertebrae?
Atlas & axis
What is the name for the C7 vertebrae?
Vertebra prominems
What is a ‘slipped disc’?
Medical condition when the annulus fibrosis of an intervertebral disc tears and the nucleus pulposus protrudes through
This can compress the spinal nerve root leading to pain/problems in half of that spinal level’s associated dermatome
In what direction must the nucleus pulposus herniate in order to compress the spinal nerve root?
Posterolateral
What are the types of ligament associated with the vertebral column?
Ligamentum flavum
Anterior longitudinal
Posterior longitudinal
Supraspinous
Interspinous
What does the ligamentum flavum connect?
The ligamentum flavum connects the laminae of adjacent vertebrae
What does the anterior longitudinal ligament connect?
The anterior sides of the vertebral bodies and the intervertebral discs
What do the interspinous ligaments connect?
Interspinous ligaments connect the spinous processes of adjacent vertebrae
What does the posterior longitudinal ligament connect?
Posterior side of vertebral bodies and the intervertebral discs
What does the supraspinous ligament connect?
Supraspinous ligaments connect the appices (ends) of the spinous processes of adjacent vertebrae
Describe the position of the vertebra prominens on the body
7th cervical vertebra - C7
Why is the interspinous gap between levels L3 and L4 used for a lumbar puncture, to obtain a sample of CSF?
There is no spinal cord at that level, only the cauda equina
This means the needle can be inserted to the canal without damaging the nervous system
Interspinous distance is also larger in the lumbar region so it is easier to insert the needle
‘The thoracic duct lies on the posterior thoracic wall, between the ____ vein and the _______ _____’
Between the Azygos vein and the descending aorta
Where does the thoracic duct drain into?
Medial end of the left subclavian vein
Where does the spinal cord end in an adult and a child?
Adult: L1
Child: L3
What spinal nerves form the cauda equina?
L2 - L5
S1 - S5
Coccygeal nerve
What levels do sympathetic nerve fibres leave the spinal cord
T1 - L2
What structures are supplied by the autonomic nervous system
Organs, involuntary muscles and glands
What are the main features of the pelvic splanchnic nerves?
Arise from levels S2-S4
Parasympathetic supply of pelvic and lower abdominal organs
Run in mixed nerve - pelvic plexus - alongside sympathetic fibres and synapse in parasympathetic ganglia in the walls of the organs they supply
Sympathetic supply of the head is allowed through the passage of post-ganglionic sympathetic fibres, up the carotid arteries into the brain n stuff
What is the name given to the mesh like network of nerves that goes up the carotid?
Periarterial plexus
