Intro to anatomy 2 Flashcards
What is segmentation?
Repetition of body segments
What is a somite?
masses of mesoderm tissue
What do somites develop into?
skin, skeletal muscles and vertebrae
Which gene controls somite formation?
Hox gene
How does Hox gene affect somite (then vertebrae) production?
Switching them on/off determines how many somites are produced and how big they are
How many pre-sacral vertebrae are there?
24
What are the names of the pre-sacral vertebrae?
cervical, thoracic and lumbar
How many sacral vertebrae are there?
5
Where are coccygeal vertebrae found?
After the sacrum
How many coccygeal vertebrae are there?
Between 1 and 7 (differs from person to person)
Why are the lumbar vertebrae the biggest?
To support body weight
What gene controls the form of the different vertebrae?
Also the Hox gene
What is the general organisation of a vertebra?
- vertebral body
- pedicles (bridges) and vertebral arch
- articular processes (x2 superior and x2 inferior)
- transverse processes
- spinous processes
Function of pedicles
Connects to the vertebral arch
Why is there a space between the vertebral body and the vertebral arch?
To allow the spinal cord and spinal nerve to run through
Function of the articular processes
Join two adjacent vertebra together through synovial joints
What are synovial joints?
Prevent fiction between bones
Function of transverse process
Acts as muscle or rib attachments
Function of spinous process
Act as point of attachment for muscle and ligament attachment
How many cervical vertebrae are there?
7
What part of the body do the cervical vertebrae make up/where are they found?
neck
Key characteristics of the cervical vertebrae
- transverse foramen
- atlas (C1) and Axis (C2)
- spinous process bifurcates
- joint facets
What is the transverse foramen?
Pair of holes on the side of the vertebrae where vertebral artery runs through when going to the head
What is different about atlas (C1) and axis (C2)?
Unique shape as opposed to the rest of the cervical vertebrae
What is the role of joint facets?
Where cartilage is and is what makes the joint mobile
In which plane can you see the joint facets?
Axial plane
How many thoracic vertebrae are there?
12
What is the distinguishing function of thoracic vertebrae?
rib-bearing
Key features of thoracic vertebrae
- no transverse foramen
- spinous process is downwards oriented
- rib articulations
- joint facets
Do cervical vertebrae have a transverse foramen and why?
No because the vertebral artery doesn’t run through them
In which plane can the joint facets be seen?
Coronal
What type of movement does the joint facet allow in the thoracic vertebrae?
Limited movement, allows just rotation
How many lumbar vertebrae are there?
5
Key features of lumbar vertebrae
- no ribs
- no transverse foramen
- joint facets
What are the spinous processes shaped like in lumbar vertebrae?
Short and square-like
In what plane can the joint facets be seen in lumbar vertebrae?
Sagittal plane
What type of movement do the joint facets allow in lumbar vertebrae?
Flexion and extension, but limited rotation
How many sacral vertebrae are there?
5 fused together
What is the function of the sacrum?
To join the spine to the pelvis
How does the sacrum join the spine to the pelvis?
Via the sacroiliac joint
What are the sacral foramina?
Holes in the transverse process that allow for the release of spinal nerves
What makes up the central nervous system?
brain and spinal cord
What makes up the peripheral nervous system?
nerves that come off the brain and spinal going to the rest of the body
What is the peripheral nervous system split into and what are their functions?
visceral nervous system: involuntary actions
somatic nervous system: voluntary movements
Name of nerve fibres going from periphery structures to CNS
Afferent/sensory fibres
Name of nerve fibres going from CNS to periphery structures
Efferent/motor fibres
How does the spinal nerve arise?
Comes out of the vertebral foramen containing sensory and motor fibres and goes to the periphery
What is a dermatome?
The area/strip of skin that receives sensory innervation from a single spinal nerve
What is a myotome?
Segment of skeletal muscles innervated by a particular spinal nerve
