Anatomy Flashcards
What is a transverse plane?
An axial plane
Cuts through the body horizontally
What is an axial plane?
A transverse plane
Cuts through the body horizontally
What is a coronal plane?
A vertical cut through the body
If you are standing with you back to a wall, the coronal plane is any cut that is parallel to the wall
What is a sagittal plane?
A vertical cut down the midline of the body only
What is a parasagittal plane?
A vertical cut down the body, but not down the midline
Perpendicular to coronal
In neuroanatomy what is the word for superior?
Dorsal
In neuroanatomy what is the word for inferior?
Ventral
In neuroanatomy what is the word for anterior?
Rostral (nose end)
In neuroanatomy what is the word for posterior?
Caudal (tail end)
Which part of the spinal cord is dorsal?
The back of it, the bit closest to the skin
What do these words mean:
- dorsal
- ventral
- rostral
- caudal?
Dorsal: superior
Ventral: inferior
Rostral: anterior (nose end)
Caudal: posterior (tail end)
What parts make up the CNS?
Brain Midbrain Pons Medulla Spinal cord
What main neurotransmitters are used in the CNS?
Dopamine
GABA
What parts make up the peripheral nervous system?
All other structures that aren’t included in the CNS
- cranial nerves
- nerves that go to or come from the peripheries
Are cranial nerves part of CNS or PNS?
PNS
What main neurotransmitter is used in the PNS?
Acetylcholine
Difference between somatic and autonomic nervous system?
Somatic: conscious control of body
Autonomic: sub-conscious control of body
Two branches of autonomic?
Sympathetic: fight, flight
Parasympathetic: rest, digest
What type of nerves are branchial nerves?
Motor
Come from brain
What type of nerves are special nerves?
Sensory
Come from brain
How many cervical vertebrae are there? And how many cervical nerves are there?
7 cervical vertebrae
8 cervical nerves
What is a spinal nerve?
A nerve that comes out of the spinal cord
How many spinal nerves are there?
31 pairs
What is a dermatome?
An area of skin supplied by a single spinal nerve
What is a myotome?
An area of muscle supplies by a single spinal nerve
How many thoracic spinal nerves are there?
12 pairs
How many lumbar spinal nerves are there?
5 pairs
How many sacral spinal nerves are there?
5 pairs
How may coccygeal spinal nerves are there?
1
Number the spinal nerves, so:
C?
T?
L?
S?
C 1-8
T 1-12
L 1-5
S 1-5
What is the conus medullaris?
The end of the main spinal cord, before it branches into the cauda equina
What is the cauda equina?
Bundle of spinal nerves which arises from the conus medullaris
These nerves spread out sort of like a horses tail (hence name)
What do the nerves of the cauda equina supply?
Pelvic organs
Lower limbs
What is the lumbar enlargement?
A widened area of the spinal cord in the lumbar region
This is where the nerves that supply the lower limb leave the spinal cord
What is the cervical enlargement?
A widened area of the spinal cord in the cervical region
This is where the nerves that supply the upper limb leave the spinal cord
What is the filum terminale?
A strand of fibrous tissue that arises from the conus medullaris and goes down to the end of the spine
Provides support for the spine
Describe the journey from the outside of meninges of the spinal cord to inside.
Epidural space Dura mater Subdural space Arachnoid membrane Subarachnoid space Pia mater Cord
What are the three layers of meninges?
From in to out: PAD out
Pia mater
Arachnoid membrane
Dura mater
Where is Broca’s area?
In the frontal lobe
In right handed people it is mostly in the dominant (left)hemisphere
In left handed people it is also mostly in the left hemisphere
Sometimes it is in the right hemisphere
What is the difference in function of Broca’s area and Wernicke’s area?
Broca’s = speech production
Wernicke’s = speech understanding
Where is Wernicke’s area?
In posterior temporal
Describe the journey of a molecule from a cerebral blood vessel to a nerve.
Through:
Capillary endothelium Basement membrane Pia mater Astrocyte foot processes Nerve
What is Brown-Sequard syndrome?
A one sided spinal cord lesion causing:
Ipsilateral paralysis
- because corticospinal tract has been blocked
Ipsilateral loss of fine touch and proprioception
- because DCML tract has been blocked
Contralateral loss of pain and temperature sensation
- because spinothalamic tract has been blocked
In Brown-Sequard syndrome, why is paralysis ipsilateral?
Because the corticospinal tract decussates at the medulla
The lesion blocks the tract after it has decussated in the medulla
So paralysis will be on the same side as the lesion
In Brown-Sequard syndrome, why is loss of fine touch and proprioception ipsilateral?
Because the DCML tract decussates at the medulla
The lesion blocks the tract before it has decussated in the medulla
So sensation from the same side of the body to the lesion is unable to get to the brain
In Brown-Sequard syndrome, why is loss of temperature and pain sensation contra-lateral?
Because the spinothalamic tract decussates two levels above its entrance to the spinal cord
The lesion blocks the tract after it has decussated
So sensation from the opposite side of the body to the lesion is unable to get to the brain
What are epidurals used for?
C-sections
Hip + knee replacements
Many more
Why are epidurals preferred to a general anaesthetic in many cases?
Because with an epidural, the heart, BP and other vital signs are still controlled by the brain whereas in general anaesthesia they are controlled by the anaesthetist
What is an epidural? Describe how it works?
Anaesthetic is injected into the epidural space
It diffuses and affects the dorsal root ganglion and blocks sensation
How come patients who have had an epidural can walk with assistance?
Motor control is preserved with an epidural
Why is a blunt needle used for an epidural?
So that you don’t puncture the dura
What happens if you puncture the dura while doing an epidural?
Injecting anaesthesia into the subdural space will mean it will go up the spinal cord to the brain and they’ll go into respiratory arrest
In a lumbar puncture where do you collect the CSF from?
The subdural space
Stick a needle through the dura and collect fluid
