Neuro anatomy intro Flashcards
What protects the spinal cord?
Vertebral column
Caudal?
Tail end
Rostral?
Towards face
Cranial?
Head end
What is the nervous system divided into?
1) CNS- brain and spinal cord
2) PNS- all nervous tissues outside CNS
Mainly nerves- cranial, spinal, autonomic
Functional division of nervous system?
1) Somatic- voluntary activity
2) Autonomic- involuntary
Brain divided what parts?
1) Cerebrum
2) Cerebellum
3) Brainstem
What is the cerebrum?
L and R cerebral hemispheres
Surface- cerebral cortex
Surface- grey matter- information processed
Deep-white matter- axons
What are folds called on cerebral cortex?
Gyri
What are grooves called on cerebral cortex?
Sulci
What are the different lobes on the brain?
1) Frontal (anterior)
2) Parietal
3) Occipital
4) Temporal (posterior)
Cerebellum location?
Inferior to posterior part of cerebrum
Attached to brainstem
Structure and contents of cerbellum?
L and R hemispheres
Highly folded cortext
White matter and nucei deep to cortex
Function of cerebellum
Balance,
Fine movement co-ordination
Sense body position
What makes up the brainstem?
1) Midbrain
2) Pons
3) Medulla
Functions of brainstem
Relays information between cerebrum, spinal cord and cerebellum
Gives rise to most cranial nerves
Contains centres regulate breathing and consciousness
Where does spinal cord end?
L1-L2- vertebral column is longer
What are tracts?
Bundles of axons that connect different parts of CNS to each other
How many spinal nerves are there?
31
What fills ventricles?
Cerebrospinal fluid (CSF)
Function of CSF?
Provide nutrients to brain
Protects brain- provides cushion against trauma
Prevents nerves and vessels being compressed between brain and skull
How many ventricles are there in brain?
4
Name meningeal layers (outside to in)
Dura mater
Arachnoid
Pia mater
DAP
Where is the dura mater?
Lines inner surface of skull and vertebral column
Thick and strong
Where is the arachnoid mater?
Lies deep to dura
Thin and loosely encloses brain and spinal cord
Where is the pia mater?
Deep to arachnoid, adhered to surface of brain and spinal cord
Thin and can’t be seen with naked eye
Functions of meninges?
Protect the brain
Provide scaffold for blood vessels
DAP
What arteries supply blood to the brain?
L and R carotid arteries
L and R vertebral arteries
What structure involved in blood supply is located on inferior surface of cerebrum?
Circle of Willis
What is an anastomosis and why is it important?
Branches from otherwise seperate arteries join
Allows blood supply to be maintained if one of vessels is blocked
How many cerebral arteries does COW give rise to?
3 on each side
Cerbellar arteries- supply cerebellum
Arteries supply brainstem and spinal cord
Communicating arteries connect cerebral arteries together
How many cerebral arteries does COW give rise to?
3 on each side
Cerbellar arteries- supply cerebellum
Arteries supply brainstem and spinal cord
Communicating arteries connect cerebral arteries together
Label
What does cerebellar supply?
What do bottom supply
What second bottom supply?
Peduncles
Medulla
Pons
Name parts of nervous system
Somatic nervous system
Autonomic nervous system
Somatic nervous system function?
Controls voluntary activity
Motor- controls voluntary contraction of skeletal muscle
Sensory- sends info about peripheral stumuli from sensory receptors in body to CNS
Autonomic nervous system function?
Control involuntary activity e.g HR, BP, resp
Motor- controls smooth muscle, glands and cardiac
Motor further divided:
Sympathetic= flight and fight
Parasympathetic= rest and digest
Sensory- info about internal env from organs to CNS- doesn’t reach conscious perception eg. bp monitoring
Sympa and Para pathways
2 neurons in pathway from CNS to target organ
Cell bodies of first neurons lie CNS: (preganglionic/presynaptic)
Sympathetic in thoracic and upper lumber (T1-L2/3)
Parasympathetic in brainstem and sacral (S2-S4)
Axons leave CNS and synapse with second neuron- lies in ganglion (postganglionic/postsynaptic)
Differences between sympathetic and parasympathetic ganglia?
Sympathetic ganglia- closer to CNS so pre axons short, post long
Parasympathetic ganglia- close to target organs so pre axons long, post short
Which system (para or sympa) is larger
Sympathetic more widely distributed- innervate sweat glands and smooth muscle in blood vessel walls and hair follicles (arrector pili muscles)
Both innervate thoracic, abdominal and pelvic viscera
Name fibres carry info from visceral back to CNS?
Visceral afferent fibres- convey info from visceral back to CNS
Function of visceral afferent fibres?
Monitor internal environment- bp, lvls O2 and CO2 and send info back to CNS- elicit reflex responses (automatic, unconscious) maintain internal env.
Convey information to CNS about distension, spasm and stretch of viscera- does reach consciousness
Travel along sympa and para
Imp in referred pain
How many cranial nerves are there?
12 pairs- part of PNS
Carry combo sensory, motor, both, para
How many spinal nerves are there?
31
● 8 cervical spinal nerves (C1 - C8) ODD
● 12 thoracic spinal nerves (T1 - T12)
● 5 lumbar spinal nerves (L1- L5)
● 5 sacral spinal nerves (S1 - S5)
● 1 coccygeal spinal nerve (Co1)
What fibers do spinal nerves carry?
● Somatic motor fibres from CNS to body
● Sympathetic fibres from CNS to the body
● Somatic sensory fibres from the body to CNS
What structure protects spinal nerves?
Spinal cord
Nerves pass through gaps between vertebrae-intervertebral foramina
Where are cell bodies of motor neurons?
Ventral horn of spinal cord (grey matter)
Axons leave the cord via rootlets- form the
ventral (motor) root of the spinal nerve
Motor fibres stimulate voluntary contraction of skeletal muscle.
Where are cell bodies of peripheral sensory neurons?
Dorsal root ganglia
Neurons 2 processes
- one peripheral into spinal nerve
- one centre dorsal horn spinal cord (grey)
Sensory info travel from periph receptors (skin) via spinal nerve to DRG to dorsal horn via rootlets
What fibres do all spinal nerves contain?
Sympathetic fibres- stimulate sweat glands, contraction smooth muscle and hair follicles
What is a dermatome?
Area of skin that is innervated by a single spinal nerve
What is a dermatome map?
Shows area which spinal cord has effect
e.g. thumb sensation- C6 spinal nerve
What is a myotome?
Group of muscles that innervate a single spinal nerve
Draw and label circle of willis?
