Lecture 6- Introduction to neuroanatomy Flashcards
Central nervous system
- Brain and spinal cord
- Cerebellum
Peripheral nervous system
- The peripheral nervous system refers to parts of the nervous system outside the brain and spinal cord.
- It includes the cranial nerves, spinal nerves and their roots and branches, peripheral nerves, and neuromuscular junctions
motor neurone
Motor neurons (motoneurons) carry signals from the central nervous system to the outer parts (muscles, skin, glands) of your body
sensory neurone
Sensory neurons carry signals from the outer parts of your body (periphery) into the central nervous system.
Interneurons
connect various neurons within the brain and spinal cord.
what is the forebrain
- consists of everything on top of the brainstem. Can be divided into the cerebrum and the diencephalon (hypothalamus, thalamus- deep structures)
- Grey matter
- Cortex
- Sulci and gyri
- Fissures
- White matter
- Brainstem
consists of the midbrain, pons and medulla
- Cerebellum
found just behind the brainstem
forebrain is in charge of
conscious awareness
cerebral hemispheres and cortex
- Grey matter (cortex of cerebrum)
- High density of cell bodies
- Folded into sulci (dip)and gyrae (ridge)
- Fissures deep sulci
- Longitudinal (separates 2 hemispheres)-
- Lateral fissure (sylvian)
- Not as deep as longitudinal
- White matter
- Density packed axons of the neurones- white due to myelination
white and grey matter in the spinal cord
more white matter than grey matter- on the periphery intead of central
Certain gyri, sulci and fissures separates hemisphere into lobes
- 4 key lobes
- Frontal
- Parietal
- Temporal
- Occipital
mid saggital view of the brain
longitudinal fissure
zoom in to the see the brain stem and more internal brain structures
why is orientation terminology neuroanatomy different to the rest of the body
orientation terminology of neuroanatomy is described as if humans (like other animals such as fish and lizards) have a straight CNS
In such animals the terms “rostral”, “caudal”, “ventral” and “dorsal” mean respectively towards the rostrum, towards the tail, towards the belly and towards the back.
neuroais is felxed at the level of the
midline 9flexure
meaning that anterior means
ventral
posterior means
dorsal
superior means
rostral (think nostril)
inferior means
caudal
the brainstem is in charge of
primitive neurological functions
function of the midbrain
- Eye movement
- Reflexes on pupils in response to light
The pons
- Feeding centre (trigeminal nerve)
- Sleep centre
Medulla oblongata
- Cardiovascular centre
- Respiratory centre
pairs of cranial nerves leave the brainstem
frontal lobe function
- violuntary motor control
- speech production
- social behaviour
- impulse control
- higher cognition, thinking
- sexual urgers
temporal lobe function
- language
- emotion
- long term memory
- sense of smell
- hearing
- taste
parietal lobe function
somatosensory percpetion
spatial awareness
occipital lobe function
visual perception
cerebellum function
co-ordination and motor learning
pre-central gyrus
in the frontal lobe= primary motor cortex
the primary motor cortex
Motor cortex has the fundamental function to control voluntary movements, including integration of motor commands with the ongoing somatic sensory state of the body.
post-central gyrus
primary somatosensory cortex
The primary somatosensory cortex
each region is highly connected to other areas of the brain, allowing the somatosensory cortex to have numerous functions, including representation of the body, tactile attention, sensorimotor integration, and the processing of painful stimuli, empathy, and emotion.
infeiror view of hemisphere
-
Uncus found in the temporal lobes
- Olfactory information
uncus and rise in intracranial pressure
- When there is a rise in pressure in the skull the uncus can herniate- uncal herniation
- Risk 3rd cranial nerve (oculomotor)- dysfunction and clinical signs and symptoms
Primary motor cortex (pre-central gyrae) and primary somatosensory cortex (post-central gyrae)
topographical representation of the body
- Head and neck- more lateral
- Arm and leg- near the longitudinal sulcus
- The primary motor cortex in one hemisphere, is responsible for motor control in the ……………side of the body
contralateral (the other side)
- Paths must cross at the level of the medulla
spinal nerve shave
uni-cortical control (supply one side of the body)
outline the cortical relationship between the primary motor corex and the spinal nerves
Pathways connecting primary motor cortex (on one side) with spinal nerves controlling the limbs (on one side)
- Decussate (cross) to the opposite side of the level of the lower medulla
- Cortical control of limb movement is from one primary motor cortex, which is contralateral
cranial nerves cortical control
cranial nerve have dual cortical control
dual cortical control of the cranial nerves
- Cranial nerves are also contralateral- but decussate at the pons instead of the medulla (at the motor nuclei it will synapse at)
- While there is contralateral primary motor cortex involvement, there is also input from the ipsilateral motor cortex (most cranial nerves have input) (we don’t see this with spinal nerves, just cranial nerves)
(contralateral will always have dominant control- ipsilateral only comes into control when something happens to the dominant contralateral pathway e.g. stroke)
corpus callosum
that ensures both sides of the brain can communicate and send signals to each other.
lateral ventricles
The right and left lateral ventricles are structures within the brain that contain cerebrospinal fluid, a clear, watery fluid that provides cushioning for the brain while also helping to circulate nutrients and remove waste.
