CSF and types of tissues Flashcards
Divisions of the NS
CNS (Brain +spinal cord )
+
PNS (cranial and spinal nerves)
Divided into :
Sensory (afferent division)
Motor (efferent division):
Autonomic (sympathetic and parasympathetic)
Somatic
What is found inside a neurone
- Lots of mitochondria and rER, Golgi apparatus-
- Cytoplasm p of cell body and axon
- Nucleus
Why are lots of proteins and ATP produced in the neurone?
Has a high metabolic rate
What are the names given to the cytoplasm of the cell body and the axon respectively?
cell body: periarkyon
axon: axoplasm
what does the nucleus contain?
Lots of loose chromatin
How are neurones defined?
Defined as long-living and amiototic
Myelination
Neurones covered In a sheath made up of layers and layers of their cell membrane
- The myelin is used to increase the rate of conduction so that action potentials can jump from one node of ranvier to another= SALTATORY CONDUCTION
- This is particularly useful in very long neurones
which cells are responsible for myelination of axons
- In the PNS- made by SCHWANN CELLS
- In the CNS- made by OLIGODENDRICITES
Characteristics of white matter
Lots of fat = myelin sheath
- Lots of axons
- Can be made up of Tracts : bundles of neurones which all carry the same sensory information (MODALITY)
- Tracts do not mix with each other
- As you go further up the spinal cord you have more spinal nerves coming in from lower limbs
Characteristics of grey matter
- Lots of neuronal bodies
- Ventral horn carries neuronal bodies of motor neurones so THICKER than dorsal horn which carries bodies of sensory neurones
what are the names given to neuronal bodies inside and outside of the CNS
Inside the CNS: nuclei
Outside of the CNS: ganglia
Types of neurones in the CNS
neurones
- Motor neurones are multipolar
- Sensory neurones are Pseudounipolar
- Olfactory mucosa and retinal nerve fibres are bipolar
Types of glial cells inside the CNS
In CNS
- Astrocytes: Most common. Form the Blood brain barrier
- Oligodendricites: responsible for myelination
- Microglia: responsable for phagocytosis
- Ependymal cells: line the ventricles
In PNS
- Satellite cells
- Schwann cells : responsible for myelination
Function of the cerebrum
seat of consciousness
Function of the cerebellum
Responsible for posture and balance
Function of the brainstem
Site of pathways and tracts
What is a Modality
Axonal tract responsible for carrying all the information responsible for one function
Pathway of the CSF
- Produced in the choroid plexus into the ventricles
- From ventricles into the 4th ventricle
- From 4th ventricle i
- Through the 4th ventricle into the subarachnoid villi via foramen of Monro and Foramen of Lushka
- From brain drains into superior sagittal sinus
Meninges of the brain and spaces formed
- Dura
- Arachnoid
- Pia
subarachnoid space: site of CSF
Subdural space: potential site for blood vessels
which is the most vascularised fold of the brain?
The pia mater
Where are the different ventricles situated
Lateral : cerebrum
Third: diencephalon
Cerebral aqueduct: midbrain
Fourth: in between the pons and the medulla (front) and the cerebellum at the back
What is found inside the cell body of the neurone?/
- Mitochondria
- Ribosomes
- Golgi apparatus
Make ATP- needed as the brain has a HIGH METABOLIC RATE
What is the cytoplasm of the axon and of the neuronal cell body called/
axon= axoplasm
neuronal body= perikaryon
what is the name of groups of cell bodies in the CNS and PNS
CNS: nuclei
PNS: ganglia
