Nerve Cells Flashcards
What are the 4 lobes of the cerebrum? Where are they located
Frontal lobe, occipital lobe, parietal lobe and temporal lobe
What cells are lost in Parkinsons disease
In the midbrain there is an area called the substantia nigra. In here there are cells found that are called dopaminergic neurons. Parkinson’s disease results in the loss of these neurons
Where is the grey matter and white matter? What do they comprise of
Grey matter is the cell bodies and white matter is the axons. In the brain grey matter is outside whereas in the spinal cord grey matter is inside
How many layers of cells are there in the cerebral cortex
6
Define those layers
Layer 1 is at the top. It has very low density of cells. This is the area where the axon tracks are traveling.
II is external granular layer, III is external pyramidal cell layer, IV is internal granular layer, V is ganglionic layer, VI is multiform (polymorphic) cell layer.
How do you identify the layer V of the cerebral cortex
Identify the large pyramidal cells
What are parenchymal cells
They are multi polar neurons, they have multiple processes coming out of them, perhaps making connection to many neurons both from the dendrites and the axons.
How do you identify cerebellum
Branched structure from low zoomed picture
What are the layers of the cerebellum
Molecular, purkinje and granular
What cells are found in the molecular layer
Stellate and Basket cells
How do you differentiate the dorsal and ventral horn
From the blood vessel coming out of the ventral horn.
Also know how to identify the central canal
What is found in the ventral horn
Cell bodies and axons of the motor neurons that make choline acetyltransferase
What does the motor neurons have that makes them particularly easy to identify in staining methods
They have nissle substance. The staining method used stain rRNA so staining the ribosomes and the nucleolus
What happens in ALS
Amyotrophic Lateral Sclerosis
Patients can think, process and recall information fine but they cannot correctly move due to diseased motor neurons.
Describe dendrons, cell body, axons, synapses
Dendrons are Input, cell body is integration, axons are conductors and synapses are output
What are the 3 types of neurons
Pyramidal neurons which are interneurons, motor neurons which only transmit signals after receiving them and then sensory neurons that only detect signal
What are glia cells of the CNS
Glia cells are supporting cells of the CNS
- Astrocytes
- Ependyma
- Microglial cells
- Oligodendrocytes
What are the functions of astrocytes
1) Supportive (in a skeletal sense)
2) Insulating, particularly with regard to synapses
3) Electrolyte balance, particularly regarding K+ ions
4) pH balance of extracellular milieu
5) Sequestration of neurotransmitters
6) Communicate with capillary endothelial cells
7) Interactions with immune system
8) Phagocytosis of extracellular debris
9) Induce blood brain barrier
What are the types of astorcyte
- Fibrous astrcytes
2. Protoplasmic astorcytes
What is the blood brain barrier
foot processes of astrocytes induce endothelial cells to form tight junctions
What are the 3 layers
- Dura Mater - highly dense connective tissue
- Arachnoid mater
- Pia Mater - very very thin layer of connective tissue
Where does the capillaries and the csf runs in the brain
In subarachnoid space
What makes csf
Choroid plexus cells
Know the ventricular system
The csf is also present here
What comprises in the ventral root of the spinal cord
The motor neurons have their axons coming out of the spinal cord and then joining the muscles
What does dorsal root has
Sensory neurons
Where does the sympathetic chain and the sympathetic ganglion reside?
What is their function
Sympathetic chain runs along the spinal cord. They form the sympathetic system
What is the function of sympathetic and parasympathetic system
Sympathetic is involved in fight or flight reponse
Parasympathetic is involved in rest and digest
When do both of the system make their synaptic contacts
Sympathetic neurons send their axons to the ganglions in the sympathetic chain system, which then send their axons to the motors or to the organs.
Parasympathetic neurons have larger axons, makes synaptic contacts with other ganglions which then connect their axons to the desired tissues or organs like the stomach
Para do not innervate in the sympathetic chain system (do not have synapses in this region)
Where does the sympathetic ganglions make their synaptic contacts with
In the brain and the between the post synaptic ganglions located in the ganglions. This is different from DRGs. (dorsal root ganglions)
The synapses are in the ganglions (in the swellings)
Where is the enteric nervous system found
In the gut
Function of submucosal plexus and myenteric plexus
Submucosal is responsible for glandular secretions and for sensing pH whereas the myenteric plexus is associated with controlling the smooth muscles of the gut
Myenteric is at the inside
Where are the sensory nerves located
At the dorsal root ganglion just outside the spinal cord.
Ganglion is basically a swelling
How are DRG and sympathetic nervous system ganglions different
DRGs do not form synapses at the ganglions but instead they make synapses at the brain and at the target organs
What are DRGs surrounded by
Satellite cells, they are quite small surround the DRGs all over
What is a peripheral nerve
Ventral roots of the spinal cord consists of the axons of the nerves that form the peripheral nerve
Difference in the function of schwann cells and oligo
Olio can myelinate mutliple axons whereas schwann can only mylienate 1 axon
What are the 3 layers in the peripheral nerves
The myelinated axons are surrounded by endoneurium, a group of them is surrounded by perineurium and all of them are surrounded by epineurium
What happens in Charcot Marie Tooth Disease
Myelins sheaths are damaged leading to a damaged neurons
Wallerian degneration
A mechanism of rapid axon degenration. it is physiological
What happens in neuropathy
Neuropathy in daibetes is assoicated with the loss of peripheral nerves which, in case if their is trauma to the foot, can lead to gangerence if undetected which can then result in the treatment involving foot amputation
