201 L4 Flashcards
Histology
What tissue interacts with all tissues and organs in the body?
Nervous tissue
What tissue is the primary component of the PNS and CNS?
Nervous tissue
———– tissue is responsible for ———- and ———– control of most of the body functions.
Nervous tissue is responsible for voluntary and involuntary control of most of the body functions.
Is nervous tissue vascularised?
Yes - highly
What tissue is specialised for signalling and integration and transmission of information?
Nervous tissue
In the —— staining technique only ——- and —— are stained.
Using this technique it was clear that —— are cells.
In the silver staining technique only neurons and glia are stained.
Using this technique it was clear that neurons are cells.
——- branches project out at 90 degrees, while ——— branch at a variety of angles.
Axons branches project out at 90 degrees, while dendrites branch at a variety of angles.
What did the silver staining technique not show?
How the information was transmitted between the neurons
How is information transmitted in neurons?
Through synaptic terminals
Name the glia cells in the CNS and PNS
Astrocytes Oligodendrocytes Microglia Schwann cells Satellite glial cells Ependymal cells Tanycytes Radial glia
Name the glia cell described below:
Influence the activity of neurons, contribute to the maintenance of ionic and transmitter metabolism and a role in repair.
Astrocytes
Name the glia cell described below:
Form the myelin sheaths of axons in the CNS. There are also non-myelinating types of these cells.
Oligodendrocytes
Name the glia cell described below:
Are the smallest glia cells and are part of the phagocytic system.
Microglia
Name the glia cell described below:
They are found in the PNS where they are responsible for the myelination of peripheral nerves.
They can also surround peripheral axons without forming a myelin sheath
Schwann cells
Name the glia cell described below:
These are found in the peripheral ganglia forming ‘baskets’ around the soma
of the ganglion cells.
Satellite glial cells
Name the glia cell described below:
Line the ventricular surface of the brain and central canal of the spinal cord.
Ependymal cells
Name the glia cell described below:
Connects the fluid in the ventricle with the endothelium of the capillaries
Tanycytes
Name the glia cell described below:
Connects the ventricular system in the brain with the outside surface of the brain
Help neurons find their final position during their development
Generate new neurons in adult brain
Radial glia
What is the role of the ECM in nervous tissue?
Tts role is not well understood.
It may be involved in the stabilisation of connections
between neurons and in the closure of sensitive periods of learning
Helps neurons navigate and migrate
Neurons organise themselves in the CNS in 3 distinct histological arrangements. What are their names?
Corticies
Nuclei
Reticular fomrations
What histological arrangment of the neurons is described below?
Around the outside of the brain the cells are organised into defined ———-.
Each layer performs a specific ——–.
The layers are ——– or —— depending on the main ——- or the ——–.
Cortices
Around the outside of the brain the cells are organised into defined layers.
Each layer performs a specific function.
The layers are expanded or shrunk depending on the main function or the area.
What histological arrangment of the neurons is described below?
When there are organised clumps of ——–.
In the PNS there are no —— but there are —– of cells called ———.
Nuclei
When there are organised clumps of neurons.
In the PNS there are no cortices but there are clumps of cells called ganglia.
What histological arrangment of the neurons is described below?
This is when ——- are not arranged in —— or ——.
Reticular system
This is when neurons are not arranged in cortices or nuclei.
Name 4 structure in the brain that have cortical organisation of cells.
Dorsal horn of the spinal cord
Hippocampus
Cerebellum
Forebrain (only in mammals)
What nervous system has the following features?
Nuclei
Axon tracts
Myelinating oligodendrocytes
CNS
What nervous system has the following features?
Ganglia
Nerves
Schwann cells
PNS
Grey matter corresponds to regions that are —— in neurons.
Rich
White matter is mostly —- and —– cells.
White matter is mostly axons and glial cells.
Which nervous system uses the concept of grey and white matter?
CNS
In the forebrain grey matter is always on the ——- and white matter is in the ——-.
In the spinal cord grey matter is in the —— and white matter is on the ———.
In the forebrain grey matter is always on the outside and white matter is in the middle
In the spinal cord grey matter is in the inside and white matter is on the outside
What region of the grey matter is mainly involved with sensory processing?
Dorsal region
What region of the grey matter is mainly involved with motor processing?
Ventral region
Pathway of nerves:
There are nerves coming from the —— carrying —— and —— information.
At one point they ——- and the —– —– ganglion contains the —– ——- of the ——— cells which then send an axon to the ——– spinal cord where the ——- information can be
processed.
The —— horn of the spinal cord is organised in specific ——, each of which specialises in what kind of —– information is being processed.
The ——– end has the somatic ——— neurons that innervate the ——— ——– of the body with the cell bodies in the ——- horn, sending the —— out through a nerve that then joins the ——- portion to form a mixed peripheral nerve
There are nerves coming from the body carrying motor and –sensory information.
At one point they divide and the dorsal root ganglion contains the cell bodies of the sensory cells which then send an axon to the dorsal spinal cord where the sensory information can be
processed.
The dorsal horn of the spinal cord is organised in specific layers, each of which specialises in what kind of sensory information is being processed.
The ventral end has the somatic motor neurons that innervate the striated muscle of the body
with the cell bodies in the ventral horn, sending the axons out through a nerve that then joins
the sensory portion to form a mixed peripheral nerve
What does myelination achieve?
It promotes the transmission of the action potential.
Schwann cells in the ——- have a —– that wraps around the nerve forming many ——.
The —– —– is continuous with the —– cell
This ——- the speed at which the ——- —- is transmitted
Schwann cells in the periphery have a cytoplasm that wraps around the nerve forming many layers.
The myelin sheath is continuous with the schwann cell
This increases the speed at which the action potential is transmitted
In the PNS where are the cell bodies of neurons usually found?
In ganglia
Is the nerve carrying the sensory information to the dorsal horn an axon?
No
The ganglion cell will have a ——– process that connects directly to the correct layer of the
——— horn depending on the kind of ———— it is bringing in.
It also has a ———- process that is associated with a ———- receptor that will provide the —– with Information about what’s going into the system
The ganglion cell will have a central process that connects directly to the correct layer of the dorsal horn depending on the kind of information it is bringing in.
It also has a peripheral process that is associated with a sensory receptor that will provide the CNS with Information about what’s going into the system
Motor neurons in the ——- horn send information through the ——– root which will then join the —— nerve to go to its target
Motor neurons in the ventral horn send information through the ventral root which will then join the spinal nerve to go to its target
Can motor neurons project out of the ventral root to be redirected to the autonomic system?
Yes
What sensory information is coming in?
Touch, pressure, heat or pain
What nerves carry information for specialised senses such as hearing, vision and smell?
Cranial nerves
What nerves carry information about proprioception (positioning of body)
Cranial nerves
where do the cranial and sensory nerves terminate in the spinal cord?
The dorsal horn of grey matter.
What two ways can the peripheral nerve end as?
loose nerve ending
Encapsulated (can translate the physical force)
Name the 3 capsules in which peripheral nerves can end.
Meissners corpuscle
Pacinian corpuscle
Ruffini corpuscle
What are muscle spindle and their function?
Specialised muscle cells encapsulaed by connective tissue and are connected to the peripheral process
of ganglion cells, telling the CNS if the Muscle is stretched or contracted.
