TOPIC 8 - NERVOUS TISSUE Flashcards
It is the main component of the nervous which regulates and controls bodily functions.
Nervous tissue
Part of nervous system that is responsible for impulse transmission.
Neurons
Part of nervous system which assist in the propagation of nerve impulses as well as providing nutrients to the neurons.
Neuroglial cells
All types of nerve cells have an axon that send action potential signal to the next cell. True or False?
True
What are the functions of the nervous system?
- Sensory input
- Integration
- Muscle and gland control
- Homeostasis
- Mental activity
Parts of neuron: Enclosed by a cell/plasma membrane and has a central nucleus
Cell body
Parts of neuron: Granules found in the cytoplasm of the cell body.
Nissl bodies
Parts of neuron: Extremely fine fibers within the cell body from the dendrites to the axon
Neurofibrils
Parts of neuron: Whitish, non-cellular fatty layer that surrounds the axon
Myelin sheath
Parts of neuron: Cellular layer outside of the myelin sheath
Neurolemma/Sheath of Schwann cells
Parts of neuron: Myelin sheath together with the neurolemma
Medullary sheath
Parts of neuron: Interrupted intervals along the medullary sheath
Nodes of Ranvier
Not all living cells have ability to react to stimuli. True or False?
False
This sheath surrounds the nerve.
Epineurium sheath of dense connective tissue
This sheath surrounds the bundles of nerve fibers.
Perineurium
There are blood vessels in the epineurium. True or False?
True
This sheath is a thin layer of loose connective tissue which surrounds the individual nerve fibers.
Endoneurium
Majority of neurons are generated after the birth. True or False?
False, before the birth
Additional neurons are important for maintenance and plasticity; they are also sufficient to replace neurons that die. True or False?
False, insufficient to replace ….
Mature neurons mitotically divide. True or False?
False
What are the keys to understand the function of neuron?
- Shape of the neuron and its processes
- Chemicals the neurons uses to communicate (neurotransmitter)
- Ways in which neuron react to the neurotransmitters released by other neurons
Other term for neuron body
Perikaryon or soma
Part of receptive surface of neuron
Dendrites
One or several primary dendrites can divide into secondary and tertiary dendrites. True or False?
True
Dendrites are always smooth. True or False?
False, they can be “studded”.
The mushroom-shaped appendages of dendrites are called ?
Spines
Axon can be more than one. True or False?
False, never more than one.
The point of origin of axon from cell body/perikaryon is called?
Axon hillock
Axon may branch like dendrites. True or False?
True
It is the transmitting process of the neuron.
Axon
It is the bulb-shaped swellings at the end of axon.
Terminal boutons
It is the bulb-shaped swellings along the course of axon.
Boutons en passant
It is a specialized contacts between a bouton formed by one neuron and the cell surface of another neuron.
Synapse
What mediates transfer of information from pre- to postsynaptic neuron?
Release of neurotransmitter into synaptic cleft
Nerve cells functionally meet at the synapse with direct contact. True or False?
False, normally without direct contact.
These are the messages that are electrical signals carried by nervous system.
Impulses
These causes excitation or inhibition to postsynaptic neurons.
Transmitters
What is the most prominent excitatory transmitter of CNS?
L-glutamate
What is the most prominent inhibitory transmitter of CNS?
Gamma-amino butyric acid (GABA)
What are the other main neurotransmitters?
- Dopamine
- Serotonin
- Acetylcholine
- Noradrenaline
- Glycine
Each neuron can use 2 or more main transmitters. True or False?
False, only one main transmitter.
One or more minor transmitters can be used together with main transmitter. True or False?
True
Give some of the minor transmitters.
- Cholecystokinin
- Endogenous
- Opiods
- Somatostatin
These are several types of non-neuronal, supporting cells in CNS tissue.
Glial cells
These are star-shaped cells which processes are often in contact with blood vessels.
Astrocytes
Other term for astrocytes
Astroglia
What do you call the processes of astrocytes?
Perivascular foot processes
It is the scar-forming cells of CNS.
Astrocytes
Give the 3 functions of astrocytes.
- Provide mechanical and metabolic support to the neurons of the CNS
- Maintenance of composition of ECF
- Removal of transmitters from synapses and metabolism of transmitters
Oligodendrocytes have fewer and shorter processes than astrocytes. True or False?
True
It forms myelin sheath around axons in the CNS.
Oligodendrocytes
SCHWANN CELLS:PNS::OLIGO:CNS
Correct or Wrong?
Correct
Both Schwann cells and oligodendrocytes may form parts of myelin sheath of several axons. True or False?
False, only oligodendrocytes
Glial cells that are small with complex shapes.
Microglia
Microglia is from what germ layer?
Mesoderm
In case of tissue damage, this glial cell can proliferate and differentiate into phagocytic cells.
Microglia
This glial cell are derived from cell lines which gives rise to monocytes.
Microglia
It lines the ventricles of the brain and central canal of the spinal cord.
Ependymal cells
Ependymal cells can be ciliated. True or False?
True
What type of epithelium lines the ependymal cells?
Simple cuboidal or low columnar epithelium
Ependymal cells has no tight junction allowing free exchange between CSF and nervous tissue. True or False?
False
Ependymal cells can specialize into ____ which are rarely ciliated with long basal processes; form ventricular lining over a few CNS regions in which the blood-brain barrier (BBB) is incomplete.
Tanycytes
Occasionally, neurons may make synapse-like contact with glial cells. True or False?
True
Other term for satellite cells
Amphycytes/Gliocytes of the PNS
It is a type of glial cell that is oval or spindle-shaped cells with scanty cytoplasm and round nucleus at expanded part of the cell.
Amphycytes
It form rosary-like capsule around individual cell bodies of neurons located in cranial and spinal ganglia.
Amphycytes
Other term for Schwann cells
Neurolemmocytes
These are the cells enclosing both the unmyelinated and myelinated axons in the PNS.
Schwann cells
It produces myelin sheath of myelinated fibers in the PNS.
Schwann cells
Single neurolemmocyte can invest one to several nerve fibers. True or False?
True
It is a classification of neuron in which only one protoplasmic process extends from the cell body.
Unipolar neurons
It is a classification of neuron having several dendrites and an axon.
Multipolar neurons
Unipolar neurons that begins as bipolar neurons during development are known as?
Pseudounipolar neurons
Unipolar neuron has only one process. What is the process?
The axon
Unipolar neurons are common in insects. True or False?
True
Unipolar neurons are present in developing or embryonic nervous system. True or False?
True
Pseudounipolar has 2 processes. True or False?
True
What are the 2 processes of pseudounipolar neuron?
Both axons
In pseudounipolar neuron, soma is small with small, round, centrally located nucleus. True or False?
False, large structures.
2 types of axons present in pseudounipolar neuron
- Efferent
- Afferent
Give 2 examples of bipolar neurons.
- Photoreceptor cells of the retina
- Olfactory hair cells of the olfactory epithelium
What are the 2 processes of bipolar neuron?
- One axon
- One dendrite