Nerve Tissue Flashcards
(17 cards)
What are the main components of the nervous system?
Central nervous system (CNS), Peripheral nervous system (PNS)
CNS includes the brain and spinal cord, while PNS includes cranial nerves and spinal nerves.
What is the function of the soma/perikaryon in a neuron?
Cell body of the neuron, contains nucleus, organelles, and Nissl bodies
Nissl bodies are aggregations of rough endoplasmic reticulum and ribosomes.
What is the role of dendrites in a neuron?
Afferent signalling system, receives excitatory and inhibitory signals
Dendrites contain ribosomes, smooth endoplasmic reticulum, and neurofilaments.
What is the role of axons in a neuron?
Efferent signalling system, transmits impulses away from the cell body
Axons do not contain Golgi complexes or ribosomes.
What are boutons/end bulbs?
Dilations at the axon terminal
They form connections with other neurons or target cells.
Define synapses.
Junctions that transmit impulses between neurons
Synapses depend on the release of neurotransmitters.
What are Nissl bodies?
Aggregations of rough endoplasmic reticulum and polyribosomes in neurons
They are basophilic and visible under a microscope.
What is the myelin sheath?
Spiral wrapping of lipid-rich cell membrane of Schwann cells or oligodendrocytes
Myelin increases the speed of nerve conduction.
What are the three main connective tissue sheaths of a peripheral nerve?
- Epineurium
- Perineurium
- Endoneurium
Epineurium is connected to surrounding tissue by mesoneurium.
Describe the function of astrocytes.
Maintain and regulate synapses, provide structural support, and help form blood-brain barrier
Astrocytes can convert glucose into glycogen.
What distinguishes unipolar neurons from multipolar neurons?
Unipolar neurons have one process, while multipolar neurons have multiple processes
Unipolar neurons are typically found in sensory ganglia.
What are the main types of glial cells?
- Astrocytes
- Oligodendrocytes
- Microglia
- Schwann cells
Glial cells support and protect neurons.
Fill in the blank: The interval between two Schwann cells is called the _______.
Node of Ranvier
True or False: Myelinated axons conduct nerve impulses more slowly than unmyelinated axons.
False
Myelinated axons conduct impulses faster due to saltatory conduction.
What are the two types of ganglia in the nervous system?
- Sensory ganglia
- Autonomic ganglia
Sensory ganglia contain unipolar neurons, while autonomic ganglia contain multipolar neurons.
What is the role of the Golgi tendon organ?
Provides proprioceptive information about muscle tension
It is sensitive to both passive stretch and active contraction.
What types of sensory receptors are found in the nervous system?
- Free nerve endings
- Encapsulated nerve endings
- Meissner’s corpuscles
- Pacinian corpuscles
- Ruffini endings
- Neuromuscular spindles
- Golgi tendon organs
Each receptor type has a specific function in detecting stimuli.
