Lecture: Anatomy 7: Nervous system Flashcards
What are neurons?
Functional units of the nervous system
What are neuroglia?
Organelle that support neurons
What are the structural components of neurons?
Soma/cell body, dendritic tree, axon hillock, axon/nerve fibre, and axon terminal
What is the purpose of the soma/cell body?
Contains the nucleus and is responsible for the synthesis of proteins/ion channels and important in cellular metabolism.
What is the purpose of the dendritic tree?
Receives input and coveys information towards the stoma.
What is the purpose of the axon hillock?
Origin of the axon
What is the purpose of the axon/nerve fibre?
Transmits action potentials
What is the purpose of the axon terminal?
Where neurotransmitter is released across synaptic cleft.
How are different neurons classified?
Classified based on number of axons/dendrites.
What are unipolar neurons?
Neurons with only one axon Eg. Primary sensory neurons
What are bipolar neurons?
Neurons with one axon and one dendrite Eg. Specialized sensory neurons
What are multipolar neurons?
Neurons with one axon and multiple dendrites Eg. Motor neurons and Autonomic ganglia
How does nerve fibre myelination effect propagation of action potentials?
Myelination allows for saltatory conduction which allows for the propagation of action fibres from node to node.
What are the gaps within the myelin sheath known as?
Nodes of Ranvier
What does the term afferent mean?
Movement of information within axon to the central nervous system.
What does the term efferent mean?
Movement of information within axon away from the central nervous system.
What are synapses?
Junctions between axon terminals and target cells
What are the 2 types of synapses?
- Electrical synapses
2. Chemical synapses
How do chemical synapses work?
Depolarisation of presynaptic membrane opens Ca+ channels which vesicles to fuse with the membrane and release neurotransmitter across the synapse.
What are the 3 main types of neuroglia in the central nervous system (CNS)?
Astrocytes, oligodendrocrytes and microglia
What are astrocytes?
Neuroglia in the CNS that provides structural support of the brain, supply scaffold for neurons in development, maintain ionic environment, and repair the nervous system.
What are oligodendrocytes?
Neuroglia in the CNS that myelinate multiple axons.
What are microglia?
Neuroglia in the CNS that promote repair and house immune cells that secrete cytokines and are involved in phagocytosis.
What neuroglia are found in the peripheral nervous system (PNS)?
Schwann cells
What is the role of Schwann cells?
Schwann cells myelinate axons (one Schwann cell myelinates one axon), house immune cells, and aid in regeneration of neuron axons.
What is the central nervous system composed of?
Brain and spinal cord
What is the role of the peripheral nervous system?
Communication between the CNS and periphery (eg. skin, glands and vessels)
What are the 3 regions of the brain?
Forebrain, midbrain and hindbrain.
What components are found in the forebrain?
Cerebral hemispheres, thalamus, and hypothalamus.
What components are found in the midbrain?
Brainstem