CSA 1 Flashcards
What is the CNS and its main function?
Central Nervous System is the brain and spinal cord, used for information processing, including reflexes and behavior
What is the Peripheral Nervous System and its main function?
Includes cranial nerves and spinal nerves, used for sensory detection and motor activation
What is the nervous system (mostly) derived from?
Ectoderm
Define Afferent and Efferent
Afferent- Towards Spinal Cord (first letter)
Efferent- Away from spinal cord (exit)
What is a ganglion?
A group of cell bodies outside the CNS. Inside CNS, they are called a nucleus.
What are autonomic ganglion?
Near certain glands and inside organs such as heart
What are parasympathetic ganglion?
smaller neurons, eccentric nuclei
What are dorsal root ganglion?
Sensory, big neurons, central nuclei
What is the term for anterior in human prefrontal cortex?
Rostral
What is the term for superior in human prefrontal cortex?
Dorsal
What is the term for inferior in human prefrontal cortex?
Caudal
What is the term for posterior in human prefrontal cortex?
Dorsal
How are Brodmann Areas numbered?
By cellular architecture
What are Brodmann Areas of the Neocortex/cerebral cortex?
Regions of the cortex numbered 1-52. Each has a particular set of inputs and outputs, and often will have a function.
Name the parts of a neuron.
Input to Dendrites, then cell body, then Axon hillock, then Axon covered with myelin sheath, breaks in myelin for axon colaterals and Nodes of Ranvier, then axon terminal for output ending in synaptic boutons
Describe myelin
hydrophobic lipid layer, provide insulation to increase conduction
What does increasing axon diameter do?
Increases signal speed
How are neurons classified?
multipolar, bipolar, unipolar. All have 1 axon.
What type of neuron are most neurons?
Multipolar: several dendrites
What are pyramidal cells, where are they, and what do they do?
Multipolar neuron shaped like a pyramid in the cerebral cortex, for thinking
What are purkinje cells, where are they?
Multipolar neuron in cerebellum
What are dorsal root ganglion, where are they, and what do they do?
very large pseudounipolar neurons with large nuclei and a single nucleolus, afferent inputs to spinal cord, for sensory information
What are bipolar neurons and where are they located?
Neurons with One Dendrite and One Axon, Retina and Cochlea
What are pseudounipolar neurons?
Look like they only have one pole, but have two poles (likely side by side)
What are unipolar neurons and what is an example?
Only one output, no input/Dendrite, Rod or Cone in Retina
Describe the chemical synapse.
Synapse = functional link. Presynaptic cell releases vesicles filled with neurotransmitter into a 30nm gap, diffuse across and are taken in by by receptor into postsynaptic cell (neuron, myocyte, gland) and initiate electric signal down the postsynaptic cell.
What is divergent signalling and what is an example?
A single neuron sends a signal to many neurons, eg skin
What is convergent signalling and what is an example?
Multiple inputs influence a single neurons, eg retina
What are interneurons and where are they located? Where do they send and receive signals?
Relay/Connector, Association, Intermediate/Local Circuit Neurons. Neither sensory nor motor, only in CNS. Receive from sensory or interneurons, send to motor or interneurons. Most central processing is by interneurons.
How are glia different from neurons?
Glia: No action potentials, do not form synapses, are able to divide, form the myelin sheath, common source of tumors in nervous system
What is the only area where neurons generally can divide?
Hippocampus
Why is PNS an ambiguous acronym?
Peripheral Nervous System or Parasympathetic Nervous System
What is a more appropriate name for basal ganglia, that they do not have?
Basal Nuclei
What is the ratio of Neurons to Glial Cells
1 : 10-50