Exam 2 Flashcards
The three functions of the nervous system
Sensory input: gather info from receptors
Integration: process info and decision making
Motor output: signal to cause a response
Sensory output
Gathering information from receptors
Integration
Processing of info and decision making
Motor output
Signal to cause a response
Somatic nervous system division
Motor neurons controlling skeletal muscle ( voluntary )
Autonomic nervous system division
Motor neurons controlling smooth and cardiac muscles and glands ( involuntary )
Has 2 divisions
Sympathetic division
The fight or flight mobilization
Parasympathetic division
The rest and digest energy conservation
Neuron characteristics
Longetivity: last a lifetime
Amitotic: once mature they cannot divide
High metabolic rate: consume large amounts of oxygen and nutrients
Supporting cells of the CNS
Astrocytes
Microglia
Ependymal
Oligodendrocytes
Astrocytes
Attach neurons to capillaries and regulate the chemical environment
Microglia
Act as phagocytes
Ependymal cells
Line fluid filled spaces of CNS and circulate fluids via cillia
Supporting cells of PNS
Satellite cells
Schwann cells
Satellite cells
Surround neuron cell bodies, function unknown
Schwann cells
Form the myelin sheath insulations of the PNS neurons
What is a dendrite
many short processes that relay input towards the soma
What is an axon ?
A single process that relays impulses away from the soma
what connects the dendrites to the neurilemma
What is the axon terminal
Bulbous ends of axons containing neurotransmitters
the end of the neuron, opposite end of dendrites
What is the myelin sheath
A white fatty wrapping of nerve fibers
Insulate the fiber, increases the speed of nerve impulses
What is white matter
Nervous tissue containing bundles of axons ( tracts )
What is grey matter
Nervous tissue containing neuron somas and neuroglia
What is the membrane resting potential
The voltage measurment across a neuron’s cell membrane
What is a chemically gated channel
Those that open in response to the binding of a specific chemical
What is hyperpolerization
An increase in the membrane potential
Why does hyperpolorization occur
Because the inside of the cell becomes more negative
What are two types of synapse
Chemical: slow, active, pseudo- unidirectional
and
electrical: very rapid, passive, bidirectional
What are the parts os a synapse
Presynaptic neuron: info sender and releases neurotransmitter from its axon terminal
and
postsynaptic neuron: the information receiver and receives neurotransmitter, usually on its dendrites
What are ventricles in the adult brain ? What do they contain ?
a communicating network of cavities filled with cerebrospinal fluid and located within the brain parenchyma
Composed of 2 lateral ventricles, the third ventricle, the cerebral aqueduct, and the fourth ventricle
What are the four regions of the brain ?
Cerebrun, diencephalon, cerebellum, and brainstem
What are the right and left cerebral hemispheres separated by ? Joined by ?
They are separated by a groove , the longitudinal fissure
joined by the corpus collasum, a bundle of nerve fibers
What is the transverse fissure?
divides cerebrum from cerebellum
What are the 5 lobes of the cerebrum?
The frontal, Paretial, Temporal, Occipital and the Insula
What is the central sulcus
prominent landmark of the brain, separates the parietal lobe from the frontal lobe and the primary motor cortex from the primary somatosensory cortex
What is the lateral sulcus
A deep fissure in each hemisphere that separates the frontal and parietal lobes from the temporal lobe
What is the parietal-occipital sulcus
the “groove”
It separates the precuneus of the parietal lobe from the cuneus of the occipital lobe on the medial surface of the cerebral hemisphere
What are nissl bodies?
a large granular body found in neurons
made of RER
What is an axon hillock?
in the area of the neuron that connects the cell body with the axon
What is a synaptic knob?
The large bulge on the presynaptic neuron
What is a collateral
subordinate or accessory part, a side branch ( nerve or blood vessel )
What is the neurilemma
sheath of Schwann, or Schwann’s sheath, the outermost nucleated cytoplasmic layer of Schwann cells that surrounds the axon of the neuron
What is a node of Ranvier?
allow ions to diffuse in and out of the neuron, propagating the electrical signal down the axon. signal jumps rapidly from node to node
What are clusters of cell processes called in the CNS
Nuclei
What are clusters of cell processes called in the PNS
ganglia short for ganglion
Frontal lobe
Voluntary movements of skeletal muscle
Paretial lobe
Somatic sensory processing
Temporal lobe
Auditory and olfactory processing
Occipital lobe
Visual processing
Brain stem
Stalk of the brain, forms connection to the spinal cord
Includes the midbrain,pons, and medulla oblongata
Spinal cord
Region of CNS enclosed within the vertebral column
What is the function of the spinal cord
White matter tracts carry impulses to and from the brain
Internal grey matter performs nervous integration
What is a spinal nerve
Fusion of dorsal and central roots , contain sensory and motor fibers
Peripheral nerve out system ( PNS )
Outside the CNS
Contains carnival and spinal nerves
Is the communication lines between the CNS and the rest of the body
Sensory divison
Afferent
Converts info to the CNS from muscles and skin and organs
Motor divisions
Efferent
Conveys impulses from the CNS to muscles and glands
What is the largest peripheral nerve
The static
Central nervous system ( CNS )
The brain and spinal cord, the integration centers
What are the four types of neuroglia
Ependymal cells
Astrocytes
Oligodendrocytes
Microglia
What is a ependymal cell
Contact neuroglia directly
What is an Astrocyte
Large cell body with many processes
What is an Oligodendrocyte
A smaller cell boy with fewer processes
What is a microglia
The smallest and least numerous neuroglia with many fine branched processes
What is action potential
-Changes in membrane potential
that involves a depolarization followed by a depolarization
depolarization
Na+ inflow when voltage gated fast Na+ channels open
Repolarization
Closure of ca+2 channels and K+ outflow
12 Cranial Nerves
- Olfactory Nerve Sensory )
- Optic Nerve ( Sensory and Technically a tract of the brain
- Oculomotor (eye)
- Trochlear ( smallest of the 12)
- Abducens ( nucleus in the pons )
- Trigeminal ( mixed cranial nerve and the largest of the 12)
- Facial ( miced cranial nerve )
- Vestibulocochlear ) Sensory cranial nerve and has two branches)
- Glossopharyngeal ( mixed cranial nerve )
- Vagus ( mixed cranial nerve that is distributed from the head and neck to the thorax and abdomen
- Accessory ( branchial cranial nerve
- Hypoglossal (motor cranial nerve)
Spinal nerves
Connect to the CNS to sensory receptors, muscles and glands
Meninges
Three protective, connective tissue covering that encircle the spinal cord and brain
- Dura Matter
- Arachnoid mater
- Pia Mater