Nervous System Flashcards
Functions of the Nervous System
Receiving sensory input
Integrating information
Controlling muscles and glands
Maintaining homeostasis
Establishing and maintaining mental activity
What are the divisions of the nervous system?
CENTRAL
* Brain
* Spinal Cord
PERIPHERAL
* Nerves
* Ganglia
from sensory receptors to the CNS
Sensory division
from the CNS to effector organs
Motor division
receive stimuli, conduct action potentials, and transmit signals to other neurons or effector organs
Neurons (nerve cells)
carry out different activities that enhance neuron
function and maintain normal conditions within nervous
tissue
Glial cells
- short, branching cytoplasmic extensions
- receive information from other neurons
Dendrites
Single long cell process extending from the neuron cell body.
Axon
The difference between Axons of sensory neurons and Axons of motor neurons.
Axons of sensory neurons conduct action potentials towards the CNS, and axons of motor neurons conduct action potentials away from the CNS.
This Glial Cell is major supporting cells in the CNS.
Astrocytes
This Glial Cell is line the fluid-filled cavities.
Ependymal cells
This Glial Cell act as immune cells of the CNS.
Microglia
This Glial Cell provides an insulating material that surrounds axons.
Oligodendrocytes
This Glial Cell provides insulating material around axons.
Schwann Cells
This Glial Cell provides insulating material around axons
Satellite Cells
specialized layers that wrap around the axons of some
neurons
Myelin Sheaths
gaps in the myelin sheath
Nodes of Ranvier
lack the myelin sheaths
Unmyelinated axons
a junction where the axon of one neuron interacts with another neuron or with cells of an effector organ
Synapse
Give the Nuerotransmitters (substances)
Acetylcholine (ACh)
Norepinephrine (NE)
Serotonin
Dopamine
Gamma-aminobutyric acid (GABA)
Glycine
Endorphins
The nerves of the PNS can be divided into two
groups, what are they?
12 pairs of cranial nerves and 31 pairs of spinal nerves
Extends from the foramen magnum at the base of
the skull to the second lumbar vertebra.
Spinal Cord
Involuntary reaction in response to a stimulus.
Reflexes
basic functional unit of the nervous system because it is
the smallest, simplest pathway capable of receiving a stimulus and yielding a response.
Reflex arc
occurs when muscles contract in response to a stretching force applied to them.
Knee-Jerk Reflex
connects the spinal cord to the remainder of the brain
Brainstem
Brainstem consist of 3 parts, what are they?
Medulla oblongata
Pons
Midbrain
Brainstem controls?
heart rate, blood pressure, and breathing
the most inferior portion of the brainstem; it regulates heart rate and blood vessel diameter, breathing, swallowing, vomiting, coughing, sneezing, balance, and coordination
Medulla Oblongata
Immediately superior to the medulla oblongata. Contains ascending and descending nerve tracts, as well as several nuclei.
Pons
Pons control the functions for?
breathing, swallowing, balance chewing and salivation
Lies superior to the pons. Smallest region of the brainstem. Involved in coordinating eye movements and controlling pupil diameter and lens shape.
Midbrain
Midbrain also contains ____________ involved in regulating general body movements.
substantia nigra
Attached to the brainstem by several large connections called cerebellar peduncles.
Cerebellum
Part of the brain between the brainstem and the cerebrum.
Diencephalon
- the largest part of the diencephalon.
- consists of a cluster of nuclei
- influences mood and registers an unlocalized,
uncomfortable perception of pain
Thalamus
- Small area superior and posterior to the thalamus.
- Consists of a few small nuclei, involved in the emotional and visceral response to odors, and the pineal gland.
Epithalamus
an endocrine gland that may influence the onset of puberty
Pineal gland (influenced by the light-dark cycle)
- most inferior part of the diencephalon
- contains several small nuclei that are very important in
maintaining homeostasis
Hypothalamus
Hypothalamus controls?
- control of body temperature, hunger, and thirst
- sexual pleasure, rage, fear, and relaxation after a meal
The largest part of the brain. It is divided into left and right hemispheres.
Cerebrum
This lobe is important in the control of voluntary motor functions, motivation, aggression, mood, and olfactory reception.
Frontal lobe
This lobe contains sensory information (touch, pain, temperature, and
balance).
Parietal lobe
This lobe is the receiving and perceiving visual input.
Occipital lobe
This lobe contains olfactory (smell) and auditory (hearing) sensations and plays an important role in memory.
Temporal lobe
connective tissue membranes that surround and
protect the brain and spinal cord
Meninges
most superficial and thickest of the meninges
dura mater
- second meningeal membrane
- “spiderlike”
- space between the dura mater and the arachnoid mater is the
subdural space
arachnoid mater
third meningeal membrane
Pia mater
Space between the arachnoid mater and the pia mater filled with cerebrospinal fluid and contains blood vessels.
Subarachnoid space
- provides a protective cushion around the CNS
- produced by choroid plexuses
Cerebrospinal Fluid
- Blockage of the openings in the fourth ventricle or
the cerebral aqueduct - CSF accumulate in the ventricles
Hydrocephalus
- are a set of 12 paired nerves in the back of your
brain - send electrical signals
- designated by Roman numerals from I to XII
Cranial Nerves
two general categories of cranial nerve function
Sensory and Motor
vision, touch and pain in the face
Sensory functions
This motor function innervates skeletal muscles in the head and neck.
Somatic motor
This motor function innervates glands, smooth muscle throughout the body, and cardiac muscle of the heart.
Parasympathetic
Name the 12 cranial nerves
Olfactory
Optic
Oculomotor
Trochlear
Trigeminal
Abducens
Facial
Vestibulocochlear
Glossopharyngeal
Vagus
Accessory
Hypoglossal
- innervate smooth muscle, cardiac muscle, and
glands - functions are largely controlled unconsciously
- composed of sympathetic division and the
parasympathetic division
Autonomic Nervous System
Fight or Flight division, located at T1-L2 for preganglionic while located at chain ganglia for postganglionic .
Sympathetic
Rest and digest division, located at CIII, CVII, CIX, CX; S2-S4 spinar nerves for preganglionic while located at terminal ganglia near for postganglionic.
Parasympathetic
Site of Release and effect of Acetylcholine (ACh).
Site of Release - CNS synpases, ANS synapses, and neuromuscular junctions
Effect - Excitatory or inhibitory
Site of Release and effect of Norepinephrine (NE).
Site of Release - Selected CNS synapses and some ANS synapses
Effect - Excitatory
Site of Release and effect of Serotonin.
Site of Release - CNS synapses
Effect - Generally inhibitory
Site of Release and effect of Dopamine.
Site of Release - Selected CNS synapses and some ANS synapses
Effect - Excitatory or inhibitory
Site of Release and effect of Gamma-aminobutyric acid (GABA).
Site of Release - CNS synapses
Effect - Inhibitory
Site of Release and effect of Glycine.
Site of Release - CNS synapses
Effect - Inhibitory
Site of Release and effect of Endorphins.
Site of Release - Descending pain pathways
Effect - Inhibitory