Chap 3: Anatomy Of The Nervous System Flashcards
The peripheral nervous system (PNS)
The division that is located outside the skull and spine
Composed of the somatic nervous system and autonomic nervous system
Central nervous system (CNS)
The division of the nervous system that is located within the skull and spine
Composed of the brain and the spinal cord
The brain is part of the CNS located in the skull
The spinal cord is the part that is located in the spine
The somatic nervous system (SNS)
The part of the PNS that interacts with the external environment. It is composed of the afferent nerves that carry sensory signals from the skin, skeletal muscles, joint ps, eyes, ears, and so on to the CNS
Autonomic nervous system (ANS)
The part of the PNS that regulated the body’s Internal environment
Afferent vs. Efferent
Afferent is going towards something in this case going toward the CNS they begin with (a) (advance, approach, arrive)
Efferent is going away from something which begins with (e) (exit, embark, escape)
Sympathetic nerves
Those autonomic motor nerves that project from the CNS in the lumbar (small of the back) and thoracic (chest area) regions of the spinal cord
Parasympathetic nerves
Those autonomic motor nerves that project from the brain and sacral (lower back) region of the spinal cord
The Three Meninges
It encases the brain and spinal cord which are the most protected organs in the body
The outer meninx is the tough membrane called the dura mater (tough mother)
Arachnoid membrane
Is immediately inside the dura mater (spider weblike membrane)
Subarachnoid space
Beneath the arachnoid membrane, which contains many large blood vessels and cerebrospinal fluid
Pia mater
Innermost meninx, which adheres to the surface of the CNS
Cerebrospinal fluid (CSF)
Protects the CNS,which fills the subarachnoid space, the central of the spinal cord & the cerebral ventricles of the brain
Central canal
A small central channel that runs the length of the spinal cord
Cerebral ventricles
Are the four large internal chambers of the brain: the two lateral ventricles, the third ventricle, and the fourth ventricle
Choroid plexuses
Networks of capillaries (small blood vessels) that protrude into the ventricles from the pia mater. It continuously produces cerebrospinal fluid
Cerebral aqueduct
Connects the third and fourth ventricles
Hydrocephalus
Produced by the buildup of fluid in the ventricles causing the walls of the ventricles and the brain to expand
It’s treated by draining the excess fluid from the ventricles and trying to remove the obstruction
Blood brain barrier
It’s a mechanism that impedes the passage of many toxic substances from the blood into the brain
Neurons
Cells that are specialized for the reception, conduction, and transmission of electrochemical signals
Cell membrane
The semipermeable membrane that encloses the neuron
Dendrites
The short processes emanating from the cell body, which receive most of the synaptic contacts from other neurons
Axon hillock
The cone shaped religion at the junction between the axion and the cell body
Axon
The long narrow process that projects from the cell body
Cell body
The metabolic center of the neuron, also called the soma
Myelin
The fatty insulation around many axons
Nodes of ranvier
The gaps between sections of myelin
Buttons
The buttonlike endings of the axon branches, which release chemicals into synapses
Synapses
The gaps between adjacent neurons across which chemical signals are transmitted
Endoplasmic reticulum
A system of folded membranes in the cell body; rough portions (those with ribosomes) play a role in the synthesis of proteins; smooth portions (those without ribosomes) play a role in the synthesis of fats
Nucleus
The spherical DNA containing structure of the cell body
Mitochondria
Sites of aerobic (oxygen consuming) energy release
Cytoplasm
The clear internal fluid of the cell
Ribosomes
Internal cellular structures on which proteins are synthesized; they are located on the endoplasmic reticulum
Golgi complex
A connected system of membranes that packages molecules in vesicles
Microtubles
Tubules responsible for the rapid transport of material throughout neurons
Synaptic vesicles
Spherical membrane packages that store neurotransmitter molecules ready for release near synapses