Chapter 8: Nervous System Flashcards
The nervous system is comprised of 2 main structures:
Brain, spinal cord
The nervous system is divided into 2 main portions:
- Anatomically
- Functionally
Anatomical portion of the nervous system
*The central nervous system (CNS)
*The peripheral nervous system.
Functional portion of the nervous system:
- Somatic nervous system (the part that regulates systems over voluntary control)
- Autonomic nervous system (controls body functions without voluntary control
Neural tissue contains two basic types of cells:
Neurons and Neuroglia
Define Neurons
Nerve cells containing axons and dendrites that make connections with adjacent cells
Define Neuroglia and 5 functions
Supporting cells that have 5 basic functions:
*Provide supporting skeleton for neural tissue
*Isolate and protect the cell membranes of neurons
*Regulate the composition of interstitial fluid
*Defend neural tissue from pathogens
*Aid in the repair of injury
Define Unmyelinated axons
Axons that are not covered by a myelin sheath
Define Myelinated nerves
Nerves with axons that are covered by a myelin sheath
What are the nodes of Ranvier?
Regions located between the individual Schwann cells of Myelinated nerves
Which axon does action potential jump between Nodes of Rainvier?
Myelinated Nerves (results in increased speed of transmission of the impulse)
Define synapse
Gap between nerve cells that consists of a axon terminal, synaptic cleft and membrane of the postsynaptic cell
Define Presynaptic terminal
End of neuron where neurotransmitters are released from synaptic vesicles into the synaptic cleft
Synaptic cleft?
The space between neurons
Postsynaptic terminal
Beginning of a neighboring neuron, opposite the presynaptic terminal and across the synaptic cleft
Electrical impulses travel down the _____ and trigger the release of ____________ from the ________ terminal
Electrical impulses travel down the nerve and trigger the release of neurotransmitters from the presynaptic terminal
neurotransmitters cross the ______ _______ to stimulate an electrical reaction in _______ _______
neurotransmitters cross the synaptic cleft to stimulate an electrical reaction in adjacent neurons
Nerve Fiber
Groups of neurons that are bundled together
Nerves are formed by:
Bundles of nerve fibers
The nervous system is divided into three parts:
- Central Nervous System (CNS)
- Peripheral Nervous Systems (PNS)
- Autonomic Nervous System (ANS)
Nervous system that is composed of the brain and spinal cord
Central Nervous System
Nervous system that includes second cranial or optic nerve
Central Nervous System
Nervous system that includes 11 pairs of cranial nerves and 31 pairs of spinal nerves
Peripheral Nervous System
Nervous system that controls smooth muscle, cardiac muscle and glands
Autonomic Nervous System
Nervous system for the Flight-or-flight response
Autonomic Nervous System
Nervous System that maintains pulse rate, blood pressure, intestinal motility and pupillary response
Autonomic Nervous System
Major regions of the adult brain are:
- Cerebrum
- Diencephalon
- Cerebellum
- Brain stem
Components of the brain stem:
- Midbrain
- Pons
- Medulla
Largest portion of the brain (three fourths volume)
Cerebrum
Which part of the brain controls the higher thought process
Cerebrum
Define Gyri
Numerous folds that greatly increase the surface area of the cortex
Define Sulci
Grooves located between the gyri
Subdivisions located within each hemisphere
- Frontal lobe
- Parietal lobe
- Occipital lobe
- Temporal lobe
(Each lobe is named after the bone of the skull that is over it)
Which lobe is important in voluntary motor action, as well as personal traits
Frontal lobe
Which lobe is the site for reception and evaluation of some sensory information (except smell, vision and hearing)
Parietal Lobe
What separates the frontal and parietal lobe?
Central sulcus
Lobe on the posture side that is responsible for processing visual info
Occipital lobe
Lobe that plays an important role in hearing and memory
Temporal lobe
Separates the temporal lobe from the rest of the cerebrum
Lateral fissure
A thin layer of gray matter comprising the outer portion of the cerebrum
Cerebral cortex
Contains about 75% of all the neuron cell bodies of the nervous system
Cerebral cortex
The part of the brain between the brain stem and the cerebrum?
Diencephalon
Components of the Diencephalon?
- Thalamus
- Subthalamus
- Hypothalamus
- Epithalamus
Function of the thalamus?
Process most sensory input and influences mood and general body movements (especially fear or rage)
Functions of the Subthalamus?
Involved in controlling motor functions
Functions of the Epithalamus?
Involve control of emotions, circadian rhythms and connecting the limbic system with the rest of the brain
Functions of the Hypothalamus?
Vital in the control of many bodily functions (heart rate, digestion, sexual development, temperature regulation, emotion, hunger, thirst and sleep cycle)
How many cranial nerves exit the brainstem?
All but 2 of the 12 cranial nerves exit from the brainstem.
Lies immediately below the diencephalon and is the smallest region of the brain stem
Midbrain
set of important structures deep within the cerebrum, diencephalons, and midbrain that plays an important role in coordination of motor movements and posture
Basal ganglia
Limbic System
- Consists of a portion of the cerebrum and diencephalon
- Includes several structures that influence emotions, motivation, mood and sensation of pain & pleasure
Lies below the midbrain and above the medulla. Contains nerve fibers for sleep, respiration and medullary respiratory center
Pons
serves as a conduction pathway for both ascending and descending nerve tracts
Medulla
Coordinates heart rate, blood vessel diameter, breathing, swallowing, vomiting, coughing, and sneezing
Medulla
Responsible for all respiratory movements
Pons and Medullary respiratory center
Communicates with other regions of the CNS, essential in coordaining muscle movements, necessary for proper balance and movement
Cerebellum
A set of three tough membranes that enclose the entire CNS
Meninges
Outer and toughest membrane of the meninges
Dura mater
Has many blood vessels and nerves and attaches to the inside of the cranial cavity
Meninges
Arachnoid
Thin, weblike second layer, lies between the dura and pia maters
Pia mater
Inner layer resting directly on the brain
If a hematoma develops, it can be classified according to its location in respect to the ________
Meninges
fluid in which the meninges float; it is manufactured in the ventricles of the brain and flows in the subarachnoid space
Cerebrospinal fluid
Located between the arachnoid mater
Subarachnoid space
CSF is manufactured by:
Specialized cells within the choroid plexus in the ventricles(hollow areas in the brain
CSF is similar in composition to _______
Plasma
________ And _______ form a fluid filled sac that cushions and protects the brain and spinal cord
Meninges, CSF
