Chapter 10 Nervous System Flashcards
Central Nervous System (CNS)
Containing the brain and spinal cord the main functions are sensory function, integrative function and motor.
Peripheral Nervous System (PNS)
Located outside the CNS and consists of the nerves that connect the CNS with the rest of the body
Sensory Function
Gathering information from inside the body and outside environment where it is then carried to the CNS.
Integrative Function
Interprets sensory information brought to the CNS where the brain makes a plan.
Motor Function
Gathering information from the CNS toward the muscles and glands. They convert the plan to a action. Motor nerves carry out plans made by the CNS.
Nervous System Cells
Neuroglia aka Glial Cells and Neurons.
CSF
Cerebrospinal Fluid
Two common types of glial cells.
Astrocytes and Ependymal cells.
Glial cells functions.
They are the most abundant of nerve cells and are mostly in the CNS. They act as nerve glue but do not conduct impulses. Some participate in phagocytosis (ingestion of bacteria) and help in the secretion of the CSF.
Astrocytes
Star shaped and are the most abundant of glial cells with many functions they support neurons structurally, cover the structure of the brain, and help form a barrier called the blood-brain barrier.
Ependymal Cells
Ependymal cells are inside the cavity of the brain and help in the formation of the CSF.
Neurons
Help in the transmission of electrical signals and help the nervous system act as a communication network. Neurons are also nonmitotic meaning they cant replicate or be replaced.
Three parts of neurons.
Dendrites, Cell Body, and Axon
Dendrites
Treelike structures that receive signals from other neurons and then transmit the signals toward the cell body.
Cell body
Contains the nucleus and is essential for the life of the cell. Receives signal from the dendrites and sends it to the axon.
Axon
- ***
- *Long extensions that transmits signals away from the cell body.**
Structures of the axon.
Myelin Sheath, Neurilemma, and Nodes of Ranvier.
Myelin Sheath
It protects and insulates the axon. Myelination begins of the fourth month of fetal life and continues to the teenage years. Immature axons lack myelination and affect the motor neurons. This is why movement from infants are slow and uncoordinated. Formation of myelin sheath differs in the PNS to the CNS.
Schwann Cells
Schwann cells surround the axon of neurons in PNS and form the myelin sheath. The nuclei and cytoplasm of schwann cells lie out myelin sheath and are called neurilemma.
Oligodendrocytes
A type of glial cell that forms the myelin sheath of neurons only found in the CNS unlike schwann cells in the PNS. Because there is no schwann cells there is no neurilemma.
Nodes of Ranvier
Areas on axons not covered by myelin sheath, they appear in regular intervals.
Tissues of CNS.
There is white and gray matter.
White Matter
Found in the CNS it is myelinated axons.
Gray Matter
Found in the CNS they are unmyelinated axons, cell bodies, interneurons, and synapses.
Nuclei
Clusters of cell bodies found in the CNS.
Ganglia
Small clusters of cell bodies in the PNS.
Nerve Impulse
Information carried along the neuron.
eg. getting a insect bite on your foot - pain is almost immediate - information travels from the foot to the brain and interprets the as pain.
It is a electrical signal that conveys information along the neuron, aka the action potential.
Phases of an action potential.
Depolarization and Repolarization.
Polarization
The neuron is resting and has negative charge. It has potassium(K) stored inside as the negative energy with sodium(Na) outside as positive energy.
Depolarization
The cell is stimulated where negative energy(K) is moved out the cell and gets replaced with positive energy(Na).
Repolarization
The cell returns to a resting state after being stimulated/depolarized where negative energy(K) is pumped back into the cell and replaces it with the positive energy(Na).
Synapse
A synapse helps information move chemically from one neuron to the next.
Synaptic Cleft
The synaptic cleft is a space, the space exists because the axon doesn’t make physical contact with the dendrite.
Receptors
Dendrites contain receptor cites where neurotransmitters bind together.
Neurotransmitter
The axon terminal contains thousands of tiny vesicles that store chemical substances called neurotransmitters.
Inactivators
These are substances that terminate the activity of the neurotransmitters when they have completed their task.
Four major areas of the brain.
The Cerebrum, the Diencephalon, the Brain Stem, and the Cerebellum.
Cerebrum
The cerebrum is divided into right and left cerebral hemispheres. They are joined together by bands if white matter that forms a larger fiber tract called the corpus callosum. The corpus callosum allow the left and right sides of the brain to communicate.
Corpus Callosum
The corpus callosum allow the left and right sides of the brain to communicate.
The cerebral hemisphere four major lobes.
Frontal, Parietal, Temporal, and Occipital.
Cerebral Cortex
A thin layer of gray matter on the outermost portion of the cerebrum. It allows higher mental task such as learning, reasoning, language, and memory.
Frontal Lobe
Its role is voluntary motor activity and also plays a role in motor speech. The Broca’s area specifically help control the motor speech.
Broca’s Area
Located in the frontal lobe its helps control motor speech.
Parietal Lobe
It receives sensations from the body, the parietal lobe is also called the primary somatosensory area. It also helps with reading, speech, and taste.
Temporal Lobe
It receives sensory information from the nose called the olfactory area, the area that senses smell. It also contains the auditory cortex which aloes you to hear.
Olfactory Area
Located within the temporal lobe, it is responsible for smell.
Auditory Cortex
Located within the temporal lobe, it is responsible for taste.
Occipital Lobe
It is associated with visual reflexes and reading, this is where the visual cortex is located where you can interpret sight.
Visual Cortex
Located within the occipital lobe, it is responsible for sight.
Speech Area
It is located in the temporal, parietal, and occipital lobes. It allows you to understand words written or spoken.
Basal Nuclei
Help regulate body movement and facial expressions. They are patches of gray matter and they’re called basal nuclei and basal ganglia.
Diencephalon
Being is located beneath the cerebrum and above the brain stem includes the thalamus and the hypothalamus.
Thalamus
Being located in the diencephalon, it receives and sorts out the sensory information for a more precise interpretation.
Hypothalamus
Being located in the diencephalon, it helps regulate body processes such as, body temperature, water balance, and metabolism.
Brain Stem
The brain stem connects the spinal cord with higher brain structures. The white matter of the brain stem includes tracts that relay both sensory and motor information to and from the cerebrum.
Medulla Oblongata
Being composed of the brain stem, it contains the vomiting center or emetic center.
Chemoreceptor Trigger Zone
Also knows as CTZ, Antiemetic agents can work on both the CTZ and medullary vomiting center to relieve nausea and vomiting.
