Structure and Function of the Nervous System Flashcards
What are the two primary types of cells
- Neurons
- Glial cells
Sensory neurons
Neurons that are sensitive to environmental stimuli and convert physical stimuli into an electrical signal and transmit that info to circuits of interneurons
Interneurons
Nerve cells within the brain and spinal cord
Interneurons are responsible for what?
- Conscious sensations
- Recognition
- Memory
- Decision making
- Cognition
Motor neurons
Nerve cells that direct a biobehavioural response appropriate for the situation
What are the common principal external features that neurons all have in common?
- The soma
- The dendrites
- The axon
Soma
The cell body, which contains the nucleus and other organelles that maintain cell metabolic function
Dendrites
Treelike projections from the soma that receive info from other cells
Axon
The single tubular extension that conducts the electrical signal from the cell body to the terminal buttons on the axon terminals
Neurons are enclosed by a semipermeable membrane called what?
The cytoplasm
Mitochondria
Responsible for generating energy from glucose
What is the name for cytoplasm within the axon?
Axoplasm
Axon hillock
The portion of the axon that is adjacent to the cell body
Axon hillock
The portion of the axon that is adjacent to the cell body
Axon collaterals give neurons the ability to do what?
Influence many more cells
Cells that release dopamine are called what?
Dopaminergic neurons
Cells that release serotonin are called what?
Serotonergic
Cells that release serotonin are called what?
Serotonergic
What are the two types of glial cells that form the myelin sheath?
- Schwann cells
- Oligodendroglia
Schwann cells
Glial cells that myelinate peripheral nerves that serve muscles, organs, and glands
Oligodendroglia
Glial cells which myelinated nerves within the brain and spinal cord
Where is the action potential regenerated during conduction of the electrical signal along the length of the axon?
At the nodes of Ranvier
What is the soma responsible for?
The metabolic care of the neuron
What part of the neuron is used for the synthesis of proteins that are needed throughout the cell for growth and maintenance?
The soma
What part of the neuron is used for the synthesis of proteins that are needed throughout the cell for growth and maintenance?
The soma
Chromosomes
Long strands of DNA
Genes
Small portions of chromosomes that code for the manufacture of a specific protein molecule
Genes
Small portions of chromosomes that code for the manufacture of a specific protein molecule
What are the important characteristics of ion channels?
- They are relatively specific for a particular ion
- ## Most channels are not normally open to allow free passage of the ions
What are the two types of ion channels?
- Ligand-gated channels
- Voltage-gated channels
What are the four types of glial cells?
- Schwann cells
- Oligodendroglia
- Astrocytes
- Microglia
Astrocytes
Large, star-shaped cells that have numerous extensions
Astrocytes
Large, star-shaped cells that have numerous extensions
Resting membrane potential
A difference in electrical charge inside the cell compared with outside of the cell
Explain the ions inside and outside the cell when the cell is at rest
More negative inside and more positive outside
Are all cells polarized at rest?
Yes
What is the resting membrane potential due to?
The uneven distribution of ions across the membrane, which occurs because ions move through relatively specific channels that normally are not open (the balance between two competing forces on K+ ions)
Action potential
The rapid change in membrane potential that is propagated down the length of the axon
Local potentials
Small, transient changes in membrane potential
At rest, neurons have an electrical charge across the membrane of what?
-70 mV
What are the two forces at play to maintain the membrane potential?
- Concentration gradient
- Na+ K+ pump
What does the Na+ K+ pump do?
Moves three Na+ ions out and moves two K+ ions in
When do EPSPs occur?
When ligand-gated Na+ channels open and allow Na+ to enter the cell on its concentration gradient, making it slightly more positive and bringing the membrane potential closer to the threshold for firing
When do IPSPs occur?
When Cl- channels open and allow Cl- to enter on it concentration gradient, making the cell more negative and farther from the threshold for firing
Central nervous system
The brain and spinal cord
Peripheral nervous system
All nerves outside the CNS
What are the two divisions of the PNS?
- Somatic nervous system
- Autonomic nervous system
How many pairs of cranial nerves are there?
12
What are the two divisions of the autonomic nervous system?
- Sympathetic
- Parasympathetic
Dorsal refers to what (head)?
The top
Rostral refers to what (head)?
The front
Caudal refers to what (head)?
The back
Ventral refers to what (head)?
The bottom
Superior refers to what?
Above
Anterior refers to what?
In front of
Posterior refers to what?
Behind
Inferior refers to what?
Beneath
Dorsal refers to what (body)?
Back
Caudal refers to what (body)?
Bottom
Ventral refers to what (body)?
Front
Rostral refers to what (body)?
Top
What is the plane through the middle, horizontal, side-to-side of the brain?
Horizontal
What is the plane through the middle, vertical, front-to-back of the brain?
Sagittal
What is the plane through the middle, vertical, side-to-side of the brain?
Coronal
What is the plane through the middle, vertical, side-to-side of the brain?
Coronal
What is the first major structure of the brainstem?
Myelencephalon, or medulla
What does the medulla do?
Regulate vital functions
What are the -cephalons?
- Myelencephalon
- Metencephalon
- Mesencephalon
- Diencephalon
- Telencephalon
What are the two large structures in the mesencephalon?
- Pons
- Cerebellum
Damage to the cerebellum can cause what?
Poor coordination and jerky movements
What are the two divisions of the midbrain?
- Tectum
- Tegmentum
What does the tectum consist of?
- The superior colliculi
- The inferior colliculi
What are the superior colliculi part of?
The visual system
What are the inferior colliculi part of?
The auditory system
What structures are within the tegmentum?
- Periaqueductal grey (PAG)
- Substantia nigra
What is the periaqueductal grey responsible for?
Modulation of pain
What are the two major structures in the diencephalon?
- Thalamus
- Hypothalamus
Thalamus
A cluster of nuclei that first process and then distribute sensory and motor info to the appropriate portion of the cerebral cortex
Thalamus
A cluster of nuclei that first process and then distribute sensory and motor info to the appropriate portion of the cerebral cortex
What does the telencephalon include?
- Basal ganglia
- Limbic system
What does the basal ganglia include?
- Caudate nucleus
- Putamen
- Globus pallidus
Identify a structure of the myelencephalon
Medulla
Identify a substructure of the medulla
Area postrema
Identify a general function of the area postrema
Initiates vomiting in response to toxins in the blood
Identify a structure of the metencephalon
Pons
Identify a substructure of the pons
Reticular formation
Identify a general function of the reticular formation
Arousal, attention, sleep, and muscle tone
Identify a structure of the mesencephalon
Tegmentum
Identify a substructure of the tegmentum
Periaqueductal gray
Identify a general function of the periaqueductal gray
Pain modulation
Identify a structure of the diencephalon
Thalamus
Identify a substructure of the thalamus
Lateral geniculate nucleus
Identify a general function of the lateral geniculate nucleus
Receiving visual info from the eyes and projecting it to the primary visual cortex
Identify a structure of the telencephalon
Limbic system
Identify a substructure of the limbic system
Amygdala
Identify a general function of the amygdala
Emotional responses
