Chapter 2: Functional Neuroanatomy Flashcards
Neuroaxis & anatomical orientations:
- Rostral/Caudal
- Dorsal/Ventral
- Medial/Lateral
- Superior/Inferior
- Proximal/Distal
- anterior (front)/posterior (back)
- towards back or top/towards belly or bottom
- middle/side
- above/below
- close/far
Anatomical orientations:
- Afferent/Efferent
- arrive, bring info in/exiting, info leaving
Laterality:
- Bilateral
- Unilateral
- Contralateral
- Ipsilateral
- both sides
- one side
- opposite sides
- same side
The brain is ________ ________.
bilaterally symmetrical
The hemispheres of the brain are __________.
contralateral
Orientations for viewing brain & body:
- Horizontal plane
- Sagittal plane
- Coronal plane
- (axial plane) divides the brain into an upper and lower part
- bisects the body into right and left halves
- (frontal plane) divides the body into front (anterior) and back (posterior) regions
What makes up the nervous system?
specialized cells: neurons & glia
Neurons
- building blocks of the brain (information-processing and information-transmitting element)
- come in many shapes and sizes
- 86 billion neurons
What is the anatomy of a neuron?
- dendrites
- soma (cell body)
- nucleus
- axon hillock
- axon
- myelin sheath
- nodes of ranvier
- axon terminal (terminal button)
Soma (cell body)
- performs most metabolic functions
- nucleus contains chromosomes
- chromosomes: strands of DNA and genes: sections of the chromosome that code for specific proteins
- experience can change genes!
- epigenetics: control of gene expression by chromosome modifications that don’t effect actual DNA code
Organelles:
- Mitochondria
- Golgi apparatus
- Ribosomes
- generate energy (ATP) from glucose (abundant where energy needs are greatest)
- located in axon & axon terminal
- neurons require large amounts of energy
- packages cellular materials (proteins, lipids) into vesicles for transport
- produce proteins
Neurons are enclosed by a ________ membrane and are filled with salty ________.
- semipermeable; cytoplasm
Dendrites
- receive information from other cells
- covered with short dendritic spines that increase surface area
What are short dendritic spines?
- blobs coming off each dendrite
- increases surface area which increases communication and conversation
Axons
- transmit electrical signals from the axon hillock (at the soma) to the terminals
A neuron usually has ________ axon.
one, but it may branch to form axon collaterals
Terminal buttons have ________ ________ containing ________ chemicals.
synaptic vesicles; neurotransmitter
Myelination
- glial cells wrap axons with fatty sheath, myelin, to insulate and speed conduction
- thicker myelin = faster neurotransmission
- nodes of ranvier: gaps between sections of myelin where the axon is exposed
- some neurons do not have myelin
Axon:
- Cytoskeleton
- Microtubules
- a network of microtubules and neurofilaments that provide shape and structure to the cell
- form a track along which packets of proteins travel by the action of motor proteins
- axoplasmic transport: proteins made in the soma must be transported to the axon terminals
Abnormalities of the cytoskeleton are one feature in the brains of people with ________ disease.
Alzheimer’s; the microtubule system breaks down and axons shrivel up, preventing communication between neurons
Anterograde transport vs Retrograde transport
- cell body to axon terminal
- axon terminal to cell body
Neurons classified by shape:
- Multipolar
- Bipolar
- Unipolar
- (most common) cell body, axon, lots of dendrites
- (relatively rare) cell body (middle), dendrite (one side), axon (other side)
- (sensory) single process, cell body (off on the side) dendrites/axon run into each other
Neurons classified by function:
- Motor neurons
- Sensory neurons
- Interneurons
- trigger movement; control muscles
- interact with environment; bring information to the brain
- facilitators of conversation; link everything together
Communication between 2 neurons occurs at ________.
synapses