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
What are the three components of synapses?
- presynaptic membrane
- postsynaptic membrane
- synaptic cleft
Glial cells
- support and enhance neuron functions
Where are glial cells found?
Peripheral nervous system (PNS) & Central nervous system (CNS)
The different types of glial cells:
- Satellite cells (don’t worry about these at this point)
- Schwann cells
- Oligodendrocytes
- Astrocytes
- Microglia
- Ependymal cells
- insulate (support cell bodies)
- outside brain and spinal cord; form myelin sheath, one cell can only produce one myelin sheath (secrete neurotrophic factors)
- form myelin sheath, lots of feet forming many myelin sheath
- overachiever: maintain physical function (support for CNS, blood brain barrier (BBB), neurotrophic factors, K+ neurotransmitters)
- attacks pathogens and damaged cells; protects the brain; HULK (scavengers)
- cerebral fluid, seaweed-like move liquid around; (create barriers between compartments)
What glial cells does the PNS contain?
satellite cells (don’t worry about these at this point) & Schwann cells
What glial cells does the CNS contain?
- oligodendrocytes
- astrocytes
- microglia (modified immune cells)
- ependymal cells
What are the divisions of the nervous system?
Central nervous system (CNS) and Peripheral nervous system (PNS)
Peripheral nervous system (PNS)
- all parts of the nervous system found outside the skull and spinal column
- NOT encased in bone
- nerves
- motor neurons transmit information from CNS to muscles, organs, and glands (efferent)
- sensory neurons convey information from the body to CNS (afferent)
- respond to environmental stimuli, such as light, odor, or touch
- divisions: somatic nervous system & autonomic nervous system
- connect brain and major muscles and sensory systems (voluntary muscles)
- nerves that control the viscera (internal organs)
- sympathetic & parasympathetic divisions
Anatomy of PNS:
- Motor nerves
- Sensory nerves
- Divisions of PNS:
- - Somatic nervous system
- - Autonomic nervous system
- transmit information from the CNS to muscles, organs, and glands (efferents)
- convey information from the body to CNS (afferents); respond to environmental stimuli, such as light, odor, or touch
- somatic nervous system & autonomic nervous system
- connect brain and major muscles and sensory system (voluntary muscles)
- nerves that primarily control the viscera (internal organs); sympathetic & parasympathetic divisions
Cranial nerves
- 12 pairs of nerves that relay sensory information to the brain or produce motor responses
- some nerves have sensory AND motor nerves
** You will need to know the name, number, & function of each cranial nerve for unit 2! **
Cranial nerves: name, number, and function
Cranial nerves
Cranial nerves
Somatic nervous system
- spinal nerves — 31 pairs
- each spinal fusion is the fusion of two distinct branches, or roots: dorsal or ventral
Dorsal root vs Ventral root
- carries sensory information from the body to the spinal cord
- carries motor information from the spinal cord to the muscles
Autonomic nervous system:
- Sympathetic nervous system
- Parasympathetic nervous system
- Dual innervation
- fight or flight (heart rate increase, sweating, heavy breathing, dilated pupils)
- neurotransmitter: norepinephrine
- rest & digest (think Picnic: resting & eating snacks)
- neurotransmitter: acetylcholine
- most organs connected to both sympathetic & parasympathetic nervous system
Automatic nervous system:
- Autonomic ganglia
- Preganglionic neuron
- Postganflionic neuron
the automatic nervous system spans the central and peripheral nervous systems
- groups of neuron cell bodies located outside the CNS
- axons extend from the CNS and synapse in the autonomic ganglia
- axons extend from the autonomic ganglia to targets in the body
Central nervous system (CNS)
- the brain and spinal cord
- encased in bone
- neurons
- the brain has two cerebral hemispheres (bilaterally symmetrical)
- cerebral cortex (gyri and sulci)
- folded outermost layer of cerebral hemispheres, comprised of neuron cell bodies, dendrites and axons)
- corpus callosum
- left and right cerebral hemispheres are connected by a bundle of axons
Central nervous system (CNS)
- the brain and spinal cord
- encased in bone
- neurons
- the brain has two cerebral hemispheres (bilaterally symmetrical)
- cerebral cortex (gyri and sulci)
- folded outermost layer of cerebral hemispheres, comprised of neuron cell bodies, dendrites and axons)
- corpus callosum
- left and right cerebral hemispheres are connected by a bundle of axons
Anatomy of CNS:
- Cerebral cortex
- - Gyri
- - Sulci
- Corpus callosum
- folded outermost layer of the cerebral hemispheres, comprised mostly of neuron cell bodies, dendrites, and axons
- physical lumps of tissue
- folds of tissue (fissures: deep sulci)
- left & right hemispheres are connected by a bundle of axons known as corpus callosum
What are the lobes of the brain?
- frontal
- parietal
- occipital
- temporal
Lobes of the brain:
- Frontal
- Parietal
- Occipital
- Temoral
- planning, pattern recognition, humor, complex human motor
- pain, touch, temperature, spatial navigation
- vision processing
- auditory processing, memory, emotions like fear
