Neuroanatomy Flashcards
Ganglia
Groups of neurons
dorsal roots
carry information from body to spinal cord
ventral roots
carry outgoing motor axons
perikaryon
cell body of a neuron
schwann cells
type of glial cell that surrounds neurons, keeping them alive and sometimes covering them with a myelin sheath, and are the major glial cell type in the peripheral nervous system
node of ranvier
periodic gap in the insulating sheath (myelin) on the axon of certain neurons that serves to facilitate the rapid conduction of nerve impulses
neuroglia
Neuronal supporting cells, non-conducting nervous system cells, provide mechanical support to neurons, insulate and prevent neural impulses from spreading in unwanted directions
Glutamate
Main excitatory neurotransmitter, stimulating neurons to fire commands, brain uses glutamate to build pathways between neurons that reinforce your memory and help you learn
GABA
main inhibitory neurotransmitter, reduces activity in the CNS and blocks certain brain signals
Produces a calming effect that slows you down
Dopamine
Floods synapse between neurons when something rewarding happens, brings feelings of pleasure, Helps with wakefulness, releasing insulin, creating voluntary muscle movement
Adrenaline (epinephrine)
responsible for fight or flight response
Produced by adrenal glands located above kidneys
Serotonin
influence over mood, promoting feelings of well-being and happiness, makes you feel full/nauseous
Oxytocin
love hormone, made in hypothalamus and released via pituitary gland, crucial for social and physical health
Acetycholine
directly affects muscles, woks at neuromuscular junction, released to muscle fibers to trigger action potential and makes muscle contract, helps with memory and learning
Diaencephalon
caudal (posterior) part of the forebrain, contains the ephithalamus, thalamus, ventral thalamus, and third ventricle
Meninges
3 layers protecting the brain, includes the dura matter, arachnoid membrane, and pia matter
Dura matter
Outer-most layer of three layers protecting the brain, tough
Arachnoid membrane
next to dura matter, middle layer
Subdural space
in between dura matter and arachnoid membrane
Subarachnoid space
in between arachnoid membrane and pia membrane, filled with CSF and blood vessels
Pia matter
membrane covering the brain
Forebrain
cerebrum
Midbrain
topmost part of the brainstem, the connection central between the brain and the spinal cord
Hindbrain
lower part of the brainstem, comprising the cerebellum, pons, and medulla oblongata
3 nuclei of cerebral hemispheres
Basal ganglia, hippocampal formation, amygdala
agenesis
born without corpus callosum
inability to see faces would be caused by damage to
right hemisphere, fusiform region
acalculia (spatial type) would be caused by damage to
right hemisphere
subtle language deficits in prosody, articulation, and use of abstract constructs would be caused by damage to
right hemisphere
area of the brain that helps us understand intended meaning of vocalizations
right hemisphere
Lissencephaly
genetic malformation characterized by absence of folds in cortex
Polymicrogyria
abnormal brain development before birth
Topamax
antiepileptic med prescribed for seizures, cognitively blunting at high doses (impacts WM and verbal fluency)
Frontal lobe lesions impair
decision-making, difficulty with probability, Acute eye deviation with persistent neglect, contralateral hemiplegia (body paralysis), and anosmia (either total or partial loss of smell)
Lesions to right frontal/parietal lobes cause
Neglect (failure to respond/report, orient to novel stimuli)
Temporal legions cause
Contralateral superior quadranopia (field deficit in the superior field of both eyes on the same side) = “pie in the sky”
Parietal lesions would likely cause
Lesions cause difficulty with tactile perception/discriminations by touch
Occipital lesions
Lesions cause bilateral hemianopia (cortical blindness), hallucinations, color agnosia, agraphia
Frontal lobe
Associated with intellectual functions, reasoning, aggression, sexual bx, speech, smell, and voluntary movements
Orbital frontal lobe
involved in response initiation and inhibition
Dorsolateral prefrontal cortex
important for sequencing, persistence, and switching
Broca’s area
located in frontal cortex, above and behind left eye, involved in language processing, speech production, and comprehension, put thoughts into words, premotor area for speech sounds
Temporal lobe
associated with emotion, interpretation of language, hearing, and memory
Heschel’s gyrus (transverse temporal gyrus)
located in temporal lobe, associated with primary auditory cortex, sort auditory stimulation for direction, pitch, loudness, and other acoustic properties rather than words
Broadman areas
cytoarchitectural areas of the neocortex, regions with similar cell structure
Wernicke’s area
located in the posterior segment of the superior temporal gyrus in dominant hemisphere, associated with comprehension of speech sounds, considered the receptive language center of the brain
Parietal lobe
associated with body sensory awareness, language, abstract thought (specifically math), and body imaging, analysis of motion and spatial relationships
Posner and Peterson’s model of attention
in parietal lobe, posterior attention system is responsible for orienting and awareness of environment and anterior attention system is associated with signal detection
Occipital lobe
associated with receiving, interpreting, discriminating visual stimuli, and visual stimuli memory
Calcarine fissure
primary visual area
Dorsal pathway
involved with visual perception of where objects are located
Ventral pathway
involved with visual analysis of what objects are
Basal ganglia
help brain control body movements, role in movement, decision-making, and reward/addiction
6 parts of basal ganglia
caudate nucleus, globus pallidus, putamen, substantia nigra, subthalamic nucleus, ventral pallidum
Caudate nucleus
pair of brain structures controlling high-level fx including planning, movement, learning, memory, reward, motivation, emotion, and romantic exchanges (oxytocin)
Dysfx - associated with dementia, ADHD, bipolar, Huntington’s, Parkinson’s, Autism, Tourette’s, OCD
Substantia nigra
produces dopamine, controls movement and muscle tone, has two sections (pars reticulata and pars compacta)
Pars reticulata
movement of eyes, ability to learn and think, GABA to stop signals going to muscles
Pars compacta
secrete dopamine, involved emotions, learning, judging risk/reward, motivation
Hippocampal formation
anterior to amygdala + posterior to corpus callosum, major part of limbic system, lie along longitudinal axis of the brain, form floor and part of the medial wall of interiors hors of the lateral ventricle, best known for learning and memory, three main parts:
Hippocampus (Ammon’s horn), Dentate gyrus, and Subiculum
Amygdala
associated with fear, aggression, learning through rewards/punishment, implicit (unconscious) memory, social communication and understanding, emotions related to parenting and caregiving, emotions connected to memories, learning, and addiction
Internal capsule
a two-way tract for the transmission of information to and from the cerebral cortex, posterior to the basal ganglia
Primary motor cortex
controls voluntary movements and limbs and trunk, contains neurons projecting directly to spinal cord to activate somatic motor neurons
Primary sensory areas
receives information from peripheral receptors with only a few synaptic relays interposed (less stops along the way)
4 principles of anatomical organization
1) each system contains relay centers 2) each system is composed of several distinct pathways
3) each pathway is topographically organized 4) most pathways cross the body’s midline
Topographic organization
the projection of adjacent neurons in one area to adjacent neurons in another
Diencephalon
thalamus and hypothalamus taken together
Thalamus
relay center, processes and distributes almost all sensory and motor info going to the cerebral cortex
lateral geniculate gyrus
part of thalamic nuclei which is part of visual pathway
Lesion may cause left homonymous visual field deficits
Hypothalamus
under the thalamus, responsible for regulations of the ANS, homeostasis, controls body temperature, thirst, hunger, and emotional bx
Suprachiasmatic nucleus
bilateral structure located in the anterior part of the hypothalamus, structure involved in the “master clock” of circadian rhythms
Cerebellum
receives sensory input from the spinal cord, motor information from the cerebral cortex, and input about balance from inner ear receptors
Control of movement on the ipsilateral side of the body (damage causes motor deficits on the same side)
hindbrain
the lower part of the brainstem, comprising the cerebellum, pons, and medulla oblongata
Brainstem
inferior (behind) to superior medulla, pons, and midbrain, Contains all nerve connecting the spinal cord to the cerebrum, receives sensory info from head, neck, and face, involved in hearing, taste, and balance
Medulla
Located in the rostral region of brainstem, regulated bp, respiration, breathing, swallowing, digestion, heart, and blood vessels
Pons
links to cerebellum and cerebrum and relays info from cerebral cortex to cerebellum, functions with sleep, arousal, facial movements, breathing
Midbrain
topmost part of the brainstem, the connection central between the brain and the spinal cord, controls response to sight (eye movements), relay station of auditory and visual signals, motor control of some skeletal muscles
Tectum
Roof of midbrain
Tegmentum
Floor of midbrain
Limbic system
functional/evolutionary division, group of structures in center of brain, superior to the brainstem, includes hypothalamus, pituitary, hippocampus, hippocampal gyrus, amygdala
Mammillary bodies
brainstem nuclei on the posteroinferior aspect of the hypothalamus, role in memory
Papez’s circuit
Heuristic device, describe disorders of emotion, refers to neuroanatomical structures involves in emotion and memory (e.g., hippocampus, cingulate, mammillary bodies, fimbria, and insula)
Carotid arteries
vessels run along front of the neck, one right and left, Stroke in this area = changes with speech, vision, sensation
Vertebral arteries
vessels run along back of neck, right and left sides
Join to form one basilar artery
Stroke in this area = changes level of wakefulness, problems with muscle movement and coordination, speech changes, and vision problems
Circle of Willis
at the base of the brain, carotid and vertebral arteries come together, make circle of arteries that provide many paths for blood to supply O2 and nutrient to brain
Anterior Cerebral Artery
vessel supplies blood to the front part of brain/frontal lobe. Stroke = leg weakness, difficulty thinking and making decisions, changes in personality
Middle cerebral artery
vessel supplies blood to middle part of brain,
Most common for strokes,
Stroke = paralysis on one side of body, changes in sensation, blindness (either side), language problems (e.g., difficulty forming words and sentences, difficulty understanding what others are saying), upper extremity hemiparesis, aphasia, and neglect
apraxia
impaired ability to carry out motor abilities despite intact motor function
