Chapter 4 Flashcards
Brain & spinal cord
Central Nervous System (CNS)
Nerves outside the brain & spinal cord
Peripheral Nervous System (PNS)
consists of axons conveying msgs from sense organs to the CNS & from CNS to the muscles.
Part of PNS is Somatic Nervous System
controls the heart, intestines, & other organs
autonomic nervous system
Toward the back
Dorsal
Toward the stomach
Ventral
Part of the CNS w/in the spinal column; communicates w/all the sense organs & muscles except those in the head
Spinal Cord
Entering dorsal roots (axon bundles) carry sensory info & exiting ventral roots carry motor info
Bell-Magendie Law
Clusters of neurons outside spinal cord (contain cell bodies of sensory neurons)
Dorsal root ganglia
in center of spinal cord-densely packed w/cell bodies & dendrites
Gray Matter
Consists mostly of myelinated axons
White Matter
Network of nerves that prepare organs for vigorous activity
sympathetic nervous system
increased breathing & heart rate, & decreased digestive activity
“fight or flight”
facilitates vegetative, nonemergency responses
Parasympathetic nervous system
Extend from spinal cord to parasympathetic ganglia close to each internal organ
Preganglionic axons
Shorter fibers that extend from parasympathetic ganglia into organs themselves
Postganglionic fibers
Cluster outside the Nervous system
Ganglion
Cluster inside nervous system
Nucleus
AKA known as craniosacral system; consists of cranial nerves & nerves from sacral spinal cord
Parasympathetic system
Brain has 3 major divisions
the hindbrain, midbrain, & the forebrain
consists of medulla, & pons, midbrain, & certain central structures of the forebrain
brainstem
consists of medulla, pons & cerebellum; located @ posterior; AKA rhombencephaion
hindbrain
enlarged extension of spinal cord-controls some vital reflexes thru cranial nerves; located just above the spinal cord & could be regarded as an enlarged extension of the spine.
Medulla; AKA Medulla Oblongata
allow the medulla to control sensations from the head muscle movements in the head & many parasympathetic outputs to the organs.
cranial nerves
lies anterior & ventral to medulla & contains nuclei for several cranial nerves
pons
has ascending & descending portions
reticular formation
one of several brain areas that control the motor areas of the spinal cord
descending
sends output to much of the cerebral cortex, selectively increasing arousal & attention
Ascending
sends axons to much of the forebrain, modifying brain’s readiness to respond to stimuli
Raphe system
lrg hindbrain structure w/many deep folds; 70 billion neurons are here; contributes to control of movement; contributes to balance & coordination; also important for shifting attention between auditory & visual stimuli
cerebellum
AKA; mesencephalon
Has the tectum, Superior colliculus & inferior colliculus, tegmentum, substantia nigra
Midbrain
roof of midbrain
tectum
swellings on each side of tectum; important for sensory processing
superior colliculus & inferior colliculus
intermediate lvl of midbrain- includes nuclei 3rd & 4th cranial nerves, & extensions of pathways between forebrain and spinal cord or hindbrain
Tegmentum
Gives rise to dopamine-containing pathway that facilitates readiness for movement
substantia nigra
AKA prosencephalon; most anterior & most prominent part of mammalian brain; consists of left & right hemispheres (cerebral hemisphere); each hemisphere organized to receive sensory info & to control muscles
Forebrain
outer portion of forebrain
cerebral cortex
interlinked structures that form border around brainstem; important for motivations & emotions; drives aggression
limbic system
Deals with smell
olfactory bulb
motivated behaviors
hypothalamus
encoding memories
hippocampus
emotional regulation
amygdala
consists of thalamus & hypothalamus
diencephalon
pair of structures in center of forebrain
thalamus
what is the exception of the thalamus?
smell doesn’t go thru the thalamus
small area near base of brain just ventral to thalamus; associated w/behaviors such as eating, drinking, sexual behavior, & other motivated behaviors.
Hypothalamus
What happens when hypothalamus is damaged?
leads to abnormalities in motivated behaviors (feeding, drinking, temp. regulation, sex behavioral, fighting, or activity lvl.
an endocrine gland attached to base of hypothalamus
pituitary gland
group of cortical structures lateral to thalamus; contains caudate nucleus, putamen, & globus pallidus; responsible for planning sequences of behavior & for certain aspects of memory & emotional expression
Basal Ganglia
lie on ventral surface of forebrain; includes nucleus basalis, which receives input from hypothalamus & basal ganglia & sends axons that release acetylcholine to widespread areas in cerebral cortex; plays key role in arousal, wakefulness, & attention
Basal Forebrain
lrg structure between thalamus & cerebral cortex; critical for learning & memory, especially for encoding new memories
hippocampus
4 fluid-filled cavities w/in brain
The Ventricles
Membranes that surround brain & spinal cord; these are the parts of the brain that have pain receptors
Meninges
inflammation of meninges
meningitis
condition in infants caused when flow of CSF is obstructed, accumulating w/in ventricles or subarachnoid space, increasing pressure on brain-skull bones may spread, causing overgrown head
hydrocephalus
most prominent part of the mammalian brain; consists of the cellular layers on the outer surface of the cerebral hemisphere
the cerebral cortex
bundles of axons thru which neurons in each hemisphere communicate w/neurons in corresponding part of other hemisphere
corpus callosum
Sagittal
from the side
view from front
cornal
straight down
horizontal
back
Posteir
anterior
front
How does cold meds work?
blocks parasympathetic; increase sympathetic
6 distinct layers of cell bodies that are parallel to surface of cortex & separated from each other by layers of fibers
Laminae
sends long axons to the spinal cord & distinct areas & is the thickest in the motor cortex
Lamina V
receives axons from the various sensory nuclei of the thalamus & is prominent in all the primary sensory areas but absent from the motor cortex
Lamina VI
cells w/in columns have similar properties to one another; lie perpendicular to the lamine
cells of cortex organized into columns
The cerebral cortex is divided into 4 lobes
occipital, parietal, temporal, & frontal
Contains primary visual cortex (striate cortex): VISION
Occipital lobe
Damage results to this; blindness that has nothing to do w/your eyes
cortical blindness
Lies between occipital lobe & the central sulcus; contains postcentral gyrus (primary somatosensory cortex); main target for touch sensations & info from muscle-stretch receptors & joint receptors
Parietal lobe
separate areas along each band receive simultaneous info from different parts of body
includes 4 bans of cells parallel to central sulcus
Lateral portion of each hemisphere near the temples; primary target for auditory info; essential for understanding spoken language ( the left temporal lobe in most cases) also contributes to complex aspects of vision, including perception of movement & recognition of faces; plays part in emotional & motivational behaviors
Temporal Lobe
Damage to temporal lobe= lose sense fear
kluver bucy syndrome
abstract thinking & planning; most anterior portion of frontal lobe; the integration center for all sensory info & other areas of the cortex
prefrontal cortex
How do the parts work together?
binding occurs if you perceive 2 sensations as happening at the same time & in the same place (ventriloquist effect)
A memory system that underlies our ability to “keep things in mind” when performing complex tasks (temporary storage & manipulation
Working Memory
A stimulus appears briefly & individual must respond to stimulus after brief delay
delayed-response task
Ppl w/prefrontal cortex damage
trouble planning stuff & impairments in delayed response tasks
Have trouble locating objects in space & often fail to bind objects
ppl w/damage parietal lobe
Which of the following methods is dependent upon injecting a radioactive chemical into the blood to measure blood flow
PET
Categories for research methods to study the brain
- examine the effects of brain damage
- examine the effects of stimulating some brain areas
- record brain activity during behavior
- correlate brain anatomy w/behavior
French surgeon
Paul Broca
what are teh limitations of these human studies?
hard to find ppl w/the same brain damage
Ablation
removal of a brain area
lesion
damage to brain area
stereotaxic instrument
device for precise placement of electrodes in brain; used to damage structures
sham lesion
lesion produced in control group
use of biochemical methods to direct a mutation to a particular gene that’s important for certain types of cells, transmitters, or recptors
gene knockout approach
application of intense magnetic field to a portion of the scalp, which temporarily inactivates neurons below the magnet
Transcranial Magnetic Stimulation (TMS)
A technique that allows researchers to turn on activity in targeted neurons by a device that shines a laser w/in the brain
optogenetics
complex behaviors depend on many brain areas, not just one
limitation
most popular to study brain; involves using a variety of noninvasive methods.
Recoding brain activity
Records electrical activity of the various brain thru electrodes applied to the scalp; high temporal resolution; can record spontaneous brain activity or activity in response to a stimulus
Electroencephalograph (EEG)
Measures faint magnetic fields generated by brain activity
Magnetoencephalograph (MEG)
both provide good temporal resolution
EEG & MEG
Provides very high-resolution of activity in a living brain by recording emission of radioactivity from injected chemicals; very good @ spatial; 1st really good method to get where in brain activity is happening
Positron-emission tomography (PET)
Disadvantages of PET
only @high end places; very expensive; expense of cyclotrons; the brain is exposed to radioactivity
modified version of MRI based on hemoglobin; uses oxygen consumption in the brain to provide a moving & detailed pic
Functional Magnetic Resonance imaging (fMRI)
Gathers light transmitted cortical tissue to image blood-oxygen consumption (oxygenated hemoglobin)
Functional Near Infrared Spectroscopy (fNIRS)
can involve the IDing of peculiar behaviors & looking for abnormal brain structures or functions
Correlating brain anatomy w/behavior
the process of relating skull anatomy to behavior; one of the qst ways used to study the brain; yielded few, ifa ny, accurate results
Phrenology (Franz Gall)
One method of examining brain anatomy; involves the injection of a dye into the blood & a passage of X-rays thru the head
Computerized axial tomography (CT or CAT scan)
method based on the fact that any atom w/an odd-numbered atomic weight (e.go hydrogen) has an axis of rotation
Magnetic resonance imaging (MRI)
Do we have the lrgest brains?
No elephants have bigger brains (for ex); brain to body ratio
What about correlation between specific brain areas & IQ?
IQ correlated w/amount of gray matter
Why are men & women equal in intellect despite lrger brains in men?
women avg more & deeper sulci on surface of cortex; women’s & men’s brains differ structurally, but accomplish the same thing; “organized differently”
