NSCI 175 Exam II UNC

dorsal

direction pointing up

ventral

direction pointing down

rostral

anterior, toward the nose

caudal

posterior, towards the back of the body, tail

midsagittal

the plane dividing the brain into equal right and left halves

horizontal

splits into dorsal and ventral halves

coronal

splits into rostral and caudal halves

ipsilateral

on the same side of the body as another structure

contralateral

on the opposite side of the body as another structure

proximal

nearer to the trunk of the body

distal

farther from the trunk of the body

CNS (central nervous system)

consists of the brain and spinal cord

PNS (peripheral nervous system)

the sensory and motor neurons that connect the CNS to the rest of the body, cranial and spinal nerves

somatic nervous system

voluntary control, the division of the peripheral nervous system that controls the body's skeletal muscles

visceral nervous system

involuntary, the portion of the peripheral nervous system composed of a motor division (autonomic nervous system) and sensory division

sympathetic nervous system

the division of the autonomic nervous system that arouses the body, mobilizing its energy in stressful situations, "fight or flight"

parasympathetic nervous system

the division of the autonomic nervous system that calms the body, conserving its energy, "rest and digest"

cerebrum

largest part of the brain, contralateral control, involved with motor, touch, and vision

corpus callosum

the large band of neural fibers connecting the two brain hemispheres and carrying messages between them

spinal cord

nervous tissue within the spinal cavity, brings information to and from the body to the brain

brainstem

relays information from cerebrum and cerebellum to the spinal cord, regulates vitals

medulla oblongata

connects brainstem to spinal cord and contains control centers for the heart and lungs, ANS, sensory and motor info travel through

pons

A brain structure that relays information from the cerebellum to the rest of the brain, head and facial sensation, motor control of facial structures, ANS

Midbrain

A small part of the brain above the pons that integrates sensory information and relays it upward

superior colliculus

receives visual sensory input and is involved in visual processes

inferior colliculus

a midbrain nucleus in the auditory pathway

substantia nigra

midbrain structure where dopamine is produced; involved in control of movement

ventricles

areas of the brain that produce transport the CSF that bathes the CNS

dorsal roots

axons that bring information to the spinal cord, ie sensory neurons

ventral roots

axons that carry information away from the spinal cord, ie motor neurons

efferent axons

sends information away from the CNS

afferent axons

brings information into a the CNS

cranial nerves

12 pairs of nerves arising from the brain that carry sensory and motor information

CT (computed tomography)

measure of x-ray absorption to map tissue density, gross organization of gray and white matter, and position of ventricles

MRI (magnetic resonance imaging)

a technique that uses magnetic fields and radio waves to see hydrogen atoms to produce computer-generated images of soft tissues, such as the brain

fMRI (functional MRI)

detects changes in brain metabolism (oxygen use) in active brain areas, the amount of oxygen is measured indirectly (BOLD), can show how networks of brain structures collaborate

BOLD

blood-oxygen-level-dependent-signal

PET (positron emission tomography)

uses radioactive chemicals injected into bloodstream and maps their destination by emissions, identifies what brain areas contribute to specific functions and detect changes in blood flow and metabolism

tract

collection of axons in CNS

nucleus

a clearly distinguishable mass of neurons

primary cortical areas

regions of the cerebral cortex that directly serve motor or sensory functions, performs the actual task of the region

Secondary cortical areas

analyze and recognize information from the primary cortex and for memory storage

associative cortical area

integrate simpler functions to perform more complex functions

frontal lobe

The lobe at the front of the brain associated with movement, speech, and impulsive behavior (cognitive skills)

parietal lobe

receives sensory input for touch and body position

occipital lobe

A region of the cerebral cortex that processes visual information

temporal lobe

A region of the cerebral cortex responsible for hearing and language

cingulate gyrus

a strip of limbic cortex lying along the lateral walls of the groove separating the cerebral hemispheres, just above the corpus callosum that is responsible for emotions, behavior, and automatic motor function

corpus callosum (function)

integrates motor, sensory, and cognitive performance, connects left and right hemispheres of the brain

thalamus

area of brain that relays messages between lower brain centers and cerebral cortex, relays sensory signals and motor skills

Hypothalamus

A neural structure lying below the thalamus; it directs several maintenance activities (eating, drinking, body temperature), helps govern the endocrine system via the pituitary gland, and is linked to emotion and reward

tegmentum

a part of the midbrain that is involved in basic body and limb movement

tectum

auditory and visual reflexes, orients a person in space

cerebellum

A large structure of the hindbrain that controls fine motor skills, such as balance and coordination; receives sensory info and regulates motor movements

6

how many layers of cells is the cerebral cortex organized into?

molecular layer

few neuron cell bodies, mostly a synaptic and integrative area

(I)

external granular layer

many small pyramidal and stellate cells (II)

pyramidal layer

Many pyramidal neurons (III)

internal granular layer

these neurons are closely packed with many short axons that end in the layer (IV)

ganglionic layer

large pyramidal cells (V)

multiform layer

primarily fusiform cells (VI)

sweet (taste)

sugars, signals carbs and calories,

salty (taste)

sodium, low concentration tastes good, high concentrations taste bad, voltage-gated Na+ & Ca2+ channels

bitter (taste)

tastes like poison, T1R &T2R receptors (g-protein)

sour (taste)

acidic, can cause tissue damage, H+ blocks K+ channels and activates Na+ channels

umami (taste)

amino acids glutamate and aspartate, G-protein receptors depolarize

papillae

structure that houses tastebuds; bumps on your tongue

taste bud

structures that house taste receptor cells; in "valley" of papillae

sweet pathway

G-protein coupled receptor, stimulates phospholipase C and IP3, this activates intracellular Ca2+ stores, Ca2+ is released and opens Na+ channels, ATP flows out of cell, uses T1R2 and T1R3 receptors

salty pathway

Na+ ions are transported across taste cell membranes, depolarizing the cell

sour pathway

H+ ions block K+ ions which depolarizes the cell, H+ ions can also activate Na+ and Ca2+ ion channels

umami pathway

g-protein, uses T1R1 and T1R3

bitter pathway

G-protein coupled, uses T1R & T2R receptors

primary gustatory axons

from the taste buds and receptor cells to the

brain stem

from the primary gustatory axons to the

VPM nucleus of thalamus

from the brain stem to the

primary gustatory cortex

from the VPM nucleus of the thalamus to the

population coding

neural representation of a stimulus by the pattern of firing of a large number of neurons that are broadly tuned to a stimulus

olfactory epithelium

the lining of the roof of the nasal cavity, containing a sheet of receptor cells for smell, supporting cells, and basal cells

olfactory receptor cells

bipolar neurons surrounded by columnar epithelial cells, sense chemical odorants

olfactory supporting cells

Columnar epithelial cells; provide nourishment, protection, and electrical insulation for receptors, detoxify chemicals that contact the olfactory hairs, help to produce mucus

olfactory basal cells

divide to form new olfactory receptor cells

olfactory receptor cells (transduction)

Olfactory transduction begins with an odorant that binds to

adenylyl cyclase

olfactory receptor cells stimulate Golf, which then activates

cAMP proteins

adenylyl cyclase aids in the formation of

nucleotide-gated ion channels

cAMP proteins bind to

Na+ and Ca2+

nucleotide-gated ion channels open to allow the influx of

Cl- channels

influx of Na+ and Ca2+ actives

receptor potential

Cl- channels depolarize the cell and generates a

350

Humans have ______ genes scattered among the genome that code for functional receptor proteins

olfactory bulb, amygdala, olfactory cortex, olfactory tubercle, medial dorsal nucleus, and orbitofrontal cortex

regions of the brain that receive olfactory information

the amygdala, the primary olfactory cortex, or the hypothalamus

olfactory receptors send information to the olfactory bulb that then sends information to

hypothalamus or medial dorsal thalamus

if information goes from olfactory bulb to the amygdala or primary olfactory cortex, it can go either to the

lateral posterior orbitofrontal cortex

If information is sent to the hypothalamus, it goes to the

orbitofrontal cortex (secondary olfactory cortex)

if information is sent to the medial dorsal thalamus, it will go to the

must not

In olfactory sensation, information must/must not be sent to the thalamus before its primary cortex

gustatory and olfactory sensation

population coding is used in both

temporal coding (olfactory)

timed based spiking of olfactory neurons that code for specific smells

photoreceptors (rods and cones)

outermost layer of retina made up of 5 to 7 rows of nuclei; photosensitive cells which receive stimulus from light and turn it into a membrane potential in bipolar cells

bipolar cells

eye neurons that receive information from the photoreceptor cells and distribute information to the ganglion cells