Neuro Quiz 1

Neuroscience

study of brain mechanisms that allow acquisition and regulation of higher cognitive functions and the production of basic and skilled actions

• study of nervous system at diff levels and perspectives

Neuroplasticity

changing of neurons, the organizations of their networks, and their function via new experiences

Frontal/Coronal Plane

divides body into front and back sections (think like wearing a crown)

Horizontal/Transverse/Axial Plane

divides the body into upper and lower sections (think horizon/flat)

Sagittal/Medial Plane

divides the body into equal left and right sections (think of Sagittarius, like shooting an arrow)

Dextral

right side of body

Sinistral

left side of body

Prone

lying face down

Supine

lying face up (think “holding soup”)

Ventral

away from backbone/toward front of body

Dorsal

towards backbone/away from front of body

Anterior

toward front/away from the back

Posterior

toward back/away from front

Superficial

toward the surface

Deep

away from the surface

Medial

toward the axis (midline)

Lateral

away from the axis (midline)

Superior

upper

Inferior

lower

Rostral

towards the head

Caudal

toward the tail, away from the head

Bilateral

related to both sides of the body

Unilateral

relating to one side of the body

Contralateral

opposite side of the body

Ipsilateral

same side of the body

Proximal

toward the body/root of a free extremity

Distal

away from the body/root of a free extremity

Ventral/Dorsal/Rostral/Caudal of dog

head = rostral, tail = caudal, belly = ventral, back = dorsal

Ventral/Dorsal/Rostral/Caudal of brain

same as dog

Ventral/Dorsal/Rostral/Caudal of brain stem and spinal cord

be aware of changes when lying down

Ventral/Dorsal of body lying down

be aware of changes when lying down

Anatomical Orientation of Head

Anterior ⬅ Posterior ➡ Superior ⬆ Inferior ⬇

black

Anatomical Orientation of Cerebrum

Rostral ⬅ Caudal ➡ Dorsal ⬆ Ventral ⬇

red

Anatomical Orientation of Cerebellum

Ventral ⬅ Dorsal ➡ Rostral ⬆ Caudal ⬇

yellow

• *cerebellum is just cerebrum rotated 90 degrees*

Orientation of the Brain

(Rostral, Ventral, Superior, Posterior, Dorsal, Caudal)

Key

Rostral/Caudal of brain and spinal cord

Key

Neuraxis is…

the central nervous system

Central Nervous system consists of…

brain and spinal cord

Gross Anatomy of the CNS

Cerebrum

Gyrus

Sulcus

Basal Ganglia

Diencephalon (T and H)

Cerebellum

Brainstem (Mi, P, Me)

Spinal Cord

Cerebrum

Gyrus

Sulcus

Basal Ganglia

Diencephalon

made of thalamus and hypothalamus

Cerebellum

Brainstem

midbrain

pons

medulla

spinal cord

Neuron

the smallest functional unit of the brain

• info-bearing cell of the nervous system

• 15 billion neurons in CNS (trillions of synapses)

Electrical Impulse

Neurons communicate information in the form of electrical impulses (action potential/nerve impulse)

• excitatory (moving)

• inhibitory (shut down)

Axon = Myelinated = faster

Axon = Unmyelinated = slower

Glial cells

provides metabolic requirements/speeds up signal transmission

produces myelin sheath (aka: myelinated)

cleans out synaptic cleft of leftover neurotransmitters (waste)

2 Types:

• oligodendrocytes (CNS)

• Schwann cells (PNS)

Cell body/Soma

contains the cell nucleus and main organelle

Dendrites

receive information from other neurons or cells

Axon Hillock

where these action potentials are generated/sent

Axon

transmit action potentials to the next structure in system  — neuron, muscle, or organ

• Axon = Myelinated = faster

• Axon = Unmyelinated = slower

myelin sheath

fatty proteins that cover/insulate the axon of some neurons

helps speed neural impulses

made of Schwann cells

• thicker = more effective at sending neural impulses

• thinner = cognitive decline, leading to disorders such as multiple sclerosis and dementia

(white matter)

Node of Ranvier

periodic gaps in the myelin sheath

facilitate the rapid conduction of nerve impulses

• Saltatory conduction

Saltatory conduction

type of neuronal transmission in myelinated fibers

• (compare to slow transmission in unmyelinated fibers)

signal is sent from axon hillock

signal jumps from one piece of myelin to next

Neural Impulse

electrical signal traveling down the axon

Terminal Fibers of Axon

branch off the end of the axon, end in terminal buttons

release neurotransmitters into the synapse

Presynaptic Neuron

where neuron sends the signal

• sent by terminal fibers of axon

Synapse

terminal structure of a neuron

Consists of:

• terminal bouton

• synaptic cleft

• postsynapse

Synaptic cleft

space between neurons

Postsynaptic Neuron

neuron receiving signal

• signal may or may not continue

• received by dendrites

Neuron Communication

Dendrites → Axon hillock → Axon → Axon terminal → Neurotransmitter → Synaptic cleft → Next neuron

____ are sensitive to various stimuli and receive direct connections from non-neural receptor cells

sensory neurons

_____ end directly on muscles, glands, or other neurons in peripheral nervous system (PNS) ganglia

motor neurons

____ reside solely in the CNS, interconnecting other neurons

interneurons

_______ are long axons connecting the cerebral cortex to the spinal cord

projection neurons

____ contains the cell nucleus and main organelles

cell body (soma)

____ receive information from other neurons or cells

dendrites

____ transmit action potentials to the next structure in system  — neuron, muscle, or organ

axons

_____ is where these action potentials are generated

axon hillock

______ are the periodic gaps in the myelin sheath. They facilitate the rapid conduction of nerve impulses

nodes of Ranvier

Types of Neurons

sensory

motor

interneurons

projection

More than 99% of neurons are either

interneurons or projection neurons

Afferent

Body —> CNS

• Info IN

Efferent

CNS —> Body

• Info OUT

Sensory Neurons

senses

sensitive to various stimuli and receive direct connections from non-neural receptor cells

AFFERENT

• Body —> CNS

Motor neurons

end directly on muscles, glands, and other neurons in PNS ganglia

EFFERENT

• CNS —> Body

Interneurons

reside ONLY in the CNS, interconnect neurons w/ other neurons

“middlemen”

• Ex) sensory neuron —> interneuron —> motor neuron

Projection

long axons connecting brain to spinal cord

delivers info between the two

• the number of extensions (projections) coming from the soma = what type of neuron it is

Types of Neurons based on # of Projections

Unipolar = 1 projection

Bipolar = 2 projections

Multipolar = many projections

Central Nervous System

Made of:

• Brain

• Spina Cord

Peripheral Nervous System

Made of:

• Cranial nerves

• spinal nerves

Subdivisions of the CNS (PIC)

Cerebral hemispheres

Diencephalon

Lobes of Brain (5 not 4!!!) —> see pic

Frontal

Parietal

Occipital

Temporal

Limbic

2 minute neuro —> divisions of the nervous system video

Grey Matter

Unmyelinated

• Cell bodies and Dendrites (everything else)

White Matter

Myelinated

• what’s on the axon! (myelin sheath)

Gray and White matter in the brain

looks completely different in different places!

Cerebral Hemispheres

Brainstem

Spinal Cord

Matter in the Cerebral Hesmispheres

Nucleus

contains the cell body/soma

Cortex

gray matter forming the surface covering parts of CNS

Ganglia

collection of nerves

Subcortical Structures

Cortical = think: cortex

putamen, caudate, etc

Diffusion Tension Imaging (pics)

wate rmolecules traveling

Fasciculus

“little bundle”

Funiculus

“string”

Lemniscus

“ribbon”

Peduncle

“little foot”