Exam 1 general - SPA 4101

What are the 7 principles of neuroscience?

1) Interconnectivity 2) Centrality 3) Laterality 4) Functional Network 5) Topographical Organization 6) Plasticity 7) Cultural Neutral

What are the 3 principles of interconnectivity?

Association (same hem), Commission (across hem), & projection

Centrality

everything is connected through the CNS

Bilateral anatomic symmetry

Hemispheres are near mirror images

Unilateral function symmetry

Each hemisphere has different functions

Contralateral sensorimotor control

Motor & sensory functions are controlled by opposite sides of the brain

Functional Network

Sensory and motor systems have specialized cells for each function

Topographical Organization

Cells are arranged in the brain according to a body’s spatial organization

Plasticity

Brain changes with experience

Culturally Neutral

Brain function is unaffected by sex, race, brain size, shape or weight

What makes up the CNS? Where is it?

Brain, & Spinal Cord; Inside the skull and vertebrae

What systems make up the PNS?

Somatic & Automatic

How thick is the gray matter that covers the cerebrum?

3-5mm

What are the 6 layers of the neocortex?

1) Molecular layer 2) External Granular layer 3) External Pyramidal layer 4) Internal Granular layer 5) Internal Pyramidal layer 6) Multiform layer

Regarding the brain, Doral (superior) refers to?

Top of the brain

Regarding the brain, Ventral (inferior) refers to?

Bottom of the brain

Regarding the brain, Lateral refers to?

structures away from the midline

Regarding the brain, Rostral (anterior) refers to?

towards the nose, near front of the head

Regarding the brain, Caudal (posterior) refers to?

towards the back of the brain

Regarding the brainstem & spinal cord, Dorsal (posterior) refers to?

toward the back

Regarding the brainstem & spinal cord, Ventral (anterior) refers to?

toward the front or the abdomen

Regarding the brainstem & spinal cord, Rostal refers to?

toward the brain

Regarding the brainstem & spinal cord, Caudal refers to?

toward the end of the spinal cord

Regarding the planes of a brain section, Coronal plane refers to?

cuts front & back

Regarding the planes of a brain section, Sagittal plane refers to?

cuts right & left (Midsagittal = equal halves)

Regarding the planes of a brain section, Horizontal plane refers to?

cuts top & bottom (axial & transverse)

Neurons

Basic Structural and functional unit of the nervous system, designed to communicate signals

The 2 main parts of a neuron are?

Soma & Neurite

The 2 main parts of a Neurite are?

Dendrites (receive) & Axon (transfer)

Soma is?

The cell body of a neuron

Neurite is?

thin tube extending from neural body

What are the parts of an axon? (there are 5)

Hillock (beginning), Proper (middle), terminal (end; that divides into telodendria [terminal bouton]), myelin sheath, Nodes of Ranvier

Neurotransmitters

Chemical substances that cause transfer of info to neighboring cells

Acetylcholine

muscle contraction heart rate

Dopamine

Regulate movement and pleasure

GABA

Inhibits firing of neurons

Glutamate

Excitatory and strengthens neuronal connections

Action Potential

Basic events that nerve cells use to transmit info from one place to another

What 3 factors affect action potential speed of transmission?

1) Diameter of axon (larger=faster) 2) Myelination of axon (more myelin=faster) 3) Length of axon (shorter=faster)

Ganglion

group of neurons outside the CNS (in the PNS)

Nucleus

Group of neurons within the CNS

Tract

group of nerve fibers (axons) within the CNS

Nerve

Group of nerve fibers (axons) outside the CNS (in the PNS)

What are the 3 functional types of neurons?

1) Motor (efferent) 2) Sensory (afferent) 3) Interneurons

Motor (efferent) neurons

carry info from CNS to PNS and cause muscles to contract

Sensory (afferent) neurons

carry sensory info from PNS into the CNS

Interneurons

Lie within the CNS and process info carried by both motor and sensory neurons

What type and direction are messages sent for afferent nerve fibers?

Sensory info from body to the brain (arriving/ascending)

What type and direction are messages sent for efferent nerve fibers?

Motor info messages from CNS to muscles (exiting/descending)

Glial Cells

Support, insulate, and provide nutrition to the brain

What are the parts of a glial cell? (5)

1) Schwann cells 2) Oligodendrocyte 3) Microglial cell 4) Ependymal cell 5) Astrocyte

Neurolia

Neuron Support

Astrocytes

most numerous glial cells, structure support, support blood brain barrier, transport nutrient to neurons, clean up cell debris & scarring after damage, facilitate neurotransmitter re-uptake via endocytosis

Microglia

Digests dead neurons like astrocytes, phagocytic

Ependymal cells

line the fluid-filled spaces of the brain & spinal cord, involved in production of CSF, and help guide cell migration during brain dev

Oligodendrocytes

provide insulation (myelin) to CNS neurons

Schwann Cells

Provide the insulation (myelin) to PNS neurons

Satellite Cells

Physical support to neurons in PNS

What cells respond to injury?

Endoneurium and Schwann cells

What system responses faster to severed nerve cells?

PNS

Neoplasm

(aka glial brain tumor) glial cells out of control and named after type of glial cell involved

• astrocytoma

• gliobastoma multiform

• oligodendroglioma

• ependymomas

What can brain tumor cause?

Aphasia, Dysarthria, Dysphagia, and Cognitive Impairment

Demyelinating Disease

Multiple Sclerosis (MS)

What 3 things protect the CNS?

1) skull and vertebrae 2) Meninges 3) Cerebrospinal Fluid (CSF)

Meninges

Three protective membranes that cover and protect the brain

What are the 3 layers of the meninges? (from outer to inner)

1) Dura mater 2) Arachnoid mater 3) Pia mater [P.A.D.]

Dura mater

Dense, fibrous, outermost layer; 2 layers itself which are Perio steal and Meningeal

Falx cerebri

A dural extension that forms vertical partition between cerebral hemisphere

Tentorium cerebelli

A dural extension between basal surfaces of temporal and occipital and cerebellum

Falx cerebelli

A dural extension between cerebellar hemispheres

Arachnoid mater

A thin membrane between dura and pia layers

Arachnoid granulations

CSF drainage into vascular system

Pia mater

Thin, adheres to surface of brain, follows the contours, highly vascular - carries arteries & veins to neural tissue

Cerebrospinal Fluid (CSF)

Fluid generated by the choroid plexus located in the ventricles, circulates in ventricles and subarachnoid space.

Function: protection, weight reduction, removal of harmful substances & delivery of nutrients

The 3 major divisions of the brain are?

1) cerebrum 2) cerebellum 3) brainstem

Neurulation

Neural plate and neural tube development (week 3-4 of gestation)

Spina Bifida

A neural tube defect that occurs when the spinal cord and surrounding membrane don’t completely close

Anencephaly

A neural tube defect the occurs when a baby is born without parts of the brain and skull

What 2 secondary brain vesicles are in the forebrain?

Telencephalon & Diencephalon

What secondary brain vesicle is in the midbrain?

Mesencephalon

What 2 secondary brain vesicles are in the hindbrain?

Metecephalon & Myelencephalon

What 4 structures are in the Telencephalon?

1) Cerebral Cortex 2) Basal Ganglia 3) Hippocampus 4) Amygdala

What 2 structures are in the Diencephalon?

1) Thalamus & 2) Hypothalamus

What 2 structures are in the Mesencephalon?

1) Tectum & 2) Tegmentum

What 2 structures are in the Metecephalon?

1) Pons & 2) Cerebellum

What is the structure in Myelencephalon?

Medulla

What two secondary brain vesicles are in the Cerebrum?

Telencephalon & diencephalon

What secondary brain vesicle is in cerebellum?

metencephalon

What 3 secondary brain vesicles are in the brainstem?

Mesencephalon, Metecephalon, and Myelencephalon

What are the 3 primary brain vesicles?

Forebrain (Prosencephalon), Midbrain (Mesencephalon), and Hindbrain (Rhombencephalon)

What is the cerebrum involved in?

sensation, abstract thinking, reasoning, planning, higher mental processes such as language

What connected the cerebral hemispheres?

commissural fibers (corpus callossum)

What separates the cerebral hemispheres?

longitudinal fissure

Gray matter

grayish/brownish cell bodies of neurons that process information

White matter

Groups of myelinated axons - white due to myelin sheath that transmit information

What two structures are made of gray matter?

gyri and sulci

Projection fibers (corona radiata)

White matter that transports info to and from cortex to the brainstem/spinal cord

Association fibers (arcuate fasciculus)

White matter that transports info to and from regions of the same hemisphere

Commissural fibers (corpus callossum)

White matter that transports info from one hemisphere to the other

What are the 4 primary lobes of the cerebral cortex?

Frontal, Temporal, Parietal, and Occipital