exam 1

chapters 1-5

What are the main divisions of the CNS?

the brain and spinal cord

What are the regions of the brain?

forebrain, hindbrain, and midbrain

brainstem

controls motor functions ranging from breathing, to balance, and to fine motor skills

hindbrain

located at the lower back part of the brain and contains the cerebellum, reticular formation, pons, and the medulla

cerebellum

“little brain” has more neurons than the brain + spinal cord and is body control and motion memory

reticular formation

netlike mixture of neurons (gray matter) and nerve fibers (white matter)

pons

“bridge” to the cerebellum

medulla

basic body regulatory functions

midbrain

the topmost part of the brainstem that contains the tectum and tegmentum

tectum

sensory input information

tegmentum

motor initiation or movement

diencephalon

located deep within the brain and contains the thalamus, hypothalamus, pineal gland, and the subthalamus

thalamus

relays sensory information to the cortex

hypothalamus

temperature control, sleep, eating, and stress response

forebrain

the most forward portion of the brain that contains the basal ganglia, the limbic system, and the cortex and lobes

basal ganglia

controls motor and control response

limbic system

associated with basic/primitive emotions and drives

hippocampus

memory and learning

amygdala

regulates emotions such as fear and agression

cerebral cortex

the part of the brain that is the most human

neocortex

contains axons, dendrites, and various cerebellar neurons

frontal lobe

executive functioning, planning, conscious thought, and decision making

temporal lobe

facial and emotional processing, language, ductory, and gustory

occipital lobe

visual processing

parietal lobe

directing movements to perform a task

What protects the brain?

the corpus callosum, blood-brain barrier, and the cerebrospinal fluid

corpus callosum

ensures that both sides of the brain can communicate and send signals to each other

blood-brain barrier

tightly packed cells of blood vessel walls prevent entry of many molecules

cerebrospinal fluid (CSF)

cushioning, waste removal, and communication

What are the four parts of the nervous system?

central nervous system, somatic nervous system, autonomic nervous system, and enteric nervous system

central nervous system (CNS)

meditated behavior

afferent

incoming information into the CNS

efferent

incoming information from the CNS

autonomic nervous system (ANS)

involuntary movements and preps the internal organs

What are the two parts of the ANS?

sympathetic division and parasympathetic division

sympathetic division

arousing (fight or flight) which uses energy

parasympathetic divison

calming and relaxation which reserves energy

somatic nervous system (SNS)

voluntary movements and provides information for the CNS

What are two parts of the SNS?

cranial nerves and spinal nerves

cranial nerves

nerves that make up the muscles, joints, and skin

enteric nervous system (ENS)

controls digestion and stomach contractions

What is the function of a neuron?

acquire information → store it as memory → interpret it → pass the information along to other neurons to produce behavior

What are the structures of the neuron?

the cell body, dendrites, axon, and presynaptic terminal

dendrites

gather information from other neurons

dendritic spine

protrusion from a dendrite that greatly increases surface area and is the usual point of contact with axons of other cells

cell body

integrates the information

axon

carries information to be passed to other cells

axon hillock

juncture of the soma and the axon where action potential begins

presynaptic terminal

uses neurotransmitters to transport neurons

What are the three types of neurons?

sensory neurons, interneurons, and motor neurons

sensory neurons

carry information from the sensory receptors in or on the body to the spinal cord (afferent)

bipolar neurons

a sensory neuron that transmits afferent sensory information from the retina's light receptors to neurons that carry information into the brain’s visual centers

interneurons

associate sensory and motor activity within the CNS

motor neurons

send signal from the brain and spinal cord to the muscles (efferent)

glial cell

the nervous system’s support cells

What are the five types of glial cells?

ependymal, astrocyte, microglia, oligodendroglia, and schwann cells

ependymal

makes and secretes cerebrospinal fluid

astrocyte

keep neurons healthy and heals if injured

microglia

originates in the blood, aids in cell repair, and scavenges debris in nervous system

oligodendroglia

cells in the CNS that myelinate axons

schwann cells

cells in the PNS that myelinate axons

How does the cell membrane act as a barrier and a gatekeeper?

by separating intercellular and extracellular fluid, regulating movement of substance into and out of the cell, and regulating the differing concentrations of salts and other chemicals on its inside and outside

How is the electrical activity of a neuron generated?

neurons convey information as a wave and those waves send ions down a voltage gradient from an area of higher charge to an area of lower charge

action potential

rapid rise and subsequent fall in voltage of membrane potential across a cellular membrane with characteristic patters

neuron, axon

_____ reaches the threshold to start the action potential down the _____ .

Na+ channels, Na+ rushes

___ _____ open and __ _____ out

close

Na+ channels _____.

K+ channels, K+ rushes

__ _____ open and __ _____ out.

Na+, K+, on

__/__ pumps turn ___.

resting membrane potential

electrical charge across the cell membrane in the absence of stimulation

Why does the electrical gradient maintain resting potential?

because the membrane is relatively impermeable to large molecules they negatively charged proteins remain inside the cell

How does the concentration gradient use channels and gates to maintain resting potential?

ungated potassium and chloride channels allow potassium and chloride ions to pass freely, but gates on sodium channels keep out positively charged sodium ions

How does the pumps maintain resting potential?

Na+--K+ pumps extrude Na+ from the intracellular fluid and inject K+

excitatory postsynaptic potential

brief depolarization of a neuron membrane in response to stimulation

inhibitory postsynaptic potential

brief hyperpolarization of a neuron membrane in response to a stimulation

How do neurons communicate?

a chemical message via neurotransmitters

neurotransmitter

chemical released by a neuron onto a target with an excitatory or inhibitory effect

synapse

the junction where the messenger molecules are released from one neuron to excite or inhibit the next neuron

presynaptic membrane (axon terminal)

where the action potential terminates to release a chemical message

postsynaptic membrane (dendritic spine)

the receiving side of the chemical message where EPSPs or IPSPs are generated

synaptic cleft

small gap where the chemical message travels from the presynaptic membrane to the post synaptic membrane

synaptic vesicles (presynaptic)

small membrane-bound sphere that contains one or more neurotransmitters

What are the four classes of neurotransmitters?

small-molecule transmitters, peptide transmitters, lipid transmitters, and gaseous transmitters

small-molecule transmitters

class of quick acting neurotransmitters

peptide transmitters

hormones that respond to stress, oxytocin, regulate eating and drinking, and contribute to learning

lipid transmitters

synthesized “on demand” when an action potential reaches the axon terminal

endocannabinoids

lipophilic (fat loving) molecules associated with appetite, pain-sensation, mood, and memory

gaseous transmitters

synthesized cells as needed to easily cross the cell membrane

What are the four activating systems of the CNS?

cholinergic, noradrenergic, dopaminergic, and serotonergic

cholinergic activating system

normal walk behavior and is thought to function in attention and memory

noradrenergic activating system

plays a role in learning by stimulation neurons to change structure

dopaminergic activating system

plays a role in motor movements and behavior

serotonergic activating system

plays a role in wakefulness and learning

depolarization

decrease in electrical charge across a membrane (more positive)

diffusion

movement of ions from one area of high concentration to an area of lower concentration

electrical stimulation

passing an electric current from one uninsulated tip to produce behavior

GABA

main inhibitory transmitter

hyperpolarization

increase in the electrical charge across a membrane (more negative)

myelin

insulating sheath around nerve fibers

nerve

signals that travel to and from the brain via neurons