Bio Sci 37 Midterm 1

What happens when a neuron's membrane depolarizes?

Neuron's membrane voltage becomes more positive

Where are neurotransmitter receptors located?

On the postsynaptic membrane

Neurons rely of glial cells for...

Protection, Metabolic support,

Insulation

In a myelinated axon, action potentials are regenerated at gaps in the myelin known as

nodes of Ranvier

A long strand made up of thousands of neurons is a

nerve

Due to their structure and function _______ are not able to divide

neurons

The primary immune response in CNS comes from the action of...

microglia

The Na+/K+ pump helps to maintain ________________ by moving three Na+ ions out of and two K+ into the cell

resting membrane potential

Neural transmission is generally ___________ within a single neuron and ___________ between neurons

electrical; chemical

Which channels set the resting membrane potential in neurons?

Sodium/Potassium ATPase and potassium leak channel

________ is a birth defect where a baby's head and brain is smaller/less developed than expected

microcephaly

The brain and spinal cord are part of the ______ nervous system

central

Nerves and ganglia are part of the ________ nervous system

peripheral

Vertebrates have 2 clumps of nerves: the _______ and ________ clumps

dorsal; ventral

The ________ vertebrae have 8 segments that innervate the back of head, neck, shoulders and arms

cervical

The _________ vertebrae have 12 segments that innervate thorax and upper abdomen

thoracic

The _________ vertebrae have 5 segments that innervate pelvic girdle and legs

lumbar

The ______________ have 5 segments innervating the urogenital and perianal structures and back of legs

sacral regions

Region of skin that innervates the spinal cord and

appears as horizontal slices across the body is called the

dermatome

The cranial and spinal nerves originate in the ___________

medulla

Spinal cord attached to brain at

rostral end

___________ characterized by complete paralysis of voluntary muscles in all parts of body but those that control eye movement

May result from traumatic brain injury, stroke, destruction of myelin sheath, or medication overdose

Locked-In Syndrome

Cells in brain capillaries form the __________ which stops infections/toxins from reaching the brain

blood brain barrier

Central canal of spinal cord and brain ventricles are filled with

cerebrospinal fluid

Difficult for molecules to diffuse across ________ cells due to size

eukaryotic

____________ studded with ribosomes

rough endoplasmic reticulum

_____________ synthesize proteins

ribosomes

New proteins are folded and processed in ________

lumen

______________ has no ribosomes

smooth endoplasmic reticulum

SER enzymes synthesize __________

fatty acids

The ____________ has a series of stacked flat membranous sacs called cisternae

golgi apparatus

__________ are used for digestion and waste processing

lysosomes

The ________ produces ATP

mitochondria

The _________ gives the cell shape and stability

cytoskeleton

The ____________ allows passage of oxygen, nutrients and waste to service volume of all cells

plasma membrane

__________ conduct electrical signals to trigger movement

neurons

Plasma membranes carry voltage (___________) from differences in concentrations of ions on inner and outer surfaces

membrane potential

Most neurons have _________ that receive electrical signals from other neurons

dendrites

Axon joins cell body at __________

axon hillock

Synaptic terminal of axon passes info across synapse with __________

neurotransmitters

_________ are located in skin, eyes, ears, and nose and transmit streams of data about environment through sensory neurons

sensory receptors

Sensory cells monitor conditions important in ___________

homeostasis

Plasma membranes of neurons have__________ and receptors that let specific charged ions across plasma membrane

protein channels

A _________ is a difference in charge between any two points that creates electrical potential (voltage)

membrane potential

_________ imports K+ and exports Na+

Na+/K+ - ATPase

___________ support neurons and

form the blood brain barrier

astrocytes

________ cells promote circulation of cerebrospinal fluids

ependymal

__________ protect the nervous system from microorganism

microglia

_________ form myelin sheaths around axons of many vertebrate neurons

oligodendrocytes

______________ are a result of uncontrolled cell division, creating a mass of cells

brain tumors

Primary brain tumors are ________ or _________

gliomas; meningiomas

An ________ is a nerve impulse or signal that carries along axon

action potential

Ion _______ and ion ________ maintain the resting potential of a neuron

pumps; channels

_________ occurs when the membrane potential is not sending signals

resting potential

The __________ allows K+ ions in when neuron is not transmitting electrical signal

K+ Leak Channel

The __________ actively transports Na out and K in

Na/K Pump

Neurons have _________ that open or close in response to stimuli

voltage-gated ion channels

The ____________ is important for restoring membrane potential following depolarization

Voltage-Gated Potassium Channel

The ______________ is important for depolarizing membrane during action potentials

and opens rapidly allowing influx of sodium

Voltage-Gated Sodium Channel

The _________ opens when membrane depolarizes and lets calcium flow into cell and is important for synaptic release

Voltage-Gated Calcium Channels

__________ occurs when gated Na+ channels open,

sodium diffuses into cell, and membrane potential becomes less negative

depolarization

After action potential, second action potential cannot start as a result of temporary inactivation of Na+ channels, called __________

refractory period

The greater the ______________, the greater the conduction speed of an action potential

axon diameter

In _____________, action potentials in myelinated axons jump between nodes of Ranvier

saltatory conduction

In _________________, electrical current flows from one neuron to another at electrical synapses

neuronal communication

Neurotransmitters diffuse across the

synaptic cleft

Chemical neurotransmitters carry information across gap junction at

chemical synapse

In chemical synapse, action potential arrives at ____________ and depolarizes membrane

synaptic terminal

Direct synaptic transmission involves binding of neurotransmitters to _______________________ in postsynaptic membrane

ligand-gated ion channels

Neurotransmitter binding causes ion channels to open and generates

postsynaptic potential

Neurotransmitter after release may:

diffuse out of synaptic cleft, be taken up by surrounding cells, or be degraded by enzymes

Five major classes of neurotransmitters:

Acetylcholine

Biogneic amines

Amino acids

Neuropeptides

Gases

____________ binds to receptors on ligand-gated channels to produce excitatory postsynaptic potentials

acetylcholine

_____________ are derived from amino acids (Serotonin, Dopamine, Epinephrine, Norepinephrine)

and affect sleep, mood, attention, learning, and memory

biogenic amines

_____________ is synthesized from amino acid tryptophan

serotonin

Excitatory pathways use _________ which is crucial for learning and memory

glutamate

________ is the main inhibitory neurotransmitter

GABA

____________ consists of neuron cell bodies, dendrites, and unmyelinated axons

gray matter

______________ consists of bundles of myelinated axons

white matter

The __________ is a part of the brainstem and a center for receipt and integration of sensory information

midbrain

The __________ is a part of the brainstem and regulates breathing centers in medulla

pons

The __________ is a part of the brainstem and a center for several function

medulla oblongata

The ___________ is important for coordination and error checking during motor, perceptual, and cognitive functions and involved in learning/remembering motor control

cerebellum

The __________ is the main input for sensory information to cerebrum/output center for motor information leaving cerebrum

thalamus

The __________ regulates homeostasis/basic survival behaviors

hypothalamus

The _________ is composed of right/left cerebral hemispheres and is the

largest/most complex brain structure

cerebrum

Hemispheres of cerebrum connected by ___________ , a thick band of axons that provides communication between right and left cortices

Corpus callosum

Each side of cerebral cortex has four lobes:

Frontal

Temporal

Occipital

Parietal

Neurons are distributed based on the body part that generates sensory input or receives motor input in

somatosensory and motor cortices

The __________ hemisphere controls language, math, logic, and processing in serial sequences

left

The __________ hemisphere controls recognition, nonverbal thinking, and emotional processing

right

___________ are generated by limbic system and other parts of brain including sensory areas

emotions

The _____________ is a ring of structures around brainstem that includes amygdala, hippocampus, and parts of thalamus

limbic system

The _________ is in the temporal lobe and stores emotional experience as emotional memory

amygdala

____________ is an emergent property of brain based activity in many areas of cortex

consciousness

________________ occurs when neurons make new connections or when strength of existing neural connections changes

memory and learning

______________ is accessed via hippocampus and allows for recall for few seconds

short-term memory

Hippocampus plays a role in

long-term memory

LTM is stored in cerebral cortex and divided into explicit (_______) and implicit (________) memories

declarative; procedural

____________ memory consists of facts taken independent of context and allows encoding of abstract knowledge about world

semantic