Chapter 2 Flashcards
What system controls everything you do?
Nervous
What organ is important for balance, coordination, and sports?
Cerebellum
What do neurons do?
Cells which receive information from and transmit information to other cells
Glia cells are responsible for?
exchange chemicals with adjacent neurons
do not transfer information over long distances
What did Santiago Ramon Cajal do?
discovered the synapse. stated that cells do not grow into each other they remain separate.
What separates the inside of the cell from the outside of the cell?
Plasma Membrane
What does the nucleus do?
structure that contains the chromosomes. The brain of the cell
What is known as the powerhouse of the cell, performs metabolic activities?
Mitochondrion
Ribosomes are part of the cell that?
synthesize new proteins
What part of the cell transports newly synthesized proteins to their locations
(ER) Endoplasmic Reticulum
What receives excitation from other neurons and conducts impulses to muscle or gland cells?
Motor neuron
What does the sensory neuron do?
Specialized to detect a particular type of stimulation highly sensitive. e.g. light,taste, touch
The tree-like branches of a neuron that receive information from other neurons are called
(increase Surface Area)
Dendrites
The information sender of the neuron, conveying an impulse toward either other neurons or a gland or muscle is called the
Axon
What is the cell body known for?
Contains the nucleus,ribosome,mitochondria. and some of the metabolic work is down here.
the insulating material which covers many vertebrate axons is called the
Myelin Sheath
one of the most distinctive features of neurons compared to the other types of cells is their
Shape
Define Node of Ranvier
Short unmyelinated section of axon between segements of myelin
what is the point from which an axon releases chemicals into the synapse?
presynaptic terminal
Afferent means?
A=admit. brings information into the structure
Efferent means?
E= exit. sends information away from the structure
axons and dendrites are all contained within one structure to form
interneuron
What does the astrocyte do?
enable the axon to send messages in waves, helps to synchronize activity
What removes waste material, viruses, fungi?
acts like an immune system
Microglia
What type of glial cells myelinate axons in the brain and spinal cord?
Oligodendrocytes
Which type of glia builds myelin sheaths around axons in the periphery of the body?
Schwann cells
What does the radial glia do?
guide the migration of neurons during embryonic development
What are the advantages and disadvantages of the blood brain barrier? (surrounds the brain)
Advantage- keeps out most viruses, bacteria, and harmful chemicals
disadvantages- keeps out most nutrients and medications but blocks chemo
What can cross through the endothelial cells?
Carbon dioxide, oxygen, water
How does glucose enter the brain?
Process that expends energy to pump chemicals from the blood?
active transport
What is korsakoff’s syndrome?
Thiamine deficiency leads to death of neurons a result of chronic alcoholism marked by severe memory loss
How are nerve impulses transmitted?
the impulse is regenerated at points along the axon so it does no weaken.
when you state that the neurons membrane is polarized, you are referring to a difference in electrical potential between
the insides and the outside of the membrane
what is the approximate resting potential of the inside of a nerurons membrane, relative to the outside
- 70 millivolts
When a neuron’s membrane is at rest, which of the following molecules crosses through it MOST slowly?
sodium
Whn a neurons membrane is at rest, the concentration gradient tends to move sodium ???? the cell and the electrical gradient tends to move it ??? the cell
into,into
when a neurons membrane is at rest, the concentration gradient tends to move potassium ???? the cell and the electrical gradient tends to move it ??? the cell
out of, into
When the neuron is at rest, what is responsible for moving potassium ions OUT of the cell?
the concentration gradient
When the neuron is at rest, what is responsible for moving sodium ions out of the cell?
sodium potassium pump
What is the result if a stimulus shifts the potential inside a neuron from the resting potential to a more negative potential?
hyperpolarization
what is the result if a stimulus shifts the potential inside a neuron from the resting potential to a potential slightly closer to zero?
depolarization
What is the all or none law?
The amplitude and velocity of an action potential are independent of the intensity of the stimulus that initiated
Where do most action potentials begin?
at the axon hillock
what is to prevent an action potential from exciting the area behind it and starting a rebound action potential traveling the opposite direction?
the refractory period
What disease is related to the destruction of myelin sheaths?
multiple sclerosis
under what conditions is it impossible for a stimulus to produce an action potential
if the membrane is in its absolute refractory period
