Week 5 Flashcards
What did Ramón y Cajal conclude
that discrete individual neurons are the structural and functional units of the nervous system
What does the Nissl stain label
The main part of the cell
What does the Golgi stain, stain?
only stains approximately 1–2% of neurons, this allows the interpreter to distinguish between one cell from another
Resting Membrane Potential?
describes what occurs in a neuron at rest, when it is theoretically not receiving or sending signals
what are the similarities between intracellular, and extracellular, resting membrane potential?
both fluids are composed of ions (electrically charged molecules). this composition is made of sodium (Na+), potassium (K+), Chloride (Cl-) and anions (A-)
Are cations positively charged ions or negative
positive
Are anions positively charged ions or negative
negative
how many neurons in the brain approx.?
100 billion
what are the 3 main components of a neuron
dendrites, somas, axons
What does a dendrite look like and what does it do
stems out of the soma, and norm. branches out several times. receives info from other neurons, main source of input for the neuron
What does the soma contain and do
contains the nucleus and supports the chemical balancing of the neuron
what does the nucleus do
contains genetic info, directs protein synthesis, supllies the energy and the resources the neuron needs to function
what does axon look like and do
stems away from the soma, carries important signal called the action potential to other neurons
What are axons covered in
myelin sheath
What is the myelin sheath purpose
allows the signal and communication of one neuron to travel quickly to another neuron.
What are nodes of ranvier and how does it interact with action potential
gaps in the myelin sheath, action potentil jumps from node to node
What is saltatory conduction
when the action potential jumps from node to node of the nodes of ranvier in the myelin sheath
Where is the terminal button located
at the end of an axon, it forms synapses with spines/protrusions on the dendrites of other neurons
What are synapses. Where do they form
where the axon comes in contact with a dendrite of another neuron. form between the presynaptic terminal button and the postsynaptic membrane
What is the synaptic gap?
tiny space between presynaptic terminal button and the postsynaptic dendritic spine.
what do neurotransmitters do and from where do they do it
carry chemical messages. they leave the presynaptic terminal button, travel thru the synaptic gap, and activate ion channels on the postsynaptic spine
3 diff types of neurons
motor neurons, sensory neurons, interneurons
what do motor neurons do?
are about initiating and allowing actions and behavior
sensory neurons?
are about our personal experiences and how we receive info from the world around us
interneurons
process the info around us: takes info from the sensory neurons, processes it to come up with the appropriate response, and then conveys the message to the motor neurons to act upon it
what are unipolar neurons made up of?
one axon, no dendrites
what do unipolar neurons do?
involved with transmission of physiological information from the body’s periphery such as communicating body temperature through the spinal cord up to the brain
what are bipolar neurons made up of
one axon and one dendrite
what do bipolar neurons do?
invovled in sensory perception, such as perception of light in the retina of they eye
what are multipolar neurons made up of
one axon and many dendrites, so as to be able to communicate with many neurons
what do multipolar neurons do
communicate sensory and motor information in the brain, and they’re the most common neuron
What do Oligodendroglia cells do
wrap their dendritic processes around the axons of neurons many times to form the myelin sheath.
whats a difference between glia cells and neurons
glia cells dont participate in communication between cells the same way neurons do
what is the cell membrane made of
a lipid bilayer of fat molecules
What is diffusion
the force on molecules to move from areas of high concentration to areas of low concentration
What is electrostatic pressure?
the force on 2 ions with similar charge to repel each other and the force of 2 ions with opposite charge to attract to one another (opposites attract)
What is electrostatic pressure?
the force on 2 ions with similar charge to repel each other and the force of 2 ions with opposite charge to attract to one another (opposites attract)
Equilibrium potential
the voltage at which no ions flow
Resting membrane potential
The voltage inside the cell relative to the voltage outside the cell while the cell is a rest. approx -70mV
What can be explained by all-or-nothing theory?
action potential, it either happens or it doesnt
What is the threshold of excitation
specific membrane potential that the neuron must reach to initiate an action potential. If it’s reached then action potential occurs
What are ionotropic receptors?
ion channels that opens to allow ions to permeate the cell membrane under specific conditions, such as the presence of a neurotransmitter or a specific membrane potential
communications within a neuron is what
electrical
communications between neurons is what
chemical
what do hormones affect
behaviour
what are hormones and what do they do?
an organic chemical messenger released from endocrine cells that travels through the blood to interact with target cells at some distance to cause a biological response
What are endocrine glands purpose
to release hormones into the blood system in response to specific biological signals
What are hormones that influence behaviour?
steroid hormones such as testosterone, estradiol, progesterone, cortisol
What do estradiol and testosterone cause to gametes?
maturation of eggs or sperm and promote mating behaviour
Neuroendocrinology
the study of how the nervous system and the endocrine system are interrelated
What are target cells?
a cell that has receptors for a specfic chemical messenger (hormone or neurotransmitter)
What are the 3 interacting components in humans for internal systems of the brain
sensory/input systems, integrators/central nervous system, output/effectors systems (like muscles)
Gonadal sex
The sex of an individual as determined by the possession of either ovaries or testes. Females have ovaries, whereas males have testes.
Chromosomal sex
The sex of an individual as determined by the sex chromosomes (typically XX or XY) received at the time of fertilization.
What are aggressive behaviours organized by
androgens
What are parental behaviours?
Behaviors performed in relation to one’s offspring that contributes directly to the survival of those offspring
What is progesterone?
A primary progestin that is involved in pregnancy and mating behaviors
What happens when a target cell is activated by a hormone
proteins activate or deactivate other genes
Psychopharmacology
the study of how drugs affect the brain and behavior — a relatively new science
at a basic level, what will a drug do to you
alter how neurons communicate with each other
What are agonists?
a drug that increases or enhances a neurotransmitters effect
antagonists
a drug that blocks a neurotransmiters effect
What is ADME
absorption, distribution, metabolism, excretion
What is metabolism
breakdown of substances (such as psychoactive drugs) happens primarily in the liver
What is enzyme induction?
an increase in the enzymes produced in the liver
