PSYC Week 5 Flashcards
Differentiate the functional roles between the two main cell classes in the brain, neurons and glia.
Neuron
-nerve cells
-dendrite: main input to the neuron
-soma: cell body, contains nucleus/genetic information
-axon: carries action potential to another neuron
-synapse: place where the axon comes to close to another neurons dendrite
-terminal button: end of axon that forms synapse with post-synaptic dendrite
-synaptic vessels: package neurotransmitters
Glia
-form myelin sheath
-digest dead neurons
-nutritional support from blood vessels to neurons
-regulate ionic composition of extracellular fluid
Describe how the forces of diffusion and electrostatic pressure work collectively to facilitate electrochemical communication.
maintain steady state of cell
-electrostatic pressure: force on two ions with same charge to repel, or different charges to attract
-have no effect on anions because they are impermeable to cell membrane
-potassium(K+): high concentration in the cell, diffusion pushes them out of the cell and electrostatic pressure pushes K+ into the cell because its attracted to negative charge of the cell
-chloride(Cl-): high concentration out the cell because of electrostatic pressure (opposite K-)
-sodium potassium pump: both forces push Na+ into cell but its impermeable, the ion channel which uses ATP from the neuron to pump 3 Na+ ions out the cell in exchange for bringing in 2 K+ ions
Define resting membrane potential, excitatory postsynaptic potentials, inhibitory postsynaptic potentials, and action potentials.
Resting membrane potential
- The voltage inside the cell relative to the voltage outside the cell while the cell is at rest (approximately -70 mV).
Excitatory postsynaptic potentials
- A depolarizing postsynaptic current that causes the membrane potential to become more positive and move towards the threshold of excitation.
Inhibitory postsynaptic potentials
- A hyperpolarizing postsynaptic current that causes the membrane potential to become more negative and move away from the threshold of excitation.
Action potential
- A transient all-or-nothing electrical current that is conducted down the axon when the membrane potential reaches the threshold of excitation.
Explain features of axonal and synaptic communication in neurons.
-when a cell becomes depolarized voltage dependent Na+ channels open causing Na+ to rush into the cell making the inside of the cell more positive, Na+ channels then close and refractory period occurs and a new action potential cannot occur until the cell returns to resting membrane potential, K+ channels open up and K+ is driven out of the cell (which causes cell to return to resting membrane potential), very rapid
Axon
Part of the neuron that extends off the soma, splitting several times to connect with other neurons; main output of the neuron.
Synapse
Junction between the presynaptic terminal button of one neuron and the dendrite, axon, or soma of another postsynaptic neuron.
Electrostatic pressure
The force on two ions with similar charge to repel each other; the force of two ions with opposite charge to attract to one another.
Sodium-potassium pump
An ion channel that uses the neuron’s energy (adenosine triphosphate, ATP) to pump three Na+ ions outside the cell in exchange for bringing two K+ ions inside the cell.
Synaptic gap
Also known as the synaptic cleft; the small space between the presynaptic terminal button and the postsynaptic dendritic spine, axon, or soma.
Synaptic vesicles
Groups of neurotransmitters packaged together and located within the terminal button.
Define the basic terminology and basic principles of hormone–behavior interactions.
-hormones: organic chemical messengers produced and released by endocrine glands
-target cells: cells with specific receptors for hormones
-hormones can mediated long term developments like growth, development, and reproduction
Explain the role of hormones in behavioral sex differentiation.
-testosterone: primary androgen (group of hormones that play a role in male traits and reproductive activity) found in mens testes
-typically female behaviour requires a lack of exposure to androgens in early life
-gondal sex: determined by ovaries and testes
Explain the role of hormones in aggressive behavior.
-evidence that androgenic steroid hormones mediate aggressive behaviour across many species
-higher blood concentration of androgens could be an explanation as to why men are more aggressive
Explain the role of hormones in parental behavior.
-progesterone: involved in pregnancy and mating behaviours
-parental behaviour is caused by hormones
-woman with high cortisol levels before nursing engaged in more talking and physically affectionate behaviours with their babies
Provide examples of some common hormone–behavior interactions.
behavior interactions -the mediation of food and fluid intake
social interactions– salt balance, learning and memory, stress coping, as well as psychopathology including depression, anxiety disorders, eating disorders, postpartum depression, and seasonal depression
