Chapter 3 - Biological Foundations of Behavior Flashcards
What is retinal and its purpose in polarizing photoreceptors?
It is a molecule derived from vitamin A in rods and cones that changes to an all-trans form when a photon of light is absorbed. The new form triggers the closing of Na+ channels, hyperpolarizing the cells.
Define presbyopia.
the inability to focus because of the loss of lens flexibility (with aging)
What are astrocytes?
glial cells in the CNS that regulate development and neurotransmitter levels
Which lobe is involved in touch and taste sensations?
parietal lobe
What are two major functions of the medulla?
It regulates vital autonomic functions and respiratory rhythmicity.
Which photoreceptors are responsible for color vision and acuity?
cones
What is spatial summation?
EPSPs (excitatory) and IPSPs (inhibitory) from all synapses at a postsynaptic membrane are summed, and based on that total will cause depolarization or hyperpolarization.
What is visual parallel processing?
Many aspects of a visual stimulus (form, motion, color, and depth) are processed simultaneously.
What are interoreceptors?
They detect stimuli from the internal environment of the body.
Which lobe is involved in voluntary movement, reasoning skills, and problem solving?
frontal lobe
With what kind of lens would farsightedness be corrected?
convex (converging)
What is temporal summation?
A presynaptic neuron fires action potential so frequently that EPSPs (excitatory) or IPSPs (inhibitory) have an additive effect and can cause depolarization or hyperpolarization in the postsynaptic cell.
What is the blood supply called in the endocrine control center of the brain?
hypothalamic-pituitary portal system
What is the endocrine control center in the brain?
hypothalamus-pituitary control axis
What is the adenohypophysis?
anterior pituitary
How is sound volume measured?
by the amplitude of its waves (larger waves cause more frequent action potentials)
What is gestalt theory and its relation to perception??
The whole exceeds the sum of its parts. Humans perceive an object, rather than all the little parts that make up the object.
Since neuronal repolarization actually hyperpolarizes, how does the membrane get back to resting potential?
After hyperpolarization, voltage-gated K+ channels close. K+ leak channels and the Na+/K+ ATPase pump continue to function.
Where are steroid hormones syntheszed and from what?
in the smooth ER from cholesterol
What is the neurohypophysis?
posterior pituitary
What is negative feedback?
inhibitory feedback (the presence of something inhibits the action the caused it)
What is a bipolar neuron?
a neuron that has only one dendrite
Where are peptide hormones synthesized and from what?
in the rough ER from amino acids
What is a chemical synapse?
An action potential is converted into a chemical signal