biology unit 2 exam Flashcards
The place where two neurons meet, or a neuron meets another cell
Synapse
What is the role of the interneuron in the reflex are described in the narrative?
To connect the sensory and motor neurons
Which of the following are true about reflexes?
Respond to stimuli more quickly than voluntary
Reflexes are involuntary
Reflex processing does not require the brain
Single EPSPs are enough to trigger the rising phase of an action potential
False
The ______, the input zone of the neuron, may be the site of the generation of an action potential
Dendrites
Which of the following best describes the trigger zone after an EPSP has been received?
The trigger zone depolarized
During the resting potential, the outside of a nerve cell is _____ charged compared to inside
Positively
During the action potential, the outside of the nerve cell is _______ charged with respect to the inside
Negatively
After repolarization, the outside of the nerve cell is _______ charged with respect to the inside
Positively
Release by presynaptic neurons depolarizes a postsynaptic neurons axon hillock, producing an EPSP that depolarizes the neurons axon hillock
Neurotransmitter
Called Schwann cells form the insulating myelin sheath around axons
Glial cells
An example of a synapse could be the site where….
Neurotransmitters released by an axon travel across a gap and are picked up by receptors on a muscle cell
The resting membrane potential in neurons requires ….
The diffusion of K+ out of the cell and a charge separation between the inside and outside of the axon set up by this movement of K+
The major role of the Na+ and K+ pump is to
Maintain the resting membrane potential at a constant negative value
In the propagation of an action potential
The refractory period begins as the K + channel opens, allowing K+ ions to flow outward along their concentration gradient
Which of the following does not contribute to propagation of action potentials
Each segment of the axon prevents the adjacent segments from firing
It transmits the action potential at the nodes of ranvier and thus speeds up the action potentials on myelinated axons
Saltatory conduction
transmission of a neural signal to its target cell requires…
An action potential to open the Ca 2+ gates so that Ca2+ ions, in higher concentration outside the axon, can flow back into the cytoplasm of the neuron
How does activating metabotropic receptors differ from activating ionotropic receptors?
Activating metabotropic receptors prices longer lasting effects on postsynaptic neurons
Which of the following are part of the central nervous system?
Central nervous system and spinal cord
Which of the following best describes the role of the autonomic nerves in the body?
Control of involuntary functions including the cardiac muscles and glands
The “fight or flight” response occurs when which group of neurons is activated?
The sympathetic neurons
Which neural circuit motif regulates the overall level of excitation?
Feedforward excitation
The hindbrain subdivides and eventually gives rise to the
Cerebellum
The autonomic nervous system is subdivided into:
Sympathetic and parasympathetic divisions
People with severe insect-sting allergies carry an epipen, an auto injector containing medication that they can use in an emergency. The medication causes smooth muscles in the lung passages to relax so they can breathe, but causes ts to pound rapidly. This is an example of stimulation of the:
Sympathetic system
The blood brain barrier reduces blood supply to brain cells compared with other body cells
False
Which one of the following structures participates in a reflex?
Gray matter in spinal cord
Brain stem neurons that release serotonin and norepinephrine…
Modulate the excitatory of neurons in the forebrain
Cushioning and nourishing the brain and spinal cord and fitting the ventricles of the brain are
Cerebrospinal fluid
Which structure and function are correctly paired below
Hypothalamus- releases hormones, sets up daily rhythms
A patient had a tumor in wernicke’s area. It was initially diagnosed when the patient could not
Understand the morning newspaper
The ______ is 5e innermost layer of the human eye
Retina
Where in the eye are most of the blood vessels found?
In the choroid layer
Where in the eye is the aqueous humor located?
In the anterior chamber, near the front of the eye
What do all sensory receptor proteins have in common?
They produce a change in membrane potential when activated
You notice an odor when you walk into a room but soon stop smelling it, even though someone else smells it when they walk into the room. This response is due to…
Sensory adaptation
Which two senses make use of mechanoreceptor proteins?
Hearing and somatosensation
What are two uses of hair cells in vertebrates?
Hearing and maintaining balance
Structures in the vertebrates ear are activated by sound waves in the following order:
Pinna, tympanic membrane, malleus, incus, stapes, oval window, cochlear duct
The eyes of vertebrates and cephalopods are similar in structure and function. A difference between the vertebrate eye and the cephalopod eye is that the vertebrate eye has:
A lens that changes shape when focusing, whereas in cephalopods the lens move back and forth to focus
Which of the following events does not occur during light absorption in the vertebrate eye?
As light absorption increases, the rhodopsin response causes an increase in the release of neurotransmitters
The variety of color seen by humans is directly dependent on the
Activation of three different opsins in cones
Which sense involves the greatest number of different receptor proteins in terrestrial animals?
Olfaction
The human perception of pain
Is activated by mechanoreceptors, thermoreceptors, and chemoreceptors
Which of the following describes the action that occurs during muscle contraction?
Thin filaments slide over thick filaments
Which two muscle components interact during muscle contraction?
Actin and myosin heads
The specialized structures that allow skeletal muscle contraction are called ______, which contain repeating contractile units called______
Myofibrils, sacromeres
May rotate one body part with respect to another
Vertebrate skeletal muscle
In muscle fiber in a completely relaxed state:
Dark A bands contain overlapping thick and thin filaments with central thin H zone composed only of thick filaments
The sliding filament contractile mechanism
Causes thin filaments on each side of a sacromere to slide over thick filaments toward the center of the A band, bringing the Z lines closer together
During contractile of skeletal muscle
Action potentials cause the release of Ca 2+ which binds to troponin causing one and uncover the binding sites on actin and myosin
When marathoners are running a race, most likely their
Slow muscle fibers will do most of the work for the run
Which description is characteristic of a motor unit?
When receiving an action potential, a motor unit is controlled by a single efferent axon that causes all its fibers to contract
Which of the following is not an example of a hydrostatic skeletal structure?
The mantle of squids
Protect internal organs and provide structures against which force of muscle contraction can work
Endoskeletons
Connecting the bones of the vertebrate skeleton are…
Synovial joints lubricated by synovial fluid
The movement of vertebrate muscles is
Antagonistic when it causes movements in the joint
