AP Biology › Understanding Other Neural Physiology
Signals travel through a neuron as __________, and travel from neuron to neuron as __________.
an electrical signal using atomic ions . . . a chemical signal using neurotransmitters
a chemical signal using neurotransmitters . . . an electrical signal using charged proteins
an electrical signal using atomic ions . . . a chemical signal using hormones
a chemical signal using hormones . . . an electrical signal using neurotransmitters
An electrical signal via charged proteins . . . a chemical signal using neurotransmitters
Neurotransmitters and hormones are both chemical signals, but hormones are used in the endocrine system, released from glands into the blood, while neurotransmitters are released from the axon terminals of neurons to signal other neurons. Signals travel across neurons as electrical signals caused by the movement of large numbers of atomic ions across the membrane via protein channels. Charged proteins would be too large to quickly move through the channels in such large numbers.
Which term is used to describe movement of an organism toward a light source?
Positive phototaxis
Positive chemotaxis
Negative thermotaxis
Negative chemotaxis
Negative phototaxis
Phototaxis is movement (taxis) in response to light (photo). Movement towards a source is positive; movement away from a source is negative. "Positive phototaxis" would be used to describe movement toward a light source.
Which of the following may result from damage to the front lobe?
Impairment of speech
Auditory impairment
Numbness in the extremities
Visual impairment
Spastic muscle activity
The brain is often divided into four lobes based on anatomy and physiology: the frontal lobe, parietal lobe, occipital lobe, and temporal lobe. Each lobe controls various aspects of cognition and motor skills. The frontal lobe is associated with reasoning, speech, movement, and emotions. The parietal lobe is associated with orientation and recognition. The occipital lobe is associated with visual processing. The temporal lobe is associated with auditory processing and memory.
Broca's area is a small region of the frontal lobe located in the left hemisphere. This region of the brain is responsible for generating speech and articulation. Damage to this region of the frontal lobe could cause speech impairment. In contrast, Wernicke's area is located in the temporal lobe and is associated with comprehension of speech.
Spastic muscle activity is not related to the brain, but results from injury to motor neurons spanning from the spinal cord to the limbs.
What occurs at a synapse?
A neuron communicates with its target cell via electrical or chemical stimulation
A neuron releases hormones into the blood stream
Nothing; synapses are layers of protection for neurons
Proteins on the axon of one neuron interface with proteins on dendrites of another
Synapses are special regions where a neuron releases a signal to its target cell. Most commonly this signal is chemical (neurotransmitters), but it can also be electrical. The synapse is a gap between the neurons, and does not allow for direct contact. Signals are released from the axon of one neuron and must traverse the synaptic cleft before interfacing with receptors on the target cell.
Neurons do not directly release hormones into the blood stream and synapses do not offer protection to neurons.
Which statement is not true about glia?
Glial cells receive action potentials from dendrites
Glial cells are not neurons
Glial cells supply oxygen and nutrients to neurons
Glial cells insulate neurons from each other
Glia help clear neurotransmitters from the synaptic cleft
Glial cells are non-neuronal cells that support neuron activity. Their functions include physical support of neurons, supply oxygen and nutrients, and take up excess neurotransmitters.