nerves and muscles

Question 1

Describe the basic nervous system response, from stimulus to response

Answer 1

The basic nervous system response involves a stimulus triggering sensory receptors, which send signals to the central nervous system, leading to a response through motor neurons.

Question 2

Describe the main parts of a neuron and the direction of information flow

Answer 2

The main parts of a neuron include the cell body, dendrites, and axon. Information flows from dendrites to the cell body and then down the axon.

Question 3

Describe how neurotransmitters are used

Answer 3

Neurotransmitters are chemicals released from neurons that transmit signals across synapses to other neurons or target cells.

Question 4

Describe the process of sensory detection

Answer 4

Sensory detection involves the conversion of external stimuli into electrical signals by sensory receptors.

Question 5

Compare and contrast direct sensory detection and indirect sensory detection

Answer 5

Direct sensory detection involves receptors directly sensing stimuli, while indirect sensory detection involves intermediary processes or structures.

Question 6

Describe what mechanoreceptors do and list examples of stimuli they are used to detect.

Answer 6

Mechanoreceptors detect mechanical changes such as pressure, vibration, and touch. Examples of stimuli include sound waves and skin pressure.

Question 7

Describe the basic operation of the crustacean statocyst and fish lateral line

Answer 7

The crustacean statocyst detects gravity and orientation, while the fish lateral line detects water movements and vibrations.

Question 8

Describe the basic steps of chemoreception and list different body structures used for chemoreception in different organisms

Answer 8

Chemoreception involves detecting chemical stimuli, processing them, and generating a response. Structures include olfactory bulbs in mammals and antennae in insects.

Question 9

Describe the basic operation of simple light detection

Answer 9

Simple light detection involves photoreceptors responding to light intensity and converting it into electrical signals.

Question 10

Describe the basic structure of compound and lens-forming eyes

Answer 10

Compound eyes consist of multiple ommatidia, while lens-forming eyes have a single lens that focuses light onto a retina.

Question 11

Describe how and why the lenses of terrestrial vertebrate eyes and cephalopod eyes differ

Answer 11

Terrestrial vertebrate eyes have a flexible lens for focusing light, while cephalopod eyes have a rigid lens adapted for underwater vision.

Question 12

Describe how the axon resting potential is established

Answer 12

The axon resting potential is established by the differential distribution of ions, primarily sodium and potassium, across the membrane.

Question 13

Describe how specific ion movements affect the resting voltage potential (hyperpolarization, depolarization)

Answer 13

Hyperpolarization occurs when potassium ions exit the cell, making it more negative, while depolarization occurs when sodium ions enter, making it less negative.

Question 14

Describe the steps of action potential generation including the state of key ion channels during each step

Answer 14

Action potential generation involves depolarization, repolarization, and hyperpolarization, with sodium channels opening and closing, followed by potassium channels.

Question 15

Describe how an action potential propagates down an axon in only one direction and the role of specific ion channels

Answer 15

An action potential propagates unidirectionally due to the sequential opening of voltage-gated sodium channels along the axon.

Question 16

Describe the structure of myelin sheaths and their role in axon potential propagation

Answer 16

Myelin sheaths are insulating layers around axons that increase the speed of action potential propagation through saltatory conduction.

Question 17

Describe how an action potential is converted into neurotransmitter release at the synapse

Answer 17

An action potential triggers calcium influx at the synapse, leading to the release of neurotransmitters into the synaptic cleft.

Question 18

Describe the basic structure of the sarcomere in both the contracted and relaxed states

Answer 18

The sarcomere consists of actin and myosin filaments. In the contracted state, the filaments overlap more, while in the relaxed state, they are more spaced apart.

Question 19

Describe the steps of muscle contraction, including the role of specific neurotransmitters, calcium, and ATP

Answer 19

Muscle contraction involves neurotransmitter release, calcium binding to troponin, and ATP hydrolysis, leading to myosin-actin interactions.

Question 20

Describe the role of antagonistic muscle pairing for locomotion in organisms with exoskeletons, endoskeletons, and hydrostatic skeletons

Answer 20

Antagonistic muscle pairing allows for coordinated movement by contracting and relaxing opposing muscle groups, facilitating locomotion.