BIO 259 Exam 4 Study Guidance – Nervous System and Sensory Physiology

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Q1. Olfactory sensory neurons have ______ on their sensory hairs that bind odor molecules.

Background

Topic: Sensory Receptors – Olfaction

This question tests your understanding of the molecular mechanisms underlying the sense of smell, specifically the type of receptor proteins present on olfactory sensory neurons.

Key Terms and Concepts:

Olfactory sensory neurons: Specialized neurons responsible for detecting odorants.
Receptor proteins: Proteins that bind specific molecules (ligands) to initiate a cellular response.
G-protein coupled receptors (GPCRs): A large family of membrane receptors involved in signal transduction.

Step-by-Step Guidance

Recall that olfactory sensory neurons detect odorants using specialized proteins on their cilia (sensory hairs).
Consider the main types of receptor proteins: ligand-gated ion channels, mechanoreceptors, adrenergic receptors, and G-protein coupled receptors.
Think about which of these receptor types is known for having seven transmembrane domains and is commonly involved in sensory transduction, especially in olfaction.

Try solving on your own before revealing the answer!

Q2. Somatic reflexes involve ______ muscles.

Background

Topic: Reflex Arcs and Muscle Types

This question assesses your knowledge of the types of muscles controlled by the somatic nervous system, particularly in reflex actions.

Key Terms and Concepts:

Somatic reflexes: Involuntary responses mediated by the somatic nervous system.
Muscle types: Skeletal, cardiac, smooth, and visceral muscles.

Step-by-Step Guidance

Recall the definition of the somatic nervous system and its primary effectors.
Review which muscle types are under voluntary control and which are involved in reflexes like the knee-jerk response.
Eliminate muscle types that are not typically associated with somatic reflexes (e.g., cardiac, smooth).

Try solving on your own before revealing the answer!

Q3. Diffusion, reuptake, and enzymatic degradation are all mechanisms by which neurotransmitters are ______.

Background

Topic: Neurotransmitter Inactivation

This question tests your understanding of how neurotransmitter signaling is terminated at the synapse.

Key Terms and Concepts:

Neurotransmitter inactivation: The process of removing neurotransmitters from the synaptic cleft.
Diffusion: Movement of neurotransmitters away from the synaptic cleft.
Reuptake: Reabsorption of neurotransmitters by the presynaptic neuron.
Enzymatic degradation: Breakdown of neurotransmitters by enzymes.

Step-by-Step Guidance

Consider what happens to neurotransmitters after they have transmitted their signal across the synaptic cleft.
Review the three main mechanisms listed and what they accomplish in terms of neurotransmitter activity.
Determine whether these mechanisms are involved in the release, synthesis, or inactivation of neurotransmitters.

Try solving on your own before revealing the answer!

Q4. The right and left cerebral hemispheres ______.

Background

Topic: Brain Lateralization

This question examines your understanding of the functional differences and similarities between the two cerebral hemispheres.

Key Terms and Concepts:

Cerebral hemispheres: The two halves of the cerebrum, each responsible for different functions.
Lateralization: The specialization of certain functions in either the right or left hemisphere.

Step-by-Step Guidance

Recall the general functions attributed to each hemisphere (e.g., language, spatial reasoning).
Consider whether the hemispheres are completely different, identical, or have overlapping but distinct roles.
Eliminate options that are clearly incorrect based on your knowledge of brain anatomy and function.

Try solving on your own before revealing the answer!

Q5. Axon tracts that travel from one region of ipsilateral cortex to another are called ______ tracts.

Background

Topic: White Matter Tracts in the Brain

This question tests your knowledge of the different types of axon tracts in the central nervous system, specifically those connecting regions within the same hemisphere.

Key Terms and Concepts:

Axon tracts: Bundles of nerve fibers in the CNS.
Ipsilateral: Refers to the same side of the body or brain.
Association tracts: Connect different regions within the same hemisphere.

Step-by-Step Guidance

Review the definitions of projection, association, and commissural tracts.
Focus on which type specifically connects areas within the same hemisphere (ipsilateral).
Eliminate options that refer to tracts connecting different hemispheres or other structures.

Try solving on your own before revealing the answer!

Q6. An IPSP is ______ of a postsynaptic neuron’s membrane potential.

Background

Topic: Synaptic Potentials

This question assesses your understanding of inhibitory postsynaptic potentials (IPSPs) and their effect on neuronal membrane potential.

Key Terms and Concepts:

IPSP (Inhibitory Postsynaptic Potential): A synaptic potential that makes a postsynaptic neuron less likely to generate an action potential.
Hyperpolarization: An increase in membrane potential, making the inside of the cell more negative.

Step-by-Step Guidance

Recall what happens to the membrane potential during an IPSP.
Review the difference between depolarization, hyperpolarization, and repolarization.
Determine which term best describes the effect of an IPSP on the postsynaptic neuron.

Try solving on your own before revealing the answer!

Q7. The local, graded change in membrane potential produced in a receptor by sensory transduction is called a ______ potential.

Background

Topic: Sensory Transduction

This question tests your knowledge of the initial electrical response generated in sensory receptors upon stimulation.

Key Terms and Concepts:

Generator potential: The local change in membrane potential in a sensory receptor.
Action potential: The all-or-none electrical signal propagated along neurons.

Step-by-Step Guidance

Recall the difference between a graded potential and an action potential.
Think about what type of potential is first produced in a sensory receptor before an action potential is generated.
Match the correct term to the description given in the question.

Try solving on your own before revealing the answer!

Q8. The ______ nuclei are part of the cerebrum but not of the cerebral cortex.

Background

Topic: Brain Anatomy – Subcortical Nuclei

This question examines your understanding of the structures within the cerebrum that are not part of the cerebral cortex.

Key Terms and Concepts:

Cerebral cortex: The outer layer of neural tissue of the cerebrum.
Basal nuclei (ganglia): Subcortical nuclei involved in motor control and other functions.

Step-by-Step Guidance

Review the main components of the cerebrum and distinguish between cortical and subcortical structures.
Recall which nuclei are located deep within the cerebrum and are not part of the cortex.
Eliminate options that are not anatomically part of the cerebrum or are part of the cortex.

Try solving on your own before revealing the answer!

Q9. In an afferent axon of a spinal nerve, action potentials travel ______ the CNS.

Background

Topic: Nervous System Pathways

This question tests your understanding of the direction of information flow in sensory (afferent) neurons.

Key Terms and Concepts:

Afferent neuron: A neuron that carries sensory information toward the central nervous system.
CNS (Central Nervous System): Composed of the brain and spinal cord.

Step-by-Step Guidance

Recall the definitions of afferent and efferent neurons.
Think about the direction in which sensory information travels relative to the CNS.
Choose the option that correctly describes this direction.

Try solving on your own before revealing the answer!

Q10. A receptor that detects the osmolarity of blood would most likely be a(n) ______.

Background

Topic: Sensory Receptors – Classification

This question assesses your knowledge of the classification of sensory receptors based on the location and type of stimulus detected.

Key Terms and Concepts:

Osmoreceptor: A receptor that detects changes in osmolarity (solute concentration) of body fluids.
Interoceptor: A receptor that detects internal stimuli.
Exteroceptor: A receptor that detects external stimuli.
Proprioceptor: A receptor that detects body position and movement.

Step-by-Step Guidance

Consider where the stimulus (osmolarity of blood) is detected—inside or outside the body.
Review the definitions of interoceptors, exteroceptors, and proprioceptors.
Match the correct receptor type to the function described.

Try solving on your own before revealing the answer!

Q11. Activation of G-Protein coupled receptor often leads to changes in ______.

Background

Topic: Signal Transduction

This question tests your understanding of the downstream effects of G-protein coupled receptor (GPCR) activation.

Key Terms and Concepts:

G-protein coupled receptor (GPCR): A receptor that activates intracellular signaling cascades via G-proteins.
Enzyme activity, ion channel state, gene expression: Common cellular responses to GPCR activation.

Step-by-Step Guidance

Recall the general mechanism of GPCR activation and the types of cellular changes it can induce.
Consider whether GPCRs can affect only one or multiple cellular processes.
Review examples of GPCR-mediated effects in different cell types.

Try solving on your own before revealing the answer!

Q12. In the contralateral extensor reflex, the axon of a ______ crosses to the other side of the spinal cord to activate the motor neuron that causes extension.

Background

Topic: Spinal Reflexes

This question examines your understanding of the neural circuitry involved in the contralateral extensor reflex, particularly which cell type's axon crosses the midline.

Key Terms and Concepts:

Contralateral extensor reflex: A reflex that activates extensor muscles on the side opposite to the stimulus.
Interneuron: A neuron that connects sensory and motor pathways within the CNS.

Step-by-Step Guidance

Review the pathway of the contralateral extensor reflex and the role of interneurons in crossing the midline.
Consider which cell types are capable of sending axons across the spinal cord.
Eliminate options that do not fit the described function.

Try solving on your own before revealing the answer!

Q13. The ______ conveys pain sensory information via the spinal anterolateral system to the contralateral reticular formation in the brain stem.

Background

Topic: Ascending Sensory Pathways

This question tests your knowledge of the specific spinal tract responsible for transmitting pain information to the brainstem.

Key Terms and Concepts:

Spinoreticular tract: A tract that carries pain and other sensory information to the reticular formation.
Spinothalamic tract: A tract that carries pain and temperature information to the thalamus.

Step-by-Step Guidance

Recall the main ascending tracts in the spinal cord and their destinations.
Identify which tract specifically targets the reticular formation in the brainstem.
Eliminate tracts that do not match the pathway described.

Try solving on your own before revealing the answer!

Q14. The Reticular Activating System (RAS) is distributed throughout the ______ and is important for regulation of many important functions including attention and consciousness.

Background

Topic: Brainstem and Consciousness

This question assesses your understanding of the anatomical location and function of the Reticular Activating System.

Key Terms and Concepts:

Reticular Activating System (RAS): A network of neurons involved in arousal and consciousness.
Brainstem: The region of the brain that includes the midbrain, pons, and medulla oblongata.

Step-by-Step Guidance

Recall the main regions of the brain where the RAS is located.
Consider the functions regulated by the RAS and which brain region is responsible for these functions.
Eliminate options that do not fit the anatomical distribution of the RAS.

Try solving on your own before revealing the answer!

Q15. In the medulla oblongata, the pyramids contain the ______.

Background

Topic: Motor Pathways

This question tests your knowledge of the anatomical structures within the medulla oblongata and their contents.

Key Terms and Concepts:

Pyramids: Paired structures on the ventral medulla containing descending motor fibers.
Corticospinal tracts: Major motor pathways from the cerebral cortex to the spinal cord.

Step-by-Step Guidance

Recall the function and location of the pyramids in the medulla oblongata.
Identify which tracts pass through the pyramids and their role in voluntary motor control.
Eliminate options that do not correspond to the known contents of the pyramids.

Try solving on your own before revealing the answer!

Q16. Habit formation is mediated by the ______.

Background

Topic: Basal Nuclei and Behavior

This question examines your understanding of the brain structures involved in the formation of habits and procedural learning.

Key Terms and Concepts:

Basal nuclei (ganglia): Subcortical structures involved in motor control and habit formation.
Limbic system: Involved in emotion and memory.

Step-by-Step Guidance

Review the functions of the basal nuclei and their role in procedural memory and habit formation.
Consider the roles of other brain regions listed in the options.
Eliminate options that are not primarily involved in habit formation.

Try solving on your own before revealing the answer!

Q17. Thermoreceptors, photoreceptors, & nociceptors are examples of sensory receptors with different ______.

Background

Topic: Sensory Receptor Classification

This question tests your understanding of the concept of sensory modalities and how receptors are classified based on the type of stimulus they detect.

Key Terms and Concepts:

Modality: The type of stimulus detected by a sensory receptor (e.g., temperature, light, pain).
Threshold: The minimum stimulus intensity required to activate a receptor.

Step-by-Step Guidance

Recall the definition of modality in the context of sensory physiology.
Consider how thermoreceptors, photoreceptors, and nociceptors differ in the type of stimulus they detect.
Match the correct term to the description in the question.

Try solving on your own before revealing the answer!

Q18. ______ area is the area of the left parietal cortex involved in the comprehension of speech.

Background

Topic: Language Areas of the Brain

This question assesses your knowledge of the cortical regions involved in language comprehension.

Key Terms and Concepts:

Wernicke's area: Region in the left hemisphere important for language comprehension.
Broca's area: Region involved in speech production.

Step-by-Step Guidance

Recall the locations and functions of Broca's and Wernicke's areas.
Identify which area is specifically involved in understanding spoken and written language.
Eliminate options that do not correspond to known language areas.