Skip to main content
Ch. 12 The Central Nervous System
Marieb - Human Anatomy & Physiology 11th Edition
Marieb, Hoehn11th EditionHuman Anatomy & PhysiologyISBN: 9780136874034Non è quello che usi tu?Cambia libro di testo
Capitolo 12, Problema 7

A professor unexpectedly blew a loud horn in his anatomy and physiology class. The students looked up, startled. The reflexive movements of their eyes were mediated by the:
a. Cerebral cortex
b. Inferior olives
c. Raphe nuclei
d. Superior colliculi
e. Nucleus gracilis

Guida verificata passo dopo passo
1
Step 1: Understand the question is asking about the neural structure responsible for reflexive eye movements in response to a sudden stimulus, such as a loud horn.
Step 2: Recall that reflexive eye movements are rapid, involuntary responses that help orient the eyes toward a stimulus, often mediated by midbrain structures.
Step 3: Review the functions of the listed options: the cerebral cortex is involved in voluntary movement and higher processing; inferior olives are related to motor coordination; raphe nuclei are involved in serotonin production and mood regulation; nucleus gracilis processes sensory information from the body.
Step 4: Identify that the superior colliculi, part of the midbrain tectum, play a key role in visual reflexes and orienting movements of the eyes and head toward stimuli.
Step 5: Conclude that the reflexive eye movements in response to the loud horn are mediated by the superior colliculi.

Risposta video verificata per un problema simile:

Questa soluzione video è stata consigliata dai nostri tutor come utile per risolvere questo problema.
Durata del video:
2m

Concetti chiave

Ecco i concetti essenziali che devi comprendere per rispondere correttamente alla domanda.

Reflexive Eye Movements

Reflexive eye movements are automatic responses to sudden stimuli, such as a loud noise or a bright light. These movements help orient the eyes toward the source of the stimulus without conscious effort, enabling quick attention shifts to potential threats or important events.
Video consigliato:
3:01
Tendon Reflex

Superior Colliculi

The superior colliculi are paired structures in the midbrain involved in processing visual and auditory information to coordinate reflexive eye and head movements. They play a key role in directing gaze and attention toward sudden stimuli, making them essential for reflexive eye movements.
Video consigliato:
03:39
Superior and Inferior

Role of Other Brain Structures in Reflexes

While structures like the cerebral cortex, inferior olives, raphe nuclei, and nucleus gracilis have important functions, they are not primarily responsible for reflexive eye movements. The cerebral cortex manages voluntary actions, inferior olives assist motor learning, raphe nuclei regulate mood, and nucleus gracilis processes somatosensory information.
Video consigliato:
1:09
Reflex Arcs Example 1
Pratica correlata
Domanda del libro di testo

Fiber tracts that allow neurons within the same cerebral hemisphere to communicate are:

a. Association fibers

b. Commissures

c. Projection fibers

121
views
Domanda del libro di testo

Choose the correct term from the key to respond to the statements describing various brain areas.

Key:

a. Cerebellum

b. Corpora quadrigemina

c. Corpus callosum

d. Striatum

e. Hypothalamus

f. Medulla

g. Midbrain

h. Pons

i. Thalamus 

________ (1) basal nuclei involved in fine control of motor activities  

________ (2) region where there is a crossover of fibers of descending pyramidal tracts  

________ (3) control of temperature, autonomic nervous system reflexes, hunger, and water balance 

________ (4) houses the substantia nigra and cerebral aqueduct 

________ (5) relay stations for visual and auditory stimuli input; found in midbrain 

________ (6) houses vital centers for control of the heart, respiration, and blood pressure 

________ (7) brain area through which all the sensory input is relayed to get to the cerebral cortex 

________ (8) brain area most concerned with equilibrium, body posture, and coordination of motor activity

1038
views
Domanda del libro di testo

a. What is the function of the basal nuclei?

b. Which basal nuclei form the striatum?

c. Which arches over the diencephalon?

37
views
Domanda del libro di testo

What constitutes the blood brain barrier?

1183
views
Domanda del libro di testo

List four ways in which the CNS is protected.

1056
views
Domanda del libro di testo

Destruction of the ventral horn cells of the spinal cord results in loss of

a. Integrating impulses

b. Sensory impulses

c. Voluntary motor impulses

d. All of these

699
views