Question

Name the part of the cerebrum concerned with each of the following: (pp. 181-184) a. Feels the cutaneous sensations b. Contains the auditory areas c. Contains the visual areas d. Connects the cerebral hemispheres e. Regulates accessory movements f. Contains the olfactory areas g. Initiates voluntary movement h. Contains the speech areas (for most people)

Short answer

Question: Identify the parts of the cerebrum responsible for the following functions: a. Feeling cutaneous sensations, b. containing auditory areas, c. containing visual areas, d. connecting cerebral hemispheres, e. regulating accessory movements, f. containing olfactory areas, g. initiating voluntary movement, and h. containing speech areas (in most people). Answer: a. Primary somatosensory cortex (postcentral gyrus of the parietal lobe), b. Primary auditory cortex (superior temporal gyrus of the temporal lobe), c. Primary visual cortex (occipital lobe at the calcarine sulcus), d. Corpus callosum, e. Basal ganglia, f. Piriform cortex (uncus of the temporal lobe), g. Primary motor cortex (precentral gyrus of the frontal lobe), h. Broca's area (inferior frontal gyrus of the frontal lobe) and Wernicke's area (posterior part of the superior temporal gyrus of the temporal lobe).

Step-by-step solution

a. Feels the cutaneous sensations

The part of the cerebrum responsible for feeling cutaneous sensations (sensations of touch, pressure, pain, and temperature from the skin) is the primary somatosensory cortex located in the postcentral gyrus of the parietal lobe.

b. Contains the auditory areas

The part of the cerebrum containing the auditory areas is the primary auditory cortex, which is located in the superior temporal gyrus of the temporal lobe.

c. Contains the visual areas

The part of the cerebrum containing the visual areas is the primary visual cortex, which is located in the occipital lobe at the calcarine sulcus.

d. Connects the cerebral hemispheres

The part of the cerebrum connecting the cerebral hemispheres is the corpus callosum, a bundle of nerve fibers that facilitates communication between the left and right hemispheres.

e. Regulates accessory movements

The part of the cerebrum responsible for regulating accessory movements is the basal ganglia, a group of subcortical nuclei located in the forebrain, responsible for coordinating and controlling voluntary movements and habit learning.

f. Contains the olfactory areas

The part of the cerebrum containing the olfactory areas is the piriform cortex, which is part of the primary olfactory cortex located in the uncus of the temporal lobe.

g. Initiates voluntary movement

The part of the cerebrum that initiates voluntary movement is the primary motor cortex, located in the precentral gyrus of the frontal lobe.

h. Contains the speech areas (for most people)

The part of the cerebrum containing the speech areas for most people is the Broca's area (speech production) and Wernicke's area (language comprehension). Broca's area is located in the inferior frontal gyrus of the frontal lobe, while Wernicke's area is found in the posterior part of the superior temporal gyrus of the temporal lobe.

Key concepts

Primary Somatosensory Cortex

The primary somatosensory cortex is a key part of the brain involved in processing tactile information. It is located in the postcentral gyrus of the parietal lobe.
This area is essential for interpreting sensations from the skin, such as touch, pressure, pain, and temperature. When you touch a hot surface, it's the primary somatosensory cortex that helps your brain recognize the heat and associate it with potential danger. This area of the brain is organized in a way that different parts correspond to sensations from different areas of the body, a phenomenon known as somatotopic organization.
For example, sensations from your hands are processed by one part of this cortex, while sensations from your feet are processed by another. This detailed mapping helps the brain respond quickly and accurately to tactile stimuli.

Primary Auditory Cortex

The primary auditory cortex is crucial for processing sounds, including the tones and rhythm of speech.
It is located in the superior temporal gyrus of the temporal lobe. This area of the brain interprets auditory signals received from the ears, enabling us to recognize and understand different sounds.

Functionality

• Processes auditory information from the ears.
• Helps in distinguishing between various sound frequencies.
• Facilitates comprehension of spoken language and musical elements.

This part of the cortex engages heavily when you enjoy music or focus on understanding someone speaking in a noisy environment. Recognizing the importance of this area can be particularly helpful in fields such as audio engineering or language learning.

Primary Visual Cortex

The primary visual cortex is the part of the brain responsible for processing visual information.
It is located in the occipital lobe around the calcarine sulcus. This area interprets signals from the eyes to build a coherent visual representation of the world.

Core Responsibilities

• Processes visual information received from the retina.
• Involves in recognizing patterns and colors.
• Essential for spatial orientation and motion detection.

When you look at a colorful picture or navigate through a busy street, the primary visual cortex is hard at work to ensure your brain correctly interprets visual cues.
Understanding its role is crucial for fields such as vision science and artificial intelligence.

Corpus Callosum

The corpus callosum is the major structure connecting the two hemispheres of the brain.
It's a thick band of nerve fibers located at the center of the brain. This connection is essential for the communication and coordination between the left and right hemispheres.

Significance

• Facilitates inter-hemispheric communication.
• Ensures coordination and cooperation between both sides of the brain.

The corpus callosum plays a crucial role when tasks require information from both hemispheres, such as reading, which involves language skills in the left hemisphere and visual processing in the right.
This structure's integrity is fundamental for seamless cognitive functioning, and its study is important in understanding certain neurological conditions.

Basal Ganglia

The basal ganglia are a group of nuclei deep in the brain that play a vital role in movement regulation and coordination.
These structures are located in the forebrain and are essential for controlling voluntary movements and learning habitual actions.

Main Functions

• Control and regulate voluntary motor movements.
• Involved in procedural learning and habit formation.
• Facilitates posture and muscle tone maintenance.

The basal ganglia are particularly highlighted when discussing movement disorders like Parkinson's disease, as they are involved in maintaining smooth and purposeful movements.
Comprehending their function is crucial in neurology and designing treatments for movement impairments.

Primary Motor Cortex

The primary motor cortex is essential for initiating voluntary movements.
It is situated in the precentral gyrus of the frontal lobe. This part of the brain sends signals to the muscles to control specific movements.

Key Roles

• Initiates and controls voluntary muscle movements.
• Coordinates complex movements such as speaking and writing.
• Contains a map of muscle control akin to the somatosensory map.

The primary motor cortex allows for movements ranging from running to articulating speech. Its significance is highlighted in stroke rehabilitation, where specific therapies aim to retrain the primary motor cortex to restore movement abilities.
Understanding its function aids in comprehending the complexities of human dexterity and motor skills.

Broca's Area

Broca's area is a crucial region for speech production, typically located in the left hemisphere for right-handed individuals.
It resides in the inferior frontal gyrus of the frontal lobe.

Functions

• Crucial for producing coherent speech.
• Involved in language comprehension and grammar processing.
• Participates in verbal communication and articulation.

Damage to this area can result in Broca's aphasia, where an individual understands speech but struggles to produce it.
This area's role is particularly emphasized in language learning and speech therapy, highlighting its significance in maintaining effective communication.