CDIS 410 Neuro Exam 2

Topics 5 + 6

Lobes of the brain

Frontal, parietal, occipital, temporal

Frontal lobe

Central sulcus and lateral sulcus

Temporal lobe

Sylvian fissure, superior temporal gyrus, middle and inferior temporal gyrus. Responsible for hearing. Primary auditory cortex and auditory association cortex. Insula lobe, auditory agnosia, pure word deafness.

Parietal lobe

A region of the cerebral cortex whose functions include processing information about touch. Primary somatosensory cortex, parietal association cortex, inferior parietal lobule, right parietal lobe lesions.

Occipital lobe

Visual processing. Primary visual processing, visual association cortex.

Central sulcus

Divides frontal from parietal.

Lateral sulcus

Sylvian fissure. Divides frontal from temporal.

Precentral gyrus (primary motor cortex)

Brodman aera 4. Precentral gyrus. Executes individual movements of different parts of the body (contralaterally). Receives info from premotor area, sensory cortex, thalamus, cerebellum and basal ganglia. Lesion: Paralysis (motor) on the contralateral (opposite) side of the body. Hands, feet, and face.

Motor homunculus

Primary motor cortex = motor homunculus. Proportional to the skills involved in preforming the movement (speech area).

Pre motor cortex

Programming/ planning motor activities of the primary motor cortex. Receives input from sensory cortex, thalamus, basal ganglia. Inferior frontal gyrus (typically the left) is involved with language processing. Brocas area: Pars opercularis (44) and pars triangularis (45). Pars orbitalis.

Pre frontal cortex

Central executor. Appears to control higher mental functions (cognition). Self awareness, attention, initiation, planning, regulations of social behavior, inhibition, pragmatic skills, judgement, decision making, humor, personality. Lesions: impaired cognition. Attention, reasoning, judgment, problem solving, self, monitoring. Inappropriate social behaviors, apathy, and aphasia.

Brocas area

Pars opercularis (44) and pars triangularis (45). Pars orbitalis. Proportional to the skills involved in preforming the movement (speech area). Production of speech.

Brocas aphasia

Condition resulting from damage to Broca's area, causing the affected person to be unable to speak fluently, to mispronounce words, and to speak haltingly.

Postcentral gyrus (primary somatosensory cortex)

Located inside the postcentral gyrus. Receives sensory input from the contralateral side of the body (touch/ tactile, temp, pain, and pressure). Receives projection fibers from the thalamus (contralateral).Lesions: contralateral sensory deficits. Pain, temp, tactile, pressure

Sensory homunculus

Primary somato cortex = sensory homunculus. The opposite half of our body is represented as inverted. Sensitivity = density of sensory receptors. But not body proportion.

Inferior parietal lobule

LH (39 and 40) Connected with auditory, visual, and somatosensory cortices. Integration of language functions, reading, writing, math.

Primary auditory cortex

Part of superior temporal gyrus. Lies within the sylvian fissure. AKA, Heschis gyrus. Identifies and pareses auditory stimuli; identifies sound location in space tonotopically organized. Unilateral lesion: parietal deafness in both ears, greater loss in the contralateral ear. Affect auditory processing and phonemic discrimination.

Auditory association cortex

Posterior to the primary auditory area in the superior temporal gyrus. Interpretation of sounds. Location: posterior two thirds of the left superior temporal gyrus. Function: receives info from auditory and visual cortices. Comprehension of spoken and written language.

Pure word deafness

Inability to recognize spoken words (meaning of speech). Normal hearing.

Insular lobe

Within the lateral sulcus (beyond heschl's gyrus). Function: visceral, taste, perception, vestibular functions, emotion and cognition. Bilateral temporal lobe lesions.

Primary visual cortex

Thin cortex, granular type. Visual perception: discrimination, colors, patterns. Receives visual info from contralateral visual fields of both eyes. Lesions: cortical blindness.

Wernicke's area

Language comprehension

Wernicke's aphasia

Lesions: Wernickes aphasia

Impaired language comprehension, fluent and empty speech. NO HEMIPARESIS

Auditory agnosia

Inability to recognize nonverbal sounds (meaning of sounds) normal hearing.

Visual association cortex

Receives afferent fibers from primary visual cortex and other cortical areas. Function: Responsible for complex visual analysis. Recognizes the visual info to past visual experiences.

Visual agnosia

Inability to identify objects by sight.

Prosopagnosia

Inability to recognize faces

Thalamus

(Diencephalon) Located at the base of the cerebral hemispheres. A large egg shaped nuclear mass. Afferent info from entire body and other CNS. Major sensory relay station: information coverages goes to distributed to cortex and other parts of the CNS.

Basal ganglia

Makes up telencephalon (with cortex). Location: subcortical, around internal capsule. Egg shaped with tail, BG: a collection of nuclei. Function: Does NOT initiate motor activity. Regulates motor functions and muscle tones and integrates motor activity: receives afferent info and sends efferent info to other parts of CNS. Some cognitive functions. Lesions: Loss of inhibitory control. Parkinsons disease and Huntington's disease.

Caudate nucleus

C-shaped with a long tial

Putamen

Half moon shape

Globus pallidus

Medial to putamen.

Substantia nigra

An area of the midbrain that is involved in motor control and contains a large concentration of dopamine-producing neurons

Limbic system

Regulates emotion, motivation for survival behaviors, learning and memory. Structures: Cingulate gyrus, amygdala, and hippocampus

Amygdala

Control drive and internal feelings

Hippocampus

Memory learning

Cingulate gyrus

Anxiety, obsessive-compulsive behaviors

Cerebellum

Location: inferior to occipital lobe. Dorsal to brainstem. Structures: two cerebellar hemispheres. Gyri, sulci, gray and white matter. Function: Coordinates muscle movement and balance muscle tone and balance. Makes adjustments in movements based sensory input (visual, auditory). Does not initiate movement, plays a role in motor learning, cognition.

Cerebellar peduncles

Receives/ sends info from/ to spinal cord, brainstem, basal ganglia, thalamus, and cortex.

Cerebral peduncles

Two paired, pillar-like bundles of nerve fibers located on the anterior side of the midbrain that connect the cerebrum to the brainstem

Limb paralysis

Monoplegia, Hemiplegia. Quadriplegia,and Paralegia

Monoplegia

Either an upper or lower limb

Hemiplegia

Both the upper and the lower limb on one side

Quadriplegia

Four limbs

Paralegia

Both lower limbs

Caduate nucleus + putamen = striatum

Putamen + globus pallidus = lenticular nucleus

Cerebellar dysfunction

Paresis (weakness of voluntary movement). Intention tremor, Disequilibrium, Ataxia, and Dysarthria.

Clinical signs of impairments of the anatomic structures of the brain.

Impairments to different areas of the brain can cause problems with movement, sensation, speech, language, memory, vision, balance, coordination, behavior, and breathing. The specific clinical signs depend on which brain structure is affected, such as frontal lobe damage causing behavior or speech changes, temporal lobe damage affecting memory or language, and cerebellum damage causing balance and coordination problems.

The importance of the primary and associational cortical areas.

Primary cortical areas handle basic functions, such as movement, hearing, vision, and sensation, while association areas interpret and combine information from these areas. Together, they allow us to understand sensory information, communicate, learn, remember, and perform complex behaviors.

The functional importance of the thalamus

The thalamus acts as a major relay center in the brain, sending sensory information to the appropriate areas of the cerebral cortex. It is important for attention, alertness, movement, and processing sensory information, especially touch, hearing, and vision.

The functional importance of the limbic system

The limbic system is important for emotion, memory, motivation, and learning. It also helps regulate behaviors and responses related to emotions, such as fear and pleasure.

The structurally and functionally related structures of the basal ganglia

The basal ganglia are a group of structures including the caudate nucleus, putamen, and globus pallidus, which work closely with the thalamus and cerebral cortex. They are important for initiating, controlling, and coordinating voluntary movements, as well as motor learning and movement patterns.

The neuronal circuitry for common basal ganglia circuits

The basal ganglia circuits involve connections between the cerebral cortex, basal ganglia, thalamus, and back to the cortex. The direct pathway facilitates movement, while the indirect pathway inhibits unwanted movements; together, they help control and coordinate voluntary movement.

Clinical signs of basal ganglia impairments

Basal ganglia impairments can cause abnormal movements, such as tremors, rigidity, involuntary movements, slowed movement, or difficulty starting movements. They can also affect muscle tone, coordination, and control of voluntary movements.

The importance of the cerebellum in motor activity

The cerebellum is important for balance, coordination, posture, and smooth, accurate movements. It also helps with motor learning and adjusting movements based on sensory feedback.

Major symptoms of the cerebellar dysfunction and cerebellar pathologies

Cerebellar dysfunction can cause poor balance, uncoordinated movements, tremors, slurred speech, and difficulty with precise movements. Common cerebellar pathologies include stroke, tumors, trauma, multiple sclerosis, and degenerative diseases.