Cerebral Lobes & Subcortical Structures

Brodmann’s Area

Divides brain into 52 areas based on brain’s gross anatomy and cellular structure of the brain

Glia and neurons level of cerebral cortex

Most superficial layer of the cerebral cortex

Glia

Non-neuronal cells that support neurons

Neurons

Responsible for transmitting chemical and electrical signals though the nervous system

Layer 2 (second most superficial) of the cerebral cortex

Small pyramidal cells

Small pyramidal cells

Types of neurons that act as a main output signal for the cerebral cortex

Layer 3 of the cerebral cortex

Large pyramidal cells

Large pyramidal cells

Projecting messages to other areas of the cortex

Layer 4 of the cerebral cortex

Nonpyramidal cells

Nonpyramidal cells

• Inhibitory cells; as electrical pulses are coming in, these cells coral the impulses. Sensory cells

• Ex. Keep you from feeling electrical current in your elbow or shoulder if it hits your finger

Layer 5 of the cerebral cortex

Betz cells

Betz cells

Direct intervation to motor neurons in both spinal cord and brain stem; efferent

Layer 6 (deepest) of the cerebral cortex

Various cells

Frontal lobe

In charge of voluntary skilled movements, reasoning, insight, personality, and attention

Primary Motor Cortex

Executing voluntary movements

Premotor Cortex

Planning and coordinating movement

Broca’s Area

Speech and language production

Broca’s Aphasia

Difficulties getting words out, forming sentences, and fluency

Prefrontal Cortex

Cognitive skills relating to executive functioning

Primary Motor Cortex, supplementary motor area, premotor cortex, Broca’s area, and prefrontal cortex are all a part of

The frontal lobe

Parietal lobe

Processing sensory info, spatial orientation/perception, reading/writing

Primary Somatosensory Cortex (parietal lobe)

Afferent pathways that tell us senses of our body; where we process information

Primary sensory cortex (parietal lobe)

Depth perception; homunculus present

Temporal lobe

• Audition (hearing)

• Language

• Visual processing

Auditory cortex (temporal lobe)

Tonographic organization of how we are hearing and processing sound

Wernicke’s Area

Language processing, adds meaning to sound

Heschl’s gyrus

Part of the temporal lobe that processes sound frequency, duration, and intensity

Occipital lobe

Processing visual info (color, form, motion, spatial awareness)

Occipital lobe dorsal stream

• A visual pathway in the brain that starts in the occipital lobe and extends to the parietal lobe; helps you perceive where objects are in space

• Known as the “where” or “how” pathway

Occipital lobe ventral stream

• A visual pathway in the brain that carries information from the occipital lobe to the temporal lobe

• Known as the “what” pathway because it helps identify objects

Cerebellum

Coordinates muscle movement & maintains balance; helps learn new motor skills

Damages to cerebellum

Ataxia (affects coordination, brain has trouble controlling muscle movements) , ataxic dysarthria (motor speech disorder, deficit in motor execution, weakness, slowness, or discoordination of movements)

Basal Ganglia

A mass of gray matter; regulates motor functions

Damage to basal ganglia

Speech difficulties, memory impairments, and movement disorders (muscle rigidity, difficulty sustaining movement, trouble initiating response)

Globus pallidus

Projecting inhibitory signals (ex. Guard rails; stops you)

Putamen and caudate nucleus (basal ganglia)

Receive signals (efferent) from the cerebral cortex (primary motor cortex)

The diencephalon is made up of the

Thalamus and hypothalamus

Thalamus

• Evaluates and direct sensory information to cortex

• Receives sensory information and relays for interpretation

• Emotional regulation, memory and learning, coordination and motor function, attention and consciousness, and sleep and awakeness

Hypothalamus

• Controls major biological functions

• More critical/life preserving functions (ex. Regulating body temperature, hunger and thirst, sleep and awake cycle, emotional regulation, endocrine system, and autonomic function)