INTRODUCTION TO NEUROANATOMY and CEREBRUM & HIGHER CORTICAL FUNCTIONS

Part 1 and Part 2

Nervous system functions maintain homeostasis

Can stimulate or inhibit activities

Nervous system functions receive sensory input

Sensory receptors detect numerous external and internal stimuli that makes us aware of different sensations from different sensory systems

Nervous system functions integrate information

The brain and spinal cord are the major organs for processing sensory input and initiating responses

Nervous system functions establish and maintain mental activity

Responsible for mental activities, such as consciousness, thinking, memory, and emotions

Nervous system functions control muscles and glands

Skeletal muscles normally contract only when stimulated by blank

Neurons

Nerve cell and all its processes or neurites, highly specialized to transmit nerve impulses from one part of the body to another

Neuroglia

Do not transmit nerve impulses, non-excitable

Astrocytes

The most abundant and versatile neuroglia

Microglial cells

Phagocytes that defend CNS cells

Ependymal cells

Line cerebrospinal fluid-filled cavities

Oligodendrocytes

Have processes that form myelin sheaths around CNS nerve fibers

Satellite cells and Schwann cells

Surround neurons in the PNS

Gray matter

Unmyelinated regions of the CNS consisting of cell bodies, dendrites, and glial cells, performing processing and integrating information

White matter

Myelinated region of the CNS consisting of myelinated axons, facilitating transmission of nerve impulses and acting as a conduit

Forebrain

Early embryonic structure known as prosencephalon, developing into telencephalon and diencephalon with lateral and third ventricles supporting higher brain functions, relay center, autonomic nerve control, and endocrine control

Midbrain

Also known as mesencephalon, associated with the cerebral aqueduct and functioning in nerve pathways and reflex centers

Hindbrain

Also known as rhombencephalon, including metencephalon and myelencephalon, associated with fourth ventricle and central canal, functioning in nerve pathways, reflex centers, muscle coordination, and balance

Cranial meninges

Connective tissue membranes that surround and protect the brain, continuous with spinal meninges, including dura mater, arachnoid mater, and inner pia mater

Cerebrum

Major part of the brain controlling perception, thought, memory, emotion, and conscious motor activity, capable of overriding most other systems

Diencephalon

Major part of the brain connecting the brainstem to the cerebrum, responsible for relay and homeostatic functions

Brainstem

Major part of the brain consisting of midbrain, pons, and medulla oblongata, connecting the spinal cord to the cerebrum

Cerebellum

Major part of the brain that controls muscle movement and tone, governs balance, regulates extent of intentional movement, and is involved in learning motor skills

Frontal lobe

Lobe important in voluntary motor function, motivation, aggression, the sense of smell, and mood

Parietal lobe

Major center for receiving and evaluating most sensory information except for smell, hearing, taste, and vision

Temporal lobe

Lobe that receives and evaluates input for smell and hearing and plays an important role in memory

Occipital lobe

Lobe that functions in receiving and integrating visual input

Association fibers

Fibers that connect areas of the cerebral cortex within the same hemisphere

Commissural fibers

Fibers that connect one cerebral hemisphere to the other hemisphere

Projection fibers

Fibers that connect the cerebrum to other parts of the brain and spinal cord

Corpus callosum

The largest bundle of commissural fibers

Corpus striatum

Structure made up of the caudate nucleus and lentiform nucleus

Lentiform nucleus

Basal structure composed of the putamen and globus pallidus

Limbic system

Part of the brain that plays major roles in motivation, emotion, learning, and memory, influences the endocrine and autonomic nervous systems, and governs the emotional aspect of behavior

Broca area

Motor speech area in the inferior part of the frontal lobe involved in planning and producing speech and word formation

Wernicke area

Sensory speech area involved in language comprehension and intelligence

Hemispheric lateralization

Functional asymmetry where each cerebral hemisphere specializes in performing certain unique functions

Working memory

Type of memory that briefly stores information required for the immediate performance of a task, transient, lasting only a few seconds to minutes, highly detailed, occurring mostly in the frontal cortex

Short-term memory

Type of memory that can be stored from minutes to days and is stored by a mechanism involving increased synaptic transmission

Declarative memory

Retention of facts such as names, dates, and places

Procedural memory

Development of skills such as riding a bicycle or playing the piano

Primary somatosensory cortex

Primary sensory area occupying the postcentral gyrus of the parietal lobe, receiving sensory information relayed from peripheral receptors

Primary visual cortex

Primary sensory area located mainly at the posterior tip of the occipital lobe

Primary auditory cortex

Primary sensory area located in the superior part of the temporal lobe

Primary motor cortex

Motor area located in the precentral gyrus of the frontal lobe that controls voluntary contractions of specific muscles

Premotor area

Motor area immediately anterior to the primary motor cortex that plans movements and serves as a memory bank for coordinated movements

Frontal eye field

Motor area that controls voluntary scanning movements of the eyes

Prefrontal cortex

Extensive area in the anterior portion of the frontal lobe involved in motivation, foresight to plan and initiate movements, and complex integrative functions

Common integrative area

Area bordered by somatosensory, visual, and auditory association areas that integrates sensory interpretations from several areas to form thoughts based on varied sensory inputs