Topic-5.1-Chapter-7-Nervous-System.pptx

Sensory Input

Gathering information through sensory receptors that monitor changes, called stimuli, inside and outside the body.

Integration

The process by which the nervous system interprets sensory input and decides whether action is needed.

Motor Output

A response or effect that activates muscles or glands.

Central Nervous System (CNS)

Composed of the brain and spinal cord; serves as the command center for processing information.

Peripheral Nervous System (PNS)

Nerves extending from the brain and spinal cord; serves as communication lines among sensory organs, the brain, and muscles or glands.

Sensory (Afferent) Division

Nerve fibers that carry information to the central nervous system

Motor (Efferent) Division

Nerve fibers that carry impulses away from the central nervous system organs to effector organs

Somatic Nervous System

Part of the efferent division; voluntarily controls skeletal muscles.

Autonomic Nervous System

Part of the efferent division; automatically controls smooth and cardiac muscles and glands.

Sympathetic Nervous System

Division of the autonomic nervous system that prepares the body for stress or emergency situations.

Parasympathetic Nervous System

Division of the autonomic nervous system that calms the body and helps conserve energy.

Neuroglia

Support cells in the CNS that support, insulate, and protect neurons.

Astrocytes

Star-shaped glial cells in the CNS that anchor neurons to blood capillaries and control the chemical environment.

Microglia

Spiderlike phagocytes in the CNS that monitor neuron health and dispose of debris.

Ependymal Cells

Glial cells that line the cavities of the brain and spinal cord and assist with the circulation of cerebrospinal fluid.

Oligodendrocytes

Glial cells in the CNS that wrap around nerve fibers and produce myelin sheaths.

Schwann Cells

Glial cells in the PNS that form myelin sheaths around nerve fibers.

Satellite Cells

Glial cells in the PNS that protect and cushion neuron cell bodies.

Neuron

Nerve cells specialized to transmit messages (nerve impulses).

Cell Body

The metabolic center of a neuron containing the nucleus.

Dendrites

Fibers that conduct impulses toward the cell body of a neuron.

Axon

A fiber that conducts impulses away from the cell body of a neuron.

Axon Terminal

The endpoint of an axon where neurotransmitters are released.

Synaptic Cleft

The gap between axon terminals and the next neuron.

Synapse

The functional junction between nerves where a nerve impulse is transmitted.

Myelin

A white, fatty material that covers axons, protecting and insulating fibers and speeding nerve impulse transmission.

Myelin Sheath

An insulating layer around axons formed by Schwann cells in the PNS and oligodendrocytes in the CNS.

Neurilemma

Part of the Schwann cell that is external to the myelin sheath.

Nodes of Ranvier

Gaps in the myelin sheath along the axon that facilitate the rapid transmission of nerve impulses.

Neurofibrils

Intermediate filaments that maintain the shape of neurons.

Nissl Bodies

Rough endoplasmic reticulum associated with the cell body of a neuron.

Peripheral Nervous System Components

Includes spinal nerves and cranial nerves.

Central Nervous System Components

Includes the brain and spinal cord.

Voluntary Control

Conscious control of skeletal muscles in the somatic nervous system.

Involuntary Control

Automatic control of smooth muscles, cardiac muscles, and glands in the autonomic nervous system.

Sensory Receptors

Specialized cells that detect changes (stimuli) in the environment.

Feedback Loop

A process in which sensory input is received, integrated, and used to generate a motor output.

Stimuli

Changes detected by sensory receptors both inside and outside the body.

Integration in the CNS

The process in which the brain interprets incoming sensory information and issues outgoing instructions.

Lateralization of Brain Functions

The specialization of certain functions in either the right or left hemisphere of the brain.

Cerebrospinal Fluid

Fluid that cushions and protects the brain and spinal cord.

Functional Classification of the Nervous System

Divides the nervous system based on the activities performed: sensory and motor.

Supporting Cells Function

Support, insulate, and protect neurons in the nervous system.

Glial Cells

Supporting cells in the nervous system that include astrocytes, microglia, ependymal cells, oligodendrocytes, Schwann cells, and satellite cells.

Brain's Role

Acts as the control center for processing sensory input and directing motor output.

Impact of Myelin on Impulse Transmission

Myelin sheaths speed up the transmission of nerve impulses along axons.

Gaps in Myelin Sheath

Nodes of Ranvier that facilitate saltatory conduction of impulses.

Functional Divisions of the PNS

Divided into sensory (afferent) and motor (efferent) divisions.

Free nerve ending

pain and temperature receptors

Meissner’s corpuscle

touch receptor

Lamellar corpuscle

deep pressure receptor

Two Proprioreceptor

-muscle spindle

-Golgi tendon organ

Multipolar neurons

many extensions from the cell body

bipolar neurons

one axon and one dendrites

unipolar neurons

have a short single process leaving the cell body

Repolarization

restoring the inside of the membrane to a negative charge and the outer surface to a positive charge

▪Five elements of a reflex arc

sensory receptor, sensory neuron, integration center, motor neuron, effector organ

Brain Region

Cerebral hemisphere, Deincephalon, Brain Stem, Cerebellum

thalamus

Transfers impulses to the correct part of the cortex for localization and interpretation

hypothalamus

Houses the limbic center for emotions, Regulates the nearby pituitary gland, Houses mammillary bodies for olfaction (smell)

epithalamus

Forms the roof of the third ventricle

Houses the pineal body (an endocrine gland)

Includes the choroid plexus—forms cerebrospinal fluid

midbrain

extends from the mammillary bodies to the pons inferiorly

medulla oblongata

The most inferior part of the brain stem that merges into the spinal cord

cerebrum

Provides precise timing for skeletal muscle activity and coordination of body movements