human anatomy Fundamental of Nervous System & CNS

Depolarization

The process during the action potential when sodium is rushing into the cell causing the interior to become more positive.

Parts of a nueron

cell body (soma) contains the nucleus of the neuron axon -transmit impulses away from the cell body , insulated by oligodendrocytes and the myelin sheath, nodes of trainer. the axon terminates at the synapse dendrites- receive impulses form sensory receptors or interneurons and transmit them towards the cell body

Coverings of the brain and spinal cord

meninges- dura mater, arachnoid mater, pia mater

sensory neurons (afferent)

neurons that carry incoming information from the sensory receptors to the brain and spinal cord

motor neurons (efferent)

neurons that carry outgoing information from the brain and spinal cord to the muscles and glands to produce movement

Interneurons

neurons within the brain and spinal cord that communicate internally and intervene between the sensory inputs and motor outputs

function of a neuron

process and transmit information

Cerebrospinal fluid (CSF) formation and flow

is a clear, colorless body fluid found in the brain and spinal cord. It is produced by the specialised ependymal cells in the choroid plexuses of the ventricles of the brain, and absorbed in the arachnoid granulations; goes from the lateral ventricles to the third ventricle via the interventricular foramina. From the third ventricle, the fluid flows to the fourth ventricle by way of the cerebral aqueduct. The fluid then flows from the fourth ventricle to the central canal and the subarachnoid space.

Neuroglia cells

specialized cells in nervous tissue that hold nerve cells in place and perform specialized functions

resting membrane potential

the electrical charge of a neuron when it is not active

Synapse

the junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron; where information is transmitted from one neuron to the next.

lobes of the brain and function

-Frontal lobe Personality, behavior, emotions Judgment, planning, problem solving Speech: speaking and writing (Broca's area) Body movement (motor strip) Intelligence, concentration, self awareness -Parietal lobe Interprets language, words Sense of touch, pain, temperature (sensory strip) Interprets signals from vision, hearing, motor, sensory and memory Spatial and visual perception -Occipital lobe Interprets vision (color, light, movement) -Temporal lobe Understanding language (Wernicke's area) Memory Hearing Sequencing and organization

Divisions of the Nervous System

Central nervous system (CNS) -Brain and spinal cord Integration, command center Peripheral nervous system (PNS) -Spinal and cranial nerves Receptors to CNS CNS to effectors Two functional subdivisions Sensory (afferent) division (to CNS) Motor (efferent) division (from CNS) Sensory (afferent) division (to CNS) -Contains fibers Somatic afferent fibers -from skin, skeletal muscles, and joints Visceral afferent fibers -from visceral organs Motor (efferent) division (from CNS) -Somatic nervous system, Autonomic nervous system (ANS) Somatic nervous system -CNS to skeletal muscles Conscious control, voluntary Autonomic nervous system (ANS) -CNS to smooth muscle, cardiac muscle, and glands Involuntary 2 subdivisions Sympathetic and Parasympathetic Sympathetic = "Fight-or-Flight" Parasympathetic = "Resting + Digesting" Opposing stimulating + inhibiting functions Effectors (most) are innervated by both

regions of the brain and function

Cerebrum: is the largest part of the brain and is composed of right and left hemispheres. It performs higher functions like interpreting touch, vision and hearing, as well as speech, reasoning, emotions, learning, and fine control of movement. Cerebellum: is located under the cerebrum. Its function is to coordinate muscle movements, maintain posture, and balance. Brainstem: acts as a relay center connecting the cerebrum and cerebellum to the spinal cord. It performs many automatic functions such as breathing, heart rate, body temperature, wake and sleep cycles, digestion, sneezing, coughing, vomiting, and swallowing.

diencephalon

Hypothalamus: is located in the floor of the third ventricle and is the master control of the autonomic system. It plays a role in controlling behaviors such as hunger, thirst, sleep, and sexual response. It also regulates body temperature, blood pressure, emotions, and secretion of hormones. Thalamus: serves as a relay station for almost all information that comes and goes to the cortex. It plays a role in pain sensation, attention, alertness and memory. Epithalmas: a part of the dorsal forebrain including the pineal gland and a region in the roof of the third ventricle of the brain.

efferent neuron

Neuron that conducts impulses away from the CNS to muscles and glands.

afferent neuron

Neuron that conducts impulses toward the CNS from the body periphery.

Repolarization

Return of the cell to resting state, caused by reentry of potassium into the cell while sodium exits the cell.

Shwann cells

Specialized cells that myelinate the fibers of neurons found in the PNS.

Nuerons

a nerve cell; the basic building block of the nervous system