MTTP 23 Flashcards
Occupies a central or medial position in the body and includes the brain, spinal cord, meninges, and cerebrospinal fluid (CSF)
Central Nervous System (CNS)
Nerves that begin and end in the brain and spinal cord but extend beyond skull and vertebral column and include the cranial and spinal nerves
Peripheral Nervous System (PNS)
Regulates skeletal muscles and joints and contains receptors of special senses, such as vision, hearing, taste, smell, and touch
Somatic Nervous System (SNS)
Regulates involuntary responses such as the activities of organs, glands, and smooth muscle
Autonomic Nervous System (ANS)
Connect rice tissues that support, nourish, protect, and insulate neurons
Neuroglia or glial cells
Increase the conduction rate of the impulse and provide insulation to prevent impulse leakage to adjacent neurons
Myelin
Glial cells found in the PNS
Schwann cells
Gaps located between Schwann cells and their myelin sheaths are the
Nodes of Ranvier
Impulse-conducting cells and represent the simplest structural unit of the nervous system
Neurons
Contains the nucleus and other organelles; attached to this are the dendrite and axon
Cell body
Short and narrow extensions that receive stimuli and transmit impulses toward the cell body
Dendrite
Nerve fiber that transmits impulses away from the cell body
Axon
Transmit sensory info towards the CNS
Afferent neurons
Transmit impulses from the CNS toward muscles or glands
Efferent neurons
Protective involuntary but predictable response to stimuli that uses a reflex arc to exert its action
Reflex
Single conduction pathway to and from the CNS
Reflex Arc
Bundles of nerve fibers in the PNS
Nerves
Term used to describe the neuron while its resting and not conducting impulses
Polarization
Mechanism producing and maintains polarization
Sodium-potassium pump
When a neuron receives stimulus, ion channels or gates located on the cell membrane open and transmits nerve impulse down the axon
Depolarization
Neuron quickly resumes its resting or polarized, state
Repolarization
Place where signals are transmitted between two neurons or between a neuron and a muscle or gland
Synapse
Chemical messengers used by chemical synapses to transmit signals between the presynaptic neuron and the postsynaptic neuron
Neurotransmitters
Consists of brain and spinal cord; surrounded by connective tissue membranes called meninges and by cerebrospinal fluid
CNS
Innermost layer and attaches to the surface of the brain and spinal cord; this layer is thin and delicate and contains blood vessels
Pia Mater
Middle layer; loose arrangement of collagen fibers gives this layer a weblike appearance
Arachnoid Mater
Outermost layer and lies against the skull and vertebral column; this is think and dense and creates a few notable partitions within the brain
Dura mater
Clear, colorless fluid surrounding the brain and spinal cord found in the subarachnoid space
Cerebrospinal fluid
The brain consists of 4 main regions:
Cerebrum
Diencephalon
Cerebellum
Brainstem
The largest and most superior portion of the brain
Cerebrum
The right and left cerebral hemispheres are connected by bundles of transverse fibers
Corpus callosum
Rhythmic patterns of cerebral electrical activity that can be displayed using an electroencephalogram (EEG)
Brainwaves
Associated with calmness and relaxation
Alpha (8-13 Hz)
Associated with alertness and mental activity
Beta (13+ Hz)
Occurs during sleep
Delta ( 4 < Hz)
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Located in the center of the brain, contains the thalamus, the hypothalamus, the pituitary gland, and the pineal gland
Diencephalon
Largest portion of the diencephalon and relays sensory info to appropriate areas of the cerebrum
Thalamus
Regulates the ANS, controls behavioral patterns, and regulates 24-hour cycles called biorhythms or circadian rhythms
Hypothalamus
SAME stands for?
Sensory neurons are Afferent and Motor neurons are Efferent
continuous with the spinal cord and contains the midbrain, the pons, and the medulla oblongata
brainstem
emerge from the inferior surface of the brain and are named by Roman numerals, for the areas they supply, or the the type of signal they carry
cranial nerves (12 pairs)
controls the muscles of facial expression, detects taste, produces saliva and tears, and is both sensory and motor
CN VII (Facial)
regulates activity of thoracic and abdominal organs, a such as gastrointestinal peristalsis, heart rate, and blood pressure, as well as sweating; sensory and motor
CN X (Vagus)
three branches; detects sensations, such as nociception and temperature on the head and face, moves muscles of mastication, and is both sensory and motor
CN V (Trigeminal)
emerge from the sides of the spinal cord
31 pairs of spinal nerves
areas of skin supplied by a single sensory spinal nerve
dermatomes
groups of skeletal muscles supplied by single motor spinal nerve
myotomes
also known as myotatic reflexes; are reflexive muscle contractions in response to muscle stretch stimuli
stretch reflexes
controls energy conservation and dominates during periods of rest and under calm conditions
parasympathetic division
controls energy expenditure and dominates during physical exertion or emotional stress; occur quickly
sympathetic division
receives external stimuli and are located on or near the surface of the body, such as skin and mucosa
exteroceptors
Specialized interoceptors found in muscles, joints, and ears
Proprioceptors
Detect changes in temperature and are found in the skin and mucosae
Thermoreceptors
