Chapter 15-16 Flashcards
Receptors containing specialized cells that monitor specific conditions and passes information to the CNS when stimulated
Sensory Receptors
Deliver somatic and visceral sensory information to their final destinations inside
the CNS using nerves, nuclei and tracts
Sensory Pathways
Parts of the Afferent Division of the Nervous System
– Receptors
– Sensory neurons
– Sensory pathways
Parts of the Efferent Division of the Nervous System
– Nuclei
– Motor tracts
– Motor neurons
Senses that describe our sensitivity to temperature, pain, touch, pressure, vibration, and proprioception
General Senses
Senses that describe our olfaction, vision, gustation, equlibrium and hearing
Special Senses
Receptors that are always active show little peripheral adaptation and are slow-adapting receptors (ex: remind you of an injury long after the initial damage has occurred)
Tonic receptors
Receptors that are normally inactive but become active for a short time whenever a change occurs; they provide information about the intensity and rate of change of a stimulus and are fast-adapting receptors
Phasic receptors
Four types of General Sensory Receptors
- Nociceptors (pain)
- Thermoreceptors (temperature)
- Mechanoreceptors (physical stimulation)
- Chemoreceptors (chemical concentration)
common sensory receptors that are found in the superficial portions of the skin, joint capsules and around the walls of blood vessels
Nociceptors (Pain Receptors)
Two types of axons found in nociceptors
Type A and Type C fibers
Also called temperature receptors, these are free nerve endings located in:
• The dermis
• Skeletal muscles
• The liver
• The hypothalamus
They are conducted along the same pathways that carry pain
sensations
Thermoreceptors
Sensory receptors that are sensitive to stimuli that distort their plasma membranes and contain mechanically gated ion channels whose gates open or close in response to stretching, compression, twisting and other distortions
Mechanoreceptors
Three Classes of Mechanoreceptors
Tactile receptors
Baroreceptors
Proprioceptors
Type of receptor that provide the sensations of touch, pressure, and vibration
Tactile receptors
Type of receptor that detect pressure changes in the walls of blood vessels and in portions of the digestive, reproductive, and urinary tracts
Baroreceptors
Type of receptor that monitor the positions of joints and muscles and are the most structurally and functionally complex of general sensory receptors
Proprioceptors
Sensory receptors that respond to water-soluble and lipid-soluble substances dissolved in surrounding fluid and exhibit peripheral adaptation over
period of seconds; they monitor pH, carbon dioxide, and oxygen levels in blood
Chemoreceptors
Sensory pathway that provides conscious sensations of poorly localized (“crude”) touch, pressure, pain, and temperature
The Spinothalamic Pathway
Sensory pathway that carries sensations of highly localized (“fine”) touch,
pressure, vibration, and proprioception
Posterior Column Pathway
Sensory pathway where cerebellum receives proprioceptive information about position of skeletal muscles, tendons and joints
The Spinocerebellar Pathway
Three integrated motor pathways
- Corticospinal pathway (voluntary muscular control)
- Medial pathway (trunk and proximal limb muscles)
- Lateral pathway (distal limb muscles precise moves)
Reflexes that provide rapid,
involuntary, preprogrammed responses that preserve homeostasis over short term
Spinal and cranial reflexes
Reflexes that control the most basic motor activities
Cranial and spinal reflexes
Functions of the Somatic Nervous System (SNS)
– Operates under conscious control
– Seldom affects long-term survival
– SNS controls skeletal muscles
Functions of the Autonomic Nervous System (ANS)
– Operates without conscious instruction
– ANS controls visceral (organ) effectors
– Coordinates system functions
(Cardiovascular, respiratory, digestive, urinary, reproductive)
What are the visceral motor neurons in the brain stem and spinal cord known as?
preganglionic neurons
two divisions of ANS
- Sympathetic division
2. Parasympathetic division
Division that increases alertness, metabolic rate, and muscular abilities; metabolic rate and promotes digestion
Sympathetic division
Division that reduces metabolic rate, promotes digestion, and controls during resting conditions
Parasympathetic division
Describe the relationship between the sympathetic and parasympathetic division
- Have opposing effects
• If the sympathetic division causes excitation, the
parasympathetic causes inhibition - The two divisions may also work independently
• Only one division innervates some structures - The two divisions may work together, with each controlling one stage of a complex process
Seven Responses to Increased
Sympathetic Activity
- Heightened mental alertness
- Increased metabolic rate
- Reduced digestive and urinary functions
- Energy reserves activated
- Increased respiratory rate and respiratory
passageways dilate - Increased heart rate and blood pressure
- Sweat glands activated
Five Responses to Increased
Parasympathetic Activity
- Decreased metabolic rate
- Decreased heart rate and blood pressure
- Increased secretion by salivary and digestive glands
- Increased motility and blood flow in digestive tract
- Urination and defecation stimulation
Cells that secrete neurotransmitters epinephrine (E) and norepinephrine (NE)
Neuroendocrine cells
Release neurotransmitters at specific organs
Ganglionic Neurons
Release nitric oxide (NO) as neurotransmitter causing neurons to innervate smooth muscles in walls of
blood vessels in skeletal muscles and the brain and produce vasodilation and increased blood flow
Nitroxidergic synapses
What happens when the Sympathetic Preganglionic
Neurons are stimulated?
– Releases ACh at synapses with ganglionic
neurons
– Excitatory effect on ganglionic neurons
Major Effects of Parasympathetic Division
– Constriction of the pupils
– Secretion by digestive glands
– Secretion of hormones
– Increase in smooth muscle activity
– Stimulation and coordination of defecation
– Contraction of the urinary bladder during urination
– Constriction of the respiratory passageways
– Reduction in heart rate and in the force of contraction
Effect of the Parasympathetic division on heart function
Acetylcholine released by postganglionic fibers slows heart rate
Effect of the Sympathetic division on heart function
NE released by varicosities accelerates heart rate
Memories that are specific bits of information
Fact memories
Memories that learned motor behaviors and are incorporated at unconscious level with repetition
Skill memories
Memories that are that can be recalled immediately and contain small bits of information; these are also known as primary memories
Short-term memories
conversion from shortterm
to long-term memory
Memory consolidation
Two types of long-term memory
- Secondary memories fade and require effort to
recall - Tertiary memories are with you for life
Receptors linked to consolidation that are activated by neurotransmitter glutamate
NMDA (N-methyl D-aspartate) Receptors
Disease caused by Destruction of ACh-secreting and GABAsecreting neurons in basal nuclei and results to difficulty controlling movements and gradual decline of intellectual abilities
Huntington’s Disease
Powerful hallucinogenic drug that activates serotonin receptors in brain stem,
hypothalamus, and limbic system
Lysergic Acid Diethylamide (LSD)
Disease caused by inadequate dopamine production which causes motor problems
Parkinson’s Disease
