BIO 107: Unit 4 - Ch 16 Sensory Pathways and the Somatic Nervous System

What are sensory receptors?

What are specialized cells that monitor specific conditions in the body or external environment?

What are the general senses?

What type of senses are these:

• Temperature

• Pain

• Touch

• Pressure

• Vibration

• Proprioception

What are the special senses (sense organs)?

What type of senses are these:

• Olfaction - smell

• Vision - sight

• Gustation - taste

• Equilibrium - balance

• Hearing - sound

What is sensation?

What is the information arriving from the general senses?

What is perception?

What is the conscious awareness of a sensation?

What are free nerve endings?

What are the branching tips of dendrites?

What are tonic receptors?

Which type of receptors:

• Are always active

What are phasic receptors?

Which type of receptors:

• Are normally inactive

• Become active for a short time whenever a change occurs

What is adaptation?

What is the reduction in sensitivity of a constant stimulus?

What are fast-adapting receptors?

Which adapting receptor type:

• Response characteristic of phasic receptors

What are slow-adapting receptors?

Which adapting receptor type:

• (Tonic) show little peripheral adaptation

• Remind you of an injury long after

What are nociceptors of the general senses?

Which receptor of the general senses is:

• PAIN

What is fast pain of nociceptors?

Which pain type of nociceptors is:

• Prickling pain, such as that caused by an injection or a deep cut

What is slow pain of nociceptors?

Which pain type of nociceptors is:

• Burning and aching pain

What are thermoreceptors of the general senses?

Which receptor of the general senses is:

• Are temperature receptors

What are mechanoreceptors of the general senses?

Which receptor of the general senses is:

• Sensitive to stimuli that physically distort, stretching, compression, & twisting

What are tactile receptors of mechanoreceptors?

Which class of mechanoreceptors:

• Provide the sensations of touch, pressure, and vibration

What are baroreceptors of mechanoreceptors?

Which class of mechanoreceptors:

• Detect pressure changes in the walls of blood vessels and in portions of the digestive, reproductive, and urinary tracts

What are proprioceptors of mechanoreceptors?

Which class of mechanoreceptors:

• Monitor the positions of joints and muscles

What is fine touch in tactile receptors?

Which touch type in tactile receptors:

• Are extremely sensitive to location, shape, size texture, movement

What is crude touch in tactile receptors?

Which touch type in tactile receptors:

• Provide poor localization, give little information about the stimulus

What are free nerve endings of tactile receptors?

Which type of tactile receptors:

• Sensitive to pain & temp. tickle, itch & touch

What is root hair plexus of tactile receptors?

Which type of tactile receptors:

• Monitor distortions and movements across the body surface wherever hairs are located

• Adapt rapidly, so are best at detecting initial contact and movements

What are tactile discs of tactile receptors?

Which type of tactile receptors:

• Also called Merkel’s discs

• Fine touch and pressure receptors

What are tactile corpuscles of tactile receptors?

Which type of tactile receptors:

• Also called Meissner’s corpuscles

• Fine touch

What are lamellated corpuscles of tactile receptors?

Which type of tactile receptors:

• Also called Pacinian corpuscles

• Sensitive to deep pressure

What are Ruffini corpuscles of tactile receptors?

Which type of tactile receptors:

• Distortion of the skin

• Located in the reticular (deep) dermis

What are muscle spindles of proprioceptors

Which major group of proprioceptors:

• Monitor skeletal muscle length

• Trigger stretch reflexes

What are golgi tendon organs of proprioceptors?

Which major group of proprioceptors:

• Monitor external tension developed during muscle contraction

• Stimulated by tension in tendon

What are joint capsule receptors of proprioceptors?

Which major group of proprioceptors:

• Free nerve endings detect pressure, tension, and movement at the joint

What are chemoreceptors?

What are receptors that monitor pH, carbon dioxide, and oxygen levels in arterial blood?

What are carotid bodies of chemoreceptors?

Which bodies of chemoreceptors are:

• Near the origin of the internal carotid arteries on each side of the neck

What are aortic bodies of chemoreceptors?

Which bodies of chemoreceptors are:

• Between the major branches of the aortic arch

What is first-order neuron?

Which neuron order type is:

• Sensory neuron delivers sensations to the CNS

• From somatic receptors → spinal cord or brain stem

What is second-order neuron?

Which neuron order type is:

• From spinal cord or brain stem → thalamus

What is third-order neuron?

Which neuron order type is:

• If the sensation is to reach our awareness, thalamus → cerebral cortex

What is the posterior column pathway?

Which major somatic sensory pathway:

• Carries sensations of highly localized (“fine”) touch, pressure, vibration, and proprioception

• Decussation - crossing over

• Medial lemniscus - tract from medulla to thalamus

What are the anterior spinothalamic tracts of the anterolateral pathway?

Which tract of anterolateral pathway:

• Carries crude touch and pressure sensations

What are the lateral spinothalamic tracts of the anterolateral pathway?

Which tract of anterolateral pathway:

• Carries pain and temperature sensations

What is referred pain in the anterolateral pathway?

Which pain type in anterolateral pathway is:

• Individual feels pain in specific part of body surface

What is the spinocerebellar pathway?

Which major somatic sensory pathway:

• From spinal cord to cerebellum

What are the posterior spinocerebellar tracts of the spinocerebellar pathway?

Which tract of spinocerebellar pathway:

• Cerebellum receives same side trunk and lower limb proprioceptive information via the inferior cerebellar peduncle

What are the anterior spinocerebellar tracts of the spinocerebellar pathway?

Which tract of spinocerebellar pathway:

• Cerebellum receives opposite side trunk and lower limb proprioceptive information via the superior cerebellar peduncle

What are visceral sensory pathways?

Which type of pathway:

• Monitors visceral tissues and organs, primarily within the thoracic and abdominopelvic cavities

What are solitary nucleus of visceral sensory pathways?

Which part of visceral sensory pathways:

• Major processing and sorting center for visceral sensory information

Which cranial nerves carry visceral information?

What do cranial nerves V, VII, IX, and X carry?

What do somatic nervous system (SNS) controls in motor pathways?

What controls contractions of skeletal muscles in motor pathways?

What is upper motor neuron?

Which motor neuron is:

• Cell body lies in a CNS processing center

• Axon synapses with lower motor neuron

• May facilitate or inhibit lower motor neuron

What is lower motor neuron?

Which motor neuron is:

• Cell body lies in a nucleus of the brain stem or spinal cord

• Only the axon extends outside CNS

• Axon innervates skeletal muscles

What are corticospinal pathways?

Which type of pathway:

• Provides voluntary control over skeletal muscles

What are corticobulbar tracts?

Which corticospinal tracts:

• Provide conscious control over skeletal muscles (using cranial nerves)

• Move the eye, jaw, face, and some muscles of neck and pharynx

What are lateral corticospinal tracts?

Which corticospinal tracts:

• Activates skeletal muscles on the opposite side (90% cross high)

• For fast & skilled movements (writing)

What are anterior corticospinal tracts?

Which corticospinal tracts:

• Activates skeletal muscles on the opposite side (10% cross low)

• For fast & skilled movements (writing)

What is motor homunculus?

What provides indication of degree of fine motor control available?

What are medial pathways?

Which type of pathway:

• Primarily concerned with control of muscle tone

• Gross movements of neck, trunk, and proximal limb muscles

What are vestibulospinal tracts of medial pathways?

Which tract of medial pathway:

• (CN VIII) monitor position and movement of the head

• Maintain posture and balance

What are tectospinal tracts of medial pathways?

Which tract of medial pathway:

• Moves head & eyes toward stimuli

What are reticulospinal tracts of medial pathways?

Which tract of medial pathway:

• Controls muscle tone & visceral motor functions

What are lateral pathways?

Which type of pathway:

• Primarily concerned with muscle tone and more precise movements of distal parts of limbs

What are rubrospinal tracts of lateral pathways?

Which tract of lateral pathway:

• Govern precise movements of distal parts of limbs

What does the cerebellum monitors?

What monitors:

• Proprioceptive (position) sensations

• Visual information from the eyes

• Vestibular (balance) sensations from inner ear

What does basal nuclei provides?

What provides background patterns of movement involved in voluntary  motor activities?