Reflex Physiology and General senses

What are the 5 steps of the reflex arc

Receptor, Sensory Relay, Integration, Motor Command Relay, Effector

Reflex

Simple automatic response to a stimulus

Most neural reflexes are designed to what?

Maintain balance and posture, protect from danger or injury, carry out routine activities like chewing or walking

Monosynaptic vs Polysynaptic

based on the number of neurons involved

Monosynaptic reflexes

Faster and integrated in the spinal cord ex, knee jerk

Polysynaptic reflex

contain at least one interneuron, most are polysynaptic

Somatic

Voluntary, involves skeletal muscles

Autonomic

Involuntary, involves smooth muscles, glands, or visceral glands

acquired reflexes

learned through experience, driving, walking

General Stimuli

temperature, pH, pressure

Classifications of General stimuli

Exteroceptors, Interoceptors

Exteroceptors monitor what?

Temperature, touch, pain, pressure

Interoceptors monitor what?

internal conditions, Ex. chemoreceptors

Free (naked) nerve endings

Dendrites terminate in epidermis/dermis junction of skin and mucosal epithelium, detect pain

Merkel cells

Located in the stratum germinitivum, detect light touch

Encapsulated Receptors

Meissner's Corpuscles, Pacinian Corpuscles

Meissner's corpuscles

more superficial, detects light touch

Pacinian Corpuscles

More deep, detects forceful pressure, vibrations

Free nerve endings vs Merkel cells

Free nerve endings terminate basically at the surface of skin or mucosa and detect pain, Merkel cells terminate at the deepest layer of the epidermis and detect touch

Label number 1 in the illustration

Merkel disk

Label number 2 in the illustration

Ruffini corpuscle

Label number 3 in the illustration

Pacinian corpuscle

Label number 4 in the illustration

nociceptor (free nerve endings)

Label number 5 in the illustration

Meissner's corpuscle

Label number 6 in the illustration

Root hair plexus

Label number 7 in the illustration

Krause and bulb

Muscle spindle purpose

monitor muscle position, ensures that muscles are not overstretched

α-motor neurons

innervate contractile region of external fibers

γ-motor neurons

innervate contractile region of intrafusal fiber

Sensory neuron sends what to what back to what via what

continual impulses, CNS, extrafusal fibers, α-motor neurons

Willful muscle contraction

Brain sends impulse to γ-motor neurons in order to contract the intrafusal fibers which relieves compression of spindle

Receptors are what

Transducers

Transducers

Convert stimuli to action potentials

Action potentials are distinguished as unique by what?

Their destination in the brain

Receptor Fields

The area within, if stimulated by two separate stimuli, is translated as a single stimulation

What is adaptation?

Desensitization to constant stimuli

Identify number 11 in the illustration

Neurotransmitter vesicle

identify number 12 in the illustration

Axon Hillox

Identify number 13 in the illustration

Mitochondria

Identify the number 14 in the illustration

Calcium channel

identify the number 15 in the illustration

Motor end plate

Identify the number 1 in the illustration

sensory receptor

Identify the number 2 in the illustration

Sensory nerve (Afferent)

Identify the number 3 in the illustration

Spinal nerve

Identify the number 4 in the illustration

Dorsal root

Identify the number 5 in the illustration

dorsal root ganglion

Identify the number 6 in the illustration

Dorsal horn

Identify the number 7 in the illustration

interneuron

Identify the number 8 in the illustration

Motor neuron

Identify the number 9 in the illustration

Motor nerve (efferent)

Identify the number 10 in the illustration

Muscle cell