“My green thumb came only as a result of the mistakes I made while learning to see things from the plant’s point of view.” -H. Fred Ale Nervous System 1 Classroom Rules
You'll get one warning, then you'll have to leave the room!
Punctuality- Everybody's time is precious: •! You get here by the start of class, I'll have you out of here on time. •! Getting back from breaks counts as being late to class.
Participation- No distractions: •! No side talking. •! No laying down. •! No inappropriate clothing. •! No food or drink except water. •! No phones in classrooms, clinic or bathrooms. Lesson Plan: 42a Nervous System 1
•! 5 minutes: Breath of Arrival and Attendance
•! 50 minutes: Nervous System 1 Introduction Introduction
The body uses two systems to monitor and stimulate changes needed to maintain homeostasis: endocrine and nervous.
Endocrine System Nervous System Introduction
The endocrine system responds more slowly and uses hormones as chemical messengers to cause physiologic changes.
Endocrine System Nervous System 1.! Slow response 2.! Hormones Introduction
The nervous system responds to changes more rapidly and uses nerve impulses to cause physiologic changes.
Endocrine System Nervous System 1.! Slow response 1.! Rapid response 2.! Hormones 2.! Nerve impulses (and neurotransmitters too) Introduction
It is the nervous system that is the body's master control and communications system. It also monitors and regulates many aspects of the endocrine system.
Endocrine System Nervous System 1.! Slow response 1.! Rapid response 2.! Hormones 2.! Nerve impulses (and neurotransmitters too) 3.! Body control 4.! Body communications 5.! Monitors and regulates the endocrine system Introduction
Every thought, action, and sensation reflects nerve activity.
We are what our brain has experienced.
If all past sensory input could be completely erased, we would be unable to walk, talk, or communicate. We would remember no pain or pleasure. Brain Spinal cord Cranial nerves Spinal nerves Cerebrospinal fluid Meninges Sense organs Neurotransmitters
Anatomy Brain Spinal Cord
Nerves Sensory input
Interpretive functions
Motor output
Higher mental functioning and emotional responsiveness
Physiology Physiology
Sensory input Sensory receptors detect changes, or stimuli , inside the body such as lowered blood sugar levels, or outside the body such as an increase in temperature. Receptors carry nerve impulses into the spinal cord and
brain . Physiology
Interpretive functions The spinal cord and brain integrate sensory ,
Information. They analyze it, store some of it, and decide on appropriate responses. Physiology
Motor output Motor neurons carry nerve impulses from the brain and spinal cord to smooth muscle, cardiac muscle, skeletal muscle, and glands . Physiology
Higher mental functioning and emotional responsiveness Examples:
cognition, memory , joy, excitement, anger, anxiety. Nervous System
Central N. S. Peripheral N. S.
Somatic N.S. Autonomic N.S.
Sympathetic N.S. Parasympathetic N.S.
Basic Organization Basic Organization
CNS Interpreting sensory info and issuing motor responses
PNS PNS Motor or Efferent Neurons
Sensory or Afferent Neurons Somatic Autonomic N.S. N.S.
Effectors Sensory Receptors ( Muscles and Glands ) Cardiac and Skeletal smooth muscles muscles. Glands Basic Organization
Central nervous system (CNS) Body system primarily concerned with
interpreting incoming sensory information and issuing instructions in the form of motor responses. Includes: brain, meninges, cerebrospinal fluid, and spinal cord. Central Nervous Brain System Spinal cord Basic Organization
Peripheral nervous system (PNS) Composed of the cranial and spinal
nerves emerging from the CNS. Brain Spinal Cord
CNS in green Nerves
PNS in yellow Basic Organization
Somatic nervous system (SNS) Voluntary division of the PNS that transmits information from bones, muscles, joints , skin, and
special senses of vision, hearing, taste, and smell into the CNS. Carries
impulses from the CNS to skeletal muscles. Basic Organization
Autonomic nervous system (ANS) Involuntary division of PNS supplying impulses to smooth muscle, cardiac muscle, and glands.
Has sympathetic and parasympathetic divisions. Neuroglia
Neuron
Cells of the Nervous System Cells of the Nervous System
Neuroglia (glia, glial cells) Connective tissue that supports, nourishes, protects, insulates, and organizes neurons. Types: astrocyte, ependymocyte, microglia, oligodendrocyte, Schwann cell, satellite cell. Cells of the Nervous System
Neuron Impulse-conducting cell. Properties: Excitability Conductibility Secretability Cells of the Nervous System
Excitability The ability to respond to a stimulus and
convert it to a nerve impulse.
Conductibility The ability to transmit the impulses to other neurons, muscles, and glands.
Secretability The ability to release neurotransmitters that help conduct an impulse. Cell body
Dendrite
Axon
Parts of a Neuron Parts of a Neuron
Cell body (AKA: cyton) Main region of the neuron containing the nucleus,
ribosomes, and other organelles. The gray matter of the nervous system. Parts of a Neuron
Dendrite Short, narrow, neural extensions that receive and transmit
stimuli toward the neuron's cell body. Parts of a Neuron
Axon Neural extension that carries nerve impulses away from the neuron toward another neuron, a muscle cell, or gland. Telodendria Synaptic bulb Synaptic vesicle Myelin sheath Nodes of Ranvier
Axon Structures Axon Structures
Telodendria Clusters of short, fine filaments located
at the end of each axon. Axon Structures
Synaptic bulb Small bud-like structure on the ends of telodendria.
Contains synaptic vesicles . Axon Structures
Synaptic vesicle Sac-like structure located within the synaptic bulbs that contain neurotransmitters . Axon Structures
Myelin sheath Fatty tissue layer surrounding most axons
in the PNS. Insulates the neuron and increases nerve impulse speed. Axon Structures
Nodes of Ranvier Gaps along myelinated axons. Increase
speed of a nerve impulse by allowing the impulse to jump from one
node to another. “My green thumb came only as a result of the mistakes I made while learning to see things from the plant’s point of view.” -H. Fred Ale Nervous System 1 “My green thumb came only as a result of the mistakes I made while learning to see things from the plant’s point of view.” -H. Fred Ale Nervous System 2 Endoneurium
Perineurium
Epineurium
Connective Tissues: Neurons to Nerves Connective Tissues: Neurons to Nerves neuron ! fascicle ! nerve endoneurium ! perineurium ! epineurium Connective Tissues: Neurons to Nerves
Fascicle (p. fasciculi) Bundles of neurons .
Nerve Bundles of fasciculi .
Endoneurium Connective tissue layer for a neuron .
Perineurium Connective tissue layer for a fascicle .
Epineurium Connective tissue layer for a nerve . Connective Tissues: Neurons to Nerves neuron ! fascicle ! nerve endoneurium ! perineurium ! epineurium Sensory neurons (afferent neurons)
Interneurons (association neurons)
Motor neurons (efferent neurons)
Classifications of Neurons Classifications of Neurons
Sensory neuron (AKA: afferent neuron) Carries impulses to the CNS. Classifications of Neurons
Sensory neuron (AKA: afferent neuron) Carries impulses to the CNS. Classifications of Neurons
Interneuron (AKA: association neuron) Nerve between a sensory , and motor neuron. Participates in integrative functions. Classifications of Neurons
Motor neuron (AKA: efferent neuron) Sends a nerve impulse to effectors. Classifications of Neurons
Effector Any muscle or gland that motor nerves act on. Nerve Impulses
Nerve impulse (AKA: action potential) An electrical signal that conveys information along a neuron. Synapse
Presynaptic neuron
Postsynaptic neuron
Synapse Synapse
Synapse Junction between two neurons or between a neuron and a muscle or gland. Synapse
Presynaptic neuron Neuron carrying a nerve impulse toward a synapse.
Postsynaptic neuron Neuron carrying a nerve impulse away from a synapse. Synaptic bulb
Synaptic cleft
Cell membrane
Synaptic vesicle
Synaptic Structures Synaptic Structures
Synaptic bulb Small bulb-like structure on the ends of telodendria. Contains synaptic vesicles . Synaptic Structures
Synaptic cleft (AKA: synaptic gap) Space between the synaptic bulb of the presynaptic neuron and the plasma membrane of the postsynaptic neuron, muscle cell, or gland. Synaptic Structures
Cell membrane (AKA: plasma membrane) Semipermeable membrane that separates cytoplasm from the surrounding external environment. Synaptic Structures
Synaptic vesicle Sac-like structure located within the synaptic bulbs that contains neurotransmitters. “A one-way process”
Excitatory response
Inhibitory response
Reuptake
Synaptic Transmission Synaptic Transmission: A one-way process
1. A nerve impulse travels down an axon to a synaptic bulb. Synaptic Transmission: A one-way process
2. Neurotransmitters travel across the synaptic cleft toward postsynaptic neuron's plasma membrane. Synaptic Transmission: A one-way process
3. The neurotransmitters bind with receptor sites on the postsynaptic neuron, which brings about either an excitatory or inhibitory response by the postsynaptic neuron depending on which neurotransmitter is being used. Synaptic Transmission: A one-way process
Excitatory response Continuing the impulse.
Inhibitory response Stopping the impulse. Synaptic Transmission: A one-way process
Reuptake Drawing up of neurotransmitters in the synapse by the presynaptic neuron. Neurotransmitters
Neurotransmitter Collective term for chemical messengers , involved in nerve impulse transmission.
Acetylcholine muscle contraction
Epinephrine regulates fight or flight
Histamine inflammatory responses
Endorphins pain-reduction
Etcetera . . . . “My green thumb came only as a result of the mistakes I made while learning to see things from the plant’s point of view.” -H. Fred Ale Nervous System 2 “My green thumb came only as a result of the mistakes I made while learning to see things from the plant’s point of view.” -H. Fred Ale Nervous System 3 Cranial nerves
Spinal nerves
Peripheral Nervous System Peripheral Nervous System
Cranial nerve Nerve pairs originating in the brain. 12 total. Mostly supply and control functions of the head, face, and throat.
12 nerve pairs total: 1. Olfactory 7. Facial 2. Optic 8. Vestibulocochlear 3. Oculomotor 9. Glossopharyngeal 4. Trochlear 10. Vagus 5. Trigeminal 11. Accessory or spinal accessory 6. Abducens 12. Hypoglossal
Peripheral Nervous System
Spinal nerve Pairs of nerves originating from the spinal cord. 31 pairs total.
31 nerve pairs total: 8 cervical 12 thoracic 5 lumbar 5 sacral 1 coccygeal Cervical nerves
Thoracic nerves
Lumbar nerves Sacral nerves Coccygeal nerves Peripheral Nervous System
Nerve root Attachment of a spinal nerve to the spinal column.
Ventral nerve root Nerve root containing motor neurons.
Dorsal nerve root Nerve root containing sensory neurons. Peripheral Nervous System
Ganglion Cluster of nerve cell bodies located in the PNS. Peripheral Nervous System
Plexus Network of intersecting nerves in the PNS. Peripheral Nervous System
Cervical plexus (C1-C5) Plexus that innervates the skin and muscles of the head, neck, and shoulders. Also the diaphragm . Peripheral Nervous System
Brachial plexus (C5-T1) Plexus that innervates the skin and muscles of the upper extremity. Peripheral Nervous System
Lumbosacral plexus (L1-S4) Plexus that innervates the skin and muscles of the abdomen, lower back, genitals, and lower extremity. Peripheral Nervous System
Dermatome Area of skin innervated by a specific sensory nerve root
Peripheral Nervous System
Myotome Group of skeletal muscles innervated by a single spinal segment. Peripheral Nervous System
Innervate To supply with nerves. Peripheral Nervous System
Reflex Involuntary, predictable response to a
stimulus. Examples: coughing, sneezing, blinking, correcting heart rate, respiratory rate, and blood pressure. Peripheral Nervous System
Reflex arc Nervous system's simplest functional unit.
Carries a stimulus impulse to the spinal cord where it connects with a motor neuron that carries the reflex impulse back to an appropriate muscle , or gland (effector).
The simplest reflex arc is one sensory neuron and one motor neuron.
Exteroceptor
Proprioceptor
Interoceptor
Receptors Classified by Location of Stimuli Receptors Classified by Location of Stimuli
Exteroceptor Receptor located in the skin, mucous membranes, and sense organs. Responds to stimuli originating from outside of the body. Receptors Classified by Location of Stimuli
Proprioceptor Receptor located in the skin, ears, muscles, tendons, joints, and fascia. Responds to movement and body position. Receptors Classified by Location of Stimuli
Interoceptor Receptor located in the viscera. Responds to stimuli such as digestion, excretion, and blood pressure originating from within the body. Receptors Classified by Location of Stimuli
Adaptation Decrease in sensitivity due to prolonged stimulus. Chemoreceptor Mechanoreceptor Etcetera . . .
Receptors Classified by Location of Stimuli Receptors Classified by Type of Stimuli they Detect
Chemoreceptor Activated by chemical stimuli. Detects smells, tastes, and changes in blood chemistry.
Mechanoreceptor Receptor that detects pressure and movement. Found in the skin, blood vessels, ears, muscles, tendons, joints, and fascia. Detects pressure, blood pressure, vibration, stretching, muscular contraction, proprioception, sound, and equilibrium. Receptors Classified by Type of Stimuli they Detect
Pressure receptor Receptor that detects pressure in skin and mucous membranes. Examples: Meissner corpuscle, Ruffini corpuscle, Pacinian corpuscle, Krause end bulbs, Merkel disks, and hair root plexus. Receptors Classified by Type of Stimuli they Detect
Stretch receptor Receptor that detects stretch in muscle fibers, tendons, and arteries. Examples: muscle spindle, Golgi tendon organ, and baroreceptor. Receptors Classified by Type of Stimuli they Detect
Muscle spindle Stretch receptor located within the muscle belly .
Detects sudden stretching, causing the nervous system to respond by reflexively contracting the muscle.
Receptors Classified by Type of Stimuli they Detect
Golgi tendon organ Receptor located at the musculotendinous junction.
Detects tension and excessive stretch, causing the nervous system to respond by inhibiting contraction.
Receptors Classified by Type of Stimuli they Detect
Baroreceptor Receptor that detects blood pressure by monitoring the amount of stretch exerted on certain arterial walls, namely carotid arteries and the aortic arch. Receptors Classified by Type of Stimuli they Detect
Photoreceptor Receptor that is sensitive to light . Examples: rods
and cones in the eyes. Receptors Classified by Type of Stimuli they Detect
Nociceptor (AKA: free nerve ending) Receptor that detects pain . Receptors Classified by Type of Stimuli they Detect
Thermoreceptor Receptor that detects temperature changes. “My green thumb came only as a result of the mistakes I made while learning to see things from the plant’s point of view.” -H. Fred Ale Nervous System 3