Chapter 14 The Spinal Cord and Spinal Nerves
![Chapter 14 The Spinal Cord and Spinal Nerves Chapter 14 The Spinal Cord and Spinal Nerves](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-1.jpg)
![Spinal Cord Begins at foramen magnum extends down to L 1/L 2. n Contiguous Spinal Cord Begins at foramen magnum extends down to L 1/L 2. n Contiguous](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-2.jpg)
![Spinal cord levels: C 1 -C 8 T 1 -T 12 L 1 -L Spinal cord levels: C 1 -C 8 T 1 -T 12 L 1 -L](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-3.jpg)
![The Meninges n 1. 2. 3. Consists of 3 layers around the brain and The Meninges n 1. 2. 3. Consists of 3 layers around the brain and](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-4.jpg)
![Vertebral column (x-section) Vertebral column (x-section)](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-5.jpg)
![Spinal cord (x-section) Spinal cord (x-section)](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-6.jpg)
![Gray matter of spinal cord Shaped like a “butterfly” with central canal. n Wings Gray matter of spinal cord Shaped like a “butterfly” with central canal. n Wings](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-7.jpg)
![Gray matter of spinal cord Gray matter of spinal cord](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-8.jpg)
![White matter of spinal cord Contains myelinated ascending and descending spinal tracts. n Divided White matter of spinal cord Contains myelinated ascending and descending spinal tracts. n Divided](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-9.jpg)
![Tracts in white matter of spinal cord Tracts in white matter of spinal cord](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-10.jpg)
![Ascending spinal tracts n Transmit sensory information from peripheral body. n Receptors relay information Ascending spinal tracts n Transmit sensory information from peripheral body. n Receptors relay information](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-11.jpg)
![Ascending tracts Three neuron chain: First-order: Receptor to afferent nerve into spinal cord. Second Ascending tracts Three neuron chain: First-order: Receptor to afferent nerve into spinal cord. Second](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-12.jpg)
![Descending spinal tracts n Take information from brain and descend in gray columns to Descending spinal tracts n Take information from brain and descend in gray columns to](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-13.jpg)
![Descending tracts Two neuron chain: Upper motor neuron: From cortex or brain stem to Descending tracts Two neuron chain: Upper motor neuron: From cortex or brain stem to](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-14.jpg)
![Ascending tracts Three neuron chain: First-order: Receptor to afferent nerve into spinal cord. Second Ascending tracts Three neuron chain: First-order: Receptor to afferent nerve into spinal cord. Second](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-15.jpg)
![Nerve structure Nerves are only in the periphery n Cable-like organs in PNS = Nerve structure Nerves are only in the periphery n Cable-like organs in PNS =](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-16.jpg)
![Nerve anatomy Nerve anatomy](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-17.jpg)
![](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-18.jpg)
![Spinal Nerves There are 31 pairs of spinal nerves. Spinal nerves are all mixed Spinal Nerves There are 31 pairs of spinal nerves. Spinal nerves are all mixed](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-19.jpg)
![Dorsal and ventral ramus nerves Dorsal ramus nerves innervate the ligaments, muscles and skin Dorsal and ventral ramus nerves Dorsal ramus nerves innervate the ligaments, muscles and skin](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-20.jpg)
![](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-21.jpg)
![Thoracic level -Dorsal ramus -Ventral ramus -Dorsal root ganglion -Sympathetic chain ganglion -white and Thoracic level -Dorsal ramus -Ventral ramus -Dorsal root ganglion -Sympathetic chain ganglion -white and](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-22.jpg)
![](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-23.jpg)
![Spinal nerve plexuses from ventral ramus - major nerves off of them. n n Spinal nerve plexuses from ventral ramus - major nerves off of them. n n](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-24.jpg)
![Spinal nerve plexuses n Spinal nerve plexuses n](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-25.jpg)
![Cervical plexus -C 1 - C 5 n Phrenic nerve -C 3 - C Cervical plexus -C 1 - C 5 n Phrenic nerve -C 3 - C](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-26.jpg)
![Brachial plexus -C 5 -C 8 & T 1 n Axillary nerve - C Brachial plexus -C 5 -C 8 & T 1 n Axillary nerve - C](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-27.jpg)
![](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-28.jpg)
![Lumbar plexus L 1 - L 4 n Femoral nerve -L 2 -L 4 Lumbar plexus L 1 - L 4 n Femoral nerve -L 2 -L 4](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-29.jpg)
![Sacral plexus -L 4 - S 4 n Sciatic nerve -Tibial n. L 4 Sacral plexus -L 4 - S 4 n Sciatic nerve -Tibial n. L 4](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-30.jpg)
![DERMATOMES n The area of skin that carries sensory information to the CNS from DERMATOMES n The area of skin that carries sensory information to the CNS from](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-31.jpg)
![](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-32.jpg)
![Reflex Arc Consists of 1. sensory receptor, 2. afferent nerve, 3. interneuron, 4. efferent Reflex Arc Consists of 1. sensory receptor, 2. afferent nerve, 3. interneuron, 4. efferent](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-33.jpg)
![Mono and Polysynaptic Reflexes Mono and Polysynaptic Reflexes](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-34.jpg)
![Receptors: Classification by location 1. 2. 3. Exteroceptors- receptors sensitive to changes outside of Receptors: Classification by location 1. 2. 3. Exteroceptors- receptors sensitive to changes outside of](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-35.jpg)
![Proprioceptors n Encapsulated receptors that monitor stretch in muscles and tendons. Ex. Muscle spindles Proprioceptors n Encapsulated receptors that monitor stretch in muscles and tendons. Ex. Muscle spindles](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-36.jpg)
![Classification by Stimulus 1. 2. 3. 4. 5. Mechanoreceptors- respond to mechanical forces: touch, Classification by Stimulus 1. 2. 3. 4. 5. Mechanoreceptors- respond to mechanical forces: touch,](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-37.jpg)
![Classification by Structure 1. Free nerve endings- in all tissues of body; abundant in Classification by Structure 1. Free nerve endings- in all tissues of body; abundant in](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-38.jpg)
![Reflex Arcs May be unilateral or contralateral n Unilateral knee jerk: Flexors contract extensor Reflex Arcs May be unilateral or contralateral n Unilateral knee jerk: Flexors contract extensor](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-39.jpg)
![Reflex Arcs n Unilateral: Excess tension on tendon causes inhibition of flexor and stimulation Reflex Arcs n Unilateral: Excess tension on tendon causes inhibition of flexor and stimulation](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-40.jpg)
![Crossed-Extensor reflex arc n Pain to one foot causes retraction of injured foot and Crossed-Extensor reflex arc n Pain to one foot causes retraction of injured foot and](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-41.jpg)
![PNS to CNS PNS to CNS](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-42.jpg)
- Slides: 42
![Chapter 14 The Spinal Cord and Spinal Nerves Chapter 14 The Spinal Cord and Spinal Nerves](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-1.jpg)
Chapter 14 The Spinal Cord and Spinal Nerves
![Spinal Cord Begins at foramen magnum extends down to L 1L 2 n Contiguous Spinal Cord Begins at foramen magnum extends down to L 1/L 2. n Contiguous](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-2.jpg)
Spinal Cord Begins at foramen magnum extends down to L 1/L 2. n Contiguous with the medulla of the brain stem. n Passes through the vertebral foramen of all vertebrae. n Consists of cervical, thoracic and lumbar divisions same as vertebral column. n PNS - 31 paired spinal nerves one at each level C 1 C 8, T 1 -T 12 and L 1 -L 5, S 1 -S 5 and Co-1. n Contains gray and white matter, however gray matter is central and white matter surrounds gray matter. n At L 1/L 2 level cona medullaris tapers into cauda n
![Spinal cord levels C 1 C 8 T 1 T 12 L 1 L Spinal cord levels: C 1 -C 8 T 1 -T 12 L 1 -L](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-3.jpg)
Spinal cord levels: C 1 -C 8 T 1 -T 12 L 1 -L 5 Cauda eqiuna S 1 -S 5
![The Meninges n 1 2 3 Consists of 3 layers around the brain and The Meninges n 1. 2. 3. Consists of 3 layers around the brain and](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-4.jpg)
The Meninges n 1. 2. 3. Consists of 3 layers around the brain and spinal cord Dura mater- tough outer fibrous connective tissue layer; two layers periosteal (periosteum) and meningeal. Arachnoid mater- inner layer attached to dura mater - subarachnoid space between arachnoid and pia mater filled with CSF. Pia mater- thin connective tissue layer closely adhered to brain surface and spinal cord. Pia mater
![Vertebral column xsection Vertebral column (x-section)](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-5.jpg)
Vertebral column (x-section)
![Spinal cord xsection Spinal cord (x-section)](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-6.jpg)
Spinal cord (x-section)
![Gray matter of spinal cord Shaped like a butterfly with central canal n Wings Gray matter of spinal cord Shaped like a “butterfly” with central canal. n Wings](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-7.jpg)
Gray matter of spinal cord Shaped like a “butterfly” with central canal. n Wings contain anterior, and posterior horns. n Thoracic and Lumbar levels also have lateral horns. n Contains neuron cell bodies, unmyelinated axons, dendrites and neuroglia. n Gray commissure has fibers that communicate between right and left halves of spinal cord. n
![Gray matter of spinal cord Gray matter of spinal cord](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-8.jpg)
Gray matter of spinal cord
![White matter of spinal cord Contains myelinated ascending and descending spinal tracts n Divided White matter of spinal cord Contains myelinated ascending and descending spinal tracts. n Divided](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-9.jpg)
White matter of spinal cord Contains myelinated ascending and descending spinal tracts. n Divided into columns or funiculi; each column consists of tracts or fasciculi. n Also has white commissural tracts that cross thru cord n Ascending tracts carry sensory information from body to brain n Descending tracts carry motor information from brain to motor nerves n Tracts named according to where they originate and n
![Tracts in white matter of spinal cord Tracts in white matter of spinal cord](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-10.jpg)
Tracts in white matter of spinal cord
![Ascending spinal tracts n Transmit sensory information from peripheral body n Receptors relay information Ascending spinal tracts n Transmit sensory information from peripheral body. n Receptors relay information](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-11.jpg)
Ascending spinal tracts n Transmit sensory information from peripheral body. n Receptors relay information to spinal cord via sensory nerve in dorsal root and may synapse in dorsal horn of gray matter, decussate or ascend to a higher level. n Tracts are named according to their origin and destination, e. g. Lateral spinothalamic tracts; anterior spinothalamic; posterior spinalcerebellar
![Ascending tracts Three neuron chain Firstorder Receptor to afferent nerve into spinal cord Second Ascending tracts Three neuron chain: First-order: Receptor to afferent nerve into spinal cord. Second](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-12.jpg)
Ascending tracts Three neuron chain: First-order: Receptor to afferent nerve into spinal cord. Second order: Interneuron to relay nucleus in thalamus. Third order: Thalamus projects information to cortex.
![Descending spinal tracts n Take information from brain and descend in gray columns to Descending spinal tracts n Take information from brain and descend in gray columns to](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-13.jpg)
Descending spinal tracts n Take information from brain and descend in gray columns to appropriate level to a lower motor neuron. n Motor innervation is contralateral i. e. the left side of the brain controls the right side of the body and vice versa. Cross over at pyramidal decussation in medulla. n Tracts are named according to their origin and destination, e. g. Lateral corticospinal tract; anterior
![Descending tracts Two neuron chain Upper motor neuron From cortex or brain stem to Descending tracts Two neuron chain: Upper motor neuron: From cortex or brain stem to](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-14.jpg)
Descending tracts Two neuron chain: Upper motor neuron: From cortex or brain stem to LMN Lower motor neuron: From spinal cord to muscle or target organ
![Ascending tracts Three neuron chain Firstorder Receptor to afferent nerve into spinal cord Second Ascending tracts Three neuron chain: First-order: Receptor to afferent nerve into spinal cord. Second](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-15.jpg)
Ascending tracts Three neuron chain: First-order: Receptor to afferent nerve into spinal cord. Second order: Interneuron to relay nucleus in thalamus. Third order: Thalamus projects information to cortex.
![Nerve structure Nerves are only in the periphery n Cablelike organs in PNS Nerve structure Nerves are only in the periphery n Cable-like organs in PNS =](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-16.jpg)
Nerve structure Nerves are only in the periphery n Cable-like organs in PNS = cranial and spinal nerves n Consists of 100’s to 100, 000’s of myelinated and unmyelinated axons (nerve fibers). n Endoneurium surrounds each axon (nerve fiber). n Axons are grouped into bundles of fascicles n Perineurium surrounds each fascicle n Epineurium surrounds each nerve bundle n Conduction is saltatory (i. e. jumps node to node) in myelinated nerves and continuous in nonmyelinated. n
![Nerve anatomy Nerve anatomy](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-17.jpg)
Nerve anatomy
![](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-18.jpg)
![Spinal Nerves There are 31 pairs of spinal nerves Spinal nerves are all mixed Spinal Nerves There are 31 pairs of spinal nerves. Spinal nerves are all mixed](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-19.jpg)
Spinal Nerves There are 31 pairs of spinal nerves. Spinal nerves are all mixed nerves (i. e. sensory and motor). Each forms by combining the dorsal and ventral roots at a segment of the spinal cord. n As spinal nerves exit intervertebral foramen they branch into a meningeal nerve and a dorsal and ventral ramus. n The meningeal branch re-enters the spinal column to supply the meninges, spinal ligaments and vertebrae. n After leaving the spinal cord, the ventral ramus of select nerves combine to form nerve plexuses that innervate the appendages and other parts of the n
![Dorsal and ventral ramus nerves Dorsal ramus nerves innervate the ligaments muscles and skin Dorsal and ventral ramus nerves Dorsal ramus nerves innervate the ligaments, muscles and skin](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-20.jpg)
Dorsal and ventral ramus nerves Dorsal ramus nerves innervate the ligaments, muscles and skin of the back. n Ventral ramus nerves innervates the anterior and lateral muscles, skin and ligaments of the trunk. They also give rise to the nerve plexuses that innervate the appendages. n
![](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-21.jpg)
![Thoracic level Dorsal ramus Ventral ramus Dorsal root ganglion Sympathetic chain ganglion white and Thoracic level -Dorsal ramus -Ventral ramus -Dorsal root ganglion -Sympathetic chain ganglion -white and](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-22.jpg)
Thoracic level -Dorsal ramus -Ventral ramus -Dorsal root ganglion -Sympathetic chain ganglion -white and gray rami communicantes
![](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-23.jpg)
![Spinal nerve plexuses from ventral ramus major nerves off of them n n Spinal nerve plexuses from ventral ramus - major nerves off of them. n n](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-24.jpg)
Spinal nerve plexuses from ventral ramus - major nerves off of them. n n n Plexus= network of nerves Cervical plexus – forms from C 1 – C 4 -Phrenic nerve is off of cervical plexus C 3 -C 5 Brachial plexus – forms from C 5 – C 8, and T 1 -Axillary, radial, median, ulnar nerves n Lumbar plexus – forms from L 1 - L 4 -Femoral and obturator nerves n Sacral plexus – forms from L 4 – S 4 -Sciatic nerve
![Spinal nerve plexuses n Spinal nerve plexuses n](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-25.jpg)
Spinal nerve plexuses n
![Cervical plexus C 1 C 5 n Phrenic nerve C 3 C Cervical plexus -C 1 - C 5 n Phrenic nerve -C 3 - C](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-26.jpg)
Cervical plexus -C 1 - C 5 n Phrenic nerve -C 3 - C 5 n
![Brachial plexus C 5 C 8 T 1 n Axillary nerve C Brachial plexus -C 5 -C 8 & T 1 n Axillary nerve - C](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-27.jpg)
Brachial plexus -C 5 -C 8 & T 1 n Axillary nerve - C 5 & C 6 n Median nerve - C 5 -C 8 & T 1 n Radial nerve - C 5 -C 8 & T 1 n Ulnar nerve - C 8 & T 1 n
![](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-28.jpg)
![Lumbar plexus L 1 L 4 n Femoral nerve L 2 L 4 Lumbar plexus L 1 - L 4 n Femoral nerve -L 2 -L 4](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-29.jpg)
Lumbar plexus L 1 - L 4 n Femoral nerve -L 2 -L 4 n Obturator nerve -L 2 -L 4 n
![Sacral plexus L 4 S 4 n Sciatic nerve Tibial n L 4 Sacral plexus -L 4 - S 4 n Sciatic nerve -Tibial n. L 4](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-30.jpg)
Sacral plexus -L 4 - S 4 n Sciatic nerve -Tibial n. L 4 -S 3 -Comn fibular -L 4 -S 2 n
![DERMATOMES n The area of skin that carries sensory information to the CNS from DERMATOMES n The area of skin that carries sensory information to the CNS from](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-31.jpg)
DERMATOMES n The area of skin that carries sensory information to the CNS from all of the spinal nerves (except C 1) and cranial nerve V (facial). n Entire body surface is supplied by a peripheral nerve. n Knowing the distribution of these nerves is very helpful diagnostically in determining whether a nerve is affected at the central or peripheral level and at what level the injury may be.
![](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-32.jpg)
![Reflex Arc Consists of 1 sensory receptor 2 afferent nerve 3 interneuron 4 efferent Reflex Arc Consists of 1. sensory receptor, 2. afferent nerve, 3. interneuron, 4. efferent](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-33.jpg)
Reflex Arc Consists of 1. sensory receptor, 2. afferent nerve, 3. interneuron, 4. efferent nerve and 5. an effector organ (muscle or gland). n Occurs at the spinal level n
![Mono and Polysynaptic Reflexes Mono and Polysynaptic Reflexes](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-34.jpg)
Mono and Polysynaptic Reflexes
![Receptors Classification by location 1 2 3 Exteroceptors receptors sensitive to changes outside of Receptors: Classification by location 1. 2. 3. Exteroceptors- receptors sensitive to changes outside of](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-35.jpg)
Receptors: Classification by location 1. 2. 3. Exteroceptors- receptors sensitive to changes outside of body. Are found on or near the body surface: pain, pressure, touch, temperature and special sense organs (eye, ear, nose, mouth). Interoceptors- visceroceptors receive stimuli from viscera; stretch, temperature, chemical, taste. Proprioceptors- located in skeletal muscles and joints, tendons, ligaments; perceive stretch in these organs
![Proprioceptors n Encapsulated receptors that monitor stretch in muscles and tendons Ex Muscle spindles Proprioceptors n Encapsulated receptors that monitor stretch in muscles and tendons. Ex. Muscle spindles](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-36.jpg)
Proprioceptors n Encapsulated receptors that monitor stretch in muscles and tendons. Ex. Muscle spindles Extrafusal fibers Intrafusal
![Classification by Stimulus 1 2 3 4 5 Mechanoreceptors respond to mechanical forces touch Classification by Stimulus 1. 2. 3. 4. 5. Mechanoreceptors- respond to mechanical forces: touch,](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-37.jpg)
Classification by Stimulus 1. 2. 3. 4. 5. Mechanoreceptors- respond to mechanical forces: touch, pressure, stretch, vibration, and itch. Thermoreceptors- respond to temperature changes Chemoreceptors- respond to chemicals in solution and blood chemistry. Photoreceptors- respond to changes in light-eye Nociceptors- respond to pain and harmful stimuli leading to pain.
![Classification by Structure 1 Free nerve endings in all tissues of body abundant in Classification by Structure 1. Free nerve endings- in all tissues of body; abundant in](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-38.jpg)
Classification by Structure 1. Free nerve endings- in all tissues of body; abundant in epithelial and connective tissue. - respond to pain, temperature, itch and light pressure Ex. - Merckels discs, hair follicle receptors 2. Encapsulated nerve endings- enclosed in a capsule of connective tissue; vary in shape and distribution. Ex. - Meissner’s, Pacinian and Ruffini’s corpuscles
![Reflex Arcs May be unilateral or contralateral n Unilateral knee jerk Flexors contract extensor Reflex Arcs May be unilateral or contralateral n Unilateral knee jerk: Flexors contract extensor](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-39.jpg)
Reflex Arcs May be unilateral or contralateral n Unilateral knee jerk: Flexors contract extensor relax n
![Reflex Arcs n Unilateral Excess tension on tendon causes inhibition of flexor and stimulation Reflex Arcs n Unilateral: Excess tension on tendon causes inhibition of flexor and stimulation](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-40.jpg)
Reflex Arcs n Unilateral: Excess tension on tendon causes inhibition of flexor and stimulation of extensor
![CrossedExtensor reflex arc n Pain to one foot causes retraction of injured foot and Crossed-Extensor reflex arc n Pain to one foot causes retraction of injured foot and](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-41.jpg)
Crossed-Extensor reflex arc n Pain to one foot causes retraction of injured foot and extension of opposite foot
![PNS to CNS PNS to CNS](https://slidetodoc.com/presentation_image/0bfc887764c0ea00bb50b11737532bfd/image-42.jpg)
PNS to CNS
Exercise 15 spinal cord and spinal nerves
Median nerve innervates
Sensory pathways
Nerves branching beyond the spinal cord into the body
The spinal nerves
Dermatome map
Spinal cord and brain
Pns
Somi brace
Spinal cord dorsal and ventral roots
What is the spinal cord made of
31 pairs of spinal nerves
Spinal cord 31 pairs
Neural circuits the organization of neuronal pools
Spinal nerves
Nerves leg
Lumbar enlargement
Urinary bladder
Structure of spinal cord
Central nervous
Cervical nerves
Spinal cord denticulate ligament
Spinal cord structures
Hyporeflexia and hyperreflexia
Anterior ramus of spinal cord
Spinocerebellum
Dorsal root ganglion
Spinal cord extends from
Christopher reeve spinal cord injury level
Bird air sac
Lateral horn of spinal cord function
Vestibulospinal tract
Neural circuits the organization of neuronal pools
Tethered spinal cord
Spinal cord arterial supply
Spinal cord
Spinal cord
Spinal cord level
End of spinal cord
Eat well live well with spinal cord injury
Icd 10 code for lumbar laminectomy with fusion
Pain pathway spinal cord
The spinal cord anatomy