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SPINAL CORD
4 main functions?
The spinal cord is useless unless it is able to send and receive signals to/from the body.
The ______ ______ contain the neurons of the motor and sensory systems of the body.
Spinal Cord: Gross Anatomy & its Relationship to other Structures
Spinal Cord
Spinal Cord: Gross Anatomy & its Relationship to other Structures
Vertebral Foramen
Spinal Cord: Gross Anatomy & its Relationship to other Structures
Vertebral Canal
Spinal Cord: Gross Anatomy & its Relationship to other Structures
Cervical Enlargement
Spinal Cord: Gross Anatomy & its Relationship to other Structures
Lumbar Enlargement
Spinal Cord: Gross Anatomy & its Relationship to other Structures
Spinal nerves
Spinal Cord: Gross Anatomy & its Relationship to other Structures
Intervertebral foramina
Spinal Cord: Gross Anatomy & its Relationship to other Structures
GUTS
Foremen =
Cervix =
Nerve =
Notice that the spinal cord is not as long as the (!)_____ ______. During fetal development the spinal cord extends to the (2)_____, but because the growth of the vertebral column outpaces the spinal cord, the end of the spinal cord is around the first (3)____ _____ (___) in children and adults.
The cone-shaped termination of the spinal cord is the (1) ____ ______. and it contains the (2) ____ and (3) _____ segments of the spinal cord.
Beyond the conus medularis, lumbar, sacral, and coccygeal spinal nerves pass through the vertebral canal on their way to the appropriate intervertebral foramen.
This bundle of spinal nerves is know as the _____ ______ for its resemblance to a horse's tail. Among these nerves lies the ____ _______, an extension of the spinal cord's __ _____. This thin membrane covers the spinal cord, and as the film terminals, it likely serves to ____ the spinal cord within the vertebral canal.
Spinal Cord: Cross Sectional Anatomy
Meninges
Spinal Cord: Cross Sectional Anatomy
Dura mater
Spinal Cord: Cross Sectional Anatomy
Epidural Space
Spinal Cord: Cross Sectional Anatomy
Arachnoid mater
Subarachnoid space
Spinal Cord: Cross Sectional Anatomy
Pia mater
Spinal Cord: Cross Sectional Anatomy
Pia mater's 2 specializations?
The spinal cord itself has 3 parts:
1. White matter
-How many columns?
The spinal cord itself has 3 parts:
2. Gray Matter
-What are the 3 columns?
-Which contain motor neurons? Sensory?
The spinal cord itself has 3 parts:
3. Central canal
Which landmark of the spinal cord allows you to orient yourself to a section of spinal cord?
GUTS
Dorsal =
Ventral =
Functional Anatomy: Gray Matter & Spinal Nerves
In their passage to or from the spinal cord, axons are bundled into peripheral ____ that comprise the peripheral nervous system (PNS). All nerves in the body are ____ nerves, ____ nerves, or their ____.
Functional Anatomy: Gray Matter & Spinal Nerves
The ___ ____ forms from the joint of two major tributaries, the ____ and _____ roots.
Functional Anatomy: Gray Matter & Spinal Nerves
The ____ ____ contains ONLY ____ neurons that are entering the ____ horn of the spinal cord.
The sensory neurons' cell bodies form a swelling with the dorsal root called the ___ ____ _____. Sensory neurons are UNIQUE in having their cell body in the MIDDLE of their length. These neurons are called _____ (or _______) because of the SINGLE process that stems from the cell body.
Functional Anatomy: Gray Matter & Spinal Nerves
The ____ _____ contains only axons of MOTOR neurons. Their cell bodies are in the gray matter previously described (ventral horn).
Functional Anatomy: Gray Matter & Spinal Nerves
Besides a simple division b/w sensory and motor, the PNS is also divided on the basis of categories, SOMATIC & VISCERAL.
SOMATIC refers to the ____ body: bones, skeletal muscles, skin.
VISCERAL refers to the _____ cavities of the body (digestive, respiratory, cardiovascular systems).
Functional Anatomy: Gray Matter & Spinal Nerves
4 functional components of spinal nerves
-What are they called and what are they responsible for?
Functional Anatomy: Gray Matter & Spinal Nerves
Each PNS neuron originates from or synapse with ___ matter of the spinal cord in a specific pattern.
Somatic sensory and visceral sensory neurons synapse with the interneurons of the ____ horn (axons sent via ___ root).
Visceral motor neurons originate in the ____ horn and somatic motor neurons originate in the _____ horn; both of these types motor neurons send their axons into the ____ root.
Spinal Reflexes: Polysynaptic reflexes
Not all sensory inputs trigger sensation in the brain, and not all motor activity is triggered by the brain. Many ___ _____, involuntary and stereotyped reactions, occur because of the simple "_____" of the nervous system.
Spinal Reflexes: Polysynaptic reflexes
Many reflexes involve one or several interneurons: ______ _______. An example of such a reflex is the ______ _____. This reflex, like most reflexes, are ______ in nature.
Suppose you stepped on a tack lying on the floor. The immediate response of your leg is to withdraw from the source of pain.
Spinal Reflexes: Polysynaptic reflexes
The stimulus travels along a ____ neuron that synapses with one or several _______ in the ____ horn. Several sets of ____ neurons are simulated in your hip, thigh, or lower leg to withdraw from the painful stimulus.
Additionally, ____ signals may be sent to muscles that would otherwise oppose withdrawal a phenomenon known as ______ _______.
Spinal Reflexes: Polysynaptic reflexes
What are the 5 basic steps of a polysynaptic reflex?
GUTS
Contralateral =
Ipsilateral =
Spinal Reflexes: Monosynaptic reflexes
The simplest of reflexes involve a sensor neuron and its synapse with a ____ neuron.
Such _____ ______ involve a stimulus that triggers the response of a _____. This results in a signal traveling along a sensory neuron that terminates in the _____ horn where ____ neuron dendrites and cell bodies reside.
Spinal Reflexes: Monosynaptic reflexes
The most common of these reflexes is known as the _____ reflex. Stretch of the muscle reflexively causes _____ of the ____ muscle leading to greater stability of joints.
Stretch reflexes, like _____ reflexes, exhibit ______ innervation.
The _____ (or knee-jerk) reflex is one example of a stretch reflex.
Spinal Reflexes: Monosynaptic reflexes
What are the 5 basic steps of a monosynaptic reflex?
Spinal cord & Nerves: Relationship to vertebrae and skin
The vertebral column is composed of ___ cervical, ___ thoracic, ___ lumbar, ___ fused sacral, and __-__ fused coccygeal vertebrae.
These vertebrae define ___ vertebral ___ of your body, each containing muscles, skin, and bones.
The neurons that supply instruction to/form these levels of the body travel within _____ _____.
The regions of your skin that are innervated by a particular pair of spinal nerves are called _________.
Spinal cord & Nerves: Relationship to vertebrae and skin
The spinal nerves are numbered according to the ______ level from which they take their ___ from the vertebral canal.
For example, notice that L1 spinal nerve exits BELOW the L1 vertebra, but the spinal segment that provides the nerve fibers is much more superiorly located, near the T10 vertebrae.
This arrangement is the result of the difference in overall ____ of the spinal cord and vertebral column.
Spinal Cord: Functional Anatomy:
Ascending Pathways
In addition to housing reflexes, the spinal cord is devoted to sending information up to the brain or sending commands down to the appropriate level of the spinal cord.
The systems of ___ neurons and interneurons that bring information up to the brain are called ______ _______. In brief, signals travels along ___ neurons, onsidered ___, ____. and ___ order neurons.
Spinal Cord: Functional Anatomy:
Ascending Pathways
We will consider the __________ tract as an example of an ascending pathway. This pathway carries ___ and ____ stimuli to the brain.
Spinal Cord: Functional Anatomy:
Ascending Pathways
The Spinothalamic tract
What are the 1st, 2nd, and 3rd order neurons?
Where does decussation occur?
GUTS
Decussate/Decussation =
Sensation from left side of body is processed by ____ side of the brain.
Spinal Cord: Functional Anatomy:
Descending Pathways
The systems of neurons that bring ____ information from the brain down t the appropriate spinal level are called _____ ______. Signals travel along ___ neurons.
The ________ tract will serve as an example of a descending pathway.
______ motor commands originate in the ____ motor cortex.
Spinal Cord: Functional Anatomy:
Descending Pathways
The Corticospinal tract
What are the two neurons from which the signal travels?
Where does decussation occur?
GUTS
motor neuron:
Is the upper motor neuron a true motor neuron?
Spinal Cord & Spinal Nerves: Functional Anatomy:
Gray Matter & Spinal Nerves
Given that there are __ functions groups of neurons, how is it that they are distributed to the correct part of the body?
The answer is _____, of course!
After forming a _____ ____ from its roots, the spinal nerve branches into ____ (=branches). The spinal nerve and its components are thus pictured as a tree with ___, a short ____, and several ______.
Spinal Cord & Spinal Nerves: Functional Anatomy:
Gray Matter & Spinal Nerves
The ____ ramus carries somatic motor AND somatic sensory to the _____ body wall.
The ____ ramus carries somatic motor AND somatic sensory to the _____ and ____ body wall.
Spinal Cord & Spinal Nerves: Functional Anatomy:
Gray Matter & Spinal Nerves
The ________ rami carry _____ motor (sympathetic) and _____ sensory neurons to and from the _______ chain.
This structure runs _____ to the spinal cord and distributes innervation to the ______ (heart, lungs, abdominal organs).
The sympathetic chain contains ____ _____ _____ that contain a second cell body for the sympathetic nervous system, the first being found in the lateral horn of spinal segments __-__.
Spinal Nerves: Plexuses
Finally, it is worth considering what happens to ____ rami as they travel distally, from the spinal nerve.
The simplest pattern can be observed in the thorax, where ventral rami simply travel along the inferior surface of the ribs. These ________ nerves send small branches to nearby muscles, bones, and skin.
In other parts of the body, the spinal nerve's ventral rami join a network called a ______. These plexuses combine somatic motor and sensory neurons from as many as ___ ventral rami.
Two of these plexuses are important for the innervation of the ____. The _____ plexus, formed of __-__ spinal nerve rami supplies the ____ limb.
The ______ plexus, formed of __-__ rami supplies the ___ limb.
