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__ consist of cells and an EC substance composed of __ embedded in a __.
In the supportive tissues, the functions are largely dependent on the __ of the __, such as __(3)__.
The three types of tissue in the supportive system are: __
- Supportive (connective) tissue
- fibers
- ground substance
EC substances
predominant fiber type (mostly collagen); arrangement and density of these fibers; the composition of the ground substance
connective tissue proper, cartilage, bone
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Connective Tissue Proper:
- not designed for __.
- primary fx?
- subdivided into?
- - resisting compressive stress
- - resisting tensile stresses
- - dense irregular, dense regular, and loose connective tissue
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When will I encounter loose connective tissue during dissection?
I will encounter it as fascia, which serves a packing and delimiting function as it separates and surrounds structures to which it conveys nerves and vessels
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Explain the two types of fascia.
Immediately deep to skin: subcutaneous tissue/ superficial fascia (contains a lot of adipose)
Deep to the subcutaneous tissue: deep fascia (in palms of hands)
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Fascial planes are what?
areas between two fascial layers where the fascial layers are united to each other by only a few fibers
ex: between two adjacent muscles
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What is a bursa?
an area between fascia-covered structures where there are no interconnecting fibers; a cavity is present filled with fluid in place to reduce friction
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Where is dense irregular CT found? Function?
deeper in the skin (dermis)
resistance of substantial tensile stressors in many directions
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Where is dense regular CT found? Function?
ligaments and tendons
due to inelasticity they resist unidirectional tensile stress
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aponeurosis
a broad flat tendon
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Cartilage function
resist compressive stress as well as tensile strength
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Where will I encounter hyaline cartilage?
covering articular surfaces of bones that participate in forming freely movable joints
in costal cartilages of the nose and bronchi
larynx
fetal skeleton
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Where will I encounter fibrocartilage?
in intevertebral discs
TIP: Has a higher density than hyaline and withstands greater pressures
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Where will I encounter elastic cartilage?
external ear, auditory tube, some laryngeal cartilages
has great resiliency and provides support
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Function of bone?
withstand substantial compressive and tensile stresses
supports body
protects orans
provides lever arms on which muscles can act
calcium metabolism
houses blood producing bone marrow
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sesamoid bone
a bone that develops within a tendon
(patella)
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All external and internal surfaces of bone are lined with __.
The ones on the external surface are in the deeper layer of a dense CT covering called the __.
cells that have bone forming and born resorbing capabilities
periosteum
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What can a bone fracture do
fracture or dislocation across the epiphyseal plate can result in a decrease or arrest of growth in length of the long bone
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The epiphyseal plate is connected to the main portin of the shaft by a tapering region of spongy bone called the __, which is __. What does this then do?
metaphysis
highly vascular in both growing and mature bone
the vascularity makes the metaphysis vulnerable to infection that is spread through the vascular system
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What causes a bone fracture? And, how does the body respond?
Thus, the displacement of the fractured bone ends is produced by __.
bending or torsional stress exceeding the limit of the bone's strength
the muscles which cross the fracture site go into a protective reflexive spasm to reduce mobility and pain at the site
both the fracturing force and the subsequent physiological muscle spasm
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Name the types of joints and their connections, an example, and their mobility.
Fibrous joint--connected by small amt of dense CT; sutures of the skulll; little to no motion
cartilaginous joint--unity by one of the types of cartilages; intervertebral discs; slight mobility
synovial joints--majority of joints in the body with space existing between the bones; free motion
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Explain the common characteristics of synovial joints.
1) covered with hyaline cartilage to reduce friction and distribute compressive force across the joint
2) joint capsule surrounding the surfaces, forming a closed joint/synovial cavity
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Explain the joint capsule.
composed of an outer fibrous layer (capsular ligament)= support
inner synovial layer
synovial lining (synovium): has cells that elaborate a small amount of synovial fluid that covers the articular surface and reduces friction
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The articular surfaces are not covered with __, since the capsule usually attaches to the bone at the end of the hyaline cartilage.
synovium
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Explain how ligaments appear in synovial joints?
they may be distinctly separated from the capsule (extracapsular ligaments) or may blend with the capsule, in which case they appear as thickenings of the capsule (intracapsular ligaments)
Inra-articular ligaments are internal to the fibrous capsule and external to the synovium
Other synovial joints have intra-articular fibrocartilaginous discs or ringlike menisci which may increase fit between two articular surfaces
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What other things determine mobility?
shapes of the surfaces and their fit (which discs may alter)
the tightness or laxness of the joint capsule and other ligaments
the location of the ligament around a joint
the presence of bulk adjacent soft tissues, whcih may limit mobility
the type and location of muscles which cross a joint and their distance of their attachment
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Characteristics of smooth muscle and location
- 1) non-striated
- 2) involuntarily controlled by the ANS
LOCATION: involuntary organs, such as GI tract and BV
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Characteristics of cardiac muscle and location
- 1) structurally striated
- 2) involuntarily regulated
LOCATION: heart
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Characteristics of skeletal muscle and location
- 1) striated
- 2) voluntarily controlled
LOCATION: around bone to move the bony levers of the body
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Describe origin and insertion
Explain contraction and extension in relation to this.
origin: more proximal attachment and "may" be the fixed end when a muscle contracts
insertion: more distal attachment and "may" be the movable end
Contraction: a muscle pulls equally on both attachments and the segment of hte body that moves is totally dependent on which segment is least fixed at that moment
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Explain times when the origin moves and the insertion remains fixed?
Ex: when the quariceps cause extension of the knee during rising to standing, in which circumstances the thigh moves on the fixed leg
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The force of muscle contraction and the range of motion (ROM) it produces at a joint is a function of __.
The velocity of muscle contraction and velocity of motion of the part are dependent on __
motor units
the rate of change of force or the rate of change of the number of motor units active at any instant in time
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The force and velocity of shortening in any given muscle are also dependent on __.
Since all muscle fibers can shorten the same percentage of their length, parallel muscles can __, meaning what
the orientation of the fibers in that muscle which can be parallel or pennate
shorten a greater percentage of their overall length than pennate muscles
This means that they can produce a greater range of motion and per unit time a greater velocity of motion.
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On the other hand, the force a muscle can generate is directly proportional to __, as measured perpendicular to the long axis of the muscle fibers.
total cross-sectional area of its fibers
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In muscles of equal volume, why is the force a pennate muscle can generate greater than a parallel?
because of the greater cross-sectional area
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WHat does the proximity of the muscular attachment have to do with the ROM, velocity, and force it can generaate?
an attachment near a joint causes a loss in rotary force but a ain in ROM and velocity
distant joints cause increase torque and decrease ROM and velocity
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The force necessary to cause joint motion is provided by either __ or __, which may be frequently combined in producing useful motions.
muscular activity or gravity
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When a prime mover makes a motion, what is the antagonist doing?
How do synergistic muscles behave?
it is completely relaxed to allow motion
they aid most motions in that they 1) stabilize other joints or 2) neutralize undesirable actions of the prime moves at the joint of interest
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What are the three types of contraction and explain?
shrotening (concentric or isotonic): when the muscle force > weight of forearm and hand (for ex)
static or isometri contraction: no change in overall length of muscle and muscle force equals te load
lengthening (eccentric) contraction: the load exceeds the muscle force
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How is a muscle test performed and for what
WHAT: evalulating primary muscular disease, peripheral nerve injuries, levels of CNS injurity
initial phase: inspection for normal contours and symmetry
Motion performance: inspection of movement and palpation of muscle contraction, checking for reduced ROM or abnormal sequences of motion
Resistance is then added
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Three methods of muscular activity "eliminination"
mechanical disadvantage: position the part so the muscle eliminated will have no effective vector component in the direction of hte function to be tested
physiological or length disadvantage: position the part so that the muscle will be slackened or will have much of its shortening capability used up by performing a function other than the one to be tested
reciproal inhibition: muscles can be turned off
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What is a nerve fiber?
Groups of nerve fibers outside the CNS are called __.
A cluster of nerve cell bodies outside the CNS is referred to as a __, some of which serve as __
an axon plus its supporting cells
peripheral nerves
ganglia; synaptic areas (where an impulse is transmitted from one neuron to another)
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A group of nerve cell bodies inside the CNS is __.
a nucleus
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Explain the organization of matter n the spinal cord?
an H shaped core of gray matter (where nerve cell bodies are located) and a surrounding zone of whtie matter composed of nerve fibers
the gray matter is subdivided into paired ventral and dorsal gray columns, separated by an intervening intermediate gray
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Explain the formation and initial branching of most spinal nerves.
From each segment of the spinal cord, a series of dorsal and ventral rootlets emerge linearly from the respective dorsolateral and ventrolateral aspects of the spinal cord.
The dorsal rootlets then combine to form one or several dorsal roots and the ventral combine to form ventral roots.
The dorsal and ventral roots then fuse to form the spinal nerve, usually at the level of the intervertebral foramen.
At the point of fusion, there is a swelling called the dorsal root ganglion.
The typical spinal nerve divides immediately outside the intervertebral foramen into a dorsal and ventral ramus, each of which typically has muscular and cutaneous branches.
The spinal nerve also gives off a recurrent meningeal branch to provide sensory innervation to the lining of the spinal canal and dura, as well as is connected to the sympathetic chain of ganglia by communicating rami.
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The nerve fibers in the dorsal root convey impulses from the __ to the __ and are __.
Most of the fibers in the ventral root conduct impulses __ and are __
- periphery to the CNS
- afferent (sensory) fiebrs
- away from the CNS
- efferent (motor) fibers
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The spinal nerve and all of its branches are __.
The typical spinal nerve supplies a specific area of skin called its __ and a specific mass of muscle called its __.
- mixed nerves
- dermatome
- myotome
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What do the dorsal rami supply?
- 1) the skin of the medial 2/3's of the back from the top of the head to the coccyx
- 2) the deep (intrinsic) uscles of the back
- 3) the intervertebral facet joints
- 4) the spinal ligaments posterior to the intervertebral foramen
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The ventral rami, except those from spinal nerves T2 through T11, form __, in the formation of which undergoes various __ and __ to form a generally predictable network. It is predictable because the peripheral nerves emerging from the plexus contain fibers derived from certain known spinal cord segments. Furthermore, the fibers from each segment contributing to the plexus are distributed into more than one peripheral nerve.
- plexuses
- splittings and fusions
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Thus, nerves emerging from a plexus typically contain fibers from more than one spinal cord segment and are called __. In contrast, branches of all dorsal rami and of ventral rami T2 through T11 contain fibers from only one spinal cord segment and are therefore __.
- multisegmental peripheral nerves
- unisegmental peripheral nerves
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How are nerve fibers named?
based on direction of conduction and structure innervated
(somatic or visceral, afferent or efferent)
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somatic efferent
visceral efferent
somatic afferent
visceral afferent
motor neurons--> skeletal muscles
two neurons in this pathway from spinal cord to end organ (motor to smooth and cardiac muscle and glands); under the control of higher CNS centers
transmit sensory information to CNS from receptors found in the skin (exteroceptors) and in deeper structures of the body wall (propioceptors)
they return interoceptive (from internal organs) sensations to the CNS from nearly all visceral structures supplied by VE neurons
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Muscular nerves innervating skeletal muscles contain what types of fibers?
- SE fibers
- VE (and possibly VA) fibers
- SA fibers from somatic receptors to muscles
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Cutaneous nerves innervating skin contain __
not only SA fibers from exteroceptors but also VA and VE fibers, which innervate BVs, arrector pili muscles and sweat lands
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How do cranial nerves differ from spinal nerves?
they arise from the brain and emerge from the cranial cavity
not formed by fusion of dorsal and ventral roots
no cranial nerves contain all ofur general functional fiber types, nor do they contain the same number of fiber types
certain contain additional special functional fiber types assosiated with special senses
some contain only one functional fiber while others have as many as five
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The ANS is divided into __.
The peripheral parts of each division consists of __.
The synapse between the two neurons occurs in a __. The neuron connecting the CNS and the ganglion is the __, while the one from the ganglion to the target organ is the __.
- sympathetic (thoracolumbar)
- parasympathetic (craniosacral)
two-neuron chains from the CNS to the effector organ
- ganglion
- preganglionic neuron
- postganglionic neuron
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Anatomically, how do the sympathetic and PSNS differ?
the ganglia of the SNS division are near the CNS, so the preganglionic fibers are short while the post are long
the PSNS ganglia are located near or within the organ innervated. So, their pre are long while post are short
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Physiologically, how do the sympathetic and PSNS differ?
- SNS: fight or flight
- PSNS: rest and digest
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Pharmacologically, how do the sympathetic and PSNS differ?
the chemical transmitter released at the ending of the sympathetic postganglionic neuron terminal is norepi (it is an adrenergic ending)
the chemical transmitter released at the ending of the parasympathetic postganglionic neuron terminal is acetylcholine and is a cholinergic ending
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The cell bodies of the preganglionic sympathetic neurons are typically found in the __. The processes of these neurons exit from the spinal through the __. From these spinal nerves or their ventral rami, the preganglionic fibers are transmitted via the __ to the __, which lies on the anterolateral aspect of the vertebral column.
lateral part of the intermediate gray of all thoracic and the upper two lumbar spinal cord segments
ventral roots of the first thoracic to the second lumbar spinal nerves
white communicating rami
sympathetic trunk
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The sympathetic trunk extends the __. It is composed of a series of ganglia which are connected by vertically oriented nerve bundles. A ganglion occurs at pprox each vertebral level except in the __ where there are typically only __.
- entire length of the vertebral column
- cervical region
- three ganglia
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After entering the sympathetic trunk, a given preganglionic nerve fiber may pursue one of four different types of courses before terminating.
- 1) synapse on a PostG neuron in the ganglion at the level of entry
- 2) ascend to the ganglion at a higher level to synapse on a PostG neuron
- 3) descend to a ganglion at a lower level to synapse on a PostG neuron
- 4) pass through the trunk without synapsing and exit from the trunk in a splanchnic nerve to terminate in a collateral ganglion located adjacent to main arterial branches in the abdominopelvic cavity
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While the input into the sympathetic trunk occurs only through white communicating rami, the outflow branches fall into one of five different patterns.
1) PostG nerve fibers leave the trunk at all levels via gray communicating rami to enter every spinal nerve in order to supply smooth muscle and glands of limbs and body wall
2) postG nerves leave the cervical and upper thoracic levels as directed visceral branches to directly innervate the cervical and thoracic viscera
3) PreG nerve fibers prev described as splanchnic nerves exit only the cervical and upper thoracic levels of the trunk, synapsing upon postG neurons within collateral ganglia which are related to major abdominopelvic arteries. PostG nerve fibers from the collateral ganglia then distribute to the abdominopelvic viscera along their arterial supply
4) PostG fibers from the superior cervical ganglion form pericarotid sympathetic plexuses about the carotid arteries, along which they are distributed to the head and neck along the branches of the carotid arteries
5) postG fibers from the superior cervical ganglion join some of the adjacent cranial nerves, to be distributed to structures innervated by these nerves
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Spinal nerves T1 through 2 typically have both _ and __, while spinal nerves above and below these levels only have __, becuase of what?
white and gray communicating rami
gray communicating rami
there is no pregangionic ouflow from the spinal cord at these levels
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The cell bodies of preganglionic parasympathetic neurons are located in __ associated with cranial nerves __(4)__, All of these preganglionic neurons synapse on postganglionic neurons in __ which are situated within or near an organ.
brain stem nuclei
III, VII, IX, X
terminal ganglia
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The pregangionic nerouns of the PSNS to head and neck structures are distributed initially in cranial nerves __. Those to thoracic and most abdominal viscera are in cranial nerve __. Preganglionic neurons to the pelvic, perineal, and a few abdominal organs emerge in __ and their __.
- III, VII, IX, X
- X
- S2, 3, and 4 spinal nerves
- ventral rami
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The aorta gives off __ to the heart just above the aortic valves. The arteries to the head and upper limbs are given off the __ within the __. Then, the aorta descends through the __ giving off branches to most of the noncardiac structures of the thorax. As the aorta descends through the abdomen, it gives off branches to the abdominal organs and terminates by dividing into __. These in turn divide into __, which primarily supply organs of the __ and __, and __ to the lower limb.
- coronary arteries
- aortic arch
- thorax
- thorax
- common iliac arteries
- internal iliac arteries
- pelvis and perineum
- external iliac arteries
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Collateral arterial circulation
the greatest turbulent flow in the arterial system occurs where branches are given off or where vessels make sharp bends, causing these areas to suffer early degenerative atherosclerotic changes
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Collateral circulation is dependent upon the presence of __ between branches given off at one level of the arterial system and more distant branches.
anastomoses
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Venous return is largely facilitated by the __ and by the _.
- negative intrathoracic pressure developed during inspiration
- intermittent deep vein compression produced by contraction of adjacent skeletal muscles
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There are four unique valveless venous return systems located within the trunk, some of which are partly or completely divergent from the arerial system.
1) subcutaneous veins of the thoracic and abdominal walls are valveless and communicate with SVC and IVC and portal systems (good for serving as collateral pathways)
2) Valveless dural and epidural venous channels, which drain the brain and spinal cord. They communicate with the SVC and IVC systems and can serve as bidirectional shunts due to their valvelessness.
3) valveless portal venous system: returns blood from teh capillary network of the abdominal part of the digestive system; enters the liver where it passes through the hepatic sinusoids before terminating in the IVC via hepatic veins
4) valveless azygos system of veins, which drains most of the noncardiac non-pulmonary sructures of the thorax. It communicated below with the portal and inferior vena caval systems and terminates in the SVC to which it can shunt portal or IVC blood in an obstruction. It can also do that in the case of an SVC shunt
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