Functional Anatomy Anatomical Position Descriptions of Directions 1/19/2016

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1/19/2016
Functional Anatomy
Anatomical Position

Standing upright, looking
straight ahead, feet straight
ahead, arms straight and at
your sides, palms forward.
Descriptions of Directions
Medial, Lateral
Proximal, Distal
 Palmar (plantar), Dorsal
 Ipsilateral, Contralateral.


Descriptions of Directions
Superior (cranial, cephallic), Inferior
(caudal)
 Anterior (ventral, frontal), Posterior
(dorsal)
 Superficial, Deep.

Anatomical Reference Planes
Sagittal – divides body
into left and right
 Frontal – divides body
into front and back
 Transverse – divides
body into top and
bottom.

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Descriptions of Motion





Flexion, Extension
Abduction, Adduction
Elevation, Depression
Internal rotation,
External rotation
Pronation, Supination
Joint Planes of Action
• Plantarflexion,
Dorsiflexion
• Lateral flexion
• Radial deviation,
ulnar deviation
• Inversion, eversion
• Circumduction.
Types of Tissues

Four tissue classifications
 Epithelial
 Nervous
 Muscle
 Connective.
Epithelial Tissue
Basically a covering, or lining, tissue
Can be specialized to absorb, secrete,
transport, excrete, or protect the underlying
organ or tissue
 Nourished via tissue fluid from capillaries
from connective tissues
 Plays a role in diffusion of fluid and heat.


Epithelial Tissue
Subject to wear - cells are constantly
being lost and regenerated
 May exist as one or more layers
 Can be arranged in squamous, cuboidal,
or columnar structures
 Not strong, typically bound to connective
tissues.

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Nervous Tissue

Comprises the main parts of the nervous
system
 brain
 spinal cord
 peripheral nerves
 nerve endings
Characteristics of Nervous Tissue
Irritability - capacity to react to chemical or
physical agents
 Conductivity - ability to transmit impulses
from one location to another.

 sense organs.
Nerve Cells

Nerve Cells
The neuron, or nerve cell, is the basic unit of
nervous tissue.
 Cell body
 Axon

The neuron, or nerve cell, is the basic unit of
nervous tissue.
 Cell body
 Dendrites.
 Axon
 Dendrites
Figure from “Structure and Function of the Musculoskeletal System”, Human
Kinetics
Nerve Cells

Figure from “Structure and Function of the Musculoskeletal System”, Human
Kinetics
Muscle Tissue
Nerve impulses are conducted toward the cell
body by the dendrites and away from the cell
body by the axon.

Three Categories of Muscle
 Smooth
 Cardiac
 Skeletal.
Figure from “Structure and Function of the Musculoskeletal System”, Human
Kinetics
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Composition

Aggregate of:
 cells
 fibres
 other macromolecules
 matrix
 tissue fluid.
Fibres
Fibre Arrangement and Density


Types of Fibres
 loose connective tissue
 dense connective tissue
○ dense irregular connective tissue
 Collagen
 Reticular
 fascia
 Elastic.
Loose Connective Tissues

Four Types
 fibroelastic - encapsulates most organs
 areolar - saturates most every area of the body
 reticular - found near lymph nodes, and in bone
marrow, liver, and spleen
 adipose - aggregate of fat cells.
Arrangement and density of fibres
distinguishes
○ dense regular connective tissue
 tendon, ligament, bone, etc.
Constituents of Connective Tissues

Resident Cells
 Undifferentiated mesenchymal cells
○ can differentiate into many different types of
connective tissue cells
○ form fibres and other components of matrix.
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Constituents of Connective Tissues

Extracellular Matrix
Migratory cells
 travel to tissue via the bloodstream
 associated with tissues reaction to injury

 simple and complex glycoproteins
part of major defense system of body
 Mast Cells - can transport heparin
(anticoagulant), histamine (vasodilator), and
serotonin (vasoconstrictor) to injured tissues.
Proteoglycan Aggregate
Blend of
 protein fibres (collagen and elastin)
 Macrophage - can assimilate foreign material,
 tissue fluid.
Collagen Fibres
Present in varying amounts in all
connective tissues
 Can be arranged randomly or in a highly
oriented fashion
 More than 20 different types of collagen

 Type I - skin, bone, tendon, ligament, cornea
 Type II - cartilage
 Type III - loose connective tissues.
Collagen Fibres

Hierarchy
More slender and extensible than collagen
Can be stretched to 150% of their original
length
 Composed of microfibrils and elastin.
 tropocollagen molecule, aligned in rows to form

 microfibrils, arranged in bundles to form

 collagen fibres

Elastic Fibres
Molecules may be cross-linked which
increases stiffness.
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Glycoproteins
Tissue Fluid

Occupy spaces between fibres
 Constitute the so-called “ground substance”
of connective tissues
 Negatively charged and hydrophilic.

Bone
Components of Bone
A filtrate of the blood
 Resides in the intercellular (interstitial)
spaces
 Aids in transport between cells and
capillaries.
Osteoblasts - responsible for bone
formation on surface of bone
 Osteocytes - formed when osteoblast
surrounds itself with mineralized matrix,
responsible for bone formation
 Osteoclasts - resorb bone
 Extracellular bone matrix.

One of the hardest and strongest tissues of
the body
 Protects organs, stores minerals, houses
bone marrow, provides levers for muscles
 Dynamic structure, constantly remodeling
itself in response to alterations in loading.

Bone
Cortical (also called compact) forms the
hard, outer shell of bones
 Trabecular (also called cancellous or
spongy).

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Development of Bone
Development of Bone
Can be influenced by movement and related
forces during skeletal development
 Normal growth can be interrupted by trauma
or fracture.

Bone with damaged growth plate
Fig 2.7
Bone Macrostructure
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Bone Microstructure
Cartilage
Hyaline - covers the surface of most joints
Elastic - found in external ear, larynx,
epiglottis, eustachian tube
 Fibrocartilage - found at stress points where
friction could be a problem.


Cartilage
Hyaline Cartilage
Has no intrinsic blood vessels, nerves, or
lymph vessels
 Nutrients and wastes transported by
diffusion.

Articular Cartilage
Tendons and Ligaments

Made up of organized bundles of collagen
fibres
 parallel in tendon
 parallel, oblique, or spiral in ligament
Have great tensile strength
 Resist stretching in one direction.

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Tendons and Ligaments

Tendon Hierarchy
Can contain sensory receptors
 Ruffini corpuscles
 Pacinian corpuscles
 Golgi tendon organs
 free-nerve endings.
Skeletal Muscle
Muscle Structure
Contain contractile proteins and connective
tissue
 Serve as prime executors (movers) of the
nervous system.

Muscle Structure
Muscle Structure
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Sliding Filament Theory
Cross-Bridge Cycle
Characteristics of Muscle Fibres
Fibre Orientation

Pennation effects the
force that a muscle can
develop as well as the
amount that it can
shorten.
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Motor Unit

Length vs. Tension
A motor unit is
the basic of the
neuromuscular
system.
Case Study: Knee and Ankle
Sprains
Force vs. Velocity
Sprains are injuries to ligaments, usually
due to sudden overstretching
 Typically associates with pain,
inflammation, and loss of function
 Other impacts are not fully appreciated.

Case Study: Knee and Ankle
Sprains
Many (all?) ligaments have nerve fibers
in them
 These sensory receptors provide
feedback that can trigger reflex muscle
contraction to dynamically stabilize joints
 Loss of this feedback can lead to further
instability and alterations in movement
patterns.

Case Study: Knee and Ankle
Sprains

Ankle Orthotics and Sprains
 Inversion sprains are common
 Previous sprains make subsequent ones more likely
 Commonly use taping or bracing to enhance stability
and attempt to prevent reinjury
 Taping is costly, time and skill intensive, and has
decreasing utility
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Case Study: Knee and Ankle
Sprains

Ankle Bracing
Case Study: Knee and Ankle
Sprains

ACL Sprains
 Bracing is not fully evaluated
 Receptors in ACL have been
 Study examined soccer players,
shown to provide feedback to the
hamstrings
 Both the ACL and hamstrings
serve to prevent anterior
translation of the tibia relative to
the femur
 Loss of ACL leads to instability, but
also alterations in gait patterns.
some of whom had previously
suffered an ankle sprain and
some who hadn’t
 Bracing was beneficial to those
with previous injury but not those
without
 Why?
Arthrology

Classification of Joints
Classifications
 With a joint cavity
○ Diarthrodial
 Freely moveable
 Without a joint cavity
○ Synarthrodial
 Immovable
○ Amphiarthodial
 Slightly moveable.
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Knee Cross-Section
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