Anatomy Exam 2

Muscular System

Muscle Tissue Types

• Smooth (involuntary)

  • non-striated fibers

• cardiac (involuntary)

  • striated fibers

• skeletal (voluntary)

  • striated fibers

How do muscles move?

• Muscles pull equally on both ends

• they create force by contracting

• must oppose gravity to produce movement or maintain a position

Extrinsic Muscles

muscles originating outside of the part of the body they act on

Intrinsic Muscles

muscles originating in the part of the body they act on, being contained within the corresponding body part

Muscle Belly

central part of muscle

Tendon

Macro:

• connects muscle to bone

• concentrates pull of muscle to small area on bone

• very strong

Aponeurosis

sheet like elastic tendon acting as insertion site for muscle fibers

Fascia

• band/sheet of connective tissue separating muscles and other internal organs

• attaches, stabilizes, encloses, and separates muscles and other internal organs.

Micro Muscle: Muscle Belly

• covered in Epimysium

• comprised of bundles of muscle fascicles

Muscle Fasicle

• Perimysium divides muscle fascicles into compartments

• comprised of bundles of muscle fibers

Muscle Fiber

• Endomysium divides muscle fibers into compartments

• comprised of bundles of myofibrils

  • Type I: slow twitch, resistant to fatigue and associated with more endurance activities

  • Type ll: fast twitch, easily fatigues, and associate with power based activities

Sarcomere

• basic contractile unit of a muscle fiber

• compromise of Myosin Filaments (thick) and Actin Filaments (thin)

Sliding Filament Theory

• overlapiing myofilaments slide past each other when muscle cell is stimulated by nerve impulse, shortening and causing muscle contraction

• shortening of the sarcomere associated with

  muscle contraction

Penate Muscle (Uni, Bi, or Multi)

• fibers angulated

• produces greater tension

• reduced speed and range of motion secondary to ineffective shortening

Parallel Muscle

• fibers are parallel

Fusiform Muscle

• larger central belly and tapered ends

• poor force production due to fewer fibers

• can shorten up to 70% of original length, contributing to improved speed and ROM

Convergent Muscle

• fibers widespread over sizeable area, converging to single attachment point

Circular Muscle

• fibers arranged concentrically

Muscle Structure

Epimysium

connective tissue surrounding the entire muscle body

Perimysium

connective tissue sheath that surrounds the muscle fasicle

Endomysium

connective tissue that surrounds each muscle fiber

Type ll Muscle Fibers

• Type llx

  • highest intensity contractions

  • short periods of time

• Type lla

  • medium amount of power for a medium amount of time

Isometric Contraction

• force of muscle equals that of resistance

• no change in joint angle or length of muscle

Isotonic contraction

• concentric

  • force of muscle is greater than that of resistance. fibers shorten

• eccentric

  • force of muscle is less than that of resistance. fibers lengthen

Agonist

muscle contracting to provide main force

antagonist

muscle positioned opposite of agonist and release/lengthens to allow agonist to contract

prime mover

muscle responsible for largest force production for given join action.

primary driving force for an action

synergist

assists prime mover to provide more fluid/accurate motion and to increase strength/power output

stabilizer

• muscle contracting isometrically to provide support or steady a body part against forces

• provide balance, control movement, and prevent injury

neutralizer

muscle that contracts to prevent secondary motion caused by prime mover or synergists

Irritability

muscles ability to recieve and respond to stimulus from associated nerve

elasticity

muscles ability to return to its resting length after being stretched

viscous

plastic properties of tissue

extensibility

ability of muscle to be stretched or increase in length beyond resting length

stretching application

• Elongation occurs for both the muscle and its connective tissue

  when stretching.

• The elastic elongation recovers and the plastic elongation remains.

• Elements are influenced by temperature, and rate/duration of applied

  forces

Central Nervous System

• Main processing center of the nervous system and control all of the body's functions

  • cerebrum

  • cerebellum

  • brain stem

  • spinal cord

Concussion Symptoms

• headache

• dizziness/nausea

• balance impariments

• imparied cognitive function

• light sensitivity

Peripheral Nervous System

• Responds To Signals/commands from your cerebral cortex.

• Relays Information From

  • Areas of your body back to cerebral cortex.

  • 
    

  • Peripheral Nervous System Structures

1. Nerve Roots

2. Brachial & Lumbar Plexus

3. Peripheral Nerves

Afferent Sensory Pathways

• carry information from the body to the spinal cord

Efferent Motor Pathways

• carry information from spinal cord to the body

Somatic Nervous System

• Voluntary somatic motor; impulses from CNS to skeletal muscles

Autonomic Nervous System

• Involuntary visceral motor; impulses from CNS to visceral organs

• Sympathetic

  • "Fight-or-flight" response. Responds to stress, danger, or physical activity.

• Increases heart rate and respiratory rate, improves visual acuity, and slows down digestion.

• Parasympathetic

  • "Rest-and-digest" response. Active when the body is relaxed, resting, or feeding.

• Decreases heart rate and respiratory rate, and increases digestion.

• Stimulates salivation, tears, and other bodily functions

Neurodynamics

• nerves move independently from other tissues

• neural tissue does not stretch

Biarticular Muscles

• crosses 2 joints

• contributes to motion at both joints

  • hamstrings for hip/knee

Multiarticular Muscles

• crosses 3 or more joints

Active Insufficiency

multi-joint muscles produce less force/tension in fully shortened position secondary to muscle producing movement at all joints it crosses

• Wrist flexion and fist making: If you flex your wrist and try to make a fist, you'll experience active

insufficiency because your wrist flexors are shortened and can't produce enough tension

Passive Insufficiency

multi-joint muscle unable to achieve full ROM secondary to muscle being lengthened across all joints it crosses

• Hamstrings: When the knee is straight, the hamstrings are stretched tightly, which limits hip lexion.

All or none principle

• a nerve or muscle fiber either responds completely or not at all to stimulus regardless of stimulus strength

• signal must pass threshold to cause firing

• greater signal strength does not equate response

Length tension relationship

• Amount of force a muscle can produce is dependent upon the length.

• Overly stretched or too short produces less force when muscle contracted.

Reciprocal Inhibition

• when muscles on one side of a joint relax to accommodate contraction of opposing muscle

autogenic inhibition

• reflex decreasing muscles excitability by contracting target muscle

Humerus Landmarks

• head of humerus

• greater tubercle

• lesser tubercle

• bicipital (intertubercular) groove

• deltoid tuberosity

Scapula Landmarks

• acromion/acromion process

• caracoid/coracoid process

• medial border

• lateral border

• superior angle

• inferior angle

• spine

• glenoid fossa

Diarthrodial joint

enarthrodial

Joints of the Shoulder

1. Acromioclavicular Joint

2. Scapulothoracic Joint

3. Glenohumeral Joint

Shoulder Ligaments

Bone to Bone

• Acromioclavicular

• Coracoclavicular

• Coracoacromial

• Coracohumeral

• Capsule

Shoulder Labrum

• ring of cartilage

• stabilizes the shoulder joint

• attachment site

Bursae

fluid filled sacs in shoulder joint

Shoulder Tendons

• supraspinatus

• biceps tendon

Shoulder Tendon Sheath

• Intertubercular Tendon Sheath

• Biceps Brachii Tendon

Glenohumeral Joint Motions

• Flexion/extension

• abduction/adduction

• internal (medial) rotation/external (lateral) rotation

• horizontal abduction/adduction

• circumduction

Scapular Motions

• elevation/depression

• protraction/retraction

• upward rotation/downward rotation

Pectoralis Major

• Horizontal Adduction, Internal Rotation

• Clavicular Head:  Flexion, Abduction above 90 degrees

• Sternal Head: Extension, Adduction

Pectoralis Minor

• depression

• protraction

• downward rotation

Deltoid

• Anterior: Flexion, Horizontal Adduction

• Middle: Abduction, Horizontal Abduction 

• Posterior: Extension, Horizontal Abduction

Trapezius

• Upper: BCS Extension, ICS Lateral Flexion, ICS Rotation, Elevation, Upward Rotation, Retraction

• Middle: Scapular Retraction

• Lower: Depression, Upward Rotation, Retraction

Latissimus Dorsi

• extension

• adduction

• internal rotation

Levator Scapulae

• Bilateral Cervical Flexion/Extension

• Ipsilateral Cervical Lateral Flexion

• Ipsilateral Cervical Rotation

• Scapular Elevation

• Scapular Downward Rotation

Rhomboid Major/Minor

• retraction

• elevation

• downward rotation

Serratus Anterior

• superior: protraction

• inferior: protraction, upward rotation

Supraspinatus

• stabilization

• abduction

Infraspinatus

• stabilization

• external rotation

Teres Minor

• stabilization

• external rotation

• adduction

Subscapularis

• internal rotation

Scapulohumeral Rhythym

• Scapula moves with humerus during shoulder elevation to maintain subacromial space and length tension relationship

Open vs. Closed Kinetic Chain in shoulder

• Open

  • Partnering

  • Visual Aesthetic

  • Traditional Corrections

  • Technical Compensations

• Closed

  • Ground Reaction Forces

  • Torsional/Rotational Forces

  • Active vs Passive Stability

Shoulder Injuries

• impingement (bicep tendonitis, supraspinatus tendonitis)

• instability (sublaxation/dislocation)

• labral tears

• muscle strains & ligament sprains

Cervical Spine

• 7

• C1 (atlas)

• C2 (axis)

Thoracic Spine

• 12

• costal facets for spinal articulation with ribs

Lumbar Spine

• 5

sacrum & coccyx

sacroiliac joint

Sternum

manubrium sternal body & xiphoid process

Ribs

• True (1-7)

• False (8-10)

• Floating (11,12)

General Vertebrae Landmarks

• Vertebral Body

• Pedicle

• Lamina

• Spinous Process

• Transverse Process

• Superior/Inferior Facet

• Vertebral Foramen 

Spinal Motions

• occur at individual facet joint

• flexion

• extension

• lateral flexion

• rotation

Spinal Degrees of Motion

• cervical spine: free in all

• throacic spine: free in rotation, limited in remaining

• lumbar spine: limited in rotation, free in remaining

Spine Ligaments

• anterior longitudinal ligament

  • limits extension

• posterior longitudinal ligament

  • limits flexion

Intervertebral Disc

• annulus fibrosis (dough)

  • concentric Type l collagen

• nucleus pulposus (jelly)

  • waster and type ll collagen

External Oblique

• Bilateral Flexion

• Ipsilateral Lateral Flexion

• Contralateral Rotation

Internal Oblique

• Bilateral Flexion

• Ipsilateral Lateral Flexion

• Ipsilateral Rotation

Rectus Abdominis

• Bilateral Flexion

• Ipsilateral Lateral Flexion

• Posterior pelvic tilt

Transverse Abdominis

• Ipsilateral Rotation

• Support to Lumbar Spine via Thoracolumbar Fascia

• Pulls Abdominal Wall Inward

Iliacus

• Hip Flexion

  Hip External Rotation

  Anterior Pelvic Tilt

Psoas Major

• Hip Flexion

  Hip External Rotation

  Anterior Pelvic Tilt

Erector Spinae

• iliocostalis

• longissimus

• spinalis

Bilateral Extension

Ipsilateral Lateral Flexion

Ipsilateral Rotation

Quadratus Lumborum

• Ipsilateral Lateral Flexion

• Bilateral Extension

• Fixes/Depresses 12th Rib

• Stabilizes Spine & Pelvis

Multifidus

• Bilateral Extension

• Ipsilateral Lateral Flexion

• Contralateral Rotation

Rotatores Longis/Brevis

• contralteral rotation

Diaphragm

• Increases intrathoracic volume, pushes abdominal viscera inferior