Musculoskeletal System Lecture Notes Ppt

MUSCULOSKELETAL SYSTEM

 Bones  Joints  Ligaments  Cartlage  Muscles

SKELETON

Functions: Support  Supports the body  Provides framework for the body  Gives shape to the body Protection  Protects vital organs  Protects soft tissues Movement  Provides locomotion (walking, movement) by attachment of muscles, tendons, and ligaments Hematopoiesis  Produces red blood cells  Produces white blood cells  Produces platelets Storage  Provides calcium  Provides phosphorus

Bones  Classification:  LONG BONES have an extended shape and provide the body with support and strength. Act as levers; support frame Arms, legs, femur, tibia, radius

 SHORT BONES approximately cube shaped Facilitate movement; transfer forces Wrists, ankles, feet

 FLAT BONES Are flat and provide broad surfaces for muscle attachment Serve as muscle attachment and for protection Cranial, ribs, shoulder blades, hips

 IRREGULAR BONES are similar to short bones, but are irregular in shape. For attachment of other structure and articulation

Sesamoid bone small, rounded bones They develop within joints and tendons

Structure  Compact bone  is hard and solid.  It composes the

shaft of long bones and the outer layer of other bones

 Spongy bone  is composed of

small bony plates.  It contains more spaces than compact bone.

 MARROW  hollow inner part of the bone is filled

with a soft substance YELLOW MARROW RED MARROW

YELLOW MARROW 

is found in the central cavities of the long bones and is mostly fat

RED MARROW 



is found in the ends of long bones, in the bodies of the vertebrae, and in flat bones. Red bone marrow is responsible for the manufacturing of red blood cells, white blood cells, and

 Periosteum  is a hard, fibrous

connective tissue membrane that covers most of the outside of the bone.

Construction of the LONG bones  The

Diaphysis

 also known as shaft

of the long bone  is hard and compact.  The

Epiphysis

 is spongelike and is

covered by shell of harder bone

 Epiphyseal

growth plate

 The place where the diaphysis and

epiphysis meet when full growth is achieved.

Markings  Facet  is a small plane of

smooth area.  The most commonly known facets are those of the spinal column.

 Condyle  is a large, rounded

projection, usually for articulation with another bone.

 Tuberosity  is a large,

elevated, knoblike projection, usually for muscle attachment

 Plate  A flat projection or

area

dental plate (dorsal or roof plate) makes up the roof of the mouth

foot plate is the flat portion of the stapes, which is one of the tiny bones in the middle ear

 Bony Process  Any prominence

or projection of bone

 Spine (spina)  is a sharp

process

 Ridge

or crest

is a thin or

 Tubercle  is a small

rounded knob or nodule, usually for the attachment of a tendon or ligament

Open Areas  Foramen  A hole through

which blood vessels, ligaments, and nerves pass

 Canal  A long, tubelike

hole

 Apical

foramen

 an opening in the

root of each tooth

 Sciatic

foramen

 in the hip bone

 Alcock’s

canal

 in the perineal area

 carotid

canal

 through which the

carotid blood vessels pass into the cranium

 Infraorbital

canal

 in the eye socket.

 sinus  is a sponge-like air

space within a bone, such as the paranasal sinuses within the skull bones

 Fossa  A dent, trench, or

depression

 Ethmoid

Fossa

 Where the

olfactory bulb lies

 Glenoid

Fossa

 Where the

mandible lies

JOINTS  The

points at which bones attach to each other.  It is also called as Articulation  It aids in motion

Classification  Synarthroses  are immovable.  Sutures

 Syndesmosis  is a type of

fibrous joint in which bones are united by fibrous connective tissue, forming an interosseous membrane or ligament

 Gomphosis  is a type of

fibrous joint in which a conical process is inserted into a socket type of structure.)

Amphiarthrose s  as those of the

symphysis pubis or the articulations between the ribs and the spinal column are slightly movable

 Synchrondosis is a type of cartilaginous joint

 Diarthroses

(synovial joints)  are freely movable,

allowing movement in various directions.  It is present at the end of the bones  It contains ligaments and cartilage

Example of Synovial joints  HINGE  Known as

ginglymus joint  Allows movement in only one plane  Examples are: Knee Elbow Jaw

 BALL-AND-SOCKET

joint  Known as spheroidal

joint

 PIVOT

joint

 One bone pivot’s or

turns within a bony cartilaginous ring

Atlas Head rotating on the axis

 GLIDING

joint

 Known as

arthrodial/pla ne joint  The bone slides against each other

 CONDYLOID

joint  Oval-shape

head of one bone moves within the elliptical cavity in another, permitting all movement except axial

 SADDLE

joint

 Movement can be

shifted in several directions

BURSAE are small, flat sacs lined with synovial membrane and filled with synovial fluid. They help ease the movement, while reducing friction

LIGAMENTS  Are

strong fibrous bands that holds bone together  They connect bone to muscle or cartilage  Support internal organs and other structures  Allows for great flexibility, stretching and movement

Types:  ARCUATE

ligament  Connects the

diaphragm with the lowest rib and the first lumbar vertebrae

 Broad

ligament of UTERUS

 A part of the peritoneum that supports

the uterus  Connects the uterus and the pelvic wall

 Broad

ligament of LIVER

 Known as falciform ligament  Fold of peritoneum that help attach the

liver to the diaphragm, and also separates the right and left lobe of the liver



Cruciate ligament of knee Arises from the femur and attach to the tibia at the knee.

 Henle’s

ligament

 Attaches rectus abdominus muscle to the

pubic bone

 Inguinal

Ligament  Known as

poupart’s ligament  Attaches anterior superior spine of ilium to spine of pubis

Medial Ligament in the knee  Known as the

patellar tendon  Attaches quadriceps femoris to the patella and down to the tibia

 Periodontal

Ligament  Connective

tissue surrounding roots of the teeth in holding them in place

 Pubofemoral

Ligament  Connects

pubis and femur

 Rhomboid

ligament  Connects

cartilage of first rib to the underside of the clavicle

 Round

Ligament of Femur  Broad ligament

arising from acetabulum and inserting on head of femur

CARTILAGE  Is

a type of connective tissue organized into a system of fibers.  Articular Cartilage Covers the end of the long bones It helps reduce friction to the joint and to distribute weight

TYPES:  HYALINE

cartilage

 Hard, transparent material rich in

collagen and proteoglycan  It covers the end of the bone to form the smooth articular surface of the joints. Found in the nose, larynx, between ribs and the sternum Bones grow via a hyaline cartilage by endochondrial ossification

 ELASTIC

cartilage

 It is a stiff cartilage yet elastic Found in: the pinna of the ears Eustachian tube The epiglottis

 FIBROCARTILAGE  It is a white, very tough material that

provides high tensile strength and support. It contains more collagen and less proteoglycan Found in: Intervertebral disc Symphysis pubis

DIVISIONS of the SKELETON  AXIAL

skeleton

 Bones in the center or axis ob the body

 APPENDICULAR

skeleton

 contains the bones of the extremities and

appendages of the body

AXIAL skeleton  Is

composed of:

 Skull  Vertebral column  Thoracic Cage

SKULL  CRANIUM  PARIETAL bone (2)  OCCIPITAL bone (1)  FRONTAL bone (1)  TEMPORAL bone (2)  SPHENOID bone (1)  ETHMOID bone (1)

 ACTIONS:  Protect the: Brain Eyes Ears

 Fontanels

newborn

of the

 Anterior (frontal)

Fontanel

Diamond shaped

 Posterior (occipital)

Fontanel

Triangular shape

 Sphenoidal

Fontanel  Mastoid Fontanel

 Purpose:  Permits the skill of the infant to change

shape as it passes through the vaginal canal  It allows growth of the infants head

 FACIAL

bones

 Nasal (2) Bridge of nose  Vomer (1) Divides the nasal cavity  Conchae (2) (inferior turbunates) Seen in the nostrils

Lacrimal (2)  Orbitals  Part of eye sockets

Zygomatic (2)  Prominent part of

cheeks  Base of eye socket

Palate (2)  Palatines  Back of hard palate

 Maxillae

(2)

 Upper jaw  Front of hard palate

 Mandible

(1)

 Lower jaw

 They are light weight  Shape are irregular  Small  The cranial and the facial bone: Gives the face its individual shape

 Auditory

Ossicles in the Ear  Malleus (pair) Hammer  Incus (pair) anvil  Stapes (pair) stirrup

 Ossicles  Are essential for hearing

 The

cranial and the facial bone:

 Gives the face its individual shape

 HYOID

bone

 Lies behind and

below the mandible and directly above the larynx It seems to float It is attached with the tongue muscle to assist with swallowing

 SINUSES  Frontal  Ethmoid  Sphenoid  Maxillary Makes the skull lighter and enhance vocal sounds

VERTEBRAL COLUMN  Holds the head  Stiffens and

supports the middle portion of the body  Provides attachment for the ribs and pelvic bones  It protects the

 Cervical

Vertebrae

(7)  Located in the neck Atlas Supports the skull

Axis Responsible for head movement

 Purpose:  is to contain and protect the spinal cord,

support the skull, and enable diverse head movement

CERVICAL NERVES  C1:

Head and neck C2: Head and neck C3: Diaphragm C4: Upper body muscles (e.g. Deltoids, Biceps) C5: Wrist extensors C6: Wrist extensors C7: Triceps C8: Hands

 Thoracic

Vertebrae (12)  Ribs are attached

 Thoracic

Nerves

 T3 – T7 Chest Muscles  T8 – T11 Abdominal Muscles

 Lumbar

Vertebrae

(5)  are the largest

segments of the movable part of the vertebral column

 Lumbar

Nerves

 L1 – L5 Leg Muscles

 Sacral

Vertebrae

 This is fused in

adults to form the Sacrum Anchors the pelvis

 Sacral

Nerves

 S1 – S3 Bowel and Bladder  S4 – S5 Sexual Function

 Coccyx  Commonly known

as the tailbone

Known as the coccygeal vertebrae in children, but is small and incomplete.

Intervertebral Disk  act

as shock absorbers during:  walking  jumping  falling

 slipped

disk

 refers to an

intervertebral disk that has shifted out of position

 Factors that

lead to injury from a slipped disk:  aging with associated degeneration and

   

loss of elasticity of the discs and supporting structures improper lifting twisting or turning excessive strain sudden forceful trauma.



For slipped disks in the neck  Numbness, tingling, weakness, or pain in the shoulder, neck, arm, or hand



For slipped disks in the lower back  Numbness, tingling, weakness, or pain in the buttocks, back, legs, or feet  Numbness and tingling around the anus or genitals  Pain down the back of each leg from the buttocks to the knee (this is called sciatica)  Pain with movement, straining, coughing, or doing leg raises  Difficulty controlling bowel movements or bladder

 Ruptured

disk

 occurs when pressure

forces some less dense tissue sideways, causing a protrusion in the walls of the disk

Spine Abnormalities:  Scoliosis  is an abnormal

lateral (sideways) curvature of the spine.  It occurs most commonly during adolescence and is more frequently found in girls than in boys.

 Lordosis  also known as

“swayback,”  is an exaggeration of the normal lumbar spine curve in the small of the back.

 Kyphosis  commonly known as

“widow’s hump” or “humpback”  may occur in aging and is more common in women

Thoracic (Rib) Cage  Ribs

(costae).

 is a cavity formed

by 12 pairs of flat, narrowed bones.  elastic cartilage provides room for the chest and the abdomen to expand



Thoracic cage protects the heart, lungs, and the great thoracic blood vessels. It attaches to the diaphragm. “true ribs” The first 7 ribs Known as the vertebro-sternal ribs They are attached to the thoracic vertebrae and the sternum

“false ribs” The next 3 ribs Known as the vertebro-costal ribs

“floating ribs” The last 2 ribs attached only posteriorly to the vertebrae and are not attached to each other.

Sternum  The

front boundary of the upper part of the thorax.  a flat, swordshaped bone in the middle of the chest opposite the thoracic vertebrae in the

The Appendicular Skeleton  Upper

Extremities  Lower Extremities  Pelvic Girdle

Upper Extremities  Shoulder  Arms  Shoulder Girdle  Clavicle  Scapula  Humerus  Forearm:  Ulna  Radius

 Wrist  Carpal Bones (8) Hamate Capitate Tapezium Scaphoid Lunate Pisiform Triquetral

 Metacarpals  Phalanges

Lower Extremities Femur  The upper bone of the leg  Thigh bone  Longest and strongest

bone

Head of the femur

Tibia

Attached to the acetabulum Neck Shaft

 Weight nearing long bone

of the lower leg

Fibula Patella Medial Maleolus Lateral Maleolus

 Tarsal

Bones (7)

 Talus  Navicular  Cuboid  Cuneiforms  Calcaneus

 Metatarsal  Phalanges

 The

hands

 are designed for fine and flexible

movements

 The

feet

 are designed for support

Pelvic Girdle Known as the pelvis This is known as the:  Ilium Identified as the hip bone

 Ischium The stronger portion

 Pubis During fetal life

 Women

has bigger pelvis to allow development of fetus.

The Muscles  determine

a person’s body shape  Functions as:  Aiding in body

movement  Blood circulation  Heat production

FUNCTIONS  Voluntary nEnable

Movement

walking, standing, sitting, and other movements nMaintain body in upright position nParticipate in body balance

FUNCTIONS  Involuntary nMaintain

Muscle action

heartbeat to pump blood nProvide arterial blood flow nPromote lymphatic and venous blood return to heart nDilate and contract blood vessels to control blood flow nMaintain respiration nPerform digestion processes nPerform elimination processes nParticipate in reflexes nEnable all other involuntary actions of body

 Protection nProtect

body in emergency by reflex action nCover, surround, and protect internal organs (viscera) nSupport internal organs

 Miscellaneous nProduce

heat nAssist in maintaining stable body temperature nProvide shape to body

Muscle Classification  Skeletal  Smooth  Cardiac

 Skeletal

and cardiac

muscles  are striated meaning that they consist of fibers marked by bands crossing them, which gives them a striped appearance.

 Smooth

muscle

 is nonstriated

 Muscles

are:

 Involuntary are smooth, unicycle nucleated, nonbranching muscles that are not directly controllable at will. Cardiac Muscle Smooth muscle They are controlled by the CNS or hormones

 Voluntary striated muscle that can be controlled voluntarily Skeletal muscle

SMOOTH MUSCLE LOCATION:  Wall of hollow organs, vessels, respiratory

passageways

CELL CHARACTERISTIC:  Tapered at each end, single nucleus, nonstriated

CONTROL:

 Involuntary

ACTION:

 Produces peristalsis; contracts and relaxes; may

sustain contraction; helps maintain blood pressure by regulating size of arteries

 controls

involuntary motions inside the body organs (viscera).  also known as involuntary or visceral muscle.  is responsible for:    

propelling urine through the urinary tract moving food along the digestive tract dilating the pupils of the eyes dilating and contracting blood vessels to assist in blood circulation. respond to nervous stimulation in

CARDIAC MUSCLE  LOCATION:  Wall of heart  CELL CHARACTERISTIC:  Branching networks, single nucleus, lightly

striated

 CONTROL:  Involuntary  ACTION:  Pumps blood out of heart; self-excitatory but

influenced by nervous system and hormones

 is

the middle layer of the heart (myocardium).  responsible for propelling blood through the blood vessels  It works automatically

SKELETAL MUSCLE LOCATION:  Attached to bones

CELL CHARACTERISTIC:  Long and cylindrical; multinucleated; heavily

striated

CONTROL:  Voluntary

ACTION:

 Produces movement at joints; stimulated by

nervous system; contracts and relaxes rapidly; produces heat through aerobic production of energy; assists in blood return to heart

Skeletal Muscles  control movements of the skeleton  Under conscious control  Constitute about 40% of body weight  Functions: Locomotion Facial expression Posture

Structure of Skeletal Muscles  are

considered organs  lie in sheets and cords beneath the skin and cover the bones.  are wrapped together in bundles, and several bundles



Fascia a sheath of connective tissue, which separates individual muscles or surrounds muscle groups, forming compartments

 The

ORIGIN

 Is one end of the

muscle.  It is immobile  attached to the more stationary of the two bones needed for movement

 The

INSERTION

 is the part of the

muscle that attaches to the bone that undergoes the greatest movement.

 The

BELLY

 The main part of

the muscle

 The

PERIOSTEUM

 The fibrous muscle tissue that covers

bone

Tendons  The

ends of fascia lengthen into tough cords  attach muscle to bones

MUSCLES of the Body Neck and Shoulder Muscles  Sternocleidomastoid Located on the side of the neck Helps keep the head erect May cause torticollis if

 Deltoid Found on the shoulders It moves upper arm outward the body It is one of the intramuscular injection sites

 Arm

and Anterior Chest Muscles  Biceps Found on the front of the upper arm Helps in the flexing of the forearms

 Triceps  Found in

the posterior of the biceps.  Helps in the extending the forearm

Pectoralis Major, Minor Serratus anterior  Found in the anterior

upper chest, anterior chest arising from ribs  Helps in bring arms across the chest  This is known as “pecs”

 Muscles

for Respiration  Diaphragm Seen between the abdominal and thoracic cavities It assist in the process of breathing

 Intercostal Found between the Ribs Helps enlarge the chest cavity

Abdominal Muscles  Internal Oblique,

External Oblique, Transversus abdominis, Rectus Abdominis These are flat bands that stretch from ribs to pelvis, overlapping in layers from various angles They support the abdominal Organ These are known as “ABS”

 Back and Posterior

Chest

Trapezius Dorsi Seen across the back and posterior chest Helps to lift shoulder

Latissimus Dorsi and other back muscles  Found across the

back and posterior chest  They work in groups; help to stand erect, balance when heavy objects are carried, and

Gluteal Muscle  Gluteus Maximus,

Gluteus Medius, Gluteus Minimus

It forms the buttocks It helps change from sitting to standing position Helps in walking It is one of the intramuscular injection sites

 Thigh

and Lower Leg Muscles  Quadriceps Femoris

Group:

Rectus Femoris, Vastus Lateralis, Vastus Intermedius, Vastus Medialis Found on the anterior thigh Helps extends legs and thigh They are known as “quads” Common site for

 Hamstring Group: Biceps Femoris, Semimembranous, Semitendinosus Located in the posterior thigh Helps in the flexion of the leg and thigh

 Gracilis Located in the thigh Flexes and adducts leg and thigh

 Sartorius Located in the thighs It flexes and rotates thigh and legs Called “tailor’s muscle” because it allows sitting in cross-legged position

 Tibialis Anterior Situated in the anterior leg Helps in the elevation and flexion of the foot

 Gastrocnemiu

s

Located in the calf Flexes foot and Leg

 Soleus Located in the calf Extends and rotates foot

 Peroneus longus Located in the calf Extends, abducts and avert foot

 Achilles Tendon Attaches calf muscle to heel bone Allows extension of foot and gives “spring” to walk

 Muscles

in the HEAD

 Orbicularis oculi Moves eyes and wrinkles forehead Disorder may cause strabismus (“cross-eye”)

 Orbicularis oris Moves mouth and surrounding facial structures

 Masseter Assists in chewing by raising lower jaw

 Buccinator Moves fleshly portion of cheek for smiling

Diaphragm and Intercostals  the primary muscles of  The contractions of the

respiration diaphragm and the intercostals work together to enlarge the chest space and to form negative pressure within the thoracic cavity.  Relaxation of these muscles causes the thoracic cavity to become smaller, thereby forcing air out of the lungs and into the atmosphere.

Muscles of the Hands and Feet The muscles and tendons of the hands and feet are arranged in a slightly different manner from those of the rest of the body. Many bones, muscles, and tendons in the hands and feet are necessary to provide movement for these complex body parts. Because bulky muscles would make clumsy motions, the larger muscles used to move the hands and feet are located in the forearms and the lower legs. Other muscles begin at the wrist and extend into long, thin tendons that attach to the bones of the fingers. This placement permits accuracy and a

Formation of Bone Tissue Osteoblast  Bone-building cells

Ossification

 is the formation of bone by osteoblasts, and

is the process by which bones become hardened, due to an increase in calcified tissue.

Osteocyte

 hardened, mature bone cell

Osteoclast

 Assist in the resorption or breakdown of cell  This process allows bones to grow and

change shape

Factors that affect bone growth and maintenance:  Heredity  Nutrition  Proteins, vitamins A, D, C and minerals:

Calcium and phosphurus

 Exercise  Hormones

BONE GROWTH  INFANCY  Rapid

 CHILDHOOD  Steady

 ADOLESCENCE  Rapid spurt before the Epiphyseal growth

plate closes

Muscle Contractions Contractility  the ability to shorten and to become thicker

Extensibility

 the ability to stretch

Elasticity

 the ability to return to normal length after

stretching

Irritability

 the ability to respond to stimulus, often a

nerve impulse that originates in the spinal cord and travels to a nerve Do not respond without stimuli

Contraction and Relaxation  Prime

mover

 A single muscle or set of muscles that

instigate movement

 Antagonist

muscles

 This muscles take over when an opposite

movement is to be made  Synergic

or synergistic muscles

 These are muscles that assist one

another in movement

Power Source  GLYCOGEN  a special form of stored glucose the body

uses to fuel  It is form by digested foods that furnish CARBON, HYDROGEN and OXYGEN  FATTY

ACIDS

These fuels are called ADENOSINE TRIPHOSPHATE (ATP)

BLOOD O2 and ATP (oxidation) Muscle cells Energy and Heat

 Most

of the body’s heat originates from muscle activity.  When muscles are very active, they draw on the reserve glycogen stored in their cells.  When the body is cold, it uses the ability of muscles to produce heat rapidly by the automatic device of general muscle action (shivering).  Total body shivering

OXIDATION Produces waste product of CO2 and Lactic Acid Removed in the lungs Removed in the kidneys and the sweat gland

Causes muscle fatigue

muscle cell + food and oxygen heat and energy by-products: lactic acid and carbon dioxide

Muscle Tone  The

state of slight contraction and the ability to spring into action  Physical exercise improves the tone of the muscles and increases their size.  An idle muscle loses its tone and wastes away.  If a person does not use certain muscles or uses them very little, the muscles become flabby and weak (atonic) and may atrophy (waste away).

Isometric and Isotonic Contractions  ISOMETRIC

CONTRACTION

 do not increase the length of a muscle,

but do increase muscle tension

 ISOTONIC

CONTRACTION

 shorten and thicken the muscle, causing

movement

Mobility  Newborns

are uncoordinated in their movements.  Maturation of CNS is needed for them to

move purposely  Sit up crawl stand takes steps with help walks without assistance climbing stairs running skipping hopping.

ADULT gait pattern develops between 3 y.o to 5 y.o  Infants have a wide-based gait.  As children mature, the base narrows. 

They swing their arms in coordination. Stride and walking speed increase, and movements become smooth and graceful.



Normal changes of aging cause the gait of older adults

 Range of motion (ROM)  is the total amount of motion that a joint

is capable of.  important for prevention and rehabilitation of musculoskeletal conditions

Effects of AGING in the system