The skeletal system includes 206 bones that provide structure, protection, movement and support for the body. The bones are made of cells, proteins and minerals. There are two types of skeleton - axial (skull, vertebrae, ribs) and appendicular (shoulder, pelvis, arms, legs). The skeletal system works with muscles to enable movement, with muscles connecting to bones via tendons. Key functions include protection of organs, blood cell production, calcium storage and enabling movement.

1. THE SKELETALSYSTEM
The skeletal system includes all of the bones and joints in the body.
Totally 206 bones form the skeletal system.
The bone is made up of many cells, protein fibres, and minerals. The
skeleton providing supportand protection for the soft tissues those make
up the rest of the body.
The skeletal system also provides attachment points for muscles to allow
movements at the joints. The ligaments and tendons all hold the bones
together.
New blood cells are produced bythe red bone marrow inside the bones.
Skeletal system divided into Axial and Appendicular,
The Axial Skeleton– 80 bones
1. Skull Bones with hyoid – Totally 29 bones
Facial bones – 14 bones.
Inferior nasal concha(2)
Lacrimal bones (2)
Zygomatic bones (2)
Maxilla (2)
Nasal bones (2)
Palatine bones (2)
Vomer
Mandible
Cranial bones – 8 bones
Ethmoid Bone
Frontal Bone
Occipital Bone
Sphenoid Bone
Parietal Bones – (2)

2. TemporalBones – (2)
Ossicles – 6 bones
Stapes – (2)
Malleus – (2)
Incus – (2)
Hyoid - 1 bone
2. Rib Cage – 12 pairs
True ribs – 1st to 7th ribs
False ribs – 8th to 10th ribs
Floating ribs – 11th & 12th ribs
Sternum - 1 bone
3. Vertebral Column – 26 bones
Cervical spine – 7 bone
Thoracic spine – 12 bones
Lumbar spine – 5 bones
Sacral spine – 5 bones fused to join together as single bone
Coccyx – 1 or 2 bones
The Appendicular skeleton – 126 bones
1. Upper Extremity – (Right side – 32 and Left side – 32 = Totally
64 bones in both side)
Pectoral girdle – 2 bones
Clavicle
Scapula
Arm – 1 bone
Humerus
Forearm – 2 bones
Ulna

3. Radius
Carpal – 8 bones
Scaphoid
Lunate
Triquetrum
Pisiform
Trapezium
Trapezoid
Capitate
Hamate
Metacarpals – 5 bones
Phalanges – 14 bones
2. Lowerextremity - (Right side – 31 and Left side – 31 = Totally 62
bones in both side)
Pelvic girdle – 1 bones
Thigh – 1 bone
Femur
Knee Cap – 1 bone
Patella
Leg – 2 bones
Tibia
Fibula
Tarsal’s – 7 bones
Talus
Calcaneum
Cuboid
Navicular
Medical cuneiform
Lateral cuneiform
Intermediate cuneiform
Metatarsals – 5 bones
Phalanges – 14 bones

4. TYPES OF BONES
There are five types of bones in the human body:
1. Long,
2. Short,
3. Flat,
4. Irregular, and
5. Sesamoid
Long Bones - Femur, Humerus, Ulna, Radius, Tibia and Fibula even the
Metacarpals, Metatarsals and Phalanges are considered as long bones,
due its shape of having body(shaft), having hard outer and spongy inner
surface containing bone marrow, two ends with growth plates /
epiphysis and both ends (upper & lower) are covered with cartilage.
Short Bones – Carpals & Tarsals, Generally for supportand stability.
Flat Bones – Scapula, Sternum, Skull bones and Ribs, Generally to
protect vital organs.
Irregular bones – Vertebrae, Sacrum and mandible
Sesamoidbones – Patella, Usually short and irregular embedded in a
tendon.
TYPES OF JOINTS
Meeting point or Junction between two bones forms joint/Articulation.
Joints are classified based on its structure and function.
Three Majortypes of Joints:
1. Fibrous
2. Cartilaginous
3. Synovial
FIBROUS JOINTS (Immovable joints / Synarthrosis)
Bones are held together by fibrous connective tissues.
Fibrous Joints are further classified into three types,

5. 1. Sutures - Skull Bones
2. Syndesmoses - Tibia and fibula & Radius and ulna
(Slightly moveable)
3. Gomphoses - Toothand maxilla or mandible.
CARTILAGINOUS JOINTS (Slightly moveable joints /
Amphiarthrosis)
The articulating end of two bones made up of cartilage. But there is no
synovial cavity and synovial fluid.
Cartilaginous joints are further classified into two types,
1. Synchondroses – First sternocostaljoints. (Immovable)
2. Symphyses - Pubic symphysis.
SYNOVIAL JOINTS (Movable joints / Diarthrosis)
Bones forming the joint is surrounded by an articular capsule, and
joints include a synovial cavity with synovial fluid.
Synovial Joints are further classified into six types,
1. Ball and socket – Shoulder & Hips (All direction movements)
2. Condyloid - RadiocarpalWrist (Flexion, Extension, Abduction and
Adduction)
3. Gliding/plane - Intercarpal & Acromioclavicular (sliding
movements)
4. Hinge - Elbow & Knee (Flexion and Extension in one plane)
5. Pivot - Atlanto-axial, Radioulnar (Rotation movements)
6. Saddle - Carpometacarpal (Flexion, Extension, Abduction and
Adduction)
BODYPLANES
Body planes are used to transect the human body, in order to describe
the location of structures and the direction of movements. Three body

6. planes are,
The sagittalplane is a plane parallel to the sagittal suture. It divides
the body into left and right.
The coronalplane or frontal plane divides the bodyinto dorsal and
ventral (back and front, or posterior and anterior) portions.
The transverse plane or axial plane divides the bodyinto cranial and
caudal (head and tail) portions.
Common conditions relatedto SkeletalSystem:
Osteoporosis:The bones become weak and prone to fracture.
Osteopenia:Bone mineral density is lower than normal.
Osteomalacia:Softening of your bones, often caused by a vitamin D
deficiency
Osteitis deformans / Paget’s disease:Excessive breakdown and formation
of bone, followed by disorganized bone remodelling.
Bone tumor: An abnormal (neoplastic) growth in the bone may be benign or
malignant
Osteomyelitis: Inflammation of bone due to infection
Scoliosis, kyphosis, andLordosis: Deformity of the vertebral column
Fracture:A break in the bone, The two major classification is open
(compound)and closed (Simple).
Further subdivision is
Greenstick fracture:
Transverse fracture:
Oblique fracture:
Spiral fracture:

7. Comminuted fracture:
Impacted fracture:
Avulsion fracture:
Arthritis: Inflammation of one or more joints and cause pain and stiffness in
the affected area. There are two major classifications are,
Osteoarthritis is a chronic degenerative joint disease. Breakdown of cartilage
and underlying bone.
Rheumatoid Arthritis, also a chronic disease, the autoimmune disease is
characterized by inflammation of the lining of the joints.
50 Diseaseand disorders related to the skeletalsystem:
MEDICALTERMS:
1. Head - Cephalo / Cranio
2. Neck - Cervico
3. Chest - Thoraco / Pectoral
4. Hand - Chiro
5. Joint - Arthro
6. Wrist - Carpo
7. Finger / toe - Dactylo
8. Rib - Costo
9. Bone - Osteo
10. Foot - Podo
11. Big toe - Hallux
12. Vertebra - Spondylo
13. Ankle - Tarso
14. Arm - Brachi
15. Cartilage - Chrondro
16. Spinal cord - Myel/o
17. Straight - Orthr/o
MEDICALABBREVIATIONS:
1. ACL - Anterior cruciate ligament
2. AKA - Above the knee amputation

8. 3. DJD - Degenerative joint disease
4. Fx / # - Fracture
5. IPJ – Interphalangeal joint
6. LCL - Lateral collateral ligament
7. MCL - Medial collateral ligament
8. ORIF - Open reduction and internal fixation
9. PCL- Posterior cruciate ligament
10. PET - Positron emission tomography
11. PIP - Proximal interphalangeal (joint)
12. RA - Rheumatoid arthritis
13. RCL- Radial collateral ligament
14. TMJ - Temporomandibular joint
15. UCL - Ulnar collateral ligament
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The MuscularSystem is consisting of skeletal, smoothand cardiac
muscles.
There are more than 600 muscles in the human body. The muscular system
helps in maintains posture, strength, balance and movement of the body
(at joints)
A. Cardiac Muscles -Muscles found in heart, is involuntary.
B. Smooth Muscles - Smooth muscle is responsible for the contraction of
hollow organs, such as blood vessels, the gastrointestinal tract, the
bladder, or the uterus
C. SkeletalMuscles -are attached to bones by tendons, and they produce
all the movements of bodyparts in relation to each other - is under
voluntary control.
List of major muscles of the human body:
CHEST - Pectoralis major, External and Internal Intercostal muscles,
Diaphragm

9. ABDOMEN - Transversus abdominis, Rectus abdominis, and Oblique
(External and Internal)
Back - Trapezius, Latissimus dorsiand Erector spinae.
UPPER EXTREMITY
A. Shoulder - Deltoid, Teres major, Rotator cuff (supraspinatus,
infraspinatus, teres minor, subscapularis)
B. Arm - Anterior compartment -Biceps, Brachialis
Posterior compartment – Triceps
C. Forearm- Anterior compartment,
Superficial - Pronator teres, flexor carpi radialis, flexor carpi ulnaris,
flexor digitorum superficialis
Deep - pronator quadratus, flexor digitorum profundus, flexor pollicis longus
Posteriorcompartment,
Superficial - Extensor digitorum, extensor digiti minimi, extensor carpi
ulnaris, extensor carpi radialis longus, extensor carpi radialis brevis,
brachioradialis
Deep - supinator, extensor indicis, extensor pollicis longus, extensor
pollicis brevis, abductorpollicis longus
D. Hand - Thenar, hypothenar, Lumbricals and Interossei.
LOWER EXTREMITY
A. Thigh:
Anterior compartment: Sartorius, quadriceps femoris (Rectus femoris,
vastus lateralis, vastus intermedius, vastus medialis)
Posteriorcompartment: Bicepts femoris, semitendinosus,
semimembranosus
B. Leg:

10. Anterior compartment:
Tibialis anterior, extensor digitorum, extensor hallucis longus
Posteriorcompartment:
Superficial - gastrocnemius, soleus
Deep- popliteus, flexor digitorum longus, tibialis posterior.
Common DiseaseofMuscularSystem:
1. Myasthenia gravis - is a chronic autoimmune neuromuscular disease
characterized by varying degrees of weakness of the skeletal (voluntary)
muscles of the body
2. Duchenne muscular dystrophy - is caused by an absenceof dystrophin,
a protein that helps keep muscle cells intact
3. RotatorCuff Tear- is a tear of one or more of the tendons of the four
rotator cuff muscles of the shoulder.
4. Talipes – Clubfoot, the front half of the foot turns inwards and downwards
5. Tendonitis - is an inflammation or irritation of a tendon.
6. Rhabdomyolysis - is a condition in which damaged skeletal muscle
breaks down rapidly.
7. Myotonia - an inability to relax the voluntary muscle after the vigorous
effort.
8. Muscle strain - A strain is an injury to a muscle in which the muscle
fibres tear as a result of overstretching.
9. Muscle cramp - is a strong, painful contraction or tightening of a
muscle that comes on suddenly and lasts from a few seconds to several
minutes

11. 50 diseases anddisorders related to the Skeletalsystem:
MEDICALTERMS:
1. Muscle - My/o
2. Diaphragm - Phreni
3. Tendon - Ten/o
4. Movement - kinesi/o
MEDICALABBREVIATIONS:
1. AROM - Active range of motion
2. DTR - Deep tendon reflex
3. EMG - Electromyogram
4. PROM- Passive range of motion; premature rupture of membranes
5. ROM - Range of motion
6. SLR - Straight leg raising