Bones and Skeletal System

• Support and movement is achieved via the skeleton

Skeleton

• The skeleton is a rigid framework of bone and cartilage
• It provides support and is involved in movement and locomotion

Bone (Osteo)

• Bone is hard connective tissue made up of different bone cells
• Periosteum is a specific connective tissue present outside the bone
• Both ends of the bone are the epiphysis
• The region between both epiphysis is the diaphysis, or shaft
• The interior part of the bone is called endosteum
• The peripheral part of endosteum is compact bone
• The inside of compact bone has a soft region called spongy bone
• Most of the red bone marrow is present in the epiphysis, but some is in the diaphysis
• Yellow bone marrow is present in the diaphysis or shaft
• Blood vessels are also present and transport blood to different parts of the body
• The liver destroys red blood cells after 120 days
• Every blood cell is produced in bone marrow, except platelets

Bone Cells (Osteogenic Cells)

• Bone cells include osteoblasts, osteocytes, and osteoclasts
• Osteoblasts are bone-forming cells
• Osteoblasts are uninucleated
• Osteoblasts secrete unmineralized ground substances
• Osteocytes are bone-maturing cells
• An osteocyte is a bone cell after the accumulation of matrix
• Elastin is a protein created by fibroblasts that form a chain of elastic fiber
• Osteoblasts eventually convert into osteocytes
• Osteocytes are mononucleated
• Osteocytes transport calcium from bone into blood
• Osteoclasts are bone-destructive cells and are called osteoclasts
• Osteoclasts destroys extra bone through phagocytosis
• Osteoclasts are multinucleated
• Osteoclasts secrete calcium and phosphorus into blood
• Osteoclasts participate in demineralization, which is the removal of minerals
• More osteoclasts indicates more soft bone

Cartilage (Chondrio)

• Collagen is a group of proteins found mainly in the connective tissue of skin
• Almost 30% of the body's protein is in the form of collagen
• Cartilage is connective tissue made up of chondrocytes, or cartilage cells
• All cartilage have same composition
• A specific connective tissue present outside the cartilage is perichondrium
• Inside the perichondrium matrix is collagen and elastin
• Open spaces in the matrix are known as lacunae
• Chondrocytes are present inside the lacunae
• Blood vessels are absent in cartilage; nutrients are transported via diffusion

Types of Cartilage

• Includes hyaline, fibrous, and elastic cartilage
• Hyaline cartilage is cartilage having equal concentrations of collagen and elastin
• This cartilage is present at the tip of the humerus, femur, and radius
• It is also present in the nose, larynx, and trachea
• Fibrous cartilage is cartilage having more collagen
• Elastic cartilage is cartilage having more elastin protein
• It is more flexible than the other two
• For example, it is in the ear pinna and epiglottis

Human Skeleton

• The axial and appendicular skeletons make up the human skeleton

Axial Skeleton

• The axial skeleton consists of the skull, vertebral column, and rib cage
• It makes the main axis of the human body
• The head has cranial bones, facial bones, middle ear ossicles, and the hyoid bone
• Paired bones include the temporal and parietal bones
• Unpaired bones include the frontal, occipital, sphenoid, and ethmoid bones
• Facial bones can also be paired or unpaired
• Paired facial bones: Nasal, lacrimal, zygomatic, maxilla, inferior nasal concha, palatine
• Unpaired facial bones: Mandible and vomer
• The only moving bone of the skull is the mandible, or jaw bone
• The hyoid bone is at the base of the skull
• There are 6 ear bones
• Malleus (1+1)
• Incus (1+1)
• Stapes (1+1)
• There are 33 bones in the vertebral column
• 7 Cervical
  • Made up of the Atlas, and Anis
• The thoracic column contains 12 vertebrae, present in the lower vertebral column
• The lumbar vertebrae contains 5 vertebrae
• The sacral vertebrae (5) fuse to form the sacrum
• There are 4 coccygeal vertebrae
• The coccyx and sacral vertebrae makes the pelvic vertebrae
• The rib cage is made up of 24 bones and 1 sternum
• The sternum is not part of the rib cage
• The first seven pairs of ribs are true ribs
• The 8th, 9th, and 10th pairs are false ribs because they are attached to the sternum with the help of coastal cartillage
• The 11th and 12th pair are called floating ribs because they do not attach to the sternum directly or indirectly

Appendicular Skeleton

• It contains the pectoral and pelvic girdles, forelimbs, hind limbs, and feet
• The pectoral girdle contains the scapula and clavicle
• The tip of the humerus is called ball
• The arm contains the humerus (1), carpels (8), radius (1), metacarpels (5), ulna (1), and phalanges (14)
• The pelvic girdle contains the ilium, ischium, and pubis
• The three bones make up one unit
• The leg has two extra bones called the patella
• The leg contains the femur (1), tarsal/ankle (7), tibia (1), meta tarsal/sole (5), fibula (1), and phalanges (24)

Joints

• Joints are where two or more bones articulate

Fibrous Joints

• Fibrous joints are held together with the help of a fibrous band
• These joints are immovable and mainly consist of collagen
• Fibrous joints are present in the head region called sutures
• Fibrous joints are present between the radius and ulna

Cartilaginous Joints

• Cartilaginous joints are joints in which cartilage is present between bone
• These joints are slightly moveable
• These joints have either no cavity or fluid
• Joint of vertebral column present in the hip region is called pubic symphysis
• Joint present between rib and coastal cartilage + sternum

Synovial Joints

• Synovial joints contain the presence of hyaline cartilage
• These joints can move in one or more direction
• These joints have a cavity known as a synovial cavity
• A specific lubricant called synovial fluid is present in these joints
• Synovial fluid membrane is on the outside
• Tissue holds the bones with each other and is called ligament
• The synovial membrane and ligament collectively are called the capsule

Hinge Joints

• Hinge joints are joints that can move in one direction
• Examples are the elbow and knee joints

Pivot Joint

• Pivot joints provide rotational movement
• Carpals and metacarpals
• Tarsals and metatarsals

Ball and Socket Joints

• Ball and socket joints can move in all directions freely
• Examples include the pectoral and pelvic girdle joints

Disorders of the Skeleton

• Include slipped disc, disc displacement, spondylosis, sciatica, arthritis, and bone fractures

Slipped Disc (Herniation)

• Nucleus pulposus is like a material present between vertebrae
• Annulus fibrosus is the gelatinous filling inside the disc
• Annulus is a fibrous cartilage that protects the nucleus pulposus
• Both the nucleus pulposus and annulus fibrosus collectively are called the disc

Disc Displacement

• Disc displacement is a condition in which the disc slips or herniates from its original position

Reasons for Disc Displacement

• Protrusion, which is extension beyond the limit
• Lifting heavy weight
• Accidental injury
• Falling from a height Symptoms
• Failure of bending and or neck movement
• Immobility
• Extensive pain Treatment
• Bed rest
• Painkillers
• Surgery

Spondylosis

• Spondylosis is the fusion of vertebrae, particularly lumbar or cervical region
• Reasons
• Aging -Disc slip -Deterioration of the vertebra
• Falling from a height Symptoms
• Extensive pain
• Immobility
• Severe pain

Sciatica

• Sciatica is the inflammation of the sciatic nerve present in the thigh region
• Reasons
• Tumor
• Disc slip
• Wrong injection in hip region
• Hip injury Symptoms
• Radiating pain
• Tingling
• Numbness
• Temporary paralysis of leg region Treatment
• Painkillers
• Physiotherapy
• Surgery

Arthritis

• Arthritis is the inflammation of a joint Symptoms
• Immobility
• Creaking sound from joints
• Difficulty to move up and down the stairs
• Swelling
• Severe pain

Types of Arthritis

• Osteoarthritis is a disease which represent the breakdown of cartilage between the joints
• Rheumatoid is an autoimmune disease is a disease in which the synovial membranes which connect the joints degrades
• Gout is a condition of arthritis which is caused by uric acid build up

Bone Fracture

• Bone fracture is the breakdown of bone
• Types of fractures include simple, compound, and complex
• Simple fracture is closed fractures where the fractured bone remains inside the muscle
• Compound fracture is an open fracture where the fractured bone comes out of skeletal muscle
• Complex fracture is where neighboring bones damage a broken bone

Bone Repair

• Hematoma Formation: After the breakdown of bone, clotted blood will form and this clot is is known as a haemoatoma
• After bone fracture the blood capillaries will rupture and cause hemorrhage
• Deficiency of nutrients in the blood cells occurs at the fracture area
• Pain and swelling are induced

Soft Callus Formation

• Soft Callus Forms after Fibrocartiliginous Callus Formation: Soft callus is a secretion composed of porous material
• Soft callus is secreted from Forming Osteoblasts
• Area undergoes phagocytosis to clear the damaged cells
• Capillaries grow into bone and start to provide nutrient to the growing cells
• The process takes appoximately 3-4 weeks
• Callus that is formed has a porous material that clears clotted blood so bonds can be made

Bony Callus Formation

• Phase which involves replacement of cartilage by bone forms bony callus over time
• In this Cartilage gets destroyed by osteoclast
• Ends of bones will join completely and forms bony callus in the 4th to 8th week.
• Bony Callus will be stiff while still fractured

Bone Remodelling

• Phase in which remodelling of the bone structure results in fracture is called bone remodelling
• Retains its previous condition is called as bone remodelling
• Fracture bone normally glows more rapidly as compared to the original bone.
• Extra bone is degraded
• Differentiated area cannot be degraded
• Dislocation-Of joint represents the displacement of the joint is termed from its region Reasons
• Phematoid-Arthritis
• weak Liggaments -Portrusion
• Accident Injure
• Aging
• Symptoms
• Immobility
• Extensive joint
• Swelling

Treatment

• Physiotherapy
• Bandage
• Surgery

Sprain

• Breakdown of joints represents the Sprain Sprained in the following joins the Ankle the knee the wrist
• Symptoms-Immobility Severe pain Swelling redness Treatment
• Ice -Therapy
• Used pain killer
• Dressing
• Bandage
• Physiotherapy

Muscles

• Specilized issues that contract or relax In movement or locomotion

• Study of muscles Called MYOLOGY .Types include Skeletal Cardiac Smooth muscles

• Skeletal musices are voluntary Stripped

• Cardiac musces are involuntary Striped

• Smooth muscle are involuntary Striped

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