Bones and Joints.pdf

HUMAN ANATOMY AND PHYSIOLOGY NOTES
RAMDAS BHAT
KARAVALI COLLEGE OF PHARMACY 1
CHAPTER NO:4
SKELETAL SYSTEM AND
JOINTS
Prepared by,
RAMDAS BHAT
Asst. Professor
Karavali college of Pharmacy
Mangalore
7795772463
Ramdas21@gmail.com

RAMDAS BHAT
Parts of the skeletal system
• Bones (skeleton)
• Joints
• Cartilages
• Ligaments
Divided into two divisions
1. Axial skeleton
2. Appendicular skeleton
Functions of Bones
1. Support - holds up soft tissues & maintains body shape
2. Protection of internal organs critical to survival such as brain, heart & lungs
3. Lever system – muscles act on bones to produce movement
4. Mineral storage – matrix composed of minerals
5. Blood cell formation - produced by marrow of many bones Functions of Cartilage
6. Model for bone growth - abundant in embryo & foetus – model from which most adult
bones develop
7. Provides a smooth cushion between adjacent bones
8. Provides firm flexible support (nose, ears, ribs & trachea)
9. Relatively rigid, but springs back to original shape if bent or slightly compressed; excellent
shock absorber
Functions of Ligaments and Tendons
Ligaments
• Attach bones to bones
• Provide stability
Tendons
• Attach muscles to bones
• Anchors muscle to bone for movement
• Example: Achilles’ tendon
Bones of the Human Body
• The adult skeleton has 206 bones - makes up 18 - 20% of your body weight
• Two basic types of bone tissue
SKELETAL SYSTEM

RAMDAS BHAT
Compact/Dense bone (solid)
• Homogeneous
• Forms diaphysis of long bones & thinner
surfaces of all other bones
Cancellous/Spongy bone (porous)
• Small needle-like pieces of bone
• Many open spaces
• Forms epiphyses of long bones & center
of all other bones.
Classification of Bones on the Basis of Shape
Classification of Bones
1. Long bones
• Typically, longer than wide
• Have a shaft (diaphysis) with heads at both ends (epiphyses)
• Contain mostly compact bone
• Examples: Femur, humerus
• If still growing, has an epiphyseal or growth plate composed of
cartilage between each epiphysis & diaphysis
2. Short bones
• Generally, cube-shape or short sized bones
• Contain mostly spongy bone
• Examples: Carpals of wrist, Tarsals of feet, Phalanges, Metatarsal and Metacarpal.

RAMDAS BHAT
3. Flat bones
• Thin and flattened o Usually curved
• Thin layers of compact bone around a layer of spongy bone
• Examples: Skull, ribs, sternum, scapula
4. Irregular bones
• Irregular shape
• Do not fit into other bone classification categories
• Example: Vertebrae and facial bones
SPECIAL TYPES OF BONES
1. Pneumatic bone:
• Pneumatic bones are those bones which contain an air-filled cavity within them.
• In humans, they are seen in relation to the nasal cavity – they enclose the paranasal
sinuses.
• Examples: maxilla, frontal bone, sphenoid and ethmoid.
2. Sesamoid bone:
• These are small nodular bone found in between Femur and Tibia-Fibula.
• The term sesmoid means seed like
• They are originated from the tendons.
• Example: Patella

RAMDAS BHAT
Bones of Human body:
There are 206 bones in the human body:
• The skeleton can be divided into two main parts.
• The axial skeleton consists of 80 bones. The primary bones of the axial skeleton are the skull, spine,
ribs and sternum (thorax).
• Anterior means front; posterior means back. This is an anterior view of the skeleton.
Name of the Bone (Axial skeleton) Number
Bones of Skull (29)
Cranial bone (8)
a) Frontal
b) Parietal
c) Temporal
d) Occipital
e) Ethmoid
f) Sphenoid
Facial bones (21)
a) Zygomatic bones
b) Maxilla
c) Mandible
d) Palatine
e) Lacrimal
f) Vomer
g) Nasal bone
h) Inferior nasal conchae
i) Ear ossicles (both ears)
j) Hyoid
01
02
02
01
01
01
02
02
01
02
02
01
02
02
06
01

RAMDAS BHAT
Ribs and sternum (24+1)
a) Ribs (24)
i. True ribs
ii. False ribs
iii. Floating ribs
b) Sternum
1st to 7th pair
8th to 10th pair
11th and 12th pair
01
Vertebrae (26)
a) Cervical bones
b) Thoracic
c) Lumbar
d) Sacrum
e) Coccyx
07
12
05
01
01
TOTAL 80
• The appendicular skeleton consists of 126 bones.
• The primary bones of this skeleton are the shoulder or pectoral girdle, arms, hands, pelvic
girdle, legs and feet.
Name of the Bone
(Appendicular skeleton)
Number
1. BONES OF UPPER PROXIMITY
a) Scapula
b) Clavicle
c) Humorous
d) Radius
e) Ulna
f) Bones of hand
Carpals
• Scaphoid
• Lunate
• Triquetral
• Pisiform
• Trapezium
• Trapezoid
• Capitate
• Hamate
Metacarpals
Phalanges
64
02
02
02
02
02
08 (each hand x 2) =16
01 x2
01 x2
01 x2
01 x2
01 x2
01 x2
01 x2
01 x2
05 x2
14 x2

RAMDAS BHAT
2. BONES OF LOWER PROXIMITY
a) Pelvic girdle
b) Femur
c) Tibia
d) Fibula
e) Patella
f) Bones of feet
Tarsals
• Calcaneus
• Talus
• Cuboid
• Navicular
• Cuneiform
Metatarsals
Phalanges
62
02
02
02
02
02
07 (each feet x 2) =14
01 x 2
01 x 2
01 x 2
01 x 2
03 x 2
05 x 2
14 x 2
TOTAL 126

RAMDAS BHAT
Diseases of bones:
OSTEOPOROSIS:
• Osteoporosis is a term that means "porous bones."
• It is a skeletal disease affecting women and men.
• Osteoporosis is a condition in which bones have lost minerals especially calcium and
making them weaker, more brittle, and susceptible to fractures (broken bones).
• Any bone in the body can be affected by osteoporosis, but the most common places
where fractures occur are the back (spine), hips, and wrists.
RICKETS:
• Rickets is the softening and weakening of bones in children, usually because of an
extreme and prolonged vitamin D deficiency.
• Some skeletal deformities caused by rickets may need corrective surgery.
• If the Rickets are seen in Adulthood they are termed as OSTEOMALACIA.

RAMDAS BHAT
JOINTS
Joints
• Articulations of bones
• Functions of joints o Hold bones together securely
• Gives the rigid skeleton mobility
• Ways joints are classified
a) Functionally
b) Structurally
Functional Classification of Joints
• Focuses on the amount of movement allowed
• Joint types restricted mainly to the axial skeleton where firm attachments and protection
of internal organs are priorities include:
a) Synarthroses – immovable joints
b) Amphiarthroses – slightly moveable joints
• Joints predominate in the limbs where mobility is important:
c) Diarthroses – freely moveable joints
Structural Classification of Joints
• Based on whether fibrous tissue, cartilage or a joint cavity separates the bony regions.
General rule:
a) Fibrous joints – Generally immovable
b) Cartilaginous joints – Some are immovable (synarthrosis), while most are slightly
moveable (amphiarthrotic)
c) Synovial joints – Freely moveable (diarthrotic)
Fibrous Joints
• Bones united by fibrous tissue
• Sutures – irregular edges of bone interlock, bound tightly by
connective tissue fibers = essentially no movement
• Syndesmoses – connecting fibers are longer and have more give
• Example: joint connecting distal end of tibia and fibula

RAMDAS BHAT
Cartilaginous Joints
• Bones ends connected by cartilage
• Slightly moveable (amphiarthrotic)
a) Pubic symphysis
b) Intervertebral joints
• Immovable (synarthrosis)
a) Hyaline-cartilage epiphyseal plates of growing long bones
b) Cartilaginous joints between the 1st ribs and the sternum
Synovial Joints
• Articulating bones are separated by a joint cavity
• Synovial fluid is found in the joint cavity
• All joints of the limbs
Features of Synovial Joints
• Articular cartilage (hyaline cartilage) covers the ends of bones forming the joint
• A fibrous articular capsule lined with a smooth synovial membrane encloses joint surfaces
• Have a joint cavity filled with lubricating synovial fluid
• Ligaments surround the capsule and reinforce the joint
Structures Associated with the Synovial Joint
• Bursae – flattened fibrous sacs
• Lined with synovial membranes
• Filled with synovial fluid
• Not actually part of the joint – act like ball bearings to reduce friction
• Common where ligaments, muscles, skin, tendons or bones rub together.
Tendon Sheath
Elongated bursa that wraps completely around a tendon that is subjected to friction

RAMDAS BHAT
• The shapes of the articulating bone surfaces determine the movement of a joint.
1. Plane joint
• Articular surfaces are essentially flat & only short, gliding movements are allowed.
• Nonaxial = no rotation.
• Ex: intercarpal joints of wrist.
2. Hinge joint
• Cylindrical end of 1 bone fits into a trough-shaped surface of another bone.
• Angular movement in one plane.
• Uniaxial = allow movement around one axis only.
• Ex: elbow, ankle, & joints between phalanges.
3. Pivot joint
• Rounded end of 1 bone fits into a sleeve or ring of bone (& possibly ligaments).
• Uniaxial – can only turn around its long axis.
• Ex: proximal radioulnar joint & joint between the atlas & the dens of the axis.
4. Condyloid joint/ A.K.A Ellipsoid joint (knuckle-like)
• Egg-shaped articular surface of 1 bone fits into the oval concavity of another.
• Both surfaces are oval.

RAMDAS BHAT
• Allows the moving bone to travel from side to side & back and forth, but can’t rotate
around its long axis.
• Biaxial (movement around 2 axes)
• Ex: metacarpophalangeal joints (knuckles).
5. Saddle joint
• Each articular surface has both convex & concave areas, like a saddle
• Biaxial like the condyloid joints
• Ex: carpometacarpal joints in the thumb (twiddling!)
6. Ball & Socket joint
• Spherical head of one bone fits into round socket in another
• Multiaxial joint (movement in all axes including rotation)
• The most freely moving synovial joint
• Ex: shoulder & hip
Inflammatory Conditions Associated with Joints
a) Bursitis – inflammation of a bursa usually caused by a blow or friction
b) Tendonitis – inflammation of tendon sheaths
c) Arthritis – inflammatory or degenerative diseases of joints o Over 100 different types
The most widespread crippling disease in the United States
Clinical Forms of Arthritis
1. Osteoarthritis
• Most common chronic arthritis
• Probably related to normal aging processes
2. Rheumatoid arthritis
• An autoimmune disease – the immune system attacks the joints
• Symptoms begin with bilateral inflammation of certain joints
• Often leads to deformities
3. Gouts Arthritis
• Inflammation of joints is caused by a deposition of urate crystals from the blood
• Can usually be controlled with diet.
Body Movements
a) Flexion - The process of bending or the state of being bent.
b) Extension - The act of straightening or extending a flexed limb
c) Hyperextension - Flexion of a limb or part beyond its normal range
d) Rotation - The process of turning around an axis.
e) Abduction - To draw away from the median plane, or (the digits) from the axial line of a
limb
f) Adduction - To draw toward the median plane or (in the digits) toward the axial line of a
limb
g) Circumduction - Movement of a part in a circular direction
h) Dorsiflexion - The turning of the foot or the toes upward

RAMDAS BHAT
i) Plantar flexion - Extension of the ankle resulting in the forefoot moving away from the
body
j) Inversion - Turning inward
k) Eversion - Turning outward
l) Supination - Applied to the hand, the act of turning the palm forward (anteriorly) or
upward, performed by lateral rotation of the forearm. Applied to the foot, it generally
implies movements resulting in raising of the medial margin of the foot, hence of the
longitudinal arch.
m) Pronation - Applied to the hand, the act of turning the palm backward (posteriorly) or
downward, performed by medial rotation of the forearm. Applied to the foot, a
combination of eversion and abduction movements taking place in the tarsal and
metatarsal joints and resulting in lowering of the medial margin of the foot, hence of the
longitudinal arch.
n) Opposition - The thumb, unlike other fingers, is opposable, in that it is the only digit on
the human hand which is able to oppose or turn back against the other four fingers, and
thus enables the hand to refine its grip to hold objects which it would be unable to do
otherwise.

RAMDAS BHAT

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