Presentation on theme: "THE SKELETAL SYSTEM. I. BONE STRUCTURE & FUNCTION A.There are 206 bones in the body. A.FUNCTION 1.Support 2.Protection 3.Movement due to muscles 4.Blood."— Presentation transcript:
I. BONE STRUCTURE & FUNCTION A.There are 206 bones in the body. A.FUNCTION 1.Support 2.Protection 3.Movement due to muscles 4.Blood formation aka hematopoesis 5.Electrolyte Balance stores and releases calcium and phosphate 6.Acid Base Balance Buffers blood by storing and releasing alkaline salts
Skeletal system is divided Into 2 parts: A.blood by storing and releasing alkaline salts Parts of the skeletal system include: bones (skeleton); joints,cartilage, & ligaments Axial Skeleton Appendicular Skeleton
IV. The Skeleton A.Organization 1.Axial Skeleton –Skull –Vertebral Column –Vertebrae –Ribs 2.Appendicular Skeleton –limbs –girdles
Spongy (cancellous) Spongy (cancellous) Compact Bone Two types of Bone
3.Mature Bone Osseous Tissue B. Microscopic Anatomy
Lamellar bone Called Lamellar bone Two kinds of bone Compact Spongy (cancellous) 3. Mature Bone
Dense, few spaces Dense, few spaces Haversian canals Haversian canals Concentric Lamellae Concentric Lamellae Compact Bone 3. Mature Bone
Osseous Vocabulary & Anatomy Osteon (Haversian System) is a unit of bone. Central (Haversian) Canal is an opening in the center of an osteon that carries bloodvessels & nerves.
Osseous Vocabulary & Anatomy Perforating (Volkman’s) Canal runs perpendicular to the central canal & carries blood vessels & nerves.
Osseous Vocabulary & Anatomy Lacunae are cavities holding the mature bone cells (osteocytes). Arranged in concentric rings.. Lamella are the concentric rings around the central canal that holds the lacunae
Osseous Vocabulary & Anatomy Canaliculi are the tiny canals radiating perpendicularly from the central canal through the lamella creating a transport system from nutrients.
Name C, D & E D = Osteoblast E = Osteocytes C = Osteoclast
I. BONE STRUCTURE & FUNCTION 4 Shapes of Bone: –Long bones Have a shaft with heads at both ends & Contain mostly compact bone. –Short bones Generally cube- shape & contains mostly spongy bone. –Flat bones thin, flattened, usually curved & has thin layer of compact bone surrounding spongy bone. –Irregular bones Do not fit into other bone classification categories
II. BONE GROWTH & DEVELOPMENT A.Two Patterns of Bone Formation 1.Intramembranous bones –originate between sheet-like layers of connective tissues
II. BONE GROWTH & DEVELOPMENT A.Two Patterns of Bone Formation 2.Endochondral bones –begin as masses of hyaline cartilage that bone tissue later replaces.
II. BONE GROWTH & DEVELOPMENT B.Growth in Long Bones 1.grow by interstitial growth at epiphyseal plates a.rate of cartilage growth is balanced by replacement with bone b.end of growth as cartilage cells slow down division
II. BONE GROWTH & DEVELOPMENT B.Growth in Long Bones 2. bones grow in width by appositional growth a.Osteoblasts in periosteum: secretes bone matrix b.Osteoclasts in endosteum: removes bone matrix (a little slower)
Appositional Growth –New bone forms at ridges around blood vessels –Periosteum becomes endosteum
– New lamella formed – More bone added forming osteon Appositional Growth
II. BONE GROWTH & DEVELOPMENT C.Hormones 1. growth hormone from pituitary: stimulates growth in childhood a.Gigantism: excessive growth hormone b.dwarfism: not enough growth hormone or thyroid hormones
II. BONE GROWTH & DEVELOPMENT C.Hormones 2. thyroid: regulates activity of growth hormone 3. sex hormones: promote growth spurt, induce epiphyseal plate closure estrogen: maintains bone density
III. Bone Maintenance & Repair A.Bone remodeling: 1.Life long process 2. Local areas of bone are destroyed and rebuilt 3. Repairs microdamage caused by normal wear and tear
C. Repair Hematoma forms 1. Hematoma forms 2. Spongy bone forms in area of hematoma forming a soft callus 2. Spongy bone forms in area of hematoma forming a soft callus III. Remodeling and Repair
C. Repair Osteoblasts lay down new bone matrix 3. Osteoblasts lay down new bone matrix converting the soft callus into a hard callus of spongy bone 4. The boney callus is remodeled to form a permanent patch 4. The boney callus is remodeled to form a permanent patch
Bone healing occurs in stages: –fracture –granulation –callus –lamellar bone –normal contour III. Types of Bone Repair
III. Calcium Homeostasis A.Blood Ca 2+ Level 1.Has a very narrow range 2. Ca 2+ Required for –For normal muscle contraction –Nerve impuses
III. Calcium Homeostasis A.Blood Ca 2+ Level 3.Abnormal levels –Hypocalcemia causes marked jitteriness and convulsive seizures
III. Calcium Homeostasis A.Blood Ca 2+ Level 3.Abnormal levels –Hypercalcemia the most common life- threatening metabolic disorder associated with cancer
III. Calcium Homeostasis B.Bone’s Role 1.Major storage site for calcium 2.Calcium moves –Into bone as osteoblasts build new bone –Out of bone as osteoclasts break down bone
III. Calcium Homeostasis C.Bone, Calcium and Hormones 1.Parathyroid Hormone – Increases blood Ca 2+ levels 2.Calcitonin Decreases blood Ca 2+ levels
D. Homeostatic Imbalances OsteopeniaOsteopenia – Inadequate ossification OsteoporosisOsteoporosis – Bone absorption outpaces deposition – Fractures common – More common in elderly women III. Calcium Homeostasis
RicketsRickets – Lack of vitamin D or calcium during growth – Bowed legs – Deformed pelvis D. Homeostatic Imbalances Rickets
Osteosarcoma – Bone cancer – Usually between ages 10-25 – Survival rate is about 50% with amputation D. Homeostatic Imbalances
Bone spurBone spur – Abnormal projection at one site of bone due to overgrowth – Common in aging bones D. Homeostatic Imbalances
Bone Markings Bony markings are the surface features of a bone. They are sites of attachments for muscles, tendons & ligaments. They can serve as passage ways for nerves & blood vessels. There are 2 Categories of Bony Markings –Projections & processes – outward growths on the bone surface. –Depressions or cavities – indentations on the surface of the bone.
Sinuses The sinuses are hollow portions of bone within the skull surrounding the nasal cavity. They lighten the face/skull, act as resonance chambers & amplify the voice.
The Hyoid Bone The only bone in the body that does not articulate w/another bone. It serves as a moveable base for the tongue.
The Fetal Skull The fetal skull is large compared to the infant’s total body length. Fontanels are fibrous membranes connecting the cranial bones The fontanels allows the brain to grow. The fontanels converts to bone within 24 months after birth.
The Vertebral Column The Vertebrae are separated by intervertebral discs made of fibrocartilage, connective tissue. The spine has a normal “S” curvature. Each vertebrae is given a name according to its location.
Bony Thorax Made of 3 parts: Sternum Ribs Thoracic vertebrae The bony thorax forms the rib cage that protects the thoracic internal organs.
The Appendicular Skeleton Includes the: Appendages (limbs) Pectoral Girdle Pelvic Girdle
Pectoral – Shoulder Girdle Made of 2 bones: Clavicle aka collarbone Scapula aka shoulder blade The pectoral girdle allows the upper limb to have free range of movement
Upper Extremity Bones Includes the: Humerus (upper arm bone) Radius (thumb side of forearm) Ulna (pinki side of forearm) & the Hand Anterior Humerus Posterior Humerus
Upper Extremity Bones The distal head of the radius is larger than the proximal The proximal head of the Ulna is larger than the distal.
Upper Extremity Bones The Hand includes: Carpals – short bones of the wrist. Metacarpals – long bones of the palm of the hand. Phalanges (Digits) – Proximal, Middle, Distal fingers.
Pelvic Girdle Made of the Coxal Bone (hip) which is 3 bones fused together: Ilium Ischium Pubic Bone The total weight of the upper body sits on the pelvis. The pelvis protects the reproductive organs, urinary bladder, & part of the large intestine
B. Male vs. Female Skeleton - Pelvis a.spines farther apart in male b.hole in ischium: smaller and triangular in female c.angle across pubic symphysis = pubic arch: less than 90° and more sharply angled in male d.distance between ischia larger in female
Lower Extremity Anterior Femur View Posterior Femur View The lower extremity is made of: Pelvis Femur (thigh) Tibia (shin) Fibula Foot
Lower Extremity The flat superior portion of the tibia is called the Tibial Plateau. The distal head of the tibia is called the medial malleolus while the distal head of the fibula is called the lateral malleolus
Lower Extremity The Foot is made up of the : Tarsals – short bones of foot Metatarsals – long bones of foot Phalanges (Digits)- long bones of the toes
The Arches The bones of the foot make up 3 arches. The 2 long arches are the lateral & medial longitudinal arches. The arch across the foot is the transverse arch.
Joints Joints are where 2 or more bones come together. Joint Functions: Holds bones together. Allows for mobility. Classified either Functionally or Structurally.
Joint Functional Classification Synarthrosis – immovable joints These joints permit no movement. Certain fibrous joints fall into this category. Amphiarthrosis – slightly moveable joints. These joints permit only a little bit of movement. Some cartilaginous and fibrous joints are in this category. Diarthroses – freely movable joints. These joints permit a variety of movements. Synovial joints fall into this category.
Joint Structural Classification Fibrous Joints – immovable joints. Formed by dense fibrous connective tissue Cartilaginous Joints – slightly moveable joints. Formed by cartilage Synovial Joints – freely movable joints. Formed by a synovial capsule
Joint Structural Classification Fibrous Joints Exaples: Sutures of Skull Syndemoses – Allows slightly more movement than sutures Medial Mallelous Lateral Mallelous
Joint Structural Classification Synovial Joints: Bones are separated by a joint cavity & surrounded by a fibrous capsule. Synovial fluid fills the joint cavity/capsule. Ends of bones covered w/hyaline cartilage. Ligaments reinforce these joints.
Structures associated w/ Synovial Joints Bursa – flattened fibrous sacs filled w/synovial fluid. Tendon Sheath – Elongated bursa/membrane that wraps around a tendon to hold it together & protection.
Types of Synovial Joints Ball-and-socket joint Hinge joint Pivot joint Gliding or Plane joint Saddle joint Condyloid or Ellipsoid joint
Types of Synovial Joints Gliding or Plane joint –allows a wide range of side-to-side movements. Ex. Carpals & Tarsals Hinge joint - permit an angular motion along one plane, which is similar to the opening and closing of a door. Ex. Knee, elbow, PIP, MIP, DIP joints. Pivot joint – This allows a rotation similar to the turning of a dial. Ex. Radius pivots w/ulna.
Types of Synovial Joints Ball-and-socket joint –produce a wide array of movements. Ex. Hip & shoulder Saddle joint – joints resemble a saddle in which one bone’s articular surface rocks back and forth upon another. Ex. Metacarpal & carpal or Metattarsal & tarsal. Condyloid or ellipsoid joint –a ball-like articular surface rests against the curve-shaped end of another articular surface. This articulation allows a circular or elliptical pattern of motion. EX. Metacarpal & phalange
Joint Homeostatic Imbalances Bursitis – inflammation of the bursa usually due to trauma or friction Tendonitis – inflammation of the tendon usually due to overuse.
Joint Homeostatic Imbalances Arthritis – inflammation or degeneration of a joint. It’s the most widespread & crippling disease in the US. There are over 100 different types. Osteoarthritis - Most common type, due mostly to aging.
Joint Homeostatic Imbalances Rheumatoid Arthritis – an autoimmune disease where the body sees it’s joints as a foreign threat & will try to destroy them. Symptoms are bilateral joint pain & can lead to deformities. Gouty Arthritis – inflammation caused by deposits of uric crystals from the blood. Typically occurs in big toe. Usually due to diet.