Skeletal System.pdf

MC_101_: ANATOMY AND PHYSIOLOGY LECTURE LECTURE 09: SKELETAL SYSTEM: Bones and Joints PROFESSOR: Dr. Janelle Tayo 1ST SEMESTER | A.Y 2022-2023...

MC_101_: ANATOMY AND PHYSIOLOGY LECTURE LECTURE 09: SKELETAL SYSTEM: Bones and Joints PROFESSOR: Dr. Janelle Tayo 1ST SEMESTER | A.Y 2022-2023 EXTRACELLULAR MATRIX (ECM) OBJECTIVES Always contains collagen, ground substance, and I. Identify and describe the major types of tissues other organic molecules, as well as water and in the human body as well as their various minerals. functions. Provides support and gives structure II. List the structural and functional characteristics Bone, cartilage, tendons, ligaments - connective of the different membranes of the body. tissues III. Describe the process of inflammation and Determines the characteristics of bone, cartilage, explain why inflammation protects the body. tendons, ligaments IV. Describe the major events involved in tissue repair. COMPONENTS: V. Describe the age-related changes that occur in ○ Collagen tissues. Tough, rope-like structure strength Provides flexibility but resists SKELETAL SYSTEM pulling or compression Subdivided in 2: ○ Proteoglycans ○ Axial skeleton - everything in the middle, Large molecules consisting of axis: skull, vertebral column, hyoid bone, many polysaccharides attaching ossicles (inner ear), thoracic cage = 6 to and encircling core proteins ○ Appendicular skeleton - the rest Forms large aggregates and attract water There are 206 bones in our body. BRITTLE BONE DISEASE OSTEOGENESIS IMPERFECTA COMPONENTS OF THE SKELETAL SYSTEM Imperfect bone formation Rare disorder caused by any one of a number of BONES faulty genes that results in little collagen formation or poor quality collagen which causes BONE MATRIX DECREASED FLEXIBILITY and EASILY CARTILAGE BROKEN THAN NORMAL BONE. Not as strong as the bones Somewhat curved and is flexible Example: Nose, External Ear, Trachea, Rib cage COMPONENTS DESCRIPTION ○ Articular Cartilages - prevents friction in Tendons and Ligaments - Large amounts of collagen bone during movement fibers TENDONS Very tough like Attaches the bones to muscles ropes and cables Cartilage - Collagen + proteoglycans Collagen - tough LIGAMENTS Proteoglycans - Attaches bone to bone smooth & resilient -Relatively Rigid but flexible; goes back to original shape FUNCTIONS OF SKELETAL SYSTEM - Excellent shock absorber Body support Organ Protection Bone - Collagen + minerals ○ Example: Skull encloses and protects the (calcium and phosphate) brain, vertebrae surround the spinal cord, Collagen - flexible rib cage protects the heart, lungs, and strength other organs of the thorax. Minerals - compression Body Movement strength Mineral Storage - Most minerals are ○ Minerals, Calcium, Phosphate hydroxyapatite - calcium Blood Cell Production phosphate crystals ○ Bones contain red bone marrow that produces blood cells and platelets. Table 1. Components of Skeletal System PINO, R., TABANAO, K. | 1NU02 1  SHAPE CLASSIFICATION BONE MARROW Long Long > Wide Inside the medullary cavity in the diaphysis Lower & Upper Soft tissues that fill the spaces in the bone called Limbs Marrow Short Wide > Long ○ Red - location of the blood forming cells; Wrist, Ankle blood cell production Flat Thin ○ Yellow - mostly fat Skull, Sternum Newborn - mostly red bone marrows; Adult - red is Irregular Bones Shapes that do not fit readily replaced with yellow in the other 3 categories Adults - red flat and long bones (femur humerus) Vertebrae, Facial Bones COMPACT/CORTICAL BONE Table 2. Shape Classification Outer part of diaphysis Thinner Surfaces of others LONG BONE STRUCTURES Osteon - structural unit of compact matrix ○ Lamella - rings of bone matrix BONE STRUCTURE Diaphysis Shaft ○ Lacunae - spaces between lamellae; Compact Bone Tissue where osteocytes are located (Outside) Epiphysis Ends spongy bone tissue ○ Canaliculus - tiny canals: transport nutrients and remove wastes; finger-like Articular Cartilage Covers Epiphysis projections; where bones are nourished; Reduces stress & friction communicates with the osteocytes Table 3. Long Bone Structure ○ Central Canal - center of osteon; contains blood vessels EPIPHYSEAL PLATES Growth plates Where growth and length occurs CANCELLOUS/SPONGY BONE Can only be seen in a growing child Epiphysis of long bones Side of growth between diaphysis and epiphysis Center of others NO OSTEONS EPIPHYSEAL LINE Trabeculae - interconnecting rods, and spaces that Can only be seen in adults contains the marrow MEDULLARY CAVITY Center of Diaphysis; red or yellow marrow PERIOSTEUM Membrane around bone’s outer surface; cover ENDOSTEUM Membrane that lines medullary cavity; inside PINO, R., TABANAO, K. | 1NU02 2  BONE CELLS OSTEOBLASTS Responsible for formation, repair, and remodeling of bone; bone-forming cells OSTEOCYTES Cells that maintain bones matrix and form osteoblast after being surrounded by the bone matrix OSTEOCLASTS Contributes to bone repair and remodeling with bone reabsorption - removes existing bone Ossification center - where bone formation starts Calcification - to harden ENDOCHONDRAL OSSIFICATION Within a cartilage model inside; hyaline cartilage: HC then bone ○ Primary OC - bone formation in the diaphysis of a long bone ○ Secondary OC - bone formation in the epiphysis ○ It starts in diaphysis, it has chondrocytes that will enlarge and calcify. The perichondrium will become a periosteum creating a bone collar. Blood vessels will start to come in as well as osteoblasts. Then, it will start and secrete depositing bone matrix and will calcify. It will form trabeculae and compact bone. Secondary OC will take place in the epiphysis. NOTE: It is a constant cycle of breaking down and depositing bone. Chondrocytes - cartilage cells; as they enlarge, they die BONE FORMATION Perichondrium - dense layer of fibrous connective tissue that covers the surface of most of the OSSIFICATION cartilage in the body. Formation of bone by osteoblasts BONE FORMATION LOCATION Results = compact & spongy bone INTRAMEMBRANOUS FORMATION within connective tissue; direct formation of bone; skull and clavicle ○ During utero, Mesenchymal stem cells would transform into osteoblasts, then will go to the ossification center. They would secrete or deposit organic extracellular matrix to form a structure. After some time, the matrix will calcify (harden). It will create trabeculae, blood vessels will start to come in and develop. Then, the trabeculae will BONE GROWTH start to radiate out (papalabas). The cells Bone growth remaining outside will become the ○ length (pataas) periosteum. ○ width (pahaba) PINO, R., TABANAO, K. | 1NU02 3 APPOSITIONAL GROWTH (WIDTH) Osteoblasts will be coming in and deposit bone Bone growth occurs by deposition of new bone matrix to develop spongy bone. Callus ossification lamellae will take place in about 4-6 weeks. Spongy bone will Osteoblasts deposit new bone matrix on the become a compact bone. surface of bones (between Periosteum & Existing BM), BONE = +WIDTH/DIAMETER NOTE: Too much immobilization results to loss of bone NOTE: Destroys the old so that the bones won’t get strength thicker Balance immobilization and exercise BONE AND CALCIUM HOMEOSTASIS Bone - major storage site for calcium; regulates the calcium blood levels In and out movements of calcium in bone helps determine blood levels of calcium ○ Ca in - Osteoblasts builds new bone ○ Ca out - Osteoclasts breaks down bone Calcium is like the cement in the bone, you can’t build a sturdy home without it Calcium homeostasis - maintained by parathyroid hormone (PTH) and calcitonin INTERSTITIAL GROWTH (LENGTH) NOTE: Major source of increase in height - occurs in Decreasing calcium levels > triggers the parathyroid epiphyseal plate (inside the bone) gland (releases parathyroid hormones and calcitonin) > releases PTH > Occurs through endochondral ossification ○ Stimulates osteoclasts > breaks down bone > releases calcium out to the blood. When a growth is triggered, chondrocytes will undergo mitosis (division). They will enlarge and ○ PTH triggers kidney > increase mature, and produce matrices at the same time. reabsorption of calcium in the urine > matrix is calcified > much of the cartilage in the activates vitamin D (vit D is important in enlarged cells are removed by osteoclasts > dead stimulating small intestine to increase chondrocytes are replaced by osteoblasts > absorption of calcium in the intestine) = osteoclasts deposits bone lamellae on surface of increase Ca in the blood calcified cartilage = new bone on diaphyseal side of epiphyseal slate Increased calcium levels > triggers parathyroid gland > releases to calcitonin > calcitonin signals NOTE: Growth is pataas, bone sa ilalim, cartilage sa taas osteoclast to stop > osteoclast would inhibit like a boom boom paw chz breaking down > osteoblasts promotes increased calcium deposition to the bone BONE REMODELING Involves a group of osteoclasts and osteoblasts that ○ Parathyroid hormone ↑ in blood travel through or across the surface of the bone. ○ Calcitonin ↓ in blood Removal of existing bones by osteoclasts and deposition of new bone by osteoblasts occurs ○ Parathyroid Hormone (PTH) in all bone Essential for the maintenance of Responsible for changes in bone shape, repair, blood calcium levels within adjustment to stress, and calcium ion regulation homeostasis. ○ Calcitriol Steroid hormone that increases blood calcium levels. ○ Calcitonin Secreted from C Cells in the thyroid gland when blood calcium levels are too high If a bone is fractured, hematoma formation will take place. After 3-4 days, some blood vessels and cells will come in and will be releasing or creating a fibrous tissue called callus formation (band-aid). PINO, R., TABANAO, K. | 1NU02 4  THE SKULL SKULL BONES Frontal Bone Parietal Bone Occipital Bone Temporal Bone Sphenoid Bone Ethmoid Bone FACIAL BONES Paired (2) ○ Maxilla ○ Zygomatic ○ Palatine ○ Lacrimal ○ Nasal Unpaired (1) ○ Inferior Nasal Concha ○ Mandible ○ Vomer (with perpendicular ethmoid plate; Nasal Septum) PINO, R., TABANAO, K. | 1NU02 5  VERTEBRAL COLUMN Foramen Magnum Central axis of the skeleton, spine Where the spinal cord passes through Base of the skull - end of the pelvis Jugular Foramen Adults: 26 Individual bones, 5 regions Where the internal Jugular vein passes through ○ 4 MAJOR CURVATURES: Cervical - anteriorly NOTE: Thoracic - posteriorly Frontal lobe = nasa harap Lumbar - anteriorly Sphenoid Bone - wing-like Sacral & Coccygeal - posteriorly Sella turcica - where pituitary gland houses 7 cervical vertebrae - C1 to C7 NOTE: Review parts of the skull 12 thoracic vertebrae - T1 to T12 5 lumbar vertebrae - L1 to L5 PARANASAL SINUSES 1 sacrum - S Large Cavities within the bones associated to the 1 coccyx - CO nasal cavity, and open up to the nasal cavity = TOTAL OF 26 BONES FEMS - ○ Frontal Atlas ○ Ethmoid ○ 1st Vertebra ○ Maxillary ○ Hold head ○ Sphenoid ○ Yes (Nod) Axis ○ 2nd Vertebra ○ Rotates head ○ No (Shakes head) HYOID BONE The only bone in the body that does not articulate with the other bone (Walang katabi) Provides attachment for some tongue muscles Attachment point for important neck muscles that elevate the larynx FUNCTIONS OF VERTEBRAL COLUMN Supports weight Protects spinal cord Allows spinal nerves to exit spinal cord Provides site for muscle attachment Provides movement of a head and truck PINO, R., TABANAO, K. | 1NU02 6  EXCESSIVE CURVATURES OF THE SPINE LORDOSIS ATLAS VERTEBRA Excessive curvature in lumbar area KYPHOSIS Excessive curvature in thoracic area SCOLIOSIS Lateral/sideway curves Transverse Foramen - where vertebral artery passes through No spinous process ○ ALL CERVICAL VERTEBRAE HAS TRANSVERSE FORAMEN VERTEBRAL ARCH Protects the spinal cord along wit the body AXIS VERTEBRA Projects posteriorly Divided into 2 left and right halves which each ahs 2 parts ○ Pedicle - attached to the body ○ Lamina - forms posterior portion of the vertebral foramen VERTEBRAL FORAMEN Vertebral Arch and the body form a complete bony circle enclosing VERTEBRAL FORAMEN VERTEBRAL CANAL Contains entire spinal cord and cauda equina Vertebral foramina of adjacent vertebrae combine to Has spinous process form vertebral canal Has a dense body that articulates with the atlas Biped - split VERTEBRA TYPICAL VERTEBRA CERVICAL VERTEBRA THORACIC VERTEBRA Vertebral Foramen - where spinal cord passes through Articular Facet - connects with another vertebra Spinous process - nasa likod PINO, R., TABANAO, K. | 1NU02 7  Has 2 articular facets ○ One Connects to another vertebra ○ One Connects with a rib LUMBAR VERTEBRA Protect the vital/internal organs BONES OF THE PECTORAL GIRDLE PECTORAL GIRDLE Composed of: SACRUM ○ Scapula - shoulder blade 5 vertebra fused into 1 ○ Clavicle - collar bone COCCYX 4 vertebra fused into 1 SACRAL HIATUS Landmark for anesthesia ○ Example: Childbirth THORACIC CAGE Protects the internal/vital organs SCAPULA AND CLAVICLE Sternum (Breast Bone) SCAPULA ○ Manubrium Acromion Process - point ○ Body Coracoid process - attachment ○ Xiphoid process Glenoid Cavity - head of the humerus attached to the scapula Classified into 3; ○ True Ribs (7) CLAVICLE One rib connects to sternum Proximal end - connects the sternum area First bone to ossify but the last to completely ○ False Ribs (8-12) ossified Ribs connects with 7th rib to connect sa sternum (yung gitna) Ribs 11, 12 - has no connection to sternum (Floating Ribs) PINO, R., TABANAO, K. | 1NU02 8  ULNA & RADIUS To differentiate; ○ In ULNA, Always check the trochlear notch HOOK ○ In RADIUS, Check the head if its CIRCULAR ○ RADIUS - THUMB (Lateral) ○ ULNA - PINKY (Medial) UPPER LIMB BONES Humerus ○ Upper Limb Ulna & Radius ○ Forearm Carpal Bones ○ Wrist Metacarpal Bones ○ Hand BONES OF THE WRIST AND HAND HUMERUS CARPAL BONES - Wrist Head METACARPAL BONES - Hands Anatomical Neck DIGITS - Fingers Surgical Neck Greater and Lesser Tubercle - attachment for Carpal Bones muscle ○ So Long Top Part Here Comes The Lateral Epicondyle - gilid Thumb Medial Epicondyle - gitna Scaphoid (Proximal) ○ Important landmark for attachment of Lunate muscle Triquetrum Pisiform Hamate (Distal) Capitate Trapezoid Trapezium DIGITS ○ Proximal Phalanx, Distal Phalanx ○ Middle Phalanx (2-5) ○ 1st Digit - THUMB ○ 5th digit - PINKY PINO, R., TABANAO, K. | 1NU02 9  COMPARISON OF THE MALE PELVIS TO THE FEMALE PELVIS MALE ○ Denser, Larger ○ Sacral promontory is more prominent, directly anterior (paharap) ○ Narrow subpubic angle FEMALE ○ Lighter, for delivery ○ Should be conducive for labor ○ Sacral promontory is more posterior (palikod) for labor ○ Subpubic angle is wider PELVIC GIRDLE Where lower limb attach to the body HIP BONE ○ Ischium Inferior and posterior ○ Ilium Most superior LOWER LIMB BONES ○ Acetabulum Femur Hip jockey ○ Thigh Head of the femur articulates Patella (Tuhod) ○ Unique; shape referred to sesamoid type of bone ○ Knee cap Tibia ○ Large lower leg Fibula ○ Small lower leg Tarsal ○ Ankle Metatarsals HIP BONE ○ Foot Ilium Ischium Phalangers Pubis ○ Toes and fingers Acetabulum ○ Head of the femur articulates BONES OF THE THIGH Femur ○ Has a longer neck Head Greater trochanter Neck Lesser trochanter Body (shaft) of femur Lateral Epicondyle - gilid Medial Epicondyle - gitna Intercondylar fossa (yung gitna na bilog) Patellar Groove Linea aspera (Posterior view) Patella (Tuhod) ○ Unique; shape referred to sesamoid type of bone PINO, R., TABANAO, K. | 1NU02 10  Metatarsal Bones ○ MILC Medial Cuneiform Intermediate Cuneiform Lateral Cuneiform Digits ○ Proximal, Middle, Distal Phalanx ○ 1st digit - Toe; 5th digit - yung maliit wahaha ano ba yun pinky toe ARTICULATIONS Commonly known as “Joints” Where two bones come together Protected by articular cartilage to reduce friction Can be classified into; ○ Structurally - according to a major connective tissue or whether a fluid-filled joint capsule is present Fibrous Cartilaginous Synovial ○ Functional - degree of motion Synarthroses Ampiarthroses Diarthroses STRUCTURAL CLASSIFICATION OF JOINTS BONES OF THE LEG Lateral Condyle FIBROUS Medial Condyle United by fibrous connective tissue Head Sutures, syndesmosis, gomphoses Tibial Tuberosity Fibula (Payat) ○ Lateral Tibia (Taba) ○ Medial Lateral Malleolus Medial Malleolus CARTILAGINOUS United by means of cartilage Synchondroses, symphysis BONES OF THE FOOT Calcaneus Tarsal Bone ○ NTC (No Thanks Cow, Pataas) Talus (Puti) Cuboid (Square) Navicular PINO, R., TABANAO, K. | 1NU02 11 SYNOVIAL Joined by a fluid cavity Most joints of the appendicular skeleton Types of Synovial (CHECK TABLE 6.4 SA BOOK FOR FULL TABLE) ○ Plane Intervertebral Etc. ○ Saddle Carpometacarpal ○ Hinge Cubital (Elbow) Knee ○ Pivot Atlantoaxial ○ Ball-and-socket Glenohumeral Hip ○ Ellipsoid Atlanto Occipital STRUCTURAL CLASSIFICATION OF JOINTS SYNARTHROSIS Non-movable joint Example: Skull bone articulations AMPHIARTHROSIS Slightly movable joint Example: between vertebrae DIARTHROSIS Freely movable joint Example: Knee, Elbow, Wrist Articulations TYPES OF MOVEMENT Flexion: Bending Extension: Straightening Abduction: Movement away from midline Adduction: Movement toward the midline Pronation: Rotation of the forearm with palms down Supination: Rotation of the forearms with palms up Rotation: Movement of a structure about the long axis EFFECTS OF AGING ON THE SKELETAL SYSTEM AND JOINTS Decreased collagen production ○ Bone becomes brittle Loss of bone density ○ Leaves diseases ○ women menopausal (loss of estrogen, the protective hormone for women) Degenerative Changes ○ Ligaments and tendons are shortened; physical activity decreases PREVENTIVE MEASURES: Intensive exercise Increase calcium intake Increase Vitamin D PINO, R., TABANAO, K. | 1NU02 12 References: Seeley’s Essentials of Anatomy and Physiology 11th Ed. Dr. Tayo’s Skeletal System Recorded Lecture PINO, R., TABANAO, K. | 1NU02 13