SEHH2233-2122-S1-Ch6-Skeletal.pdf

Lecture Outline The Skeletal System 1 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. After this lecture, studen...

Lecture Outline The Skeletal System 1 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. After this lecture, students should be able to 1. describe the microscopic structures and organization of bone 2. name and locate bones in human skeleton 3. understand various bone disorders 2 Skeleton: Overview Functions of the Skeleton Skeleton – axial 軸心 and appendicular Anatomy of a Long Bone Bone Growth and Repair Surface features of Bones e.g. Head, foramen Joints (articulation 關節) Disorders of bones and joints Homeostasis 3 Functions of the Skeleton  Support  Protection  Blood cell production (hematopoiesis / haematopoiesis)  Storage of fat & minerals e.g. calcium ions (Ca2+) & phosphate ions (PO43-)  Movement 4 Skeleton: Classification according to shape a. Long –a long shaft (柄) with two expanded ends. b. Short – cube shaped c. Flat – plate-like, with broad surfaces d. Irregular – varied shapes e. Round – circular in shape 5  Lies in the midline of the body Bones of the axial skeleton  Skull  Hyoid bone 舌骨  The vertebral column  The thoracic cage  Middle ear bones 6  Axial Skeleton: Skull https://www.youtube.com/watch?v=WRmNC_yPQZ8 Formed by the cranium and facial bones Protects the brain Has immovable joints – Sutures骨縫 Bones of the cranium 顱 Composed of 8 bones Frontal bone X 1 額骨 Parietal bones X 2 頂骨 Occipital bone X 1 枕骨 Temporal bones X 2 顳骨 Sphenoid bone X 1 蝶骨 7 Ethmoid bone X 1 篩骨 Axial Skeleton:Cranium Sphenoid 蝶骨 Base of cranium - bat/butterfly shape Sides of skull and floors and sides of orbits Sella turcica 蝶鞍 - supports the pituitary gland 腦下垂體 Sphenoidal sinuses 蝶竇 Ethmoid 篩骨 Roof and walls of nasal cavity Transverse section Frontal section Floor of cranium Medial sides of the orbits Perpendicular plate Superior and middle nasal conchae 鼻甲 Ethmoidal sinuses篩竇 8  Axial Skeleton: Cavity Sinuses 竇 https://www.youtube.com/watch?v=rfKUQH784gY  Air spaces within the bones  Lined by mucous membranes  Reduce the weight of the skull  Give resonance 共鳴 to the voice  Paranasal sinuses  Maxillary  Frontal  Sphenoidal  Ethmoidal  Mastoid sinuses 乳突竇 9  Axial Skeleton Bones of the Face  Maxillae上頜骨  Palatine bones 齶骨  Zygomatic bones 顴骨  Lacrimal bones 淚骨  Nasal bones 鼻骨  Vomer bone 犁骨  Inferior nasal conchae  Mandible下頷骨 https://www.youtube.com/watch?v=uMhQW1F78aA https://www.youtube.com/watch?v=2JelardIO8Y 10 https://www.youtube.com/watch?v=J4aZjh1Nvh0 Axial Skeleton: Hyoid Bone Hyoid bone  Superior to larynx 喉  Only bone in the body that does not articulate with another bone  Anchors the tongue  Site of attachment for muscles associated with swallowing 11 Axial Skeleton: Vertebral Column (Spine)  Supports rib cage  Serves as a point of attachment for the pelvic girdle  Protects the spinal cord  Consists of a series of separate bones named for their location  7 cervical vertebrae (neck)  12 thoracic vertebrae (chest)  5 lumbar vertebrae (lower back)  5 sacral vertebrae 骶骨 fused to form 1  3-5 coccygeal vertebrae fused to form 1 coccyx 尾骨 12 https://www.youtube.com/watch?v=i1Uw0jRNgy4  Posterior Normal curvatures  Cervical and lumbar – convex anteriorly  Thoracic and sacral – concave anteriorly  Provide support and balance  Abnormalities  Lordosis 脊柱前凸 – exaggerated lumbar curvature  Kyphosis 脊柱後彎(駝背) – increased roundness of the thoracic curvature  Scoliosis 脊柱側凸 – abnormal lateral curvature that occurs most often in the thoracic region Anterior 13  Intervertebral Discs  Prevent vertebrae from grinding against one another  Absorb shock, Allow motion between vertebrae 14  Vertebrae  Body – anterior portion  Vertebral foramen – canal for spinal cord  Bony projections - serve as sites for muscle attachment  Atlas (C1) – supports the head; allows head movement up and down  Axis (C2) - serves as a pivot for the atlas; allows head movement from side to side  Sacrum – fused sacral vertebrae; forms posterior wall of the pelvic cavity  Coccyx – formed from a fusion of three to five vertebrae 15 Axial Skeleton: Rib Cage  Protects the heart and lungs  Provides support for the bones of the pectoral girdle  The ribs Twelve pairs that connect to the thoracic vertebrae a) True ribs – upper seven pairs connect directly to the sternum by costal cartilages b) False ribs – next five pairs that attach indirectly to the sternum or no at all (‘floating’ ribs)  The sternum Flat, blade-shaped bone Composed of three bones that fuse a) Manubrium 垂管 b) Body c) Xiphoid process 劍突 https://www.youtube.co m/watch?v=3IlbLTMNer8 16 Appendicular Skeleton 1. Pectoral girdle 肩胛帶 2. Upper limbs 上肢 3. Pelvic girdle骨盆帶 4. Lower limbs 下肢 1 2 3 4 17 Appendicular Skeleton: Pectoral Girdle 肩胛帶  Clavicles 鎖骨 manubrium Articulate medially with the manubrium Only attachment to the axial skeleton Serves as a brace for the scapula and stabilizes the shoulder  Scapulae (pl) scapula (Sl.)肩胛骨 Spine processes Glenoid cavity關節盂 Source: Mcgrawhill publisher https://www.youtube.com/watch?v=f3I0288WoDM 18 Appendicular Skeleton: Upper Limb 1. Humerus 肱骨 Long bone of the arm Head articulates with the glenoid cavity of the scapula https://www.liberaldictionary.com/glenoid/ https://www.youtube.com/watch?v=1s_q-Znnmwo 19 Appendicular Skeleton 2. Radius 橈骨  Lateral side of the forearm  Head of radius articulates with and fits into the radial notch of the ulna  Radial tuberosity attaches a tendon from the biceps brachii 肱二頭肌  Ulnar notch of radius articulates with the head of the ulna 3. Ulna 尺骨  Longer bone of the forearm  Coronoid 冠狀的 process articulates with the coronoid fossa when elbow is flexed  Olecranon 鷹嘴的 process articulates with the olecranon fossa when the elbow is extended  Trochlear notch articulates with the trochlea of the humerus  Radial notch articulates with the Source: head of the radius Mcgrawhill 20 https://www.youtube.com/watch?v=O-yQoHmcunk publisher Appendicular Skeleton 4. Hand  Wrist (carpus腕) contains eight small bones  Metacarpal bones 掌骨 form the palm  Phalanges 指骨/趾骨  Bones of the fingers  The thumb has only two phalanges (proximal and distal)  The other fingers have three phalanges each (proximal, middle, and distal) 21 Appendicular Skeleton:Pelvic Girdle  Coxal bones (hip bones 髖關節)  Ilium 髂骨  Ischium 坐骨  Pubis 恥骨 - Pubic symphysis 恥骨聯合 - Obturator foramen 骨盤孔  Gender differences  Female has broader hips  Female pelvis is wider  Female inlet and outlet of the true pelvis are wide  Female pelvic cavity is more shallow  Female bones are lighter and thinner  Female pubic arch is wider 22 https://www.youtube.com/watch?v=yK-8ZwLFarc Appendicular Skeleton: Lower Limb  Femur 股骨  Longest and strongest bone in the body  Head fits into acetabulum 髋臼 of coxal bone  Greater and lesser trochanters attach muscles of the thigh and buttocks  Lateral and medial condyles articulate with the tibia 脛骨  Patellar surface articulates with the patella 膝蓋骨 https://www.youtube.com/watch?v=ZSvb4enXyGU 23 Appendicular Skeleton 2. Tibia 脛骨  Medial bone of the lower leg  Bears the weight from the femur  Medial and lateral condyles articulate with the femur  Medial malleolus articulates with the talus 距骨 in the foot 3. Fibula 腓骨  Lateral to the tibia  Stabilizes the ankle https://www.youtube.com/watch?v=uUb2pyzOWHg 24 Appendicular Skeleton 4. Foot  Seven tarsal bones 跗骨  Only the talus can move freely  The calcaneus 跟骨 and the talus support the weight of the body  Five metatarsal bones 跖 骨 form the instep 腳背  The phalanges form the toes  Big toe has only two  Three each in other toes 25 Anatomy of a Long Bone I  Periosteum骨膜 tough, connective tissue covering  Epiphysis (sg.) 骨骺 expanded portion at the ends of bones  Diaphysis 骨幹 portion between the epiphyses (pl.) 26 Anatomy of a Long Bone II  Medullary cavity hollow portion of diaphysis containing yellow marrow黃骨髓  Articular cartilage layer of hyaline cartilage透明 軟骨 where bones join together  Endosteum 骨內膜  lines the medullary cavity髓 腔 and the spaces of spongy bone 鬆質骨 27  Bone parts: Compact Bone I https://www.youtube.com/watch?v=inqWoakkiTc Structural unit = Haversian system (哈弗氏) or Osteon 骨單位 Central canals or Haversian canals with blood vessels and nerves - transport nutrients and wastes. Lamellae骨板 - concentric layers of matrix containing collagen fibers and mineral salts Osteocytes骨細胞 (spider-shaped bone cells) - found in Lacunae - 腔隙 (fluid filled space) - form concentric circles around central canal. 28 Bone parts: Compact Bone II Communicating canals: 1.Central or Haversian canals Volkmann’s canal 2.Volkmann’s canals 福爾克曼管 (or perforating canals) connect the blood & nerve supply of adjacent Haversian systems together at right angles 3.Canaliculi (骨小管) connect the lacunae of osteocytes Central Source: canal Electron micrograph shows the central canal and it is extracted from: http://www.guwsmedical.info/blood-vessels/microscopic-structure.html 29  Bone parts: Spongy Bone (cancellous bone) Lighter, no osteons Contains bony bars and plates called trabeculae骨小樑 Trabeculae follow lines of stress, giving bones strength Do not aggregate around central canal Obtain nutrients through canaliculi from capillaries in the endosteum by diffusions http://mandevillehigh.stpsb.org/teachersites/laura_decker/ biology2_compact_spongy_bone_diagrams.html http://www.gla.ac.uk/ibls/US/fab/tutorial/generic/bone2.html 30  Skeleton: Bone Growth and Repair Rely on the bony cells: 1. Osteoprogenitor cells – unspecialized bone cells 2. Osteocytes – mature bone cells surrounded by the matrix (usually derived from osteoblasts) 3. Osteoblasts – bone forming cells 4. Osteoclasts – bone dissolving cells (for bone resorption) Picture showed an osteocyte in the canaliculus, extracted from the Pajevic PD, IBMS BoneKEy (2009), p63-70 31 Skeleton: Bone Development and Growth Ossification骨化作用 – formation of bone 1. Intramembranous ossification 膜內骨化 https://www.youtube.com/watch?v=ZTe_P_qgOGM https://www.youtube.com/watch?v=__-NhGfOJy0 Form bones of the skull Bone forms between two sheets of fibrous connective tissue 2. Endochondral ossification 軟骨骨化 - Form most bones of the human body https://www.youtube.com/watch?v=Z-vRCYuH4uI - Hyaline cartilage models are replaced by bone 32 Growth of a long bone 1. Epiphyseal growth 骺板增長 https://www.youtube.com/watch?v=V9knxKdDf9A o Growth at a band of cartilage in the epiphyses of long bones, continues until plate is ossified 33 2. Appositional 同位的 growth – increase in bone diameter (occur at osteogenic layer 生骨層 of periosteum) A - Infant B - Child C – Bone E – Young adult F – Adult resorption by osteoclasts D – Bone deposition by http://www.youtube.com/watch?v=X6E5Rz9tOKE osteoblasts 34  Skeleton: Remodeling of Bones https://www.youtube.com/watch?v=0dV1Bwe2v6c Bone is continually being broken down (resorbed) and built up remodeling Osteoclasts remove worn cells and dissolve calcium from bone matrix, and deposit calcium in the blood Osteoblasts remove calcium from the blood and form new bone  Three important hormones regulating bone growth 1. Parathyroid hormone(甲狀旁腺激素) 2. Calcitonin 降鈣素 3. Growth hormone 35  Skeleton: Bone Repair https://www.youtube.com/watch?v=qVougiCEgH8 https://www.youtube.com/watch?v=P5HwYWShBhw  Occurs after a fracture骨折  Steps involved in bone repair 1. Hematoma 血腫 formation 2. Fibrocartilaginous callus 纖維軟骨的愈合組織 formation 3. Bony callus formation 4. Remodeling 1 3 2 36  Skeleton: fractures骨折 https://www.youtube.com/watch?v=tXFFaMdNNJk https://www.youtube.com/watch?v=3O_boTBkX-U  Complete – bone is broken through  Incomplete – bone is not separated into two parts  Simple (closed) – does not pierce the skin  Compound (open) – pierces the skin  Impacted – broken ends are wedged into each other  Spiral – ragged break due to twisting of bone  Comminuted – break into more than 2 bone fragments  Reduction 復位 – repair of a fracture (1) Closed reduction – re-aligning bone fragments without surgery (2) Open reduction – surgical repair of the bone using plates, screws, or pins 37 Bone Surface Features 38 39 Joints (Articulations)  Classification according to the amount of movement Synarthrosis 不動關節 – immoveable Amphiarthrosis 微動關節 – slightly moveable Diarthrosis 動關節 – freely moveable  Classification according to structure Fibrous 纖維性的 joint  Fibrous connective tissue joins bone to bone  Typically immovable e.g. Sutures of the cranium, Joints formed by each tooth in its socket Cartilaginous 軟骨的 joint  Bones are joined by fibrocartilage or hyaline cartilage  Usually slightly moveable, e.g. intervertebral disc Synovial 滑膜的 joint  Bones do not touch each other, separated by a joint cavity  Usually freely moveable, Fluid filled e.g. knee joints 40 41 Synovial joints 42 Joints (Articulations): Types of synovial joints https://www.youtube.com/watch?v=0cYal_hitz4 (1:17) a. Saddle joint 鞍狀關節 –carpometacarpal joint of thumb b. Ball-and-socket joint球窩關節 – shoulder and hip c. Pivot joint 樞軸關節 – ends of ulna and radius, atlas and axis d. Hinge joint 屈戌關節 – elbow and knee e. Gliding joint 滑動關節 – within wrist and ankle f. Condyloid joint 髁狀關節 – knuckles 44 Joints (Articulations): Movements of synovial joints  Angular movements  Flexion 屈曲  Extension 伸展  Adduction 內收  Abduction 外展  Circular movements  Circumduction 環動  Rotation 旋轉  Supination 旋後  Pronation 旋前  Special movements  Inversion 反向 and eversion 外翻  Elevation 提升 and depression 降低 45 Anatomical terms of movement: https://www.youtube.com/watch?v=5YcNAPzDxDg Angular movements and Circular movements  Disorders of bones Dislocation (脫臼)– temporary displacement of two bones in which the two bone surfaces lose contact entirely  Pathogenesis  Often accompanied by fracture because stress is placed on areas of bone  Manifestations  Pain, swelling, limitation of motion and joint deformity Sprains 扭傷– ligaments tear Strains – tendons tear  Pathogenesis  Inflammatory process begins when a tendon or ligament is torn  Manifestations  Sharp and localized pain, joint swelling and tenderness 47 Disorders of bones Osteoporosis 骨質疏鬆  Pathogenesis  Reduced bone mass or density, imbalance in bone resorption and formation  Manifestations  Pain and bone deformity, fracture, increased radiolucency 射線透過性 Tendinitis 腱炎 – inflammation of tendons  Pathogenesis  Fluid from inflammation  accumulates, causing swelling and its enclosing sheath  Manifestations  Pain and soreness around a joint 48 Disorders of bones Rickets 軟骨病  Pathogenesis  Inadequate and delayed mineralization, osteoid tissue (骨樣組織) not mineralized  Manifestations  Pain, bone fractures, vertebral collapse 49 Disorders of joints Osteoarthritis (OA) 骨關節炎 – degenerative non- inflammatory disease  Pathogenesis  Deterioration of the joint cartilage  Manifestations  Deep, aching joint pain particularly after exercise or weight bearing, stiffness in the morning and after exercise 50 Disorders of joints Rheumatoid arthritis (RA) 類風濕關節炎 – systemic inflammatory autoimmune disease  Pathogenesis  Inflammation of the synovial membrane  Damage or destruction of synovial membrane extends to articular cartilage joint capsule and surrounding ligaments and tendons  Manifestations  Systemic: fever, fatigue, weakness, anorexia, weight loss, and generalized aching and stiffness  Joint painful, tender, and stiff, swelling, deformities 51 Disorders of joints Gout 痛風 – excessive buildup of uric acid 尿酸  Pathogenesis  Closely linked to purine metabolism and kidney disease  Manifestations  Severe pain (usually noticed at night), affected joint becomes hot, red, and extremely tender and may be slightly swollen  Drug treatment: allopurinol, inhibitor of xanthine oxidase to block the formation of uric acid 52 Homeostasis Functions of the Skeletal System  Protection of internal organs  Bones assist in all phases of respiration  Bones store and release calcium  Bones assist the lymphatic system and immunity  Bones assist digestion  The skeleton is necessary to locomotion 53 Homeostasis Functions of Other Systems  The integumentary system and the muscles assist in protecting internal organs  The digestive system absorbs calcium from food and the endocrine system regulates the storage of calcium in the bones  Movement of the bones is only possible because of the contraction of skeletal muscle 54