Musculoskeletal System (Part A-1) Module 7 -Chapter 10 Overview. Functions

Transcription

1 Musculoskeletal System (Part A-1) Module 7 -Chapter 10 Overview Susie Turner, M.D. 1/8/13 Muscles Attachments Bones Bone types Surface features of bones Divisions of the skeletal system Joints or Articulations Bones Functions Provide the framework of the body & protect internal organs Act as levers when muscles contract Store calcium & phosphate & other minerals If body needs calcium can withdraw from bones Produce blood cells within the bone marrow 1

2 Hematopoiesis or Hemopoiesis Formation of blood cells Occurs in red bone marrow Contains immature & mature blood cells in various stages of development. 4 Principal types of bones Short Cube-shaped Ex; wrist & ankle bones Irregular Complex shape Ex; vertebrae Flat Flat shape Ex; skull bones & sternum Long Longer than they are wide Ex; bones of leg, arm, fingers Bone Shapes 2

3 Bone Make-up 2 Forms Cancellous Also called Spongy bone Blood cells produced here Compact Dense & supportive Parts of Long Bones Diaphysis Shaft Epiphyses Ends (2) Singular is epiphysis 3

4 Parts of Long Bones Diaphysis Shaft Canal in center is called medullary or marrow cavity. Bone Marrow of a Long Bone Inside the central canal is the medullary or marrow cavity In child has red bone marrow (blood cells) In adult has yellow marrow (fat cells) 4

5 Parts of Long Bones Epiphysis Ends Proximal & Distal Ends covered with cartilage Articular Cartilage Type of hyaline cartilage Smooth surface to reduce friction & absorb shock Epiphysis Epiphyseal Plate Growth Plate Thin area of cartilage in young bone Responsible for growth in length. Epiphyseal Line Remanent of epiphyseal plate after growth ceases. 5

6 Epiphysis Epiphyseal plate Epiphyseal line Dense, white fibrous membrane Covers non joint surface of bone Serves as point of attachment for muscles, ligaments, & tendons Contains numerous blood & lymph vessels & nerves Periosteum Periosteum 6

7 Specialized Bone Cells Osteoblasts -primitive bone-forming cells (make new bone) Osteoclasts -bone-destroying cells (break down bone). Osteocytes -mature bone cells (support bone) Surface Features of Bones Called Bone Markings Bones not usually smooth Consist of 2 major categories; 1. Projections 2. Depressions and openings 7

8 1. Projections Stick out ; 2 Types a. Articulating Help form Joint Ex; head, condyle b. Non-Articulating Outside of Joint Usually sites of muscle & ligament attachment Ex; trochanters, tubercle, tuberosity Bone Markings Head trochanter tuberosity Condyle tubercle Bone Markings 2. Depressions & Openings Open or push into bone Sites for blood vessel, nerve, and duct passage. Ex; foramen (hole), fissure, meatus, sinus (cavity or hollow space in bone) sinus foramen 8

9 Divisions of Skeletal System Axial Skeleton Bones that lie around the body s center of gravity Appendicular Skeleton Bones of the limbs (appendages) & supporting girdles. 2 Main Divisions Axial Skeleton Divisions of Skeleton Forms the body s vertical axis or center Appendicular Skeleton Includes the Appendages Upper & lower extremities Pelvic & Shoulder Girdles Bones that attach them to axial skeleton 9

10 How Bones Are Named Bones have both a common name and a scientific name Example; Sternum = Breastbone Can be named after their shape Example; Pelvis means basin Or the area of the body where they are located Example; Femur located in thigh Axial Skeleton 3 Major Regions 1. Skull 2. Thorax (Rib Cage) Ribs Sternum 3. Vertebral Column 10

11 Skull Cranial Bones Facial Bones Sutures Immovable joints of skull Fontanels Soft Spots Fibrous C.T. between bones of infant s skull Allow bones to move during birth Allow growth of brain Cranial Bones Cranial Bones (8) Frontal bone, Occipital bone 2 Parietal bones 2 Temporal bones Sphenoid Ethmoid 11

12 Cranial Bones Frontal Bone Forehead Parietal Bones (2) Walls or sides Coronal Suture Joint between 2 parietal & frontal bones Cranial Bones Temporal Bones (2) Temple Contains Mastoid Process Provides attachment for muscles of neck Occipital Bone Back of head & base of skull 12

13 Cranial Bones Sphenoid Bone Keystone of cranium Central wedge that holds other cranial bones together Sphen/o = wedge Resembles a bat Ethmoid Forms most of boney area between nasal cavity Ethm/o means sieve-like or spongy Witch shaped Cranial Bones 13

14 Facial Bones Joined together by sutures Except mandible Mandible Maxillae Nasal Bones Lacrimal Bones Zygomatic Bones Vomer Mandible Lower Jaw Bone Important in speaking & chewing Mastication = chewing Maxillae 2 Upper jaw bones Form anterior hard palate Facial Bones 14

15 Facial Bones Nasal Bones Form bridge of nose Rest is cartilage Lacrimal Bones Located inner eye corners Form a groove for lacrimal sac & canals Tears pass to nose Facial Bones Zygomatic Bones Cheekbones Vomer Forms lower part of nasal septum Names means Ploughshare 15

16 Paranasal Sinuses Air cavities in bones Paranasal sinuses 2 maxillary, 2 frontal, sphenoid, & ethmoid 16