ANIM 1005 Veterinary Anatomy and Physiology Lecture Notes (Sept 17, 23 2024) PDF

2024-09-13 ANIM 1005 Veterinary Anatomy and Physiology Dr. Pauline Smith Contact: [email protected] Rm 00600 1 1 ...

2024-09-13 ANIM 1005 Veterinary Anatomy and Physiology Dr. Pauline Smith Contact: [email protected] Rm 00600 1 1  2024-09-13 Outline for today’s class: Musculoskeletal System *Unit 2 Test (mini; 2.5%): Monday Sept 30th* 50 min Format: True/False, MC, Short Answer Lecture to follow 2 2  2024-09-13 The Musculoskeletal System muscul/o skelet/o -al The musculoskeletal system consists of two systems that work together to support the body and allow for movement of the animal: 1) the skeletal system = bones, joints, cartilage, and various connective tissues 2) the muscular system = muscles and various connective tissues 3 3  2024-09-13 The Skeletal System The skeletal system consists of bones, joints, tendons, ligaments, and cartilage. 4 4  2024-09-13 Functions of the Skeletal System Function of the skeletal system: 1) form the framework that supports the body 2) protects the body 3) aid in body movement/leverage (joints) 4) hematopoesis: hemat/o (blood) –poiesis (formation) 5) store and release minerals such as calcium and phosphorus 6) energy reserve (adipose within the yellow marrow of long bones) 5 5  2024-09-13 The Skeleton The skeleton is divided into two parts: 1) Axial skeleton: protects the major organs of the nervous, respiratory, and circulatory systems. consists of the skull, hyoid bones, vertebral column, ribs, and sternum. 2) Appendicular skeleton: is the framework that consists of the extremities, shoulder, and pelvic girdle. includes the bones of the front (thoracic) and hind (pelvic) limbs. 6 6  2024-09-13 The Axial Skeleton - protects the major organs of the nervous, respiratory, and circulatory systems. - consists of the skull, hyoid bones, vertebral column, ribs, and sternum. Pelvic Thoracic Limb Limb 7 7  2024-09-13 Parts of the Axial Skeleton Axial skeleton: the framework for the body (skull, vertebral column, ribs and sternum) 1) Cranium (skull): crani/o the portion of the skull that protects the brain Brachycephalic: (brachi- short) Dolichocephalic: (dolich/o- long) Mesocephalic (mesaticephalic) :(mes- ; mes/o middle) Brachycephalic Mesocephalic Dolichocephalic 8 8  2024-09-13 Parts of the Axial Skeleton (cont.): 2) Vertebral Column: supports the head and protects the spinal cord consists of vertebra (spondyl/o, vertebr/o) Vertebral foramen: the opening in the middle of the vertebra through which the spinal cord passes Foramen means ‘opening’ 9 9  2024-09-13 Order of Vertebrae 10 10  2024-09-13 Parts of the Axial Skeleton (cont.): 3) Ribs (costals): cost/o: paired bones that attach to the thoracic vertebrae 4) Sternum: stern/o forms the midline ventral portion of the ribcage thoracic cavity = ribs + sternum + thoracic vertebrae 11 11  2024-09-13 The Appendicular Skeleton Framework of the body that consists of the extremities, shoulder and pelvic girdle 12 12  2024-09-13 Fore (Thoracic) Limb Scapula: shoulder blade Clavicle: collar bone Forelimb: humerus radius ulna carpals (‘wrist’ in humans) (‘carpus’ in sm. animals) (‘knee’ in large animals metacarpals:(meta- means beyond) phalanges: bones of the digit 13 13  2024-09-13 Hind (Pelvic) Limb pelvis femur patella tibia fibula tarsal bones metatarsal bones (cannon bone livestock) phalanges 14 14  2024-09-13 Postures Unguligrade Digitigrade (walk only on (intermediate the distal-most stage) tips of their digits) Plantigrade (flat footed) 15 15  2024-09-13 Structures of the Skeletal System Structures of the Skeletal System : 1) Bone 2) Cartilage 3) Joints 4) Ligaments 5) Tendons 6) Bursa 7) Synovial Membrane, Synovial Fluid 16 16  2024-09-13 Structures of the Skeletal System: Bone 1) Bone: oste/o, oss/e, oss/i Recall: Bone: specialized connective tissue matrix (ground substance, collagen fibres and cells) 17 17  2024-09-13 Structures of the Skeletal System: Bone 1) Bone Cells (Osteocytes: bone cells (-cyte means ‘cell’) Osteoprogenitor cells: Mature into osteoblasts Osteoblasts: immature bone cells that produce bony tissue -blast means ‘immature’ -responsible for osteogenesis: -genesis means ‘producing’ Osteoclasts: bone cells that break down bony tissue -clast means ‘break’ - derived from embryological WBCs - secrete enzymes for osteolysis –lysis means ‘break apart’ - necessary for calcium homeostasis Ossification: the formation of bone from fibrous tissue 18 18  2024-09-13 Bone Formation 1) Endochondral Formation: make cartilage template first which will be replaced by bone - cartilage-bone development occurs in the fetus except the epiphyseal growth plates and skull sutures - primary growth center: diaphyses - secondary growth centers: epiphyses 2) Intramembranous: bone forms in the fibrous tissue membranes that cover the brain in the developing fetus - flat bones of cranium 19 19  2024-09-13 Endochondral Formation (FYI): epiphyseal growth plates (between epiphyses and diaphysis of long bones) allow long bones to lengthen in growing animals 20 20  2024-09-13 Epiphyseal Growth Plates 21 21  2024-09-13 Types of Bone 1) Cortical (Compact) bone: hard, dense, strong bone that forms the outer layer of bone. cortex = bark or shell in Latin 2) Cancellous (Spongy) bone: the lighter, less strong bone that is found in the ends and inner portions of long bone. cancellous = latticework in Latin 22 22  2024-09-13 Types of Bone (cont) (cancellous) (dense) 23 23  2024-09-13 Types of Bone (cont): Compact Bone 1) Compact Bone: Characteristics very dense, stress bearing shafts of long bones, outside layer of all bones composed of tiny, tightly compacted cylinders of bone called “haversian systems” or “osteon” that run lengthwise with the bone The primary anatomical and functional unit of compact bone is the Osteon/Haversian system 24 24  2024-09-13 Compact Bone: Haversian System provides routes for nutrients and O2 to reach osteocytes, and wastes to diffuse away 25 25  2024-09-13 Types of Bone(cont): Cancellous Bone 2) Cancellous (Spongy)Bone: Characteristics light, spongy found at ends of long bones, ribs, sternum, hips, vertebrae, cranium no Haversian systems vascular frequently contains red bone marrow The primary anatomical and functional unit of cancellous bone is the trabecula (branching network of bony tissue) 26 26  2024-09-13 Types of Bone: Summary 27 27  2024-09-13 Bone Classification (more in lab) 1) Long Bones 2) Short bones (lab) 3) Flat bones (lab) 4) Irregular Bones (lab) 28 28  2024-09-13 1) Long Bone Structure Long bones consist of a shaft (diaphysis), two ends (epiphysis) covered with hyaline cartilage (for articulating bones, and a medullary canal (marrow cavity). covered with periosteum for bone growth, repair, and nutrition used as levers Examples: femur, humerus, tibia, fibula, ulna, radius, clavicle 29 29  2024-09-13 Long Bone Structure (cont) Epiphysis: end of a long bone (each has a proximal and distal) Diaphysis: shaft portion of a long bone Endosteum: inner membrane lining interior regions of bone Epipheseal Plate: growth plate of long bones (located at proximal and distal junctions of epiphysis and diaphysis) Medually Cavity: central region within shaft of long bones 30 30  2024-09-13 Long Bone Structure (cont) Periosteum: outer membrane covering of all bones except at articular (joint) surfaces - composed of fibrous tissue - inner layer that contains osteoblasts - plays important role in bone healing/fracture repair 31 31  2024-09-13 Long Bone Structure (cont) Bone Marrow: fills the spaces within bones (areas between the spicules of cancellous bone and medullary cavities of compact bone) 1) Red Bone Marrow - hematopoietic (RBCs, platelets, some WBCs) - destroys old RBCs, some foreign materials - majority of bone marrow in young -confined to a few specific locations in older animals (ends of long bones, interior of the pelvic bones, sternum) 2) Yellow Bone Marrow - adipose CT -most common type of marrow in adult animals -can revert to red bone marrow if needed 32 32  2024-09-13 Sesamoid Bones Sesamoid bone: a bone embedded within a tendon Found in locations where a tendon passes over a joint. Helps disperse force of tendon (allow muscles to exert powerful forces on the bones without the tendons wearing out from constant back and forth movement over the joint) small bone buried in the tendon of the extensor muscles (the quadriceps muscles) of the thigh 33 33  2024-09-13 Types of Fractures Broken into several pieces 34 34  2024-09-13 Fractures: Radiographs 35 35  2024-09-13 2) Short Bones Cube-shaped Allows flexible movement Carpals, tarsals, metacarpals, metatarsals, phalanges 36 36  2024-09-13 3) Flat Bones Expand in 2 directions Broad surfaces are attachment points for large muscle masses and protects underlying structures Examples: scapula, pelvic girdle, skull 37 37  2024-09-13 4) Irregular Bones Peculiarly shaped to provide support and protection with flexibility Examples: vertebrae, ribs, hip, hyoid 38 38  2024-09-13 Bone Markings Purpose 1) Join one bone to another 2) Provide a surface for attachment of muscles 3) Create an opening for passage of blood vessels and nerves 4) Used as landmarks Two types of bone markings: 1) Projections (processes) that grow out from the bone (ie head, spine) 2) Depressions (cavities) that indent the bone to allow blood vessels or nerves to pass through (ie foramen, sinus etc) 39 39  2024-09-13 Structures of the Skeletal System (cont.) 2) Cartilage: chondr/o Tissue which makes the flexible parts of the skeleton Articular cartilage is a type of cartilage that covers the joint surfaces of bone. 40 40  2024-09-13 Structures of the Skeletal System (cont.) 3) Joints (articulations): arthr/o Connections between bones that allows motion between the parts Joints are classified based on their degree of movement Synarthosis: joints which allow no movement (syn- union association; arthr/o; -osis condition) Amphiarthrosis: joints which allow slight movement (amph- around; arthr/o; -osis ) Diarthrosis: joints which allow free movement (dia- through, between; arthr/o; -osis) 41 41  2024-09-13 Types of Joints See supplemental slides for more info! joints which allow no movement joints which allow free movement joints which allow slight movement 42 42  2024-09-13 Structures of the Skeletal System (cont.) 4) Ligaments: ligament/o band of tissue that connects bone to bone 5) Tendon: ten/o, tend/o, tendin/o band of tissue that connects muscle to bone 6) Bursa: burs/o sac that acts as a cushion to ease movement in areas of friction 7) Synovial membrane, synovial fluid: synovi/o Synovial Membrane: inner lining of bursae and synovial joints (a diarthrosis) Synovial Fluid: lubricant which makes joint movement smooth 43 43  2024-09-13 Tendon, Ligament Bursa and Synovial Membrane 44 44