Chapter 7 /8 pgs. 189-250 SKELETAL TISSUES AND THE SKELETAL SYSTEM
Skeletal Tissue Introduction Bone and cartilage are a specialized types of connective tissue Individual Bones are considered separate organs Articulations (joints) contact points between bones that make movement possible
Bone Tissue Two types: 1. Compact Bone dense and solid in appearance. 2. Cancellous or Spongy Bone characterized by open space partially filled with needle-like structures
Types of bones (4) Bones are classified based on shape 1. Long Bones 2. Short Bones 3. Flat Bones 4. Irregular Bones
Long Bones Characterized by a long longitudinal axis Uniquely shaped articular (joint) ends EX: Humerus, femur, tibia
Short Bones Described as cube or box shaped About as wide (broad) as they are long Ex: bones of the wrist and ankle
Flat Bones Generally broad and thin with flattened and curved surface Ex: shoulder blades (scapulae), certain skull bones, ribs and breastbone (sternum)
Irregular Bones Often clustered into groups Come in various shapes and sizes Ex: vertebral bones, facial bones, and kneecap (patella)
Part of a long bone 1. Diaphysis main shaft of the bone. Hollow, cylindrical, and made of compact bone 2. Epiphyses the ends of a long bone. Bulbous in shape for muscle attachment, made of spongy bone and filled with red marrow. Epiphyseal Plate layer of caritlage between diaphysis and epiphyses
Parts of a Long Bone 3. Articular Cartilage layer of hyaline cartilage that covers the surface of the epiphyses 4. Periosteum- dense white membrane that covers the bone except for the joint surfaces. Contains blood vessels, and bone forming/destroying cells
Parts of a Long Bone 5. Medullary Cavity hollow space inside of the diaphysis which is filled with fatty yellow marrow 6. Endosteum thin membrane that lines the medullary cavity
Microscopic Structure of Compact Bone Compact bone is made of many cylinder-shaped structures called osteons which are made of 4 parts: Lamellae- cylinder shaped layers of calcified matrix Lacunae small spaces containing fluid in which the cell lies imprisoned Canaliculi small canals radiating in all directions from the lacunae Haversian canal extends lengthwise throughout the center of each osteon, contains blood vessels, lymphatic vessels, and nerves moves nutrients and oxygen through osteon
Microscopic Structure of Compact Bone
Microscopic Structure of Cancellous *(spongy bone) No osteons in spongy bone Instead contain trabeculae needle- like bony spicules
Types of Bone Cells 3 types of cells 1. Osteoblasts (bone forming cells) small cells that make organic matrix called osteoid. Collagen lies up around the osteiod and serves as a framework for the deposition of calcium 2. Osteoclasts very large multinucleate cells responsible for the active erosion of bone minerals 3. Osteocytes mature, non-dividing osteoblasts that have become surrounded by matrix and now lie within the lacunae
Bone Marrow - specialized type of soft tissue that serves as the site of blood production Found in the medullary cavities of long bones and in the spaces of some spongy bone 2 types 1. Red Marrow produces red blood cells - virtually all of a child bones are filled with red marrow that becomes yellow marrow as the individual ages - adult bone w/ red marrow ribs, vertebrae, pelvis, femur, thigh bone 2. yellow marrow cells have been saturated with fat and are inactive in blood cell production
Functions of Bone Support framework of the body, contribute to shape and alignment Protection protect structures they enclose like skull - brain, ribs- lungs and heart Movement joints constitute levers, muscles are attached to bones; pull on bones producing movement Mineral Storage serves as a reservoir for calcium, phosphorus, and other minerals Hematopoiesis (blood cell formation) carried out by red marrow
Cartilage Connective tissue consisting of 3 types: Hyaline, Elastic, Fibrocartilage Hyaline most common type of cartilage, glassy in appearance, covers the ends of bone, connects anterior and posterior ribs to the sternum, forms cartilage rings in the trachea, and bronchi of lungs, and the tip of the nose
Cartilage Elastic gives form to the external ear, the epiglottis, and the auditory tubes that connect middle ear to the nasal cavity Fibrocartilage characterized by small quantities of matrix, very strong and rigid. Found in the pubis, intervertebral disks, and points of attachment of some large tendons to bones
Divisions of the Skeleton Two Main divisions: Axial and Appendicular Skeleton Axial 80 bones that form the upright axis of the body Appendicular 126 bones form the appendages
Axial/ Appendicular Skeleton
Axial/ Appendicular Skeleton Axial Cranium/Skull (28) Face (14) Ear (3) Hyoid Bone (1) Spinal Column (26) Sternum and Ribs (25) Appendicular Upper Extremities (64) Lower Extremities (62)
Skull and Facial Bones
Skull and Facial Bones Frontal forehead bone Parietal lateral and top of the skull Mandible Lower Jaw Maxilla- Upper Jaw Temporal Temple Occipital back of the head Palatine- hard palate ( roof of mouth) Nasal Bridge of nose Lacrimal tear duct Vomer in between nostrils (close to lip) Ethmoid extends from the temporal into the eye socket and into the nostrils
Hyoid Bone Single bone in the neck U-Shaped just above the larynx Only bone in the body that does not articulate (connect with any other bone in the body) Attaches the tongue to the floor of the mouth
Vertebrae Bones Spinal column in flexible rather than rigid Consists of 24 bone plus the sacrum and coccyx Joints between vertebrae permits forward, backwards, and side to side movement Separated into segments: Cervical Vertebrae (7) make up the neck Thoracic Vertebrae (12) make up the chest (thoracic region) Lumbar Vertebrae (5) make up the lower back Sacrum single bone resulting from 5 fused vertebrae Coccyx single bone resulting from 4 fused vertebrae
Vertebrae Bones
Bones of the Rib Cage and sternum Sternum (breast plate) middle part of the chest; dagger-shaped bone made of 3 parts: 1. manubrium upper part 2. body middle 3. xiphoid process end tip
Bones of the Rib Cage and sternum 12 pairs of ribs make up the rib cage First 7 pairs known as true ribs because the connect to the spine and to the cartilage that attaches to the sternum Last 5 pairs known as false ribs because the do not attach directly to the sternum. The cartilage of pairs 8,9, and 10 attach to the cartilage of the rib above it Last 2 pairs of the false ribs are known as floating ribs because they do not attach at all to the sternum, even indirectly
Bones of the Rib Cage
Bones of the upper Extremities -Upper extremities consist of the shoulder girdle, upper arm, wrist, and hand 2 bones scapula and clavicle make the shoulder girdle
Bones of the upper Extremities The humerus is the upper arm bone and the radius (on the thumb side) and ulna (on the little finger side) make up the lower arm
Bones of the upper Extremities 8 carpal bones make up the wrist 5 metacarpal bones make up the hand Phalanges bones of the fingers
Lower Extremity Bones Bones of the lower extremities include the hip, thigh, lower leg, and foot. The hip bone or pelvis can be separated is made of 3 bones: - 1. ilium largest and uppermost bone -2. ischium - strongest and lowermost bone -3. pubis - anterior
Lower Extremity Bones Femur thigh bones; longest and heaviest bones in the body Patella kneecap Tibia larger and stronger of the two lower leg bones Fibula smaller of the two lower leg bones
Lower Extremity Bones Tarsals bones of the ankle Calcaneus heel bone Metatarsals bones of the foot Phalanges bones of the toes