Unit 4 - Introduction to Bone Osteology - MQA PDF

Diploma in Physiotherapy Please do not reproduce, redistribute or share without the prior express permission of the author.  Lecture notes ANATOMY I INTRODUCTION TO BONE OSTEOLOGY Please do not reproduce, redistribute or share without the prior express permission...

Diploma in Physiotherapy Please do not reproduce, redistribute or share without the prior express permission of the author.  Lecture notes ANATOMY I INTRODUCTION TO BONE OSTEOLOGY Please do not reproduce, redistribute or share without the prior express permission of the author. Please do not reproduce, redistribute or share without the prior express permission of the author.  Learning Outcome At the end of the lesson, students will be able to: Define structure and function of skeletal system Describe bones of the appendicular and axial skeleton Describe classification and parts of bones Identify the ossification of bone and its types Please do not reproduce, redistribute or share without the prior express permission of the author. DEFINITION Osteology is the scientific study of bones. Osteology is a detailed study of the structure of bones, skeletal elements, function, disease, pathology, the process of ossification , the resistance and hardness of bones. Please do not reproduce, redistribute or share without the prior express permission of the author. SUB DIVISIONS OF SKELETAL SYSTEM Skeleton composed of the following divisions and their subdivisions: A. Axial skeleton Bones that form the longitudinal axis of the body. B. Appendicular skeleton Portion of the skeleton consisting of the pectoral girdle, the pelvic girdle, and the bones of the arms and legs. Please do not reproduce, redistribute or share without the prior express permission of the author. Please do not reproduce, redistribute or share without the prior express permission of the author. Please do not reproduce, redistribute or share without the prior express permission of the author. Please do not reproduce, redistribute or share without the prior express permission of the author. STRUCTURE OF SKELETAL SYSTEM The skeletal system is a living, dynamic system, with networks of infiltrating blood vessels. Living mature bone is about 60% calcium compounds and about 40% collagen. Hence, bone is strong, hard and slightly elastic. All humans were born with over 300 bones but some bones, such as those in the skull and lower spine, fuse during growth, thereby reducing the number to 206. Individual bones meet at areas called joints and are held in place by connective tissue. The connective tissues linking the skeleton together at the joints are tendons and ligaments. Because the bones making up the human skeleton are inside the body, the skeleton is called an endoskeleton. Please do not reproduce, redistribute or share without the prior express permission of the author. FUNCTIONS OF SKELETAL SYSTEM 1. Support The skeleton is the framework of the body, it supports the softer tissues and provides points of attachment for most skeletal muscles. 2.Protection The skeleton provides mechanical protection for many of the body's internal organs, reducing risk of injury to them. For example, cranial bones protect the brain, vertebrae protect the spinal cord, and the ribcage protects the heart and lungs. 3.Assisting in Movement Skeletal muscles are attached to bones, therefore when the associated muscles contract they cause bones to move. 4.Storage of Minerals Bone tissues store several minerals, including calcium (Ca) and phosphorus (P). When required, bone releases minerals into the blood - facilitating the balance of minerals in the body. 5.Production of Blood Cells The red bone marrow inside some larger bones blood cells are produced. Please do not reproduce, redistribute or share without the prior express permission of the author. BONES OF THE APPENDICULAR AND AXIAL SKELETON Axial skeleton It includes bones associated with the body's main axis, the spine. This includes the spine, the skull, and the rib cage. There are 28 bones in the skull. It protects the brain. The spine, also called the spinal column or backbone, consists of 33 vertebrae, the lower ones fused. The spinal column helps to support the weight of the body and protects the spinal cord. Please do not reproduce, redistribute or share without the prior express permission of the author.  Twelve pair of ribs (a total of 24) extend forward from the vertebrae of the upper back. The ribs (the first 7 pair) attach in the front of the body via cartilage to the breastbone, or sternum. These ribs are called true ribs. The next 3 pair of ribs, called false ribs, do not attach to the sternum. They are connected by cartilage to the ribs above them. The lower two pair of ribs that do not attach in the front are called floating ribs. Ribs give shape to the chest and support and protect the body's major organs, such as the heart and lungs. Please do not reproduce, redistribute or share without the prior express permission of the author. Bony Thorax (Thoracic Cage) Please do not reproduce, redistribute or share without the prior express permission of the author. the axial skeleton consists of the 80 bones in the head and trunk of the human body. it is composed of five parts; the human skull, the ossicles of the inner ear, the hyoid bone of the throat, the rib cage, and the vertebral column. Skull (22) Facial Bones (14) Cranial Bones (8) Maxilla (2) Parietal (2) Zygomatic (2) Temporal (2) Mandible (1) Frontal (1) Nasal (2) Occipital (1) Palatine (2) Ethmoid (1) Inferior nasal concha (2) Sphenoid (1) Lacrimal (2) Vomer (1) Please do not reproduce, redistribute or share without the prior express permission of the author. Please do not reproduce, redistribute or share without the prior express permission of the author.  Auditory Ossicles Ossicles (6) Malleus (2) Incus (2) Stapes (2) Hyoid bone (1) U-shape bone located in the neck. It anchors the tongue and is associated with swallowing. Vertebral Column (33) Cervical vertebrae (7) Thoracic vertebrae (12) Lumbar vertebrae (5) Sacrum (5) (fused) Coccyx (4) (fused, varies between 3-5) Chest Thoracic cage (25) Sternum (1) Ribs (24) Please do not reproduce, redistribute or share without the prior express permission of the author. Please do not reproduce, redistribute or share without the prior express permission of the author. Appendicular skeleton The appendicular skeleton joins with the axial skeleton at the shoulders and hips. It is composed of 126 bones. 1) Pectoral Girdles (4 bones) - Left and right Clavicle (2) and Scapula (2). 2) Arm and Forearm (6 bones) - Left and right Humerus (2) (Arm), Ulna (2) and Radius (2) (Fore Arm). 3) Hands (58 bones) - Left and right Carpal (16) (wrist), Metacarpal (10), Proximal phalanges (10), Middle phalanges (8), distal phalanges (10), and sesamoid (4). 4) Pelvis (2 bones) - Left and right os coxae (2) (Ilium). 5) Thigh and leg (8 bones) - Femur (2) (thigh), Tibia (2), and Fibula (2) (leg). 6) Feet (48) - Tarsal (14) (ankle), Metatarsals (10), Proximal phalanges (10), middle phalanges (8), distal phalanges (10), and sesamoid (4). Please do not reproduce, redistribute or share without the prior express permission of the author. Please do not reproduce, redistribute or share without the prior express permission of the author.  Compact bone CLASSICIFICATION OF BONES Based on the bone tissue: Compact bone (dense, smooth & homogenous). Spongy bone (small needle like pieces of bone with lots of Spongy bone open spaces). Please do not reproduce, redistribute or share without the prior express permission of the author. Based on the shape: Long bones (mostly compact bone) Short bones (mostly spongy bone) Flat bones (two thin layers of compact bone sandwiches a layer of spongy bone) Irregular bones Please do not reproduce, redistribute or share without the prior express permission of the author. Please do not reproduce, redistribute or share without the prior express permission of the author. Please do not reproduce, redistribute or share without the prior express permission of the author. STRUCTURE AND PARTS OF A LONG BONE Please do not reproduce, redistribute or share without the prior express permission of the author. Osteon Lamellae Osteon Perforating fibers Periosteum Haversian / central canal Perforating / Volkmann's canal Blood vessel Spongy bone Osteocyte MICROSCOPIC STRUCTURE OF A LONG BONE Please do not reproduce, redistribute or share without the prior express permission of the author. Please do not reproduce, redistribute or share without the prior express permission of the author. DEFINITION OF OSSIFICATION Ossification is a medical term that is synonymous with bone tissue formation. The formation of bone occurs by 2 methods: 1. Intramembranous and 2. Endochondral ossification Please do not reproduce, redistribute or share without the prior express permission of the author. Intramembranous ossification mainly occurs during formation of the flat bones of the skull; the bone is formed from mesenchyme tissue. Endochondral ossification occurs in long bones, such as limbs; the bone is formed from cartilage. Please do not reproduce, redistribute or share without the prior express permission of the author. Endochondral ossification It begins with points in the cartilage called "primary ossification centers." They mostly appear during fetal development, though a few short bones begin their primary ossification after birth. They are responsible for the formation of the diaphyses of long bones, short bones and certain parts of irregular bones. Please do not reproduce, redistribute or share without the prior express permission of the author. Please do not reproduce, redistribute or share without the prior express permission of the author. Secondary ossification occurs after birth, and forms the epiphyses of long bones and the extremities of irregular and flat bones. The diaphyses and the epiphyses of long bones remain separated by a growing zone of cartilage (the metaphysis) until the child reaches skeletal maturity (18 to 25 years of age), whereupon the cartilage ossifies, fusing the two together (epiphyseal closure). Please do not reproduce, redistribute or share without the prior express permission of the author. Remodeling is the process of resorption followed by replacement of bone with little change in shape and occurs throughout a person's life. Its purpose is the release of calcium and the repair of micro-damaged bones (from everyday stress) Repeated stress results in the bone thickening at the points of maximum stress. It has been hypothesized that this is a result of bone's piezoelectric properties, which cause bone to generate small electrical potentials under stress. Please do not reproduce, redistribute or share without the prior express permission of the author.  Intramembranous ossification It is one of the two processes during fetal development of the mammalian skeletal system in which bone tissue is created. It is also an essential process during the healing of bone fractures and the rudimentary formation of bones of the head. Unlike endochondral ossification which is the other process, cartilage is not present during intramembranous ossification. Please do not reproduce, redistribute or share without the prior express permission of the author. Please do not reproduce, redistribute or share without the prior express permission of the author. Blood supply to the bone Nutrient artery/vein – Enters the bone through nutrient foramen – Supplies inner part of compact bone tissue and red marrow up to the epiphyseal plate Metaphyseal arteries/veins – Supplies the red bone marrow and bone tissue of the metaphysis Epiphyseal arteries/veins – Supplies the red bone marrow and bone tissue of the epiphysis Please do not reproduce, redistribute or share without the prior express permission of the author. Nerve supply to bone Accompany the blood vessels that supply bone tissue Periosteum is rich in sensory nerves - Is the reason for the extreme pain when your bone is break (fracture) Please do not reproduce, redistribute or share without the prior express permission of the author.  Thank you Address Telephone Website Lot 33-40, Blok C, Plaza Juta, +6088 431 025/35 kk.cyberjaya.edu.my KM 7.2 Off Jalan Tuaran, 88400 Likas, Kota Kinabalu, Email Sabah, Malaysia [email protected] Please do not reproduce, redistribute or share without the prior express permission of the author. Q&A Session Please do not reproduce, redistribute or share without the prior express permission of the author.