Locomotor System 1 (AL AZHAR UNIVERSITY) PDF

AL AZHAR UNIVERSITY Faculty of Medicine for Girls Year 1-Semester I Academic year: 2023 / 2024 Module Name: human body Course code: IMP 07- 10212 Credit hours: Locomotor system 1 ANATOMY DEPARTMENT By Prof Dr/Manal El kaf...

AL AZHAR UNIVERSITY Faculty of Medicine for Girls Year 1-Semester I Academic year: 2023 / 2024 Module Name: human body Course code: IMP 07- 10212 Credit hours: Locomotor system 1 ANATOMY DEPARTMENT By Prof Dr/Manal El kafrawy The locomotor system is also known as the musculoskeletal system. It is made up of the skeleton, skeletal muscles, ligaments, tendons, joints, cartilage and other connective tissue. These parts work together to allow your body to move. The musculoskeletal system (locomotor system) is a human body system that provides our body with movement, stability, shape, and support. It is subdivided into two broad systems: Muscular system, which includes all types of muscles in the body. Skeletal muscles, in particular, are the ones that act on the body joints to produce movements. Besides muscles, the muscular system contains the tendons which attach the muscles to the bones. Skeletal system, whose main component is the bone. Bones articulate with each other and form the joints. The integrity and function of the bones and joints is supported by the accessory structures of the skeletal system; articular cartilage, ligaments, and bursae. the skeletal part plays an important role in other homeostatic functions such as storage of minerals (e.g., calcium) and hematopoiesis, while the The adult human skeleton is composed of 206 bones and their associated cartilages. The bones are supported by ligaments, tendons, bursae, and muscles. The bones of the body are grouped within the two distinct divisions: Axial skeleton, that includes the bones along the long axis of the body. The axial skeleton consists of the vertebral column, bones of the head and bones of the thoracic cage. Appendicular skeleton, that involves the bones of the shoulder and pelvic girdle, as well as the Bones Skeletal system Bones are rigid structures made of calcified dense connective tissue. Bone tissue is composed of a mineralized bone matrix that consists of type 1 collagen fibers dispersed throughout the ground substance. The cellular component of the bones is represented by three types of specialized bone cells called osteocytes, osteoblasts and osteoclasts. The bones consist of two distinct layers that differ in histological appearance and characteristics; Compact (cortical) bone is the outer much denser layer of the bone which gives it its smooth, white, and solid appearance. The outer surface of the compact bone is covered with a layer of dense connective tissue called the periosteum. On its inner surface, the compact bone is covered with endosteum, which is the boundary between the compact and spongy bones. Spongy (cancellous) bone is the deep airy layer of the bone. Unlike the compact bone, spongy bone is highly vascularized and more metabolically active. It is typically found within the ends of long bones and in the Bones can be classified according to their shapes as follows: Long bones have a tubular shape, with a longer longitudinal and a shorter transverse diameter. They are composed mostly of compact bone, while the spongy bone and bony marrow fill the ends of the bones. Examples of long bones include the humerus, ulna, tibia and clavicle. Short bones have a roughly cuboid or round shape, and only contain a thin layer of compact bone surrounding the spongy bone. Examples include the tarsal and carpal bones. Flat bones are mostly thin, flattened and usually curved. They contain two parallel layers of compact bones surrounding a layer of spongy bone. Examples include most of the skull bones, scapula, sternum. Sesamoid bones are small, rounded unique types of bones that are embedded in muscle tendons where the tendon passes over a joint. The largest sesamoid bone in the body is the patella, but several other smaller sesamoid bones can be found in the hand and foot, usually in close proximity to the joints. Example patella Irregular bones do not fit into any of the other categories. Generally, irregular bones contain foramina through which soft tissue and neurovascular structures pass. Examples include the vertebrae, hip bone and some bones of the skull. Features of Long Bone: Epiphysis: Ends of the Diaphysis: bone. The“ shaft” of the bone which surrounds the medullary cavity. B. Growth in length occurs on both sides of the cartilaginous epiphysial plates (blue arrows) Cartilage Cartilage is a flexible connective tissue found in multiple organ systems of the body. Cartilage is composed of specialized cells called chondrocytes, collagen fibers and abundant ground substance rich in proteoglycan and elastin fibers. Cartilage is classified into the following types based on its composition: Hyaline cartilage is composed of type II collagen and an abundance of ground substance, which gives it a glossy appearance. It is the most abundant type of cartilage found in joints (articular cartilage), as well as the nose, larynx, trachea and ribs. Elastic cartilage is similar to hyaline cartilage but contains more elastic fibers. It is found in structures such as the pinna of the ear, auditory tube and epiglottis.  Skeletal System The skeletal system divided into two functional parts: *The axial skeleton consists of the bones of the skull ,hyoid bone, ribs, sternum and vertebral column. *The appendicular skeleton consists of the bones of the limbs, including those forming the pectoral (shoulder) and pelvic girdles. Axial Skeleton The word "Axial" is taken from the word "axis" and refers to the fact that the bones are located close to or along the central "axis" of the body. The axial skeleton consists of 80 bones: The skull, which contains 22 bones, from which 8 are cranial and 14 are facial, 6 middle ear ossicles (3 in each ear),1 hyoid bone in the neck, 26 bones of vertebral column, 1 chest bone (sternum), and 24 ribs (12 pairs). The skull consists of the cranial bones and the facial skeleton. The cranial bones compose the top and back of the skull and enclose the brain. The facial skeleton, as its name suggests, makes up the face of the skull. Facial Skeleton (14 bones ) is formed by the mandible, maxillae ,zygomatics ,and the bones that give shape to the nasal cavity: lacrimals ,nasals ,vomer, palatines ,and the nasal conchae. Cranial Bones: The eight cranial bones support and protect the brain: occipital bone, parietal bone, Bones of the Inner Ear Inside the petrous part of the temporal bone are the three smallest bones of the body: the malleus, incus, and stapes. These three bones articulate with each other and transfer vibrations from the The thoracic cage, formed by the ribs and sternum, protects internal organs and gives attachment to muscles involved in respiration and upper limb movement. The sternum consists of the manubrium, body of the sternum, and xiphoid process. Ribs 1-7 are called true ribs because they articulate directly to the sternum, and ribs 8-12 are known as false ribs. Vertebral column serve three important functions: protecting of the spinal cord and spinal nerves, transmitting the weight of the body and providing a flexible axis for movements of the head, neck and trunk. The vertebral column extends from the base of the skull to the pelvis. The spinal cord passes from the foramen magnum of the skull through the vertebral canal within the vertebral column.. Vertebral column is formed by 33 vertebrae, which are subdivided into 5 groups according their position:  7 cervical vertebrae (CI – CVII)  12 thoracic vertebrae (TI – TXII)  5 lumbar vertebrae (LI – LV)  sacrum (formed by 5 fused sacral vertebrae)  coccyx (formed by 3-5 fused coccygeal vertebrae) Characteristics of a Typical Cervical Vertebra The transverse processes possess a foramen transversarium for the passage of the vertebral artery and veins (note that the vertebral artery passes through the transverse processes C1 to 6 and not through C7). The spines are small and bifid. The body is small and broad from side to side. The vertebral foramen is large and triangular. The superior articular processes have facets that face backward and upward; the inferior processes have facets that face downward and forward. Characteristics of the Atypical Cervical Vertebrae The first, second, and seventh cervical vertebrae are atypical. The first cervical vertebra, or atlas ,does not possess a body or a spinous process. It has an anterior and posterior arch. It has a lateral mass on each side with articular surfaces on its upper surface for articulation with the occipital condyles (atlanto-occipital joints) and articular surfaces on its lower surface for articulation with the axis (atlantoaxial joints). Typical cervical vertebra, The second cervical vertebra, or axis ,has superior aspect. B. Atlas, or odontoid process that projects from the first cervical vertebra, superior aspect. C. Axis, or superior surface of the body (representing the second cervical vertebra, body of the atlas that has fused with the body from above and behind. D. of the axis). Seventh cervical vertebra, superior aspect; the foramen The seventh cervical vertebra, or vertebra transversarium forms a Characteristics of a Typical Thoracic Vertebra The body is medium size and heart shaped. The vertebral foramen is small and circular. The spines are long and inclined downward. Costal facets are present on the sides of the bodies for articulation with the heads of the ribs. Costal facets are present on the transverse processes for articulation with the tubercles of the ribs (T11 and 12 have no facets on the transverse processes). The superior articular processes bear facets that face backward and laterally, whereas the facets on the inferior articular processes face forward and medially. The inferior articular processes of the 12th vertebra face laterally, as do those of the lumbar vertebrae. Characteristics of a Typical Lumbar Vertebra The body is large and kidney shaped. The pedicles are strong and directed backward. The laminae are thick. The vertebral foramina are triangular. The transverse processes are long and slender. The spinous processes are short, flat, and quadrangular and project backward. Sacrum The sacrum consists of five rudimentary vertebrae fused together to form a wedge- shaped bone, which is concave anteriorly. The upper border, or base, of the bone articulates with the fifth lumbar vertebra. The narrow inferior border articulates with the coccyx. Laterally, the sacrum articulates with the two iliac bones to form the sacroiliac joints. The anterior and upper margin of the first sacral vertebra bulges forward as the posterior margin of the pelvic inlet and is known as the sacral The vertebral foramina are present and form the sacral canal. The laminae of the fifth sacral vertebra, and sometimes those of the fourth also, fail to meet in the midline, forming the sacral hiatus. The sacral canal contains the anterior and posterior roots of the sacral and coccygeal spinal nerves, the filum terminale, and fibro fatty material. It also contains the lower part of the subarachnoid space down as far as the lower border of the second sacral vertebra. The anterior and posterior surfaces of the sacrum each have four foramina on each side for the passage of the anterior and posterior rami of the upper four sacral nerves. Coccyx The coccyx consists of four vertebrae fused together to form a single, small triangular bone that articulates at its base with the Abnormal Curves of the Vertebral Column Kyphosis is an exaggeration in the sagittal curvature present in the thoracic part of the vertebral column. It can be caused by muscular weakness or by structural changes in the vertebral bodies or by intervertebral discs. Lordosis is an exaggeration in the sagittal curvature present in the lumbar region. Lordosis may be caused by an increase in the weight of the abdominal contents, as with the gravid uterus or a large ovarian tumor, or it may be caused by disease of the vertebral column. Scoliosis is a lateral deviation of the vertebral column. This is most commonly found in the thoracic region and may be caused by muscular or vertebral defects. Paralysis of muscles caused by poliomyelitis can cause severe scoliosis. The appendicular Skeleton The appendicular skeleton includes the bones of the shoulder girdle, the upper limbs, the pelvic girdle, and the lower limbs. The pectoral or should er girdle consists of the scapulae and clavicles. The shoulder girdle connects the bones of the upper limbs to the axial skeleton. These bones also provide attachment for The upper limbs include the bones of the arm (humerus), forearm (radius and ulna), wrist, and hand. The only bone of the arm is the humerus, which articulates with the forearm bones–the radius and ulna– at the elbow joint. Wrist Bones. The wrist, consists of eight carpal bones. the Scaphoid, Lunate, Triquetral, Pisiform, Trapezoid, Tr apezium, Capitate, Hamate. Hand Bones. The hand includes 8 bones in the wrist, 5 bones that form the palm, and 14 bones that form the fingers and thumb.. The bones that form the palm of the hand are called metacarpals. The pelvic girdle is a ring of bones attached to the vertebral column that connects the bones of the lower limbs to the axial skeleton. The pelvic girdle consists of the right and left hip bones. Each hip bone is a large, flattened, and irregularly shaped fusion of three bones: the ilium, ischium, and pubis. Female and Male Pelvis. The female and male pelvises differ in several ways due to childbearing adaptations in the female. The female pelvic brim is larger and wider than the male’s. The angle of the pubic arch is greater in the female pelvis (over 90 degrees) than in the male pelvis (less than 90 degrees). The male pelvis is deeper and has a narrower pelvic outlet Foot Bones. The bones of the foot consist of the tarsal bones of the ankle, the phalanges that form the toes, and the metatarsals that give the foot its arch. As in the hand, the foot has five metatarsals, Ankle Bones. The ankle, or tarsus, consists of seven tarsal bones: the calcaneus, talus, cuboid, Put (√) or(X) 1-Cervical vertebrae have facets for the ribs on the bodies. 2-Floating ribs are connected to the body of sternum. 3- A typical lumbar vertebra has bifid spinous process_. 4-The transverse processes of Cervical vertebrae are perforated by foramen transversarium. 5-Thoracic vertebrae have bifid spinous process. 6-The sternum consists of only two parts, the manubrium and xiphoid process. 7. The number of cervical vertebrae present is a. 6. b. 7. c. 8. d. 9. 8. Which cervical vertebra is known as the axis? a. C1. b. C2. c. C4. d. C7. 9. The spinous process is bifid in all EXCEPT which cervical vertebrae? a. C2. b. C4. c. C6. d. C7. 10. Which cervical vertebra does NOT have a body? a. C1. b. C2. c. C5. d. C7.  THANK YOU