HLTH 10078 Anatomy Lecture Guide PDF

HEALTH, WELLNESS AND FITNESS 1 HLTH 10078 – ANATOMY Lecture Guide Endocrine & Digestive System Overview Cartilage Function of bone Anatomy of bone Bone development...

HEALTH, WELLNESS AND FITNESS 1 HLTH 10078 – ANATOMY Lecture Guide Endocrine & Digestive System Overview Cartilage Function of bone Anatomy of bone Bone development Axial skeleton Appendicular skeleton Figure 6.1 Cartilages in the body. Types of Cartilage Hyaline cartilage Most abundant cartilage Chondrocytes appear spherical Collagen unit fibril is the only type of fiber in the matrix Ground substance holds a large amount of water Provides support through flexibility Elastic cartilage Contains many elastic fibers Able to tolerate repeated bending Locations—epiglottis and cartilage of external ear Fibrocartilage Resists strong compression and strong tension An intermediate between hyaline and elastic cartilage Locations—pubic symphysis, menisci of knee, anulus fibrosus Growth of Cartilage Appositional growth Chondroblasts in surrounding perichondrium produce new cartilage Interstitial growth Chondrocytes within cartilage divide and secrete new matrix Cartilage stops growing when the skeleton stops growing One Minute Paper  HEALTH, WELLNESS AND FITNESS 2 Function of Bones Support—provide hard framework Movement—skeletal muscles use bones as levers Protection of underlying organs Mineral storage—reservoir for important minerals Blood cell formation—bone contains red marrow Energy metabolism—osteoblasts secrete osteocalcin Classification of Bones Long bones—longer than wide; a shaft plus ends Short bones—roughly cube-shaped Flat bones—thin and flattened, usually curved Irregular bones—various shapes, do not fit into other categories Figure 6.3 Classification of bones. Gross Anatomy of Bones Compact bone Dense outer layer of bone Spongy (cancellous) bone Internal network of bone Trabeculae—little “beams” of bone Open spaces between trabeculae are filled with marrow Bone design and stress Anatomy of a bone reflects stresses Compression and tension greatest at external surfaces Figure 6.6a Bone anatomy and bending stress. Bone Markings Superficial surfaces of bones reflect stresses on them There are three broad categories of bone markings: Projections for muscle attachment Surfaces that form joints Depressions and openings Refer to Table 6.1 Partner Activity Using any resources, find the following: The name of the bone that has a ___________________________________________________________ The name of a bone that has a ___________________________________________________________ The name of the bone that has a ___________________________________________________________ The name of a bone that has a ___________________________________________________________  HEALTH, WELLNESS AND FITNESS 3 Endochondral Ossification All bones except some bones of the skull and clavicles Bones are modeled in hyaline cartilage Begins forming late in the second month of embryonic development Continues forming until early adulthood Figure 6.11 Endochondral ossification of a long bone. Figure 6.12 Organization of the cartilage within the epiphyseal plate of a growing long bone. Postnatal Growth of Endochondral Bones As adolescence draws to an end: Chondroblasts divide less often Epiphyseal plates become thinner Cartilage stops growing Replaced by bone tissue Long bones stop lengthening when diaphysis and epiphysis fuse Growing bones widen as they lengthen Osteoblasts—add bone tissue to the external surface of the diaphysis Osteoclasts—remove bone from the internal surface of the diaphysis Appositional growth—growth of a bone by addition of bone tissue to its surface Bone Remodeling Bone is a dynamic living tissue 500 mg of calcium may enter or leave the adult skeleton each day Bone matrix and osteocytes are continually removed and replaced Cancellous bone of the skeleton is replaced every 3–4 years Compact bone is replaced every 10 years Bone deposit and removal Occurs at periosteal and endosteal surfaces Bone deposition—accomplished by osteoblasts Bone reabsorption—accomplished by osteoclasts Figure 6.13 Remodeling of spongy bone. The Skeleton Throughout Life Skeleton grows until the age of 18–21 years In children and adolescents, bone formation exceeds rate of bone reabsorption In young adults, bone formation and bone reabsorption are in balance In old age, reabsorption predominates Bone mass declines with age Bones, Part 1: The Axial Skeleton The Skeleton Consists of: Bones, cartilage, joints, and ligaments  HEALTH, WELLNESS AND FITNESS 4 Joints—also called articulations Is composed of 206 named bones grouped into two divisions Axial skeleton (80 bones) Skull, vertebral column, and thoracic cage Appendicular skeleton (126 bones) Upper and lower limbs (Chapter 8) Figure 7.18 The vertebral column. Regions and Normal Curvatures The vertebral column has five major regions 7 cervical vertebrae of the neck region 12 thoracic vertebrae 5 lumbar vertebrae Sacrum—five fused bones Inferior to lumbar vertebrae Coccyx—inferior to sacrum Curvatures of the spine Cervical and lumbar curvatures Concave posteriorly Thoracic and sacral curvatures Convex posteriority Ligaments of the Spine Major supporting ligaments Anterior longitudinal ligament Attaches to bony vertebrae and intervertebral discs Prevents hyperextension Posterior longitudinal ligament Narrow and relatively weak Attaches to intervertebral discs Figure 7.19b Ligaments and intervertebral discs of the spine. Intervertebral Discs Are cushion-like pads between vertebrae Composed of Nucleus pulposus Anulus fibrosus Figure 7.20 Structure of a typical vertebra. General Structure of Vertebrae Common structures to all regions Body Vertebral arch Vertebral foramen Spinous process Transverse process  HEALTH, WELLNESS AND FITNESS 5 Superior and inferior articular processes Intervertebral foramina Refer to Table 7.2 for differences in vertebrae Figure 7.23 The sacrum and coccyx. Coccyx Is the “tailbone” Formed from 3–5 fused vertebrae Offers only slight support to pelvic organs The Thoracic Cage Forms the bony framework of the chest Components Thoracic vertebrae—posteriorly Ribs—laterally Sternum and costal cartilage—anteriorly Protects thoracic organs Supports shoulder girdle and upper limbs Provides attachment sites for many muscles of the back Figure 7.24a The thoracic cage. Sternum Formed from three sections Manubrium—superior section Clavicular notches articulate with medial end of clavicles Body—bulk of sternum Sides are notched at articulations for costal cartilage of ribs 2–7 Xiphoid process—inferior end of sternum Ossifies around age 40 Ribs All ribs attach to vertebral column posteriorly True ribs—superior seven pairs of ribs Attach to sternum by costal cartilage False ribs—inferior five pairs of ribs Ribs 11–12 are known as floating ribs Figure 7.25b Ribs. Figure 7.25c Ribs. The Axial Skeleton Throughout Life Aging of the axial skeleton Water content of the intervertebral discs decreases By age 55, loss of a few centimeters in height is common Thorax becomes more rigid Bones lose mass with age  HEALTH, WELLNESS AND FITNESS 6 Bones, Part 2: The Appendicular Skeleton The Appendicular Skeleton Pectoral girdle Attaches the upper limbs to the trunk Pelvic girdle Attaches the lower limbs to the trunk Upper and lower limbs differ in function Share the same structural plan The Pectoral Girdle Consists of the clavicle and the scapula Pectoral girdles do not quite encircle the body completely Medial end of each clavicle articulates with the manubrium and first rib Laterally—the ends of the clavicles join the scapulae Scapulae do not join each other or the axial skeleton Mobility of the pectoral girdle Only clavicle articulates with the axial skeleton Scapula can move freely Socket of the shoulder joint (glenoid cavity) is shallow Good for flexibility, bad for stability Figure 8-1a The pectoral girdle and clavicle. Scapulae Lie on the dorsal surface of the rib cage Located between ribs 2–7 Have three borders Superior Medial (vertebral) Lateral (axillary) Have three angles Lateral, superior, and inferior Figure 8-2a The scapula. Figure 8-2b The scapula. Figure 8-2c The scapula. The Upper Limb 30 bones form each upper limb Grouped into bones of the: Arm Forearm Hand Arm Region of the upper limb between the shoulder and elbow  HEALTH, WELLNESS AND FITNESS 7 Humerus The only bone of the arm Longest and strongest bone of the upper limb Articulates with the scapula at the shoulder Articulates with the radius and ulna at the elbow Figure 8-3a The humerus of the right arm and detailed views of articulation at the elbow. Forearm Formed from the radius and ulna Proximal ends articulate with the humerus Distal ends articulate with carpals Radius and ulna articulate with each other At the proximal and distal radioulnar joints The interosseous membrane Interconnects radius and ulna In anatomical position; the radius is lateral and the ulna is medial Ulna Main bone responsible for forming the elbow joint with the humerus Hinge joint allows forearm to bend on arm Distal end is separated from carpals by fibrocartilage Plays little to no role in hand movement Figure 8-4a Radius and ulna of the right forearm. Hand Includes the following bones Carpus—wrist Metacarpals—palm Phalanges—fingers Carpus Forms the true wrist The proximal region of the hand Gliding movements occur between carpals Composed of eight marble-sized bones Carpal bones Are arranged in two irregular rows Proximal row from lateral to medial Scaphoid, lunate, triquetral, and pisiform Distal row from lateral to medial Trapezium, trapezoid, capitate, and hamate A mnemonic to help remember carpals: “Sally left the party to take Carmen home” Figure 8-6a Bones of the hand. Pelvic Girdle  HEALTH, WELLNESS AND FITNESS 8 Attaches lower limbs to the spine Supports visceral organs Attaches to the axial skeleton by strong ligaments Acetabulum is a deep cup that holds the head of the femur Lower limbs have less freedom of movement Are more stable than the arm Consists of paired hip bones (coxal bones or pelvic bone) and the sacrum Coxal bones unite anteriorly with each other and articulate posteriorly with the sacrum Ilium Large, flaring bone Forms the superior region of the coxal bone Site of attachment for many muscles Articulation with the sacrum forms sacroiliac joint Ischium Forms posteroinferior region of the coxal bone Anteriorly—joins the pubis Ischial tuberosities Are the strongest part of the hip bone Pubis Forms the anterior region of the coxal bone Lies horizontally in anatomical position Pubic symphysis The two pubic bones are joined by fibrocartilage at the midline Pubic arch—inferior to the pubic symphysis Angle helps distinguish male from female pelvis Figure 8-7a Bones of the pelvic girdle. The Lower Limb Carries the entire weight of the erect body Bones of lower limb are thicker and stronger than those of upper limb Divided into three segments Thigh, leg, and foot Thigh The region of the lower limb between the hip and the knee Femur—the single bone of the thigh Longest and strongest bone of the body Ball-shaped head of the femur articulates with the acetabulum Figure 8-9b The right patella (a) and femur (b).  HEALTH, WELLNESS AND FITNESS 9 Patella Triangular sesamoid bone Embedded in the tendon that secures the quadriceps muscles Protects the knee anteriorly Improves leverage of the thigh muscles across the knee Leg Refers to the region of the lower limb between the knee and the ankle Composed of the tibia and fibula Tibia—more massive medial bone of the leg Receives weight of the body from the femur Fibula—sticklike lateral bone of the leg Interosseous membrane Connects the tibia and fibula Tibia articulates with femur at superior end Forms the knee joint Tibia articulates with talus at the inferior end Forms the ankle joint Fibula does not contribute to the knee joint Stabilizes the ankle joint Figure 8-10a The tibia and fibula of the right leg. The Foot Foot is composed of Tarsus, metatarsus, and the phalanges Important functions Supports body weight Acts as a lever to propel body forward when walking Segmentation makes foot pliable and adapted to uneven ground Figure 8-11a Bones of the right foot.