Biol 2401 Fundamentals of Anatomy and Physiology Mrs. Willie Grant wgrant4@alamo.edu (210) 486-2780

© 2015 Pearson Education Inc.

An Introduction to the Axial Skeleton Learning Outcomes 7-1 Identify the bones of the axial skeleton, and specify their functions. 7-2 Identify the bones of the cranium and face, and explain the significance of the markings on the individual bones. 7-3 Identify the foramina and fissures of the skull, and cite the major structures using the passageways. 7-4 Describe the structure and functions of the orbital complex, nasal complex, and paranasal sinuses. 7-5 Describe the key structural differences among the skulls of infants, children, and adults. 7-6 Identify and describe the curvatures of the spinal column, and indicate the function of each. 7-7 Identify the vertebral regions, and describe the distinctive structural and functional characteristics of vertebrae in each region. 7-8 Explain the significance of the articulations between the thoracic vertebrae and the ribs, and between the ribs and sternum.

7-3 The Cranial Bones of the Skull Sinuses Cavities that decrease the weight of the skull Lined with mucous membranes Protect the entrances of the respiratory system Auditory Ossicles Three tiny ear bones in the middle ear that connect the tympanic membrane with one of the receptor complexes of the internal ear. Anvil Malleus Stapes

7-4 The Orbital and Nasal Complexes The Eye Sockets (Orbits) Frontal bone (roof) Maxilla (floor) Maxillary, lacrimal, and ethmoid bones (orbital rim and medial wall) Sphenoid and palatine bones 2 Which seven bones for the orbit?

7-4 The Orbital and Nasal Complexes Bones of the Nasal Cavities and Paranasal Sinuses Make Up the Nasal Complex Frontal bone, sphenoid, and ethmoid Superior wall of nasal cavities Maxillae, lacrimal bones, ethmoid, and inferior nasal conchae Lateral walls of nasal cavities Maxillae and nasal bones Bridge of nose

Figure 7-14a The Nasal Complex FRONTAL BONE Frontal sinuses Sphenoidal sinuses ETHMOID NASAL BONE SPHENOID PALATINE BONE (bony palate) Superior Nasal conchae of ethmoid MAXILLA (bony palate) Middle INFERIOR NASAL CONCHA A sagittal section through the skull, with the nasal septum removed to show major features of the wall of the right nasal cavity. The sphenoidal sinuses are visible. 9

7-4 The Orbital and Nasal Complexes Paranasal Sinuses Air-filled chambers connected to the nasal cavities Lighten skull bones Provide mucous epithelium (flushes nasal cavities) 3 What are the functions of the paranasal sinuses?

Is large compared to the body Has many ossification centers 7-5 Fontanelles The Infant Skull Grows rapidly Is large compared to the body Has many ossification centers Fusion is not complete at birth Two frontal bones Four occipital bones Several sphenoidal and temporal elements Fontanelles Are areas of fibrous connective tissue (soft spots) Cover unfused sutures in the infant skull Allow the skull to flex during birth

4 Which fontanel is bordered by four different skull bones? 5 Which fontanel is considered the “soft spot”? 6 How long does it persit?

7-6 The Vertebral Column The Vertebral Column (Spine) Protects the spinal cord Supports the head and body 26 bones 24 vertebrae, the sacrum, and the coccyx

Figure 7-16 The Vertebral Column Spinal Curves Vertebral Regions Primary curves develop before birth, and secondary curves after birth. Regions are defined by anatomical characteristics of individual vertebrae. The cervical curve, a secondary curve, develops as the infant learns to balance the weight of the head on the vertebrae of the neck. Cervical (7 vertebrae) The thoracic curve, a primary curve, accommodates the thoracic organs. Thoracic (12 vertebrae) The lumbar curve, a secondary curve, balances the weight of the trunk over the lower limbs; it develops with the ability to stand. Lumbar (5 vertebrae) The sacral curve, a primary curve, accommodates the abdominopelvic organs. Sacral 7 Which curves of the adult vertebral column are concave relative to the anterior side of the body? Coccygeal 15

“Swayback” Bending backwards “Crookedness” Lateral curvature “Hunchback” Exagerrated normal thoracic curve

7-7 Vertebral Regions The Cervical Vertebrae Vertebra prominens (C7) Transitions to thoracic vertebrae Has a long spinous process Has large transverse processes Ligamentum nuchae (elastic ligament) extends from C7 to skull

7-8 The Thoracic Cage Ribs 1–7 (True Ribs) Vertebrosternal ribs Connected to the sternum by costal cartilages Ribs 8–12 (False Ribs) Do not attach directly to the sternum Vertebrochondral ribs (ribs 8–10) Fuse together Merge with cartilage before reaching the sternum Floating or vertebral ribs (ribs 11–12) Connect only to the vertebrae and back muscles Have no connection with the sternum 8 With which ribs does the body of the sternum articulate?

Clinical Case—Knocked Out What are the seven bones that make up the orbital complex? What are the four paranasal sinuses surrounding the orbital complex?

© 2015 Pearson Education, Inc.

An Introduction to the Appendicular Skeleton Learning Outcomes 8-1 Identify the bones that form the pectoral girdle, their functions, and their superficial features. 8-2 Identify the bones of the upper limbs, their functions, and their superficial features. 8-3 Identify the bones that form the pelvic girdle, their functions, and their superficial features. 8-4 Identify the bones of the lower limbs, their functions, and their superficial features. 8-5 Summarize sex differences and age-related changes in the human skeleton.

8-1 The Pectoral Girdle The Pectoral Girdle Also called shoulder girdle Connects the arms to the body Positions the shoulders Provides a base for arm movement Consists of: Two clavicles Two scapulae Connects with the axial skeleton only at the manubrium 9 What is the function of the pectoral girdle?

8-3 The Pelvic Girdle The Pelvic Girdle Made up of two hip bones (coxal bones) Strong to bear body weight, stress of movement Part of the pelvis Coxal bones Made up of three fused bones Ilium (articulates with sacrum) Ischium Pubis 10 What is the function of the pelvic girdle?

8-3 The Pelvic Girdle Comparing the Male Pelvis and Female Pelvis Female pelvis Smoother and lighter Less prominent muscle and ligament attachments Pelvis modifications for childbearing Enlarged pelvic outlet Broad pubic angle (>100°) Less curvature of sacrum and coccyx Wide, circular pelvic inlet Broad, low pelvis Ilia project laterally, not upwards

Figure 8-10 Anatomical Differences between a Male and Female Pelvis Ischial spine Ischial spine 90° 100° or more or less Male Female 28

© 2015 Pearson Education, Inc. 8-4 The Lower Limbs Arches of the Feet Arches transfer weight from one part of the foot to another The longitudinal arch Calcaneal portion Lateral Talar portion Medial The transverse arch Formed by a difference in curvature between medial and lateral borders of the foot © 2015 Pearson Education, Inc.

8-5 Individual Skeleton Variation Studying the Skeleton Reveals characteristics Muscle strength and mass (bone ridges, bone mass) Medical history (condition of teeth, healed fractures) Sex and age (bone measurements and fusion) Body size

Clinical Case—The Orthopedic Surgeon’s Nightmare What skeletal structures are still attached to the distal humeral fracture fragment? Why would the surgeon want to avoid a circular cast in the immediate post-fracture period and apply a posterior splint instead?