Chapter 3 – Anatomy The Skeletal System

Structures and Functions Consists of bones, bone marrow, cartilage, joints, ligaments, synovial membrane (and fluid), and bursa Bones act as the body’s framework They support and protect the internal organs They work with muscle, ligament and tendon to create movement Calcium is stored in bone Red bone marrow creates blood cells

Bone Marrow Red bone marrow is located in the spongy bone It is hemopoietic – (hem/o = blood, poietic = pertaining to formation) Red blood cells are formed in the spongy bone

Cartilage Blue/white connective tissue that acts as a shock absorber between bone Articular cartilage covers the surface of bones where they form joints The meniscus is the curved cartilage found in some joints

Cartilage

Anatomic Landmarks of Bones Diaphysis – long shaft of the bone Epiphysis – the wide end of a long bone Foramen – an opening in the bone where blood vessels, nerves, and ligaments may pass Process – a normal projection on the surface of a bone where muscles and tendons may attach

Bone Parts

Joints Known as articulations The place of union between two bones Classified by their construction Also classified by their degree of movement

Fibrous Joints Known as sutures in adults Do not allow any movement Connective tissue hold them tightly together They may be moveable in infants and small children to allow for growth Fontanells (soft spots) on the head of an infant are an example of this type of joint

Fibrous Joints

Consists of bones connected entirely by cartilage Cartilaginous Joints Allow slight movement Consists of bones connected entirely by cartilage Where the ribs connect to the sternum The pubic symphysis (between the pubic bones)

Cartilaginous Joints

Synovial Joints Where two bones articulate to permit a variety of movements They include ball and socket and hinge joints Synovial capsule - the sleeve that surrounds the joint Synovial membrane – lines the capsule and secretes fluid Synovial fluid – flows within the cavity and acts as a lubricant for smooth movement

Ligaments – connect bone to bone Synovial Joints Ligaments – connect bone to bone Bursa – sacs or “pillows” that cushion and ease movement

Axial Skeleton (green) THE SKELETON Axial Skeleton (green) Protects the major organs. 80 bones, including the skull. Ribs, sternum, and vertebrae are also included.

THE SKELETON Appendicular Skeleton (red) Makes body movement possible. 126 bones; split into upper and lower extremities The “appendages”

BONES OF THE SKULL The CRANIUM Crani means skull, um is a noun ending Frontal bone forms the forehead Parietal bones form the roof and upper sides Occipital bone forms the posterior floor and walls Temporal bones form the sides and base Sphenoid bone forms parts of the base, floor and sides of the orbit Ethmoid bone forms part of the posterior of the nose, the orbit, and the floor of the cranium

BONES OF THE SKULL

BONES OF THE SKULL

BONES OF THE SKULL Bones of the Face Nasal bones – nose bones Zygomatic bones – cheek bones Maxillary bones – upper jaw Palatine bones – roof of the mouth; “palate” Mandible – jaw bone

BONES OF THE SKULL

Thoracic Cavity Known as the RIB CAGE Ribs – called costals; 12 pair First 7 are true ribs Next 3 are false ribs Last 2 are floating ribs Sternum – known as the breastbone Manubrium is the top part The body of the sternum forms the middle Xiphoid process is cartilage that forms the lower tip

Thoracic Cavity

The structure that supports the arms The Shoulder The structure that supports the arms Clavicle – also known as the collar bone Scapula – the shoulder blade Acromion – the high point of the scapula where the clavicle attaches

The Shoulder

The Shoulder

The Arm Humerus – the bone of the upper arm Radius – the smaller, shorter bone of the forearm on the thumb side Unla – the longer forearm bone that joins the humerus to form the elbow joint

The Arm

Wrists, hands and fingers Carpals – the 8 small bone that make up the wrist Metacarpals – the 5 bones that form the palm and hand Phalanges – the 14 bones of the fingers

Wrists, hands and fingers

Known as the vertebral column Supports the head and body The Spinal Column Known as the vertebral column Supports the head and body Consists of 26 vertebrae (a single segment of the spinal column)

The Spinal Column

The Spinal Column Vertebrae – 5 sections – Cervical, thoracic, lumbar, sacral, and coxyx Has a body, a foramen, a lamina, a transverse process, and a spinous process

The Spinal Column

The Spinal Column Cervical vertebrae Thoracic vertebrae form the neck 7 vertebrae Thoracic vertebrae Make up the torso 12 vertebrae Lumbar – 5 vertebrae of the low back Sacrum and Coccyx make up the connection to the pelvis

The Pelvic Girdle Consists of the pelvis and hips Illium – broad blade shaped bone that forms the back and sides of the hips Ischium – forms the lower posterior portion of the pubic bone The pubis forms the anterior portion of the pubic bone The sacroiliac joint is slightly moveable and is the connection of the spine to the pelvis The acetabulum is the hip “socket” where the leg joins the body

The Pelvic Girdle

Legs and Knees

Legs and Knees The femur is the upper leg bone It articulates with the acetabulum It is “L” shaped at the head, forming the femoral neck The knee is the articulation of joints that join the upper and lower leg Consists of a tibial-femoral joint and a patello-femoral joint The patella is the knee cap The knee contains cruciate and co-lateral ligaments, and a meniscus

Legs and Knees

The Lower leg The tibia, also known as the shinbone, is the larger, weight bearing bone in the lower leg The fibula is the smaller, lateral bone The distal heads of the tibia and fibula make up the maleoli.

The Ankle The ankle joins the foot with the lower leg The tarsal bones, similar to the carpals of the wrist, are the talus and the calcaneus. The talus articulates with the tibia and fibula to make the joint

Feet and Toes The five metatarsals form the mid foot area The phalanges of the foot attach to the metatarsals

Feet and Toes

Anterior skeleton

Posterior Skeleton