anatomical terms & skeletal system

Introduction to the Skeletal System : 

Introduction to the Skeletal System 9th Grade Biology Woodinville Montessori School

Anatomical Position : 

Anatomical Position Anatomical position for a human being: Standing, with feet slightly closer than shoulder-width apart Facing forward Palms are facing forward (this keeps the bones of the forearm from crossing each other)

Anatomical Directions : 

Anatomical Directions Superior Toward the head Inferior Toward the feet Dorsal Toward the back Ventral Toward the belly Anterior Toward the front Posterior Toward the back Medial Toward the center Lateral Toward the side Superficial Toward the surface Deep Toward the center Proximal Toward the trunk Distal Away from the trunk

The Skeletal System : 

The Skeletal System The skeletal system consists of bones, cartilage and ligaments, all of which are considered to be connective tissue Connective tissue holds together and supports other tissues Other examples of connective tissue are blood, fat, and loose connective tissue

Cartilage, Ligaments and Tendons : 

Cartilage, Ligaments and Tendons Cartilage is a flexible connective tissue. It cushions bones when they meet in a joint and is also found in the earlobes and tip of the nose. Ligaments are strong connective tissues that connect bones to other bones, as in forming a joint. The ACL (Anterior Cruciate Ligament) is a commonly injured ligament in the lower leg. Tendons are tough bands of connective tissue that connect the head (end) of a muscle to a bone. The Achilles tendon is an example of a tendon; it is found on the back of the heel and ankle.

Anatomy of a Bone : 

Anatomy of a Bone Bones are made of dense connective tissue called bone matrix Cartilage cushions the ends of bones and protects them from rubbing against each other Inside the bone is a cavity containing bone marrow Yellow marrow stores fat and serves as energy reserves Red marrow (found in long bones) produces blood cells

Types of Joints : 

Types of Joints Hinge Back-and-forth movement in a single plane Examples: knee, elbow, fingers Ball-and-socket Rotation in many different directions and planes Examples: shoulder, hip

Types of Joints : 

Types of Joints Gliding Bones slide over each other Examples: wrist, ankle Pivot Rotation on a single axis Example: neck

Types of Joints : 

Types of Joints Saddle Allows back-and-forth movement in two directions Example: base of thumb Fixed No movement Example: skull (the joints are called sutures)

Facts About Bones : 

Facts About Bones Adult humans have 206 bones. A newborn baby has 270 bones, but during childhood many of those fuse together, most noticeably in the skull. Extreme bone sizes Largest bone: femur (thighbone) Smallest bone: stapes (stirrup) of the inner ear Teeth are considered part of the skeletal system, but are not made of bone. (They are made of pulp and dentin, covered with enamel).

Important Bones of the Skeletal System: Head and Neck : 

Important Bones of the Skeletal System: Head and Neck Cranium (top of skull) Zygomatic arch (cheekbone) Mandible (jawbone) Cervical vertebrae (neck bones) Clavicle (collarbone)

Important Bones of the Skeletal System: Torso : 

Important Bones of the Skeletal System: Torso Scapula (shoulder blade) Thoracic vertebrae (upper back) Sternum Xiphoid process Ribs

Important Bones of the Skeletal System: The Ribs : 

Important Bones of the Skeletal System: The Ribs True Ribs (7 pairs) Connect directly to sternum with cartilage False Ribs (3 pairs) Connect to cartilage that connects to cartilage that connects to the sternum Floating Ribs (2 pairs) Do not connect to cartilage or to the sternum at all

Important Bones of the Skeletal System: Arms : 

Important Bones of the Skeletal System: Arms Humerus(upper arm) Radius (forearm; connects to thumb) Ulna (forearm) Carpals (wrist) Metacarpals (hand) Phalanges (fingers & thumbs)

Important Bones of the Skeletal System: Pelvis : 

Important Bones of the Skeletal System: Pelvis Lumbar vertebrae (lower back) Sacrum (fused top of tailbone) Coccyx (tailbone) Ilium (hipbone)

Important Bones of the Skeletal System: Legs : 

Important Bones of the Skeletal System: Legs Femur (thighbone) Tibia (shin) Patella (kneecap) Fibula (lower leg) Tarsals(ankle) Metatarsals (foot) Phalanges (Toes)

Important Bones of the Skeletal System: Divisions of the Vertebral Column : 

Important Bones of the Skeletal System: Divisions of the Vertebral Column

The Skeletal System : 

The Skeletal System How many bones can you name?