Chapter 7 Skeletal System Flashcards

Structures of the Skeletal System

• Composed of bones, cartilage, ligaments, and tendons.

Functions of the Skeletal System

• Provides structural support for the body.
• Protects vital organs such as the heart and lungs.
• Facilitates movement by acting as levers.
• Acts as a storage reserve for minerals like calcium.
• Responsible for blood cell formation in red bone marrow.

Bone Marrow

• Red bone marrow is essential for forming red blood cells, white blood cells, and platelets.

Calcium Management

• Blood calcium levels are maintained by storing excess calcium in the bone matrix or releasing it when levels decrease.

Bone Composition

• Spongy bone is lighter and less dense than compact bone.
• An osteon is the microscopic structural unit of compact bone.

Bone Cell Types

• Osteoblasts: Cells responsible for bone formation.
• Osteoclasts: Cells that break down or resorb bone tissue.
• Osteocytes: Mature bone cells that help maintain bone tissue.

Cartilage

• The epiphyseal plate contains hyaline cartilage, important for bone growth.

Human Skeleton Structure

• Adults have a total of 206 bones.
• The human skull consists of 28 bones.
• The vertebral column is made up of 26 vertebrae.

Ear Bones

• The middle ear contains three small bones: malleus, incus, and stapes.

Cranial Bones

• Composed of the frontal, parietal, occipital, temporal, sphenoid, and ethmoid bones.

Intervertebral Disks

• Act as shock absorbers and allow flexibility, increasing the strength and resilience of the spine.

Vertebrae Distribution

• Cervical: 7 vertebrae (C1-C7)
• Thoracic: 12 vertebrae (T1-T12)
• Lumbar: 5 vertebrae (L1-L5)

Thoracic Cage Functions

• Provides protection for the heart, lungs, and major blood vessels.
• Supports the shoulder girdle and assists in breathing.

Rib Structure

• There are 12 pairs of ribs in total.
• True ribs directly attach to the sternum, while false ribs do not.
• Floating ribs have no anterior attachment.

Appendicular Skeleton

• Aids in body movement and consists of the pectoral girdle and pelvic girdle.

Pectoral Girdle

• Composed of the anterior clavicle (collarbone) and posterior scapula.

Arm and Hand Bones

• The upper arm contains the humerus.
• Forearm bones include the radius (lateral) and ulna (medial).
• Hand bones: carpals are wrist bones, metacarpals form the palm, and phalanges are the finger bones.

Pelvic Girdle Functions

• Supports body weight and protects the bladder, large intestine, and reproductive organs.

Leg and Foot Bones

• The thigh bone is the femur, while the kneecap is called the patella.
• The foot consists of tarsal (ankle), calcaneus (heel), metatarsal (midfoot), and phalanges (toes).

Joint Types

• Amphiarthrosis: Slightly movable joints (e.g., ribs).
• Diarthrosis: Freely movable joints, also known as synovial joints.
• Synarthrosis: Immovable joints, such as cranial sutures.

Bone Structure

• Diaphysis refers to the shaft of a long bone, while yellow bone marrow is found in the medullary cavity.

Jaw Bone Structure

• The maxilla forms the upper jaw, while the mandible forms the lower jaw.

Zygomatic Bones

• These bones form the cheek prominences, also known as malar bones.

Hyoid Bone

• A U-shaped bone in the neck that serves as a base for the tongue and supports muscles for swallowing.

Joint Conditions

• Arthritis: Inflammation of a joint.
• Gout: Acute arthritis caused by uric acid crystals in a joint, leading to inflammation, swelling, and pain.

Common Root Words

• arthr/o: Joint
• -osis: Condition
• dia-: Through
• epi-: Above or upon
• oste/o: Bone
• -blast: Immature cell
• -clast: To break
• -cyte: Cell