Skeletal System: Classification and Anatomy

Questions and Answers

What determines the classification of bones?

Location

Shape

Function

All of the above (correct)

What does 'axial' refer to in the context of bones?

Found on the axis of the body.

What does 'appendicular' mean in relation to the skeletal system?

Found on appendages and girdles.

What are girdles in the skeletal system?

Pectoral and pelvic, muscle attachment. Signup and view all the answers

What is the significance of a dorsally located scapula?

It allows for a lot of movement and enables brachiation. Signup and view all the answers

What physical capability was the human body built for?

Long distance running. Signup and view all the answers

What characterizes long bones?

Longer than they are wide, with distinct ends. Signup and view all the answers

What is the structure of short bones?

Cube-like, sides of equal length. Signup and view all the answers

What are irregular bones?

Bones that do not fit into the standard categories, such as vertebrae. Signup and view all the answers

What are pneumatic bones?

Bones that contain air-filled cavities or sinuses. Signup and view all the answers

What are the functions of bones?

Support, protection, movement, mineral storage. Signup and view all the answers

What is the role of bones in mineral storage?

Storage and release of phosphate and calcium. Signup and view all the answers

What is hematopoiesis?

Blood cell formation in the marrow of bones. Signup and view all the answers

What happens to red marrow as we age?

It is replaced by yellow (fat) marrow. Signup and view all the answers

Describe the structure of compact bone.

Concentric rings that are very organized. Signup and view all the answers

What is unique about the structure of spongy bone?

It is unorganized and consists of trabeculae. Signup and view all the answers

What does PTH hormone do?

Increases calcium in blood, 'chews up' bone cells. Signup and view all the answers

What is the function of calcitonin hormone?

Decreases calcium in blood and 'makes bone' cells. Signup and view all the answers

How do cartilaginous bones develop?

Replaced by elongation due to endochondral ossification. Signup and view all the answers

How do membranous bones develop?

Fibrous membranes replaced by bone. Signup and view all the answers

Study Notes

Classification of Bones

Bones classified by location, shape, function, structure, and development type.
Two primary classifications: axial (central body axis) and appendicular (limbs and girdles).

Axial Skeleton

Comprises bones along the body’s midline, supporting the head, neck, and trunk.

Appendicular Skeleton

Includes bones of the limbs (appendages) and girdles connecting them to the axial skeleton.
Girdles are composed of pectoral (shoulder) and pelvic (hip) structures, aiding in muscle attachment.

Scapula Functionality

Dorsally positioned scapula provides extensive movement, enabling arm brachiation.
Ball-and-socket joint structure allows for a wide range of motion, with potential issues arising from arthritis.

Human Locomotion

Human body adapted for endurance in long-distance running.
Plantigrade locomotion means entire foot contacts the ground, increasing friction during movement.

Types of Bones

Long bones: Longer than wide, with distinct ends (proximal and distal) and a central shaft.
Short bones: Cube-like, with equal length sides, providing stability.
Irregular bones: Do not fit into the above categories; examples include vertebrae, sphenoid, and pelvis.
Pneumatic bones: Feature air-filled cavities (sinuses), aiding in weight reduction and vocal resonance.

Bone Functions

Provide structural support for organs and protect vital systems (brain, viscera, spinal cord).
Facilitate movement through attachment to skeletal muscles.

Mineral Storage

Bones store and release minerals like phosphorus and calcium, regulated by hormones (PTH and calcitonin).
Bone health is linked to cardiovascular health.

Hematopoiesis

Blood cell formation occurs in bone marrow, predominantly in flat bones during adulthood, while all bones contribute in juveniles.

Triglyceride Storage

With aging, red marrow is replaced by yellow marrow (fat storage).

Bone Structures

Compact bone: Organized structure with concentric rings for strength.
Spongy bone: Unorganized structure composed of trabeculae, housing blood supply.

Hormonal Regulation of Calcium

Parathyroid hormone (PTH): Released from the parathyroid gland, increases blood calcium levels by promoting bone resorption.
Calcitonin: Produced in the thyroid gland, lowers blood calcium levels by promoting bone formation.

Bone Development

Cartilaginous bones: Develop via hyaline cartilage models, with elongation through endochondral ossification; typical of long bones.
Membranous bones: Formed from fibrous membranes replaced by bone, through intramembranous ossification; characteristic of flat bones.

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Description

This quiz explores the classification and anatomy of the skeletal system. It covers various terms related to bone classification, including axial and appendicular skeletons, as well as the significance of girdles. Enhance your understanding of skeletal structures and their functions.