Anatomy Chapter 6 Flashcards

Questions and Answers

Describe the axial and appendicular divisions of the skeleton

The axial skeleton is composed of the bones of the skull, thorax, and vertebral column, containing a total of 80 bones. The appendicular skeleton includes the bones of the limbs and the pectoral and pelvic girdles, containing a total of 126 bones.

Identify the functions of the skeletal system

The skeletal system supports the body, stores minerals and lipids, produces blood cells, protects delicate organs and tissues, and functions as levers for movement.

Identify the six broad categories for classifying a bone according to shape

The six broad categories for classifying bones according to shape are flat bones, sutural (wormian) bones, long bones, irregular bones, sesamoid bones, and short bones.

Define bone marking

Bone markings (surface features) are characteristics of a bone's surface that have certain functions, such as forming a joint or serving as a site for muscle, tendon, or ligament attachment. Signup and view all the answers

List the major parts of a long bone

The major parts of a long bone are the epiphysis, metaphysis, diaphysis, and medullary cavity. Signup and view all the answers

Describe the functions of the medullary cavity

The medullary cavity contains red bone marrow, which is the site of blood cell production, and yellow bone marrow, which is adipose tissue important for energy reserves. Signup and view all the answers

Where is articular cartilage found, and how is it nourished?

Articular cartilage covers the epiphyseal portions of bones that articulate with other bones. It is avascular and obtains nourishment by diffusion from synovial fluid within the joint. Signup and view all the answers

Why are bone injuries usually painful?

Bone injuries are usually painful because of the extensive presence of sensory nerves within the periosteum, diaphysis, medullary cavity, and epiphyses. Signup and view all the answers

Describe the functions of osteogenic cells and osteoblasts

Osteogenic cells are stem cells that form osteoblasts. Osteoblasts are immature bone cells that secrete the organic components of the bone matrix. Signup and view all the answers

Describe the functions of osteocytes

Osteocytes are mature bone cells that maintain the bone matrix and participate in repairing damaged bone. Signup and view all the answers

How would the compressive strength of a bone be affected if the ratio of collagen to hydroxyapatite increased?

If the ratio of collagen to hydroxyapatite in a bone increased, the bone's compressive strength would decrease, and the bone would also become more flexible. Signup and view all the answers

If osteoclast activity exceeds osteoblast activity in a bone, how will the bone mass be affected?

If the activity of osteoclasts exceeds osteoblast activity, then the bone's mineral content and mass would decrease, making the bone weaker. Signup and view all the answers

Define osteon

An osteon is the basic functional unit of mature compact bone; it consists of osteocytes organized around a central canal and separated by concentric lamella. Signup and view all the answers

Compare compact bone and spongy bone

Compact bone consists of compactly arranged osteons, protects, supports, and resists stress, while spongy bone makes up most of the volume of short, flat, and irregular bones, stores marrow, and provides some support. Signup and view all the answers

Define appositional growth

Appositional growth is an increase in bone diameter that occurs through the addition of bony matrix at the bone's surface. Signup and view all the answers

As a bone increases in diameter, what happens to the medullary cavity?

As a bone increases in diameter, the medullary cavity also increases in diameter. Signup and view all the answers

Distinguish between the periosteum and the endosteum

The periosteum is the superficial layer that surrounds a bone, consisting of an outer fibrous layer and an inner cellular layer, while the endosteum is an incomplete cellular lining on the inner (medullary) surfaces of bones. Signup and view all the answers

Define endochondral ossification

Endochondral ossification is the replacement of a cartilage model with bone. Signup and view all the answers

Study Notes

Axial and Appendicular Skeleton

The axial skeleton includes 80 bones, consisting of the skull, thorax, and vertebral column.
The appendicular skeleton comprises 126 bones, including limbs and pectoral and pelvic girdles.

Functions of the Skeletal System

Provides support and structure to the body.
Stores minerals and lipids, contributing to energy reserves.
Produces blood cells within bone marrow.
Protects vital organs and tissues.
Serves as levers for movement, facilitating physical activity.

Bone Classification by Shape

Bones are categorized into six types:
- Flat bones
- Sutural (wormian) bones
- Long bones
- Irregular bones
- Sesamoid bones
- Short bones

Bone Markings

Surface features have specific functions, such as:
- Forming joints
- Serving as attachment sites for muscles, tendons, and ligaments
- Allowing passage for nerves and blood vessels

Major Parts of a Long Bone

Key components include:
- Epiphysis (ends of bone)
- Metaphysis (transitional region)
- Diaphysis (shaft)
- Medullary cavity (central space)

Functions of the Medullary Cavity

Houses red bone marrow for blood cell production.
Contains yellow bone marrow, which is adipose tissue for energy storage.

Articular Cartilage and Nutrition

Articular cartilage covers the ends of bones at joints, aiding in smooth movement.
It is nourished by diffusion from synovial fluid due to its avascular nature.

Pain Induction from Bone Injuries

Bone injuries cause pain because of abundant sensory nerve presence in periosteum, diaphysis, medullary cavity, and epiphyses.

Osteogenic Cells and Osteoblasts

Osteogenic cells are stem cells that develop into osteoblasts.
Osteoblasts are immature bone cells that function in the secretion of the bone matrix.

Functions of Osteocytes

Osteocytes are mature bone cells responsible for maintaining bone matrix.
They play a role in the repair of damaged bone.

Effect of Collagen to Hydroxyapatite Ratio

An increased ratio of collagen to hydroxyapatite reduces compressive strength and enhances flexibility of bone.

Osteoclasts vs. Osteoblasts Activity

If osteoclast activity surpasses osteoblast activity, bone mass decreases, leading to weaker bones due to reduction in mineral content.

Definition of Osteon

An osteon is the fundamental functional unit of mature compact bone, organized around a central canal and separated by concentric lamellae.

Comparison of Compact Bone and Spongy Bone

Compact bone comprises tightly arranged osteons, serving to protect, support, and resist stress, forming the diaphysis of long bones.
Spongy bone is less dense, located in the interiors of short, flat, and irregular bones, primarily for marrow storage and structural support.

Appositional Growth

Appositional growth refers to the increase in bone diameter through the addition of new bone matrix on the surface.

Medullary Cavity and Bone Diameter

As bone diameter increases, the medullary cavity also enlarges to accommodate structural changes.

Periosteum vs. Endosteum

The periosteum is the external protective layer of bone, made of an outer fibrous layer and an inner cellular layer.
The endosteum is a thin cellular lining covering the internal surfaces of bones.

Endochondral Ossification

Endochondral ossification is the process where a cartilage model is replaced by bone tissue during development.

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Description

Test your knowledge of the skeletal system with these flashcards from Chapter 6. You will learn about the axial and appendicular divisions of the skeleton, as well as the key functions of the skeletal system. Great for reinforcing anatomy concepts and preparing for exams.