ANAT 121 Lecture 4: Skeletal System

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Questions and Answers

What is the primary function of the enlarged extremity of a long bone?

To improve blood supply to the bone

To increase the density of the bone

To increase the length of the bone

To decrease the risk of dislocation and provide a bearing surface for articulation (correct)

Which type of bone is primarily associated with the spread of pressure in specific regions?

Long Bones

Flat Bones

Short Bones (correct)

Irregular Bones

What is the role of sesamoid bones in the skeletal system?

To create additional joints

To serve as attachment points for ligaments

To alter the course of tendons where friction is greatest (correct)

To support long bones by distributing weight

What is contained in the medullary cavity of young bones?

Only red marrow Signup and view all the answers

What is the periosteum?

A layer of specialized connective tissue covering non-articular surfaces of the bone Signup and view all the answers

What is the primary function of bones in the human body?

Supports and protects soft organs Signup and view all the answers

Which type of bone is primarily found in the limbs?

Long bones Signup and view all the answers

What components primarily make up the matrix of bone tissue?

Calcium and phosphate Signup and view all the answers

Which of the following is NOT a classification of bone shape?

Circular bones Signup and view all the answers

What type of bone covers the ends of long bones?

Hyaline cartilage Signup and view all the answers

What provides the strength and flexibility of bone tissue?

Collagen Signup and view all the answers

How many bones are typically found in an adult human body?

206 Signup and view all the answers

What is the spongy bone of the skull referred to as?

Diploe Signup and view all the answers

What is the primary function of cartilage in the skeletal system?

To prevent friction and withstand shocks Signup and view all the answers

How is the matrix of cartilage different from that of bone?

It contains more collagen and less mineral than bone Signup and view all the answers

Which of the following structures is NOT part of the axial skeleton?

Pectoral limb Signup and view all the answers

What is the total number of bones in the average adult skeletal system?

319 Signup and view all the answers

What type of connective tissue attaches muscles to bones?

Tendons Signup and view all the answers

Which component of the skeletal system provides stability and prevents dislocation?

Ligaments Signup and view all the answers

What term is used to describe the bony structure in some mammals such as dogs that is found in the penis?

Os penis Signup and view all the answers

In the appendicular skeleton, how many bones are found in each limb combined?

92 in pelvic and 92 in pectoral limbs Signup and view all the answers

What is the primary function of flat bones?

For protection Signup and view all the answers

Which of the following describes pneumatic bones?

Bones that contain air cavities Signup and view all the answers

What are irregular bones primarily characterized by?

Having jutting processes Signup and view all the answers

What is the perichondrium?

Connective tissue covering cartilage Signup and view all the answers

What type of bones arise from cartilage during development?

Endochondral bones Signup and view all the answers

The endosteum serves what primary role in bones?

Lining the medullary cavities Signup and view all the answers

What is mucoperiosteum associated with?

The covering of bones related to the respiratory or digestive system Signup and view all the answers

Which type of arteries are primarily involved in supplying nutrients to bones?

Nutrient arteries Signup and view all the answers

Study Notes

Skeletal System Overview

Composed of 319 bones in adult dogs; standard adult human has 206 bones.
Three major groups: Axial, Appendicular, and Visceral.
Functions include body structure support, organ protection, and red blood cell production.

Bone Composition

1/3 organic and 2/3 inorganic materials.
Matrix rich in collagen for flexibility; minerals like calcium and phosphate provide rigidity.
Osteocytes (living cells) aid in growth and repair.

Cartilage

Flexible connective tissue found at bone ends, in the nose, ears, and trachea.
Softer and more elastic compared to bone, contains living cells.

Bone Types

Long Bones: Found in limbs, with a diaphysis (shaft) and two epiphyses (ends). Function as levers.
Short Bones: Include carpal and tarsal bones, designed to spread pressure.
Sesamoid Bones: Change tendon direction, reducing friction at joints.
Flat Bones: Provide protection; examples include the skull and ribs.
Irregular Bones: Have unique shapes, e.g., vertebrae and parts of the hip bone.

Axial Skeleton

Comprises the skull, vertebral column, ribs, and sternum.
Contains approximately 50 vertebrae and an equal number of skull bones, with 34 ribs and the sternum.

Appendicular Skeleton

Includes 92 bones in each limb (Pectoral and Pelvic).
Supports locomotion and interaction with the environment.

Bone Functionality

Provides structure and protection for organs.
Acts as levers to facilitate muscular movement.
Stores calcium and phosphorus, essential for metabolic functions.
Encloses hematopoietic cells that produce red and white blood cells.

Bone Structure

Compact bone provides strength; cancellous (spongy) bone lightens weight.
Diaphysis is the shaft housing the medullary cavity, containing red and yellow marrow.

Bone Covering and Membranes

Periosteum covers non-articular surfaces; perichondrium covers cartilaginous surfaces.
Endosteum lines medullary cavities and Haversian canals.

Development of Bone

Bones arise from two processes:
- Endochondral (replacement of cartilage)
- Membrane/Dermal (develop from connective tissue sheets).

Tendons and Ligaments

Tendons connect muscles to bones, made of strong collagen fibers.
Ligaments attach bones to other bones, composed of elastic fibers for stability and flexibility.

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Description

This quiz covers the essential aspects of the skeletal system as presented in ANAT 121 Lecture 4. It includes information on the importance of the skeletal structure, cartilage, and the composition of bones. Test your knowledge on these fundamental principles of gross anatomy.