Human Anatomy Lecture 3: Basic Bone Structures

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Questions and Answers

What is the primary function of sesamoid bones?

To protect the underlying bone from friction and pressure (correct)

To provide attachment points for tendons and ligaments

To act as shock absorbers in the joints

To store fat and energy reserves

Which type of bone marrow is responsible for the production of circulating blood cells?

Neither red nor yellow bone marrow

Both red and yellow bone marrow

Yellow bone marrow

Red bone marrow (correct)

Which type of cartilage has the highest resistance to wear and tear?

Hyaline cartilage (correct)

Neither hyaline nor white fibro-cartilage

White fibro-cartilage

Both hyaline and white fibro-cartilage

Where is white fibro-cartilage typically found?

In the intra-articular discs and intervertebral discs Signup and view all the answers

What is the primary function of the air-filled cavities in the skull bones?

To reduce the weight of the skull Signup and view all the answers

How does the composition of bone marrow change as we grow and mature?

Red marrow is replaced by yellow marrow Signup and view all the answers

Which of the following is NOT a type of bone based on its shape?

Compact bone Signup and view all the answers

The medullary cavity containing bone marrow tissue is found in which type of bone?

Long bones Signup and view all the answers

Which of the following is an example of a flat bone?

Sternum Signup and view all the answers

What is the main part or shaft of a long bone called?

Diaphysis Signup and view all the answers

The bones that make up the axial skeleton include all of the following EXCEPT:

Femur Signup and view all the answers

How many bones are there in the human skeleton approximately?

206 Signup and view all the answers

Which of the following statements about the pulmonary veins is true?

They carry oxygenated blood Signup and view all the answers

What is the primary function of the lymphatic system?

To transport lymph, a fluid containing white blood cells, throughout the body Signup and view all the answers

Which of the following is NOT a component of the lymphatic system?

Pulmonary veins Signup and view all the answers

What is the role of lymph nodes?

To filter lymph from foreign particles before it returns to the bloodstream Signup and view all the answers

Which of the following is an example of a lymphatic tissue?

Thymus gland Signup and view all the answers

What are arterio-venous anastomosis?

Sites where blood is transferred from arteries to veins without passing through capillary plexus Signup and view all the answers

What is the main function of the yellow elastic cartilage?

To provide structural support and flexibility Signup and view all the answers

Which of the following is true about arteries?

They carry oxygenated blood from the heart to the body Signup and view all the answers

What is the primary function of capillaries?

To facilitate the exchange of nutrients, oxygen, and waste products Signup and view all the answers

Which of the following statements about veins is incorrect?

Veins are thin-walled blood vessels Signup and view all the answers

What is the main difference between arterioles and venules?

Arterioles have a smaller diameter than venules Signup and view all the answers

Where is the yellow elastic cartilage found in the body?

In the cartilage of the external auditory meatus and auditory tube Signup and view all the answers

Study Notes

Bone Classification

Bones can be classified according to their position in the skeleton into axial and appendicular skeleton
Axial skeleton consists of skull, mandible, hyoid bone, vertebral column, sternum, and ribs
Appendicular skeleton consists of shoulder girdles, arms, hands, pelvic girdle, thighs, and legs, and feet
The skeleton is bilaterally symmetrical and has approximately 206 bones

Bone Types

Long bones: found in extremities, have a main part (diaphysis), two ends (epiphysis), and a medullary cavity containing bone marrow tissue
Examples: Femur and humerus
Short bones: small, cuboidal in shape
Examples: Tarsals, Carpals
Flat bones: consist of two layers of compact bone with spongy or cancellous bone in between
Examples: Sternum
Irregular bones: have irregular shapes, compact bone surrounding spongy bone in between
Examples: Vertebrae

Sesamoid Bones

Developed in tendons of certain muscles at sites of friction or pressure
Examples: Patella

Pneumatic Bones

Skull bones having air-filled cavities called air sinuses
Examples: Frontal sinuses, maxilla sinuses

Bone Marrow

Soft, gelatinous tissue that fills the medullary cavities, the centers of bones
Two types: red bone marrow (myeloid tissue) and yellow bone marrow (fatty marrow)
From birth to early adolescence, the majority of bone marrow is red marrow
As we grow and mature, increasing amounts of red marrow are replaced by yellow marrow
Circulating blood cells are produced by a process known as hematopoiesis

Cartilages

Firm and resilient structure that forms a small part of the skeleton
A form of connective tissue in which the living cells (chondrocytes) are embedded in the gel matrix
Three types: hyaline cartilage, white fibro-cartilage, and yellow elastic cartilage

Hyaline Cartilage

Has great resistance to wear and tear and has a very large amount of amorphous intercellular matrix
Found at articular surfaces of the joints, epiphyseal plate of growing bones

White Fibro-Cartilage

Has a large number of collagen fiber bundles embedded in a small amount of matrix
Found at intra-articular disc of the joints, inter-vertebral discs of the vertebral column

Yellow Elastic Cartilage

Has a large number of elastic fibers embedded in the matrix
Stretchable and more resilient than other two forms of cartilage
Found at cartilage of external auditory meatus, cartilage of auditory tube

Lymphatic System

Essentially a drainage system that helps rid the body of toxins, waste, and other unwanted materials
Primary function is to transport lymph, a clear, colorless fluid, throughout the body
Consists of lymphatic tissues, lymphatic vessels, and lymph nodes

Lymphatic Tissues

Connective tissue that contains large numbers of lymphocytes, essential for the immunologic defenses of the body
Organized into organs such as thymus gland, spleen, and tonsils

Lymphatic Vessels

Consist of a network of fine vessels called lymph capillaries that drain lymph from the tissue spaces
Capillaries are in turn drained by small lymph vessels
Lymph vessels have numerous valves along their course

Lymph Nodes

Small, round or bean-shaped clusters of cells, also called lymph glands
Examples: axillary lymph nodes, inguinal lymph nodes
Inside lymph nodes, different types of immune system cells play a vital role to fight off infections and filter the lymph from all foreign particles before it returns to the bloodstream

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Description

Learn about the basic structures of bone in human anatomy with Dr. Mortadha Sami. Explore the composition of bones, including cells, fibers, and inorganic salts like calcium phosphate. Discover the classification of bones based on their position in the skeleton.