Question

Read the following statements and select the correct option. Statement 1 : Bone and cartilage are rigid connective tissues. Ire Statement \(2:\) Blood is a connective tissue \(_{\text {with }}\) (plasma) matrix. (a) Both statements 1 and 2 are correct and statement 2 is the correct explanation of statement 1 . (b) Both statements 1 and 2 are correct but statement is not the correct explanation of statement 1 (c) Statement 1 is correct and statement 2 is incorrect (d) Both statements 1 and 2 are incorrect.

Short answer

Both statements are correct; however, Statement 2 does not explain Statement 1. The correct answer is (b).

Step-by-step solution

Assess Statement 1

Determine the accuracy of Statement 1. Bone and cartilage are indeed types of rigid connective tissues. They provide structure and support to the body. Bones are hard and dense, mostly due to the presence of calcium compounds, while cartilage is more flexible and provides cushioning in joints.

Assess Statement 2

Evaluate the correctness of Statement 2. Blood is a fluid connective tissue, not rigid as bones and cartilage, comprising a liquid matrix called plasma. It contains blood cells and platelets which are suspended within the plasma matrix.

Determine the Relationship between the Statements

Analyze if Statement 2 is the correct explanation for Statement 1. Statement 2 describes blood as a connective tissue with a liquid matrix, which is correct, but it is not an explanation for the rigidity of bone and cartilage.

Select the Correct Option

Given that both Statement 1 and Statement 2 are correct but Statement 2 is not the correct explanation of Statement 1, the correct option is (b).

Key concepts

Bone Structure

Bones are a remarkable component of the vertebrate skeletal system, serving numerous roles from providing structural support to facilitating movement. The complexity of bone structure is astounding; bones are composed of a rigid matrix that is primarily made up of collagen fibers – a type of protein that provides strength and a little flexibility – and hydroxyapatite, which is a mineral compound consisting largely of calcium and phosphate. These elements combine to give bones exceptional hardness and the capability to withstand stress.

Inside bones, there is a softer, spongy tissue known as marrow, which is involved in the production of blood cells. Bone tissue is also dynamic; it continually remodels and repairs itself through cells called osteoblasts, which build bone, and osteoclasts, which break bone down. This balance is crucial for maintaining the bone mass and inherent strength that protect our internal organs and anchor muscles.

Anatomy of a Bone

When examining the anatomy of a bone, we can see it's composed of two main layers: the compact bone, which is the dense outer layer, and the cancellous or spongy bone, filled with marrow, that lies within. The compact bone houses the Haversian system, which includes channels for blood vessels and nerves, critical for maintaining bone health.

Cartilage Function

Cartilage is another essential type of connective tissue which differs markedly from bone. It is less rigid and more flexible, which is imperative for its role in the body. Cartilage is found in various places such as the ear, nose, and joints, where it serves crucial functions. In joints, cartilage acts as a shock absorber and reduces friction during movements – imagine it as a cushion between bones that prevents them from grinding against each other.

Composed of chondrocytes, the cells responsible for producing cartilage, this tissue lacks blood vessels, nerves, and a lymphatic system, which is why it's slower to heal than other tissues when injured. In growing children and adolescents, cartilage helps in the formation of long bones and is an integral part of the growth plates – areas at the ends of long bones where new bone is formed during growth spurts.

Types of Cartilage

There are three types of cartilage: hyaline, which is the most common and found on many joint surfaces; elastic, which gives structure to the ear and epiglottis; and fibrocartilage, which is tough and found between vertebrae and in the meniscus of the knee.

Blood Composition

Blood, the life-sustaining fluid that courses through our veins and arteries, is indeed a connective tissue. This categorization may seem odd given that it's liquid, but it’s due to its integral role in connecting the body systems by transporting vital substances. Blood is composed of a liquid matrix known as plasma and cellular components that float within it.

Plasma makes up about 55% of blood and is primarily water, but it also contains proteins, glucose, electrolytes, hormones, and waste products. The cellular components, which constitute the remaining 45%, include red blood cells (erythrocytes), white blood cells (leukocytes), and platelets (thrombocytes).

Functions of Blood

Red blood cells are tasked with carrying oxygen from the lungs to the rest of the body and returning carbon dioxide for exhalation. White blood cells are the warriors of the immune system, defending against infection. Platelets play a crucial role in blood clotting, stopping bleeding and allowing for healing to occur. Altogether, blood not only supports the immune response and transports nutrients and waste products but also regulates body temperature and pH balance, showcasing its indispensability to health and life.