zoology exam based question

 

Q  Define simple epithelial tissue , describe structure location and function of different type of simple epithelial tissue .

ans.     Simple epithelial tissue is a type of tissue that is composed of a single layer of cells that are tightly packed together. This tissue can be found lining the cavities and surfaces of the body, where it functions to provide a protective barrier, regulate the exchange of materials between different areas, and secrete or absorb substances as needed. There are three main types of simple epithelial tissue:

Simple squamous epithelium: This tissue is composed of a single layer of flattened cells that are tightly packed together. It is found lining the walls of blood vessels, air sacs in the lungs, and the lining of body cavities. The thin, flat cells of this tissue make it ideal for allowing for rapid diffusion of gases and other small molecules across its surface.

Simple cuboidal epithelium: This tissue is composed of a single layer of cube-shaped cells that are tightly packed together. It is found lining the walls of small ducts and glands, such as those in the kidney and thyroid gland. The cells of this tissue are specialized for secretion and absorption, and their shape allows them to facilitate the movement of substances across the surface.

Simple columnar epithelium: This tissue is composed of a single layer of elongated, column-shaped cells that are tightly packed together. It is found lining the walls of the digestive tract, uterus, and uterine tubes. The cells of this tissue are specialized for absorption and secretion, and they often have microvilli or cilia on their surface to increase their surface area and facilitate movement of materials.

Pseudostratified columnar epithelium: This tissue appears to be composed of multiple layers, but is actually composed of a single layer of elongated cells of varying heights. It is found lining the respiratory tract, where it functions to move mucus and debris out of the airways.

Transitional epithelium: This tissue is found in the urinary system, specifically lining the bladder and ureters. It is capable of stretching and changing shape as the volume of urine in the bladder changes.

Simple ciliated columnar epithelium: This tissue is similar to simple columnar epithelium, but with the addition of cilia on the surface of the cells. It is found lining the respiratory tract, fallopian tubes, and some parts of the brain. The cilia help to move mucus, fluids, or particles across the surface of the tissue.

Overall, simple epithelial tissue is essential for the proper functioning of many parts of the body. It provides a protective barrier, facilitates the exchange of materials, and is involved in secretion and absorption of substances. Different types of simple epithelial tissue have unique structures and functions that allow them to perform specialized tasks in different parts of the body.

Q. Define connective tissue ,structure,  type , function, location . 

ans. Connective tissue is a type of tissue that provides support and structure to the body. It is composed of cells and extracellular matrix, which is made up of fibers and ground substance. The cells of connective tissue are often surrounded by this matrix and secrete it as well.

structure of its 

basically a connective tissue is composed of three components -; cell , fibres and matrix .

The cells of connective tissue can include fibroblasts, chondrocytes, adipocytes, and osteocytes, among others, and they are responsible for secreting and maintaining the extracellular matrix.

The extracellular matrix is made up of a combination of fibers and ground substance, which varies depending on the type of connective tissue. The fibers include collagen, elastin, and reticular fibers, which give the tissue its strength, elasticity, and support. The ground substance is composed of glycosaminoglycans, proteoglycans, and glycoproteins, which provide cushioning and hydration to the tissue.

In loose connective tissue, the fibers and cells are loosely arranged, allowing for movement and diffusion of substances. Dense connective tissue, on the other hand, has densely packed collagen fibers that provide strength and durability. Adipose tissue is composed of adipocytes, which store energy in the form of triglycerides, while cartilage and bone have a matrix that is made up of collagen fibers and other specialized components such as proteoglycans and mineralized calcium.

type of its 

Loose connective tissue: This tissue is composed of loosely arranged fibers and cells. It can be found throughout the body, where it functions to provide support and cushioning to organs, as well as allowing for the movement and diffusion of substances.

a.  Areolar ;-Areolar tissue is a type of connective tissue that is made up of loosely arranged fibers, including collagen and elastic fibers, and a gel-like ground substance. It contains a variety of cell types, including fibroblasts, macrophages, and mast cells. Areolar tissue is found throughout the body and provides support, cushioning, and flexibility to organs and tissues. It also allows for the diffusion and movement of substances, and plays a role in immune function.

b. Adipose ;- Adipose tissue, also known as fat tissue, is a type of connective tissue that is composed of adipocytes, or fat cells, which store energy in the form of triglycerides. Adipose tissue is found throughout the body, but is particularly abundant in subcutaneous tissue and around organs. It provides insulation, cushioning, and protection to organs, as well as serving as a source of energy for the body. Adipose tissue also produces hormones and signaling molecules that play a role in metabolism and inflammation.

Dense connective tissue: This tissue is composed of densely packed collagen fibers, which give it strength and durability. It is found in tendons, ligaments, and the dermis of the skin, where it provides support and stability to these structures.

a. white fibrous tissue ;-White fibrous tissue, also known as dense regular connective tissue, is made up of densely packed collagen fibers that are arranged in parallel bundles. It provides strength, durability, and resistance to stretching, and is found in structures such as tendons, ligaments, and aponeuroses. Tendons connect muscles to bones and transmit forces generated by muscle contraction, while ligaments connect bones to other bones and help stabilize joints. Aponeuroses are flat, sheet-like tendons that attach muscles to other muscles or to bone.

b. yellow elastic tissue ;- Yellow elastic tissue, also known as elastic connective tissue, is made up of elastic fibers that provide elasticity and flexibility to the tissue. It is found in structures such as the lungs, walls of blood vessels, and the vocal cords. The elastic fibers allow these structures to stretch and recoil without tearing, while still maintaining their shape and function.

Cartilage: This tissue is composed of chondrocytes, which are embedded in a matrix of collagen fibers and proteoglycans. It is found in areas such as the nose, ears, and joints, where it provides a smooth surface for movement and shock absorption.

a. Hyaline Cartilage:- Hyaline cartilage is a type of cartilage that is found in the joints, ribcage, and respiratory tract. It is made up of a gel-like matrix of collagen and proteoglycans, which provides cushioning and support to the bones and joints. Hyaline cartilage is also involved in growth and development, as it serves as a template for bone formation during ossification.

b. Elastic Cartilage:-Elastic cartilage is a type of cartilage that is found in the ears, epiglottis, and larynx. It is similar in structure to hyaline cartilage, but contains more elastic fibers, which provide greater elasticity and flexibility to the tissue. This allows the tissue to maintain its shape and function even after repeated bending and stretching.

c. Fibro Cartilage:- Fibrocartilage is a type of cartilage that is found in areas of the body where there is high stress and pressure, such as the intervertebral discs and knee joints. It is composed of a dense network of collagen fibers that are arranged in parallel bundles, which provides strength and durability to the tissue. 

d. Calcified Cartilage:-Calcified cartilage is a type of cartilage that is found in the growth plates of developing bones, as well as in areas where cartilage attaches to bone.

Bone: This tissue is composed of osteocytes, which are embedded in a matrix of collagen fibers and calcium salts. It is found in the skeleton, where it provides support, protection, and allows for movement

a. spongy bone;-Spongy bone, also known as cancellous or trabecular bone, is a porous type of bone tissue that is found at the ends of long bones, in the vertebrae, and in the flat bones of the skull. It is made up of a network of bony spicules, or trabeculae, that form a lattice-like structure.

b. compact bone ;- Compact bone, also known as cortical bone, is a dense type of bone tissue that forms the outer layer of bones and the shafts of long bones. It is made up of tightly packed osteons, which are cylindrical structures that contain layers of bone tissue surrounding a central canal.

Connective tissue has several important functions in the body, 

Providing support and structure: Connective tissue provides support and structure to the body, from the framework of the skeleton to the soft tissue structures that support and protect organs. It provides strength, stability, and shape to the body.

Facilitating movement: Many types of connective tissue are involved in facilitating movement, from tendons and ligaments that connect muscles and bones, to cartilage that provides a smooth surface for joint movement. Connective tissue also helps to absorb shock and distribute forces during movement.

Storing and transporting materials: Adipose tissue stores energy in the form of triglycerides, while bone stores calcium and other minerals. Blood, a type of connective tissue, transports oxygen, nutrients, and other important substances throughout the body.

Providing protection: Connective tissue provides protection to various organs and tissues, such as the skull protecting the brain or the dermis of the skin protecting the internal organs from environmental hazards.

Supporting immune function: Some types of connective tissue, such as lymphoid tissue, contain immune cells that help protect the body from foreign substances and pathogens