Define Cell:
- The cell is the basic structural, functional, and biological unit of all known organisms.
- A cell is the smallest unit of life. Cells are often called the “building blocks of life”.
- The study of cells is called cell biology, cellular biology, or cytology.
- Cells provide six main functions.
- They provide structure and support, facilitate growth through mitosis, allow passive and active transport, produce energy, create metabolic reactions and aid in reproduction.
Define Tissue:
- The term tissue is used to describe a group of cells found together in the body.
- The cells within a tissue share a common embryonic origin.
Although there are many types of cells in the human body, they are organized into four broad categories of tissues: epithelial, connective, muscle, and nervous. - There are 4 basic types of tissue: connective tissue, epithelial tissue, muscle tissue, and nervous tissue.
- Connective tissue supports other tissues and binds them together (bone, blood, and lymph tissues).
- Epithelial tissue provides a covering (skin, the linings of the various passages inside the body)
Define cartilage:
- Cartilage is an avascular, flexible connective tissue located throughout the body that provides support and cushioning for adjacent tissues.
- Cartilage is a flexible connective tissue that keeps joint motion fluid by coating the surfaces of the bones in our joints and by cushioning bones against impact.
- It is not as rigid as bone, but is stiffer and less flexible than muscle tissue.
- There are three types of cartilage:
- Hyaline – most common, found in the ribs, nose, larynx, trachea. Is a precursor of bone.
- Fibro- is found in intervertebral discs, joint capsules, ligaments.
- Elastic – is found in the external ear, epiglottis and larynx.
Define Bone:
- A bone is a rigid organ that constitutes part of the vertebrate skeleton in animals.
- Bones protect the various organs of the body, produce red and white blood cells, store minerals, provide structure and support for the body, and enable mobility.
- The conventional function of the skeleton is as a static structural organ supporting body movement, protecting the internal organs, and as a reservoir of minerals.
- Cellular components:
- Osteoblasts (bone forming cells),
- osteocytes (inactive osteoblasts),
- osteoclasts (cells that reabsorb the bone).
- The 7 functions of bone:
- Support: Bones provide a framework that supports the body and cradles its soft organs.
- Protection :The fused bones of the skill protect the brain.
- Anchorage.
- Mineral and Growth factor storage.
- Blood Cell Formation.
- Triglyceride (Fat) storage.
- Hormone production.
Define Muscular Tissue:
- Muscle tissue consists of elongated cells also called as muscle fibers. This tissue is responsible for movements in our body.
- Muscles contain special proteins called contractile protein which contract and relax to cause movement.
- Muscle tissues vary with function and location in the body.
- Each of these muscles is a discrete organ constructed of skeletal muscle tissue, blood vessels, tendons, and nerves.
- Muscle tissue is also found inside of the heart, digestive organs, and blood vessels.
- In these organs, muscles serve to move substances throughout the body.
- Types of Muscle Tissue:
- Skeletal Muscle Tissue
- Cardiac Muscle Tissue
- Smooth Muscle Tissue.
Define Nervous Tissue:
- Nervous tissue is found in the brain, spinal cord, and nerves.
- It is responsible for coordinating and controlling many body activities.
- The cells in nervous tissue that generate and conduct impulses are called neurons or nerve cells.
- These cells have three principal parts: the dendrites, the cell body, and one axon.
- Nervous tissue contains two categories of cells — neurons and neuroglia.
Define Epithelium
- The outside layer of cells that covers all the free, open surfaces of the body including the skin, and mucous membranes that communicate with the outside of the body.
- Layer of cells closely bound to one another to form continuous sheets covering surfaces that may come into contact with foreign substances.
- By contrast the endothelium is the layer of cells lining the closed internal spaces of the body such as the blood vessels and lymphatic vessels.
- Epithelium may be protective, absorptive, or secretory.
- It may produce special outgrowths (hairs, nails, horns on animals), and manufacture chemical material (e.g., keratin).
Define Skin:
- Skin is the largest organ in the body and covers the body’s entire external surface.
- It is made up of three layers, the epidermis, dermis, and the hypodermis, all three of which vary significantly in their anatomy and function.
- The skin’s structure is made up of an intricate network which serves as the body’s initial barrier against pathogens, UV light, and chemicals, and mechanical injury.
- The skin is primarily made up of three layers.
- The upper layer is the epidermis, the layer below the epidermis is the dermis, and the third and deepest layer is the subcutaneous tissue.
- The epidermis, the outermost layer of skin, provides a waterproof barrier and contributes to skin tone.
- The bottom or deepest layer of the skin is Hypodermis.
Define Histology:
- Histology is the science of the microscopic structure of cells, tissues and organs.
- It also helps us understand the relationship between structure and function.
- Microanatomy or microscopic anatomy, The study of cells and tissues, from their intracellular components to their organization into organs and organ systems.
CATHERINE SHALINI RAJA
M.P.T.,MIAP.,PGDYN
CARDIO RESPIRATORY PHYSICAL THERAPIST
FITNESS & SPORTS REHABILITATION SPECIALIST.
