The Structure of skin is the largest organ of the body and serves multiple essential functions. It is composed of three main layers, each with distinct structures and roles. Epidermis: The outermost layer of the skin, composed mainly of keratinocytes, which produce the protein keratin. Layers of the Epidermis: Stratum Corneum: The topmost layer, made … Read more
The integumentary system includes the skin, hair, nails, and glands, playing a crucial role in protection, sensation, temperature regulation, and more. Key Components of Integumentary System Skin The largest organ, with three layers: Epidermis: Outermost layer, protective barrier, contains melanocytes for skin color and UV protection. Dermis: Middle layer with connective tissue, blood vessels, nerve … Read more
Nervous tissue is a highly specialized tissue that forms the nervous system, responsible for coordinating and controlling many body activities. It consists of neurons and supporting cells known as neuroglia or glial cells. Nervous tissue is essential for sensing stimuli, transmitting signals, and regulating bodily functions Structure of Nervous Tissue 1. Neurons Cell Body (Soma): … Read more
Muscle tissue is a specialized tissue found in animals which functions by contracting and thereby causing movement. This contraction is achieved through the interaction of actin and myosin filaments within muscle cells, known as muscle fibers. Muscle tissue is categorized into three types: skeletal muscle, cardiac muscle, and smooth muscle, each with distinct structures and … Read more
Connective tissues provide support, protection, and structure to the body. Types of Connective Tissues Loose Connective Tissue Areolar Tissue Structure: Contains a loose arrangement of fibers and various cell types. Location: Widely distributed under epithelia, surrounds capillaries. Function: Provides cushioning, binds tissues, and allows for nutrient diffusion. Adipose Tissue Structure: Comprised mainly of adipocytes filled … Read more
Epithelial tissues cover body surfaces, line cavities and form glands. They function in protection, secretion, absorption, and transportation. Epithelial tissues are classified based on the number of cell layers and cell shape Simple Epithelium tissue Single layers of cells primarily functions in absorption, secretion, and filtration. Types Simple Squamous Epithelium Structure: Single layer of flat … Read more
Intracellular signalling refers to the communication between cells using signalling molecules and cellular pathways. These signals allow cells to respond to their environment and coordinate their functions. There are several forms of intracellular signalling, which can be classified based on the mode of signal transmission: Contact-dependent signalling In this form of signalling, the signalling molecule … Read more
Intracellular signalling pathways are activated by extracellular signal molecules, which allow cells to respond and adapt to changes in their environment. The process of activating an intracellular signalling pathway typically involves the following steps: Signal Generation A signalling molecule (ligand) is produced and released by a signalling cell in response to a specific stimulus. Signal … Read more
Cell communication is a vital process in multicellular organisms that allows cells to coordinate their activities, respond to changes in their environment, and maintain homeostasis. The general principles of cell communication can be summarized in the following step Signal generation In response to a stimulus, a signalling molecule or ligand is produced and released by … Read more
Cell junctions are specialized structures that connect cells to each other or to the extracellular matrix. These junctions play crucial roles in maintaining the integrity and function of tissues by allowing communication between cells, holding cells together, and regulating the passage of molecules between them. There are three main types of cell junctions: Tight Junctions … Read more