Animal Tissues: Epithelial, Connective, Muscular, Nervous - PDF

Animal Tissues (Epithelial, Connective, Muscular, Nervous) Structure and Function When discussing structure and function, biologists distinguish anatomy from physiology. ⮚ Anatomy is the study of the form of an organism’s structures - A biologist interested in anatomy, for instance, might...

Animal Tissues (Epithelial, Connective, Muscular, Nervous) Structure and Function When discussing structure and function, biologists distinguish anatomy from physiology. ⮚ Anatomy is the study of the form of an organism’s structures - A biologist interested in anatomy, for instance, might focus on the arrangement of muscles and bones. ⮚ Physiology is the study of the functions of those structures. - A physiologist might study how muscles function. Tissue A tissue consists of a group of closely associated, similar cells that carry out specific functions. Types of Tissues  4 types of Animal Tissues ❑ Epithelial Tissue ❑ Connective Tissue ❑ Muscular Tissue ❑ Nervous Tissue The Epithelial Tissue 1. Epithelial Tissue ❑ forms the covering or lining of free body surfaces, both internal and external. ⮚ ex. outer layer of the skin is formed from epithelial tissue as are the inner lining of the digestive tract and blood vessels. 1. Epithelial Tissue ❑How is it nourished? Epithelium is an Avascular tissue Nutrients and water reach cells through Diffusion so, gases and nutrients that reach the epithelium must diffuse across the basement membrane from underlying tissues. 1. Epithelial Tissue ❑ Functions: Protection, absorption, excretion, secretion, and lubrication. ❑FEATURES: ▪ Basement Membrane - separates Epithelium from underlying connective tissue; - it is a non-cellular membrane (polysaccharide rich membrane) According to number of cell layers: 1. Simple epithelium 2. Stratified epithelium 3. Pseudo stratified epithelium 4. Transitional epithelium According to cell shape: 1. Squamous 2. Cuboidal 3. Columnar  Simple squamous epithelium ❑ STRUCTURE ⮚ single layer of thin flat cells. ❑ FUNCTION ⮚Allows passage of materials by diffusion and filtration in sites where protection is not important; secretes lubricating substances in serosae. Simple squamous epithelium ❑LOCATION ⮚Kidney tubules, air sacs of lungs, lining of heart, blood vessels, and lymphatic vessels; lining of ventral body cavity(serosae).  Simple cuboidal epithelium ❑ STRUCTURE ⮚Single layer of cubed shape cells; some cells have microvilli (kidney tubules) or cilia (terminal bronchioles of lungs). ❑ FUNCTION ⮚Secretion and absorption by cells of kidney tubules. ⮚Movement of mucus- containing particles out of the terminal bronchioles by ciliated cells. Simple cuboidal epithelium ❑LOCATION ⮚Kidney tubules, glands & their ducts, choroid plexus of the brain, terminal bronchioles of lungs, and surface of ovaries and retina.  Simple columnar epithelium ❑ STRUCTURE ⮚Single layer of tall, narrow cells; some have microvilli and cilia. ❑ FUNCTION ⮚Secretion by cells of stomach, intestines, and glands. ⮚Absorption by cells of intestine. ⮚Movement of mucus by ciliated cells that clear the lungs; movement of egg through the uterine tubes. Simple columnar epithelium ❑LOCATION ⮚Stomach, intestines, glands, some ducts, bronchioles of lungs, auditory tubes, uterus, and uterine tube. Stratified squamous epithelium ❑ STRUCTURE ⮚Many layers of cells in which the basal layer is cuboidal and becomes flattened at the free surface. ❑ FUNCTION ⮚Protection against abrasion and infection. Stratified squamous epithelium ❑LOCATION ⮚Skin, mouth, throat, esophagus, anus, vagina, and cornea. Stratified cuboidal epithelium ❑ STRUCTURE ⮚Generally two layers of cubelike cells. ❑ FUNCTION ⮚Protective tissue Stratified cuboidal epithelium ❑LOCATION ⮚Largest ducts of sweat glands, mammary glands, and salivary glands.  Stratified columnar epithelium ❑ STRUCTURE ⮚ It consists of a top layer of elongated cells, and lower layers of cubeshaped cells ❑ FUNCTION ⮚protection and secretion Stratified cuboidal epithelium ❑LOCATION ⮚Rare in the body; small amounts in male urethra and in large ducts of some glands  Pseudo stratified epithelium ❑ STRUCTURE ⮚Single layer of cells; some are tall and thin. ⮚The nuclei & at different levels appears stratified. ❑ FUNCTION ⮚Movement of mucus (or fluid) that contains foreign particles. Pseudo stratified epithelium ❑LOCATION ⮚Nasal cavity, nasal sinuses, auditory tubes, pharynx, larynx, trachea, and bronchi of lungs.  Transitional epithelium ❑ STRUCTURE ⮚Stratified cells that appear cube-like when the organ or tube is relaxed and appear squamous when the organ or tube is distended by fluid. ❑ FUNCTION ⮚Accommodation by fluid fluctuation in an organ or tube; protection against the caustic effects of urine. Transitional epithelium ❑LOCATION ⮚Urinary bladder, ureters, and superior urethra. The Connective Tissue 2. Connective Tissue ❑Fibrous tissue ❑cells surrounded by large amounts extracellular material. ❑Functions: ⮚Hold other tissues together. ⮚Provide supporting framework of the body. ⮚Transport substances. ex. BLOOD Types of Connective Tissue  Loose or areolar ❑ STRUCTURE ⮚Cells (fibroblast, macrophages, and lymphocytes) within a fine network of mostly collagen fibers; the cells and fibers are separated from each other by fluid-filled spaces. ❑ LOCATION ❑ FUNCTION ⮚Widely distributed throughout the body, it is the substance on ⮚Loose packing, support, and which most epithelial tissue nourishment for the structures rests. It is the packing with which it is associated. between glands, muscles, nerves and attaches the skin (dermis) to underlying tissues.  Dense connective tissue ❑ STRUCTURE ⮚ Matrix consist entirely of collagen fibers produced by fibroblast. The fibers can all be oriented in the same direction (tendons and ligaments), or in many different directions (dermis and capsules). ❑ FUNCTION ⮚Able to withstand great pulling forces in the direction of fiber orientation. ❑ LOCATION ⮚ Tendons (attached muscle to bones) ⮚ ligaments (attached bone to bones) ⮚ dermis of skin, and organ capsule.  Adipose tissue ❑ STRUCTURE ⮚Little extracellular material between adipose cells; the cells are so full of lipids and the cytoplasm is pushed to the periphery of the cell. ⮚“fat tissue” ❑ FUNCTION ⮚Energy storage, packing material that provides protection, and heat insulator. ❑ LOCATION ⮚Under skin, around organs such as the heart and kidneys, in the breast, and in bones.  Cartilage ❑ STRUCTURE ⮚Solid matrix with fibers dispersed throughout the ground substance. ⮚Chondrocytes are found within lacunae. ❑ FUNCTION ⮚Hyaline cartilage forms a smooth surface joints, a site of bone growth, and embryonic skeleton. Fibrocartilage can withstand great pressure, and elastic cartilage returns to original shape when bent. Cartilage ❑ LOCATION ⮚Hyaline cartilage found in ribs, respiratory tract, end of bones, embryonic skeleton. ⮚Fibrocartilage found in intervertebral disks, symphysis pubis and articular disk of knees. ⮚Elastic cartilage found in external ear.  Bone tissue ❑ STRUCTURE ⮚Hard, mineralized matrix with osteocytes located within lacunae. ⮚Surrounded by collagen and calcium ❑ FUNCTION ⮚Provides great strength and support and protects internal organs such as the LOCATION brain. ⮚Bones.  Blood ❑ STRUCTURE ⮚Blood cells with in fluid matrix called plasma. ❑ FUNCTION ⮚Transport oxygen, carbon dioxide, hormones, nutrients, waste products, and other substances. LOCATION ⮚Protects the body from ⮚Within the blood infection and is involved in vessels and the heart. temperature regulation. Elastic Connective Tissue ❑ STRUCTURE ⮚Branching elastic fibers interspersed with fibroblasts ❑ FUNCTION ⮚Confers elasticity ❑ LOCATION ⮚Framework of liver; lymph nodes; spleen Reticular Connective Tissue ❑ STRUCTURE ⮚Consists of interlacing reticular fibers ❑ FUNCTION ⮚Support ❑ LOCATION ⮚Structures that must both expand and return to their original size, such as lung tissue and large arteries The Muscular Tissue 3. Muscular Tissue ⮚ Functions to produce force and cause motion, either locomotion or movement within internal organs ⮚Comprised of contractile proteins 3. Muscular Tissue ⮚ Contractile proteins ▪ Actin and Myosin ▪ Found in cytoplasm of muscle cells 3. Muscular Tissue ⮚ Characteristics of muscle cells ▪ Found aggregated into bundles ▪ Elongated and found oriented w/ their long axes in the same direction ▪ Cells’ nuclei are arranged in parallel orientation to the elongation of these cells 3. Muscular Tissue ⮚ the ability to contract or shorten, making movements possible. Types: ❑ CARDIAC MUSCLE ❑ SKELETAL MUSCLE ❑ SMOOTH MUSCLE Types of Muscular Tissue CARDIAC MUSCLE ❑STRUCTURE ⮚Cylindrical in shaped and striated, and have a single nucleus. ⮚The cells are branched and are connected to other by intercalated disk. ❑FUNCTION ⮚Responsible for pumping of blood. ❑LOCATION ⮚Muscle of the heart  SKELETAL MUSCLE ❑STRUCTURE ⮚Are cylindrical in shape, striated, and multinucleated. ⮚Attaches to bone and normally thought as a "muscle". ⮚It is the meat of an animals comprises 40 % of person's body weight. ❑FUNCTION ❑LOCATION ⮚Body movements ⮚between skin and bones. (voluntary control).  SMOOTH MUSCLE ❑ STRUCTURE ⮚Also known as “visceral muscle tissue” ⮚Tapered at each end, not striated, and have a single nucleus. ❑ FUNCTION ⮚Responsible for pumping of blood under involuntary control. ⮚Movement of food through digestive tract. ⮚Emptying the urinary bladder. ❑LOCATION ⮚Muscle of the heart, skin, eyes, G.I. tract The Nervous Tissue 4. Nervous Tissue ⮚Forms the brain, spinal cord, and nerves. ❑Functions: ⮚Responsible for coordinating and controlling many of the body's activities. ex. conscious control of skeletal muscles and unconscious regulation of cardiac muscle. ⮚Awareness to external environment, emotions, reasoning skills, and memory. action potential- communication of nervous tissue to each other by electrical signals. 4. Nervous Tissue ❑Cells that comprise the central nervous system and peripheral nervous system; ❑Neurons and supporting cells associated to neurons ❑CNS-brain and spinal cord ❑PNS-cranial nerves and spinal nerves, inclusive the motor nerves ❑Responsible for movement, sensing and thinking (cells are able to transmit messages between them) FUNCTIONS ❑ Sensory input- nerve cells receive and process information from external environment ❑ Integration –neurons are able to transmit electrical impulses from one site in the body to another. They are also able to integrate those impulses ❑ Homeostasis- body’s ability to regulate it’s inner environment to ensure stability every time there is a change in the external environment ❑ Mental Activity- brain is comprised of nervous tissue 4. Nervous Tissue contains........ ❑NEURONS or nerve cell. ⮚Responsible for action potential conduction and support cells. ⮚Has processes which are used to communicate/interact with other nerve cells or with epithelial and muscle cells ❑NEUROGLIA ⮚support cells of the nervous system. ⮚function to nourish, protect (surround the axon), and insulate neurons.  Types of NEURONS according to Function ❑Sensory neurons (afferent) ❑Detect changes in the environment (stimuli) ❑Transmit information to the brain and spinal cord ❑Motor neurons (efferent) ❑Sent signals from CNS to muscles and glands (effectors) ❑Organs that carry out responses are called effectors ❑Interneurons ❑Lie between sensory and motor pathways in CNS ❑Process, store and retrieve information ❑90% of our neurons are interneurons Neuron Parts of Neurons ❑Dendrite ⮚are nerve cell processes (extensions). ⮚received action potential and conduct them toward the cell body. ❑Cell body ⮚contains nucleus and is the site of general cell functions. ❑Axon ⮚are nerve cell processes (extensions). ⮚usually conducts action potentials away from cell body. ⮚only 1 per neuron is present.