Animal Tissues Structures and Functions PDF

STRUCTURES AND FUNCTIONS ANIMAL TISSUES  Cells group together to form tissues and tissues combine to form organs  Just like cells vary according to their functions, tissues also differentiate and broadly classified into four types FOUR TYPES OF ANIMAL TISSUES EPITHELIAL TISSUE (COVERING)...

STRUCTURES AND FUNCTIONS ANIMAL TISSUES  Cells group together to form tissues and tissues combine to form organs  Just like cells vary according to their functions, tissues also differentiate and broadly classified into four types FOUR TYPES OF ANIMAL TISSUES EPITHELIAL TISSUE (COVERING)  tightly-joined/ closely-packed cells  one side of epithelium exposed to air or internal fluid, other side attached to a basement membrane, a dense mat of extracellular matrix (connective tissue)  commonly seen outside the body as coverings or linings of organs and cavities  barrier against mechanical injury, invasive microorganisms, and fluid loss  provides surface for absorption, excretion and transport of molecules Ex. skin, lining of the mouth & nose, lining of digestive system TYPES OF EPITHELIAL TISSUE  Cell shape  Squamous  Cuboidal  Columnar  Number of cell layers  Simple  Stratified  Pseudostratified  RELATE STRUCTURE TO FUNCTION! CELLS THAT MAKE UP EPITHELIAL TISSUES CAN HAVE A DISTINCT ARRANGEMENT:  Simple Cuboidal – The tissue is made of cube-shaped cells, it is for secretion.  Ex. surface of ovaries, lining of nephrons, walls of the renal tubules, parts of the eye and thyroid, and in salivary glands CELLS THAT MAKE UP EPITHELIAL TISSUES CAN HAVE A DISTINCT ARRANGEMENT:  Simple columnar – brick-shaped cell; for secretion and active absorption  Ex. Lining of digestive tract – stomach and intestines; also with uterine lining CELLS THAT MAKE UP EPITHELIAL TISSUES CAN HAVE A DISTINCT ARRANGEMENT:  Simple squamous - plate-like cells; for exchange of material through diffusion  Ex. skin, capillary walls, glomeruli, pericardial cavity in the heart, pleural and alveolar lining in the lung, and peritoneal cavity CELLS THAT MAKE UP EPITHELIAL TISSUES CAN HAVE A DISTINCT ARRANGEMENT:  Stratified squamous -multilayered and keratinized surface (w/c makes it impermeable and dry) that regenerates quickly; for protection  Ex. skin, palm, sole of foot, and masticatory mucosa CELLS THAT MAKE UP EPITHELIAL TISSUES CAN HAVE A DISTINCT ARRANGEMENT:  Pseudo-stratified columnar - single layer cells; may just look stacked because of varying height; for lining of respiratory tract; usually lined with cilia.  Ex. Nasal passage, trachea, bronchi, inner ear, vas deferens, prostate gland, epididymis, endometrium CONNECTIVE TISSUE (FRAMEWORK)  made up of fibrous cells  Main Function: binding and support other tissues  connective tissue cells secrete large amount of extracellular matrix (non-living matter) with fewer cells  extracellular matrix consists of network of fibers in liquid, jelly-like or solid matrix  these part helps hold other tissues together during the formation of organs (ability to stretch and contract) EXAMPLE OF CONNECTIVE TISSUES  Blood is made up of plasma (liquid extracellular matrix) that contains water, salts, and dissolved proteins; and  erythrocytes that carry oxygen (RBC)  leukocytes for defense (WBC)  platelets contain fibrinogen for blood clotting  Plasma contains heparin (anticoagulant) to prevent clotting in the blood.  It is the only fluid connective tissue. EXAMPLE OF CONNECTIVE TISSUES  Connective tissue proper (CTP) is made up of loose connective tissue that is made up of collagenous fibers  found in tendons (hold muscle and bone together) and ligaments (hold bones together and keeps them in place).  Adipose tissues are examples of loose connective tissues that store fats which functions to insulate the body and store energy. EXAMPLE OF CONNECTIVE TISSUES  Cartilage is characterized by collagenous fibers embedded in chondroitin sulfate.  Chondrocytes are the cells that secrete collagen and chondroitin sulfate.  functions as cushion between bones.  they are present at the tips of external ears, bronchi, vertebral column, etc. EXAMPLE OF CONNECTIVE TISSUES  Bone is a mineralized connective tissue made by bone-forming cells called osteoblasts which deposit collagen  it is a hard-connective tissue which forms the framework of the body  the matrix of collagen is combined with calcium, magnesium, and phosphate ions to make the bone hard  Blood vessels and nerves are found at a central canal surrounded by concentric circles of osteons. MUSCLE TISSUE  composed of long cells called muscle fibers (MOVEMENT)  contraction → movement CATEGORIES OF MUSCLE TISSUES Skeletal – comprises 30-40% of the total body mass  striated in appearance; voluntary movements  The presence of actin and myosin protein fibers allow us to perform wide range of movement and functions SKELETAL MUSCLE TISSUE CATEGORIES OF MUSCLE TISSUES Smooth – consists of thick and thin filaments that are not arranged into sarcomeres giving it a non-striated pattern  appears homogenous in microscopic examination; involuntary  cytoplasm contains a large amount of actin and myosin which act as the main proteins involved in muscle contraction. CATEGORIES OF MUSCLE TISSUES  Cardiac – striated with intercalated disk for synchronized heart contraction; involuntary NERVOUS TISSUE (CONTROL)  composed of nerve cells called neurons and glial cells as support cells that hold nerve Glial cells cells in place and help them work the way they should Axon  senses stimuli and transmits signals called nerve impulses Dendrite from one part of an animal to another Cell body  consists of a cell body and long extensions called dendrites (towards cell body) and axons (towards another cell or an effector)  Do not have the ability to regenerate.  Tissue Type Epithelial Connective Muscle Nerve Cell Shape Flattened, Irregular or round Elongated Cell appendages cuboidal, branched columnar Cell Single → Scattered in In sheets or Isolated or Arrangement multilayered matrix bundles networked Location Body covering or Supports other Lining internal Concentrated in lining organs or organs organs, make brain and spinal cavities skeletal muscles cord + all over the body Surface Feature Cilia, microvilli - - - of Cells Matrix Type Basement Varied – protein - - membrane fibers + liquid, gelatinous, firm to calcified Matrix Amount Minimal Extensive Absent Absent Unique Feature No direct blood Cartilage has no Can generate Can generate supply, except for blood supply electrical signals, electrical signal glands force and movement