Tissues Epithelial Tissue  Tissue that always faces a free surface Examples: Skin; lining of mouth Examples: Skin; lining of mouth Cells are layered on top of one another Part of cells opposite the free surface attaches to a basement membrane Basement membrane  membrane packed with proteins and carbohydrates

Basement Membrane

Types of Epithelial Tissue Simple  single layer of cells Used for absorption, diffusion, and excretion Stratified  2 or more cell layers Used for protection Used for protection Pseudostratified  single, staggered layer of cells Usually ciliated; cilia sweep mucus across cell surface

Shapes of Epithelial Cells Squamous epithelial --> Flattened cells Cuboidal epithelial  Cube shaped cells Columnar epithelial  Column shaped

Putting it All Together Simple Squamous cells  lining of blood vessels; lungs Simple Cuboidal Cells  ducts and glands Simple Columnar Cells  stomach and intestines Stratified Squamous Cells  skin Stratified Cuboidal Cells  ducts of sweat glands Stratified Columnar Cells  ducts of salivary glands Pseudostratified Columnar Cells  throat, nasal passages

Epithelial Tissue Types The following pix are NOT in your Notes! I just want you to SEE what these tissues types look like I also want you to see SOME of their functions & locations

Location: outer layers of skin Function: to protect

Description: single layer of columnar cells with cilia Location: lines uterus, central canal of spinal cord, and some upper respiratory tract Function: moves particles and fluids along Description: two or more layers of cubed shape cells Location: sweat glands Function: to protect Function: to protect

Description: several layers of polyhedral cells Location: excretory ducts in some glands Function: secretion and protection

Glands Glands  cells that secrete substances; made from epithelial cells Exocrine Glands  secrete substances to the free surface of epithelial cells through ducts Example: Goblet Cells  secrete mucus into trachea Saliva, earwax, and oil Endocrine Glands  secrete substances directly into fluid Example: Hormones are released directly into bloodstream Thyroid, adrenal, and pituitary gland

Glands Endocrine glandExocrine gland

Membranes Membranes  sheet-like coverings over organs Mucous Membranes  line the cavity of digestive, respiratory systems; have ducts that release mucous Serous Membranes  enclose organs

Cell to Cell Contact & Connective Tissue How do cells stick together? Tight Junctions  rows of proteins that seal cells together Prevents molecules from getting stuck in between cells Important in epithelial cells of the intestines Adhering Junctions  Mass of proteins (called desmosomes) that spot weld the cell together at a very specific point Important in areas where stretching occurs Found in skin cells, lining of stomach Gap Junctions  protein channels that connect cells Promotes cell-to-cell communication; allows ions to move through cells Found in heart & and other organs

Connective Tissues Connective Tissue  Most abundant tissue in the body Small numbers of cells embedded with connective fibers such as collagen and elastin Collagen  structural protein fibers give mass and volume to structures Fibroblasts  secrete jelly-like substance; gives structure to organs Elastin  stretchable fibers that allow for elasticity All connective tissue has the same ingredients, just in different proportions

Loose Connective Tissue Many Cells; few fibers Collagen & Elastin Fibers are loosely arranged Macrophages & Fibroblasts are the most common cells Surrounds blood vessels and nerves

Dense Irregular Connective Tissue Lots of collagen fibers and fibroblasts Deep regions of the skin

Dense Regular Connective Tissue Collagen fibers run parallel to each other Creates strong attachments between muscles and bones Found in ligaments and tendons

Cartilage & Bone Cartilage  type of connective tissue that cushions and maintains shape of body parts Structure of Cartilage  Stretchable fibers similar in texture to rubber. Newly divided cells are called chondroblasts; mature into chondrocytes Very few blood vessels innervate cartilage; difficult to heal CartilageBone

Types of Cartilage Hyaline Cartilage  Consists of collagen fibers. Found where bone meets bone or at joints in the body Reduces friction between moving bones Found on either side of femur; end of nose, in between ribs Chondrocytes 

Types of Cartilage Elastic Cartilage  Consists of elastic fibers made from protein; also some collagen Found in parts of the body where stretchability is important Found in outer edge of ear, surrounding esophagus, epiglottis

Types of Cartilage Fibrocartilage  Rigid and Resilient; can withstand large amounts of pressure Densely packed with collagen fibers Found in kneecaps, in between vertebrae Collagen Fiber 

Bone Weight bearing tissue of bodyWeight bearing tissue of body Bones are joined with muscles to bring about movementBones are joined with muscles to bring about movement Bones store calcium & produce some kinds of blood cellsBones store calcium & produce some kinds of blood cells Bones made from densely packed collagen fibers and calcium saltsBones made from densely packed collagen fibers and calcium salts Inside fibers are lacunae, cavities that contain the living bone cells, osteocytesInside fibers are lacunae, cavities that contain the living bone cells, osteocytes Bone is innervated by more blood vessels than cartilageBone is innervated by more blood vessels than cartilage

Types of Bone Compact Bone Found on the outside of larger bones, embedded with lots of blood vessels and nerves

Types of Bone Spongy Bone Found at the ends of bones, loosely packed collagen and calcium

Muscles & Nerves Muscles  tissues that contract and relax to move body parts Fibers are arranged in parallel for increased resiliency

Types of Muscle Skeletal Muscle  Muscle attached to bones Individual cells are called muscle fibers Each cell has multiple nuclei, caused from the fusion of juvenile muscle cells Proteins are embedded in the muscle fibers (called Actin & Myosin) Actin & Myosin form bands in skeletal muscle that make it striated Fibers are bundled together in fasicles & wrapped in connective tissue

Types of Muscle Smooth Muscle  muscle of stomach, blood vessels, & internal organs Fewer Actin & Myosin fibers, no banding; unstriated Maintains constant tension, smaller contractions Often called involuntary muscle

Types of Muscle Cardiac Muscle Striated like skeletal muscle Involuntary like smooth muscle Muscle fibers are tightly packed together by specialized fibers called intercalated discs

Nerve Tissue Nerve Tissue  exercises control over body’s activities Individual cells called neurons Structure of Neurons Main Structure is cell body Dendrites  branched “arms” that pick up incoming chemical information Axons  “arms” that send out chemical information Nerve  cluster of neurons

Nervous Tissue

Sensory Neurons  Used to detect chemical changes Examples  Olfactory neurons Retinal Neurons in the eye Epithelial Neurons embedded in the skin

Blood & Adipose Tissue Blood  specialized tissue that carries proteins, ions, oxygen, fibrin (clots tissue) Blood cells are made in bone marrow (center of bone) 3 Parts of Blood Plasma  fluid portion of blood Platelets  white blood cells Red Blood Cells  Carry Oxygen to muscles; adult cells are non-nucleated White Blood Cells  function in immunity, cell defense Platelets  fragments of cells (called mekaryocytes) that aid in blood clotting Blood carries nutrients and proteins to cells and carries waste away from cells

White Blood Cells & Red Blood Cells

Adipose Tissue Large clustered cells used for fat storage Excess carbohydrates and proteins are converted to fat Adipose tissue is connected with lots of blood vessels Where does adipose tissue collect? Hips, abdomen, thighs, under skin, around kidneys