Tissues

A. Tissues 1. Def – a group of cells that are organized into groups and layers. 2. Types (Table 5.1) a. Epithelial b. Connective c. Muscular d. Nervous 3. Extracellular Matrix a. Non-living b. Supports cells c. Transmits signals

A. General Characteristics 1. covers organs 2. forms inner linings of body cavities 3. lines hollow organs *always has an exposed surface *basement membrane – adheres epithelial layer to other tissues 4. Other characteristics a. Lack blood vessels b. Readily divide c. Tightly packed

5. Types of epithelial cells a. Squamous – thin and flattened b. Cuboidal – cube shaped c. Columnar – tall and elongated *simple – single layer *stratified – two or more layers

A. Def – pg Characteristics a. Substances pass easily (filtration and diffusion) b. Location…  alveoli (lungs) O 2  CO 2  capillaries  blood and lymph vessels  covers membranes that line body cavities c. Easily damaged

A. Def – pg Characteristics a. Acts as a cover b. Location…  ovaries  lines kidneys, salivary, and thyroid glands  pancreas and livers c. Secretion and absorption  hormones

A. Def – pg Characteristics a. Nuclei are located near basement membrane. b. Can contain cilia or microvilli c. Good protectors of underlying tissue d. Contain goblet cells - secretions e. Location…  female reproductive tubes  digestive tract

A. Def – pg Characteristics a. Pseudo = false b. Nuclei are located at different levels c. Have cilia d. Goblet cells e. Location…  respiratory tract (mucous/flem)

A. Def – pg Characteristics a. Generally thick b. Push old ones towards the surface c. Location…  skin (epidermis / dermis) -keratin (protein)  oral cavity, esophagus, vagina, anal canal

A. Def – pg Characteristics a. Protective lining b. Location…  glands (mammary, sweat, salivary, pancreas)  male and female reproductive tubules

A. Def – pg characteristics a. Superficial cells – columnar b. Deep cells – cuboidal c. Location…  urethra and vas deferens  pharynx

A. Transitional 1. characteristics a. specialized to change due to tension b. ability to change shape c. Location…  urinary tract B. Glandualar 1. characteristics a. Produce secretions and substances b. Form glands c. types

1. Exocrine gland – secrete into ducts that lead into the skin or lining of digestive tract  merocrine – watery protein  apocrine – small portions of cells  holocrine – cells break off and lyse. 2. Endocrine gland – secrete into tissue or blood

A. Characteristics 1. multiple…  framework, support, protection, store fat, repair tissue, protect against infections, produce blood cells… B. Cell Types 1. Fibroblast – most common a. Large and star shaped b. Produce fibers

2. Macrophages a. White blood cells – phagocytosis  scavengers  ability to move 3. Mast Cells a. Heparin – prevents blood clotting b. Located near blood vessels c. Produce histamine  allergies and inflammation

C. Connective Tissue Fibers (fibroblasts) 1. Collagenous – thick threads a. Great strength b. Ex: ligaments and tendons 2. Elastic – thin fibers a. Elastin protein b. Stretch easy and return to normal shape c. Ex: vocal cords 3. Reticlular – thin fibers a. Form delicate supporting networks b. Hold organs in place

D. Categories of Connective Tissue 1. Loose Connective Tissue a. Description – delicate thin membrane b. Mainly fibroblasts c. Binds skin to organs (usually muscles) d. Large blood supply 2. Adipose Tissue a. Description – energy storage center b. Adipocytes – store fat droplets within cells. c. Location… -underneath skin -around organs (protection) -in between muscles

3. Dense Connective Tissue a. Description – closely packed collagenous fibers and elastic fibers. b. Strong yet stretchy c. Location…  tendons and ligaments d. Poor blood supply = slow tissue repair 4. Cartilage a. Description – rigid connective tissue that provides support and protection. b. Chondrocytes – cells that produce collagenous fibers. c. Little/no blood supply = poor healing

d. Types of cartilage  Hyaline – most common (collagenous) - ends of bone, tip of nose, throat  Elastic – (elastic) - more flexible than hyaline - ears and larynx  Fibrocartilage – tough (collagenous) - shock absorber - spinal column, knees, pelvic girdle - meniscus

5. Bone Tissue a. Description – most rigid connective tissue b. mineral salts (calcium) c. Purpose a. Supports body structures b. Protects body structures c. Attachment site for muscles d. Red marrow – white blood cells d. Osteocytes – bone laying cells

6. Blood Tissue a. Description – transports materials b. Helps to maintain stability (homeostasis) c. Types  Red BC’s  White BC’s  Platelets

A. Def – ability to contract in response to stimuli B. Characteristics 1. elongated 2. ability to contract C. Types of Muscle Tissues 1. Skeletal 2. Smooth 3. Cardiac

D. Skeletal 1. Characteristics a. Connect bones b. Voluntary c. Contain striations d. Allow movement

E. Smooth 1. Characteristics a. No striations b. Shorter in length c. Found in internal organs -stomach, intestine, urinary bladder d. Involuntary

F. Cardiac 1. Only found in the heart 2. striated 3. involuntary