Tissues

Chapter 5

Introduction

• Tissue-a group of similar cells that perform a specialized function

• Four major types of tissue:– Epithelial-form protective coverings and function in

secretion and absorption

– Connective-support softer body parts and bind structures together

– Muscle-produce body movements

– Nervous-conduct impulses that help control and coordinate body activities

http://www.bio.davidson.edu/people/kabernd/BerndCV/Lab/EpithelialInfoWeb/index_clip_image001.jpg

Epithelial Tissues: General Characteristics

• They…cover organs, form inter linings of cavities, and line hollow organs

• Always has a surface exposed

• The underside is anchored to connective tissue by a thin, nonliving layer, called the basement membrane

• They lack blood vessels but nutrients get to them by diffusion through the connective tissue below it

http://bioserv.fiu.edu/~walterm/FallSpring/review1_fall05_chap_tissue5_files/image009.jpg

• Epithelial cells divide quickly which allows for injuries to heal rapidly (where they are they get damaged quite a bit)

• Tightly packed which allows them to be great protective barriers like outside of skin

• They secrete, absorb, excrete, and aid in sensory reception

http://www.stegen.k12.mo.us/tchrpges/sghs/ksulkowski/images/10_Simple_Squamous_Apical_Epithelial_Tissue.jpg

• Classified according to shape and number of layers:– Simple-composed of a single layer of cells

– Stratified-two or more layers of cells

– Squamous-thin flattened cells

– Cuboidal-cube shaped

– Columnar-elongated cells

• Structure affects function with these tissues!!!!

http://upload.wikimedia.org/wikipedia/commons/8/8f/Illu_epithelium.jpg

Simple Squamous epithelium

• Single layer of thin, flattened cells– Main function is diffusion and filtration– Line air sacs (alveoli) of lungs and capillaries

of blood and lymph for gas exchange– Easily damaged

http://www.bio.davidson.edu/people/kabernd/BerndCV/Lab/EpithelialInfoWeb/handdrawn2.jpg

Simple Cuboidal Epithelium

http://webanatomy.net/histology/epithelium/simple_cuboidal.jpg

http://www.biosci.ohiou.edu/introbioslab/Bios171/images/lab1/columnar.jpg

Pseudostratified Columnar Epithelium

http://faculty.une.edu/com/abell/histo/Pseudostratw.jpg

webanatomy.net

http://antranik.org/wp-content/uploads/2011/09/stratified-cuboidal-epithelium.png

http://www.baileybio.com/plogger/images/anatomy___physiology/13.powerpoint_-_urinary_system/transitional_epithelium.jpg

http://images.tutorvista.com/content/tissues/glandular-epithelium-tissue.jpeg

Glandular Epithelium

• Glands secrete their products into ducts that open onto some internal or external surface are called exocrine glands

• Glands that secrete their products into tissue fluid or blood are called endocrine glands

• Exocrine glands are split into three groups

http://home.earthlink.net/~bellastuff/nutrition/glands.gif

Excretory glands

Sweat and saliva Mammary glands

Sebaceous glands of the skin

Connective Tissues

• Connective tissues– Bind structures– Provide support and protection– Serve as frameworks– Fill spaces– Store fat– Produce blood cells– Protect against infections– Help repair tissue damage

Connective tissue video

General Characteristics

• Father apart than epithelial cells, have an abundance of intercellular material or matrix between them (made of fibers and ground substance)

• Can usually divide

• Most have good blood supplies

• Quite rigid (bone and cartilage)

• Some flexible (loose connective tissue, adipose tissue, and dense connective tissue)

http://asavory.edublogs.org/files/2012/11/20_05ConnectiveTissue-L-10fyvfx.jpg

Major cell types

• Some are fixed cells (fibroblasts and mast cells) appear in stable numbers, some are wandering cells (macrophages) which appear temporarily

• Fibroblasts-produce fibers by secreting proteins into the matrix of connective tissues (most common fixed cells)

Fibroblasts

• Macrophages (histocytes)- start as white blood cells and carry on phagocytosis– Can move around and are scavenger cells

that clear foreign particles from tissues

http://srxa.files.wordpress.com/2010/09/macrophage-2.jpg

• Mast cells large and usually located near blood vessels they release heparin (prevents blood clotting) and histamine (promotes inflammation and allergies)

http://www.nhs.uk/Conditions/Mastocytosis/PublishingImages/Human_mast_cell.jpg

Three types of connective tissue fibers

• Collagenous fibers - thick threads of the protein collagen– Collagenous fibers are important components of body

pats that hold structures together– Ligaments – connect bones to bones– Tendons – connects muscles to bones

• Elastic fibers – composed of protein called elastin– Elastic fibers are weaker and stretch easily– Found in body parts that stretch like vocal cords

• Reticular fibers – thin collagenous fibers– Highly branched and form delicate support networks

http://www.whitetigernaturalmedicine.com/craniosacral-therapy/story-craniosacral-therapy-inst-08

6 Types of connective tissue

• Connective tissue proper:– Loose connective tissue– Adipose tissue– Dense (fibrous) connective tissue

• Specialized connective tissue:– Cartilage– Bone– Blood

http://asavory.edublogs.org/files/2012/11/20_05ConnectiveTissue-L-10fyvfx.jpg

Loose connective tissue

• Function: Binds organ together; holds tissue fluids

• Location: Beneath skin, between muscles, beneath epithelial tissues

• General characteristics: Forms thin membranes throughout the body

Loose connective tissue

http://stevegallik.org/sites/histologyolm.stevegallik.org/images/areolar_01.jpg

Adipose tissue

• Function: Protects, insulates, stores fat

• Location: Beneath skin, around kidneys, behind eyeballs, on surface of heart

• General characteristics: Fat, which is a specialized form of loose connective tissue, develops when certain cells store fat in droplets within their cytoplasm that enlarge

Adipose tissue

http://www.deltagen.com/target/histologyatlas/atlas_files/musculoskeletal/adipose_tissue_white_40x.jpg

Dense connective tissue

• Function: Binds organs together

• Location: Tendons, ligaments, deeper layers of skin

• General characteristics: Consists of many closely packed, thick, collagenous fibers and a fine network of elastic fibers

Dense connective tissue

http://kentsimmons.uwinnipeg.ca/cm1504/15lab42006/lb4pg6_files/image013.jpg

Hyaline cartilage

• Function: Supports, protects, provides framework

• Location: Nose, ends of bones, rings in the walls of respiratory passages

• General characteristics: Most common type; has very fine collagenous fivers in its matrix and looks somewhat like white glass

Hyaline cartilage

http://washington.uwc.edu/about/wayne.schaefer/TISSUES/hyaline_cartilage1.jpg http://www.chiropractic-help.com/images/Hyaline-cartilage-degenerate.jpg

Elastic cartilage

• Function: Supports, protects, provides flexible framework

• Location: Framework of external ear and parts of larynx

• General characteristics: Contains a dense network of elastic fibers; is more flexible than hyaline cartilage

Elastic cartilage

http://biology.clc.uc.edu/fankhauser/Labs/Anatomy_&_Physiology/A&P201/Connective_Tissues/Cartilage_Integument/Elastic_Cartilage_400x_PA112033lbd.JPG

Fibrocartilage

• Function: Supports, protects, absorbs shock

• Location: Between bony parts of spinal column, parts of pelvic girdle and knee

• General characteristics: Very tough tissue, contains many collagenous fibers

Fibrocartilage

http://medcell.med.yale.edu/histology/connective_tissue_lab/images/fibrocartilage.jpg

Bone

• Function: Supports, protects, provides framework

• Location: Bones of skeleton

• General characteristics: Most rigid connective tissue, made of bones cells or osteocytes

Bone

http://upload.wikimedia.org/wikipedia/commons/thumb/9/94/Illu_long_bone.jpg/250px-Illu_long_bone.jpg

Blood

• Function: Transports substances, helps maintain stable internal environment

• Location: Throughout body within a closed system of blood vessels and heart chambers

• General characteristics: Transports a variety of material between interior body cells and those that exchange substances with the external environment; has red blood cells, white blood cells and platelets (cell fragments)

Blood

http://0.tqn.com/d/hepatitis/1/0/e/0/-/-/I2Blood.jpg

Skeletal muscle tissue (striated)

• Function: Voluntary movements of skeletal parts

• Location: Muscles usually attached to bones

• General characteristics: Found in muscles that attach to bones and are controlled by conscious effort

Skeletal muscle tissue (striated)

Smooth muscle tissue (lacks striations)

• Function: Involuntary movements of internal organs

• Location: Walls of hollow internal organs

• General characteristics: Its cells do not have striations; cells cannot be stimulated by conscious effort

Smooth muscle tissue (lacks striations)

http://www.deanza.edu/faculty/mccauley/6a_site_images/tissues-images/smooth-muscle-670.jpg

Cardiac muscle tissue (striated)

• Function: Heart movements

• Location: Heart muscle

• General characteristics: Is only in the heart, controlled involuntarily

Cardiac muscle tissue (striated)

http://faculty.irsc.edu/faculty/sschwartz/Lab%20No19.jpg

Nervous tissue

• Function: Sensory reception and conduction of nerve impulses

• Location: Brain, spinal cord, and peripheral nerves

• General characteristics: Basic cells are called neurons, also includes neuroglial cells which are supporting cells that connect neurons to other body parts

http://www.okc.cc.ok.us/deanderson/dennis-tutorial/dennis-jpeg/Nervous%20Tissue-high%20mag%20D-%20copy