Chapter 4 My Notes PDF

Tissue Microscopy allows us to study tissue ◦ Must be xed (preserved) and cut into thin sections enough to transmit light nally it has to be stained so that charged molecules bind to different parts of cells and tissue making it possible to visually distinguish different anatomical...

Tissue Microscopy allows us to study tissue ◦ Must be xed (preserved) and cut into thin sections enough to transmit light nally it has to be stained so that charged molecules bind to different parts of cells and tissue making it possible to visually distinguish different anatomical structures Transmission electron microscopy (TEM) ◦ Stained but heavy salt metals ◦ Provides contrast by Tissue under the microscope has de ecting electrons been exposed that alters its original condition and has minor distortions called artifacts Scanning electron ◦ most structures view under microscopy (SEM) the microscope are not ◦ Provides 3D exactly like living things pictures of an unsectioned tissue surfaced Epithelium cells are avascular (no blood Nearly all substances received or given off by the vessels) but it is innervated (supplied body must pass through an epithelium by nerve bers) ◦ many functions are accomplished such as Epithelial tissue is a sheet of cells ‣ Protection that covers a body surface or lines a ‣ Absorption body cavity ‣ Filtration ◦ Covering and lining epithelium ‣ Excretion ‣ Covering outer layer of the ‣ Secretion skin, covers the walls and ‣ Sensory receptors organs of the closed ventral (anterior) body cavity and dips into and lines open cavities urogenital, digestive, respiratory systems ◦ Glandular epithelium ‣ Fashions the glands of the body  Polarity All epithelial have two different structure and function (exhibits a apical-basal polarity) ◦ Apical surface is not attached to surrounding tissue and it’s exposed Basal ◦ Basal surface is attached to the surface underlying connective tissue Basement membrane ◦ epithelial sheets (basal lamina) are supported by connective tissue and basement menbranes are between epithelial and connective tissue ◦ Reinforcing the sheets and helps resist stretching and tearing ◦ Consist of ‣ Basal lamina Non cellular thin supportive sheets near the basal surface consisted of glycoproteins and ne collagen bers Selective lter that determines which molecules can enter epithelium ‣ Reticular lamina deep to basal lamina Layer of extracellular collagen protein bers and reticular bers Epithelial cells t close together to form sheets and are tied together by tight junctions (prevents leakage) and desmosomes (keeps cells from pulling apart)  Simple epithelia ◦ Consist of a single cell layer ‣ usually found where absorption, secretion and ltration occur Strati ed epithelial ◦ Consist of two or more layers ‣ usually found in high abrasion areas where protection is important like lining of the mouth Squamous ◦ Are attened and scale like( at and long like a pancake) Cuboidal ◦ Are box like, as tall as they are wide(like peas) Columnar ◦ are tall and column shaped(are stretched up) Simple Squamous Thin, at cells in a single layer Asa Found in No ◦ Heart and blood vessels ◦ Lungs ‣ Alreoli - gas exchange ◦ Kidney ‣ Glomeruli - solutes ( ltration) Their function is diffusion and ltration  i Simple WADIDAL Single layer of cubed shaped cells Found in ◦ walls of small ducts of glands ◦ Lining of ovaries ◦ Kidney tubules Their function is secretion and absorption Simple COLUMNAR Single layer of tall cells Most epithelial have ◦ Microvili Microvili ‣ so dense that have a fuzzy appearance ‣ Increases surface area and absorption kidney tubules or lining of the Mucous intestine ◦ Goblet cells ‣ secrete mucous and traps substances) Intestines and respiratory tract ◦ Cilia ‣ Propulsion uterine tubes Found in ◦ lining digestive tract Their function is absorption, secretion and produce mucus  imple PseudoStratified Cells are single layers but appear strati ed Cilia due to height difference Goblet cells ◦ secrete mucous ‣ in trachea Cilia ◦ Propulsion ‣ in trachea Their function is absorption, secretion and protection Stratified Squamou Basal layer could be cuboidal or columnar but top layer at squamous Can contain keratin (palms and soles or skin) Found in ◦ Skin (keratinized) ◦ Lining esophagus (non keratinized) ◦ Mouth (non keratinized) ◦ Vagina (non keratinized) Function is protection Transitionary Surface cells are rounded Found in lining urinary organs or bladder Like simple squamous but cells become attened when stretched Their function is stretching  Stratified u IDAL Their function is protection They are found in ◦ Largest ducts of sweat glands ◦ Mammary glands ◦ Salivary glands Stratified COLUMNAR Their function is to protect and secrete Found in ◦ they are rare in body ◦ Small amounts in male urethra ◦ In large ducts of some glands Two simple squamous epithelia ◦ Endothelium ‣ Inner covering ‣ Provides a slick, friction-reducing lining ‣ Found in lymphatic vessels and in all hollow organs in cardiovascular system ◦ Mesothelium ‣ Middle covering ‣ Found in serous membranes, lining the ventral (anterior) body cavity and organs  A gland consist of one or more cells that secrete a particular product. This product is called secretion, is an aqueous uid that usually contains proteins Glands are classi ed to two sets of traits ◦ Where they are released ‣ Endocrine internally secreting ‣ Exocrine Externally secreting ◦ Number of cells Endocrine glands or ductless glands ‣ Unicellular ◦ Produce hormones one cell Exocrine glands (have a duct bc they release) ‣ multicellular ◦ Secrete products to body surface or into body cavities ‣ includes liver (bile), pancreas and salivary glands (digestive enzymes), sweat and oil glands, etc. ◦ Unicellular exocrine glands secrete by exocytosis ‣ mucous cells and goblet cells ‣ Found in intestinal and respiratory tract ‣ Mucin production ◦ Multicellular exocrine do so via epithelium walled duct ◦ Multicellular exocrine glands are categorized by ‣ simple glands have an unbranched duct ‣ Compound glands have a branched duct AND ‣ Tubular- secretory cells from tubes ‣ Alveolar- secretory cells from small at like disc ‣ Tubuloalveolar- both AND ‣ Merocrine (most are this, secrete products by exocytosis as they are produced ) ‣ Holocrine (accumulate products until rupture) ‣ Apocrine (not sure if humans have this, accumulates products but only on free surface) Mucin is a complex glycoprotein that dissolves in water when secreted ◦ in goblet cells the mucin distends the top cell making the cell look like a glass with stem Skin consist primarily of connective tissue, but the brain contains so little Types of connective tissue extracellularmatrix ◦ Connective tissue proper ◦ Cartilage aroundsubtance ◦ Bone ◦ Blood I tiff Functions ◦ More than just connect body parts ◦ Binding and supporting ◦ Protecting ◦ Insulating ◦ Storing reserved fuel ◦ Transporting substances Characteristics that set connective tissue apart from primary tissue ◦ Extracellular matrix (composed of ground substance and bers) ‣ This separates the living cells of the tissue and because of this matrix connective tissue can bear weight Withstand great tension Endure abuse such as physical trauma and abrasion ◦ Common origin ‣ all connective issue comes from mesenchyme connective tissue three main components are ◦ Ground substance ◦ Fibers ◦ Cells Ground substance Unstructured material that lls up space between cells and contains bers 3 components ◦ Interstitial uid ‣ Helps nutrients and other substances diffuse between blood and the cells ‣ The bers in here makes it less pliable and makes diffusion harder ◦ Cell adhesion proteins ‣ serve mainly as glue allowing connective tissue cells attach to extracellular matrix ◦ Proteoglycans ‣ consists of a protein core and glycosaminoglycans attached ‣ GAGs stick out from protein core GAGs intertwine and trap water forming a substance, the more GAG content the more viscous the ground substance Connective tissue bers Collagen bers ◦ provide high tensile strength (ability to resist being pulled apart) to the matrix ◦ constructed primarily of collagen ◦ Most abundant ◦ Located in extracellular space Elastic bers ◦ contain rubber like protein (elastin) allowing them to stretch and recoil like rubber bands (long and thin) ◦ These form branching networks in the extracellular matrix ◦ Found in skin, lungs and blood vessel walls (where elasticity is needed) Reticular bers ◦ short, ne bers made of a different type of collagen (thicker collagen bers) ◦ They connect to a coarser collagen ber (they branch extensively) forming a delicate network (reticul) surrounding small blood vessels and support soft tissue if organs ◦ Found in spleen, lymph nodes, bone marrow, kidney Connective tissue cells Resident cell types in connective tissue -immature (-blast) -mature (-cyte) Mass cells ◦ initiate local in ammatory against microbes ◦ Contain secretory granules with chemicals ‣ Herapin prevents blood clotting ‣ Histamine makes capillaries leaky Macrophages ◦ cell that devours bacteria and disposed of dead tissue cells ◦ Found in loose connective tissue, bone marrow, lymphoid tissue soar Proteins sticky celladhesion Proteoglycans 1 Extracellular matrix Get fibers xtracellular Fluid interffal Plasma 1 Collagen nutrient SYTange Diffusion Types of connective tissue All connective tissue except for bone, cartilage and blood are connective tissue proper ◦ Loose connective tissue ◦ Dense connective tissue ‣ Areolar ‣ Dense regular ‣ Adipose ‣ Dense irregular ‣ Reticular ‣ Elastic Loose connective tissue Elastic Areola (looks like spider webs with pitaya seeds) Groundstance ◦ Wraps and cushions organs ◦ Binds body parts together while still Fibroblast allowing them to move freely ◦ Plays important role in in ammation Collagen ◦ Widely distributed fibers ◦ Cells are broblast Adipose (looks like bubbles on glass) ◦ provides fuel reserve ◦ Insulates against heat lost Nucle ◦ Supports and protects organs ◦ Cells are adipocytes ◦ Found ‣ around kidneys and eyeballs Ftp ‣ Within abdomen ‣ Breast Reticular (looks like a closed up tree branches with leaves) ◦ Forms stroma (internal lymphocyte skeleton) that supports other cell types, immunity ◦ Found in spleen, lymph nodes and bone marrow EEyar ◦ Cells are leukocytes  Dense regular connective tissue Dense regular (looks like Red Sea going in one direction) ◦ holds, protects and supports Collagenfibers ◦ Attaches muscles to bones ◦ Attaches bones to bones ◦ Withstands great tensile stress when pulled in one direction ◦ Found in tendons and ligaments ◦ Cells are broblast Dense irregular (looks like a sea going everywhere) ◦ Withstand tension exerted in many directions ◦ Provide structural strength ◦ Found in brous capsules of joints and dermis of the skin ◦ Cells are broblast Collagen fibers Dense elastic connective (looks like old burned skin) ◦ Allows tissue to recoil after stretching ◦ Found in walls or large arteries, some ligaments and aorta (tube above the heart) Elastiers  Other connective tissues that aren’t proper Cartilage Bone Blood Cartilage Tough but exible Lacks nerve bers and it’s avascular (no blood vessels) Receives nutrients via diffusion by perichondrium Cartilage is made up to 80% water Chondroblast - chondrocytes are the cells in cartilage ◦ Found in lacunae Three types of cartilage Hyaline cartilage Elastic cartilage Fibrocartilage  Hyaline cartilage (looks like pitaya seeds in something smooth) ◦ Supports and reinforces ◦ Most abundant cartilage ◦ Looks glassy because it has collagen ◦ Found in ‣ ends of long bones ‣ Costal cartilage of ribs ‣ Nose, trachea and larynx Fibrocartilage (looks like looks like brushed ne clothes bers with seeds) greatest strength absorbs compressive shock Found in intervertebral discs, public symphysis, discs of knee joints Elastic cartilage (looks like oysters) ◦ Maintains shape of a structure but still allows exibility ◦ Found in ears and epiglottis Blood (looks like blood red Bone (looks like a log cut in blood cells) half Transports Supports and protects ◦ respiratory gases Provides levers for muscles ◦ Nutrients Calcium storage ◦ Wastes Dry vascularized ◦ Found in blood vessels Muscle tissue Vascularized tissues responsible for movement Possess myo laments ◦ Networks of actin and myosin laments 3 types of muscle tissue ◦ Skeletal (voluntary muscle) ◦ Cardiac (involuntary) ◦ Smooth (involuntary) Skeletal muscle (looks like a broken dry erase marker on a board making lines) Voluntary movement; locomotion; manipulation of the environment, facial expressions Found in skeletal muscles attached to bones or sometimes skin  Cardiac muscle (straight lines with good marker but not smooth) Blood propulsion into circulation Branching cells that that form junctions Found in walls of the heart Smooth muscle (smooth marker with small nucleis) Propels substances along internal passageways Found in most walls of hollow organs Nervous tissue (looks like a costras with a tails) Main component of the nervous system ◦ Brain ◦ Nerves ◦ Spinal cord Contains neurons ◦ generate and conduct nerve impulses ◦ Transmit electrical signals from receptors and effectors ◦ Excitability and conductivity Contains supportive cells Covering and lining membranes Cutaneous Mucous Cutaneous Serous Basically skin Keratinized strati ed squamous ◦ Attached to dermis Functions as protection Mucous or mucosae Lines all body cavities that open to the outside of the body ◦ hollow organs of the digestive, respiratory, and urogenital tracts Strati ed squamous or simple columnar Adapted for absorption and secretion Serous Found in closed ventral cavities Consist of simple squamous Functions as lubricant for facing surfaces an  AM Developmental aspect of tissue Primary germ layers include ◦ Ectoderm ‣ Nervous tissue ◦ Mesoderm ‣ Muscle and connective tissue ◦ Endoderm ‣ GI tract Epithelium from all three layers Tissue repair Occurs in two major ways ◦ Regeneration ‣ replaces destroyed tissue with the same kind of tissue ◦ Fibrosis ‣ replaces destroyed tissue with scar tissue (dense connective tissue) Which one occurs depends on ◦ tissue type Tissue repair broken down ◦ Severity of injury 1. In ammation ◦ trauma causes in ammation Regenerate extremely well ◦ in ammation makes vessels leaky allowing ◦ Epithelial tissue substances to seep into injured area ◦ Bone ◦ Clotting seals off area preventing infection ◦ Areolar connective tissue ‣ exposed to air later becomes scab ◦ Dense irregular tissue 2. Organization restores blood supply ◦ Blood forming tissue ◦ clot is replaced with fragile capillaries Regenerate moderately ‣ characterized as granulation tissue ◦ Smooth muscle restoring vascular supply ◦ Dense regular connective tissue ◦ broblast multiply making Regenerate weakly ◦ Macrophages phagocytized dead and dying ◦ Skeletal muscle cells ◦ Cartilage 3. Regeneration and brosis No functionally regenerative capacity ◦ margins get pulled together ◦ Cardiac muscle ◦ Epithelial thickens under scab so it detaches ◦ Nervous tissue in the brain and spinal cord ◦ Scar tissue results as a while line fam 0A