KIN216ch4 - KIN 216 KIN Applied Human Anatomy Chapter 2 and...

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Unformatted text preview: KIN 216 KIN Applied Human Anatomy Chapter 2 and 4 Slides adapted from Dr Pfeiffer The Life Cycle of a Cell The From formation to reproduction Not cell death! Set of processes that each cell Set undergoes undergoes The time this takes varies between The types of cells types The Life Cycle of a Cell The Consists of two main periods Interphase • When cell is growing and carrying out regular When metabolic activites metabolic Cell Division • When a cell divides into two cells (also thought When of as reproduction) of Interphase Interphase Period of growth Period and preparation for division for Consists of three Consists subphases subphases G1 – Gap 1 S – Synthetic G2 – Gap 2 Interphase Interphase Gap 1 Gap Focus on cell growth; most variable stage (can last hours or years!) (can At the end, centrioles begin to replicate G1 checkpoint occurs to make sure cell is large enough large Synthetic Phase DNA replicates itself Mitosis produces two identical cells Interphase Interphase Gap 2 Very quick Enzymes needed for cellular division are Enzymes produced produced G2 checkpoint checks to make sure the DNA replication was accurate Mitosis can be stopped at the Mitosis checkpoints to ensure damaged cells are not produced are Cell Division Cell Some cells undergo reproduction often Some (skin cells) others only when needed (liver cells) and others don’t after maturation (nerve cells) This phase of division is known as the This mitotic phase mitotic Cell Division Cell Mitosis can be broken Mitosis into four phases into 1) Prophase • Chromatin Chromatin condenses into chromosomes; nuclear envelope ‘dissolves’; microtubules attach to chromosomes chromosomes Cell Division Cell Mitosis can be broken Mitosis into four phases into 2) Metaphase • Chromosomes line Chromosomes up in the Middle of the cell the Cell Division Cell Mitosis can be broken Mitosis into four phases into 3) Anaphase • Centromeres split Centromeres Apart; one of each chromatid will go into the new cells into Cell Division Cell Mitosis can be broken Mitosis into four phases into 4) Telophase • Chromatids begin Chromatids to uncoil; nuclear envelope “reappears” “reappears” Cell Division Cell Cytokinesis Separation of two Separation daughter cells daughter Begins at Begins anaphase and completes after mitosis mitosis Cleavage furrow is Cleavage where cells pinch apart apart Cellular Diversity Cellular Cells differentiate meaning they Cells specialize and will have different sizes, shapes, and components based on the function they will perform function This is why there is differences in the This number and type of organelles in particular cells particular Muscle cells have lots of mitochondria Cellular Diversity Cellular Cells can be categorized as the Cells following: following: Cells that connect body parts or line Cells organs organs Cells that produce movement Cells that store nutrients Cells that fight disease Cells that gather info and control body Cells functions functions Cells of reproduction Cellular Diversity Cellular Tissues Tissues Cells of a similar Cells structure and function that work together with extracellular matrix in between Tissue = “to Tissue weave” weave” Histological Classes and Subtypes Subtypes Hist = tissue Histology = the study of body’s tissue Histology the 4 basic types basic Epithelial, Connective, Muscle, Nervous For each, KNOW Cell types and prominent organelles Matrix properties (mostly for connective tissue) Function and specialized structures for function Examples of locations within body Epithelial Tissue Epithelial Coverings, linings, and Coverings, exocrine glands (very little matrix) little 2 kinds Membranous and glandular One surface always One exposed to a body cavity, lumen (hollow portion of tube), or skin surface surface Functions Form coverings, linings of Form tubes and cavities tubes Absorption, secretion, Absorption, protection (w/ nerves), filtering, ion transport filtering, Epithelial Tissue Key characteristics Cellularity (i.e. LOTS of Cellularity cells) cells) Specialized contacts Specialized with other cells with Polarity: One side One exposed; unexposed side is bounded by basement membrane: basement binds epithelial tissue to underlying connective tissue (nourishes, provides support) support) Epithelial Tissue Epithelial Key Characteristics cont. Avascular: no direct blood supply to epithelial no tissue, THEREFORE it cannot be very thick because it relies on diffusion of nutrients from underlying connective tissue (only one cell layer thick or limited # of layers) thick Innervated: nerve endings are found in epithelial Innervated: tissue tissue Capable of RAPID regeneration- needed because Capable of exposure to trauma, injury of Commonly found organelles in tissue: those that Commonly use O2 use Special Characteristics Special Lateral surface features (NOT on exam) Cell junctions Cell • Tight junctions – prevent molecules from Tight passing passing • Adhesive junction – reinforces the tight Adhesive junctions junctions • Desmosomes – holds cells together and helps Desmosomes form a network of connections through the whole epithelium whole • Gap junctions – allow small molecules to pass Gap through into other cells (help cellular communication) communication) Special Characteristics Special Basal surface feature Basal lamina: thin, non-cellular sheet thin, made up of proteins, acts as filter and serves as scaffolding for new cell generation (basement membrane = basal lamina + reticular fibers) lamina • Many anatomists use the terms basal lamina Many and basement membrane interchangably and Apical Surface Features Apical Microvilli Finger-like extensions of plasma membrane Maximize surface area for nutrient transport Maximize (kidneys) and absorption (intestines) (kidneys) Abundant on epithelia that secrete mucus to Abundant anchor it to the surface anchor Apical Surface Features Apical Cilia Tail-like extensions Tail-like that bend and move in coordinated waves in Push mucus and Push other substances across epithelial surface surface Flagellum = extremely Flagellum long cilium (only seen on sperm for humans) humans) Classification of Epithelia Classification Each specific epithelia receives two Each names First name = How many cell layers • Simple = 1 layer Simple • Stratified = 1+ layers Second name = Shape of cell • • • Squamous = Flattened cells Cuboidal = Cube-like cells Columnar = Cells that are taller than they are Columnar wide wide Membranous Epithelial Tissue Membranous Simple = one cell layer Simple (all cells in layer have same shape); shape indicative of function indicative Stratified = multiple Stratified layers (cell shapes can differ among layers); named according to apical layer (unbound side); protection (basal layers divide to replace apical surface) apical Membranous Epithelial Tissue Squamous = wide cells Squamous (more wide than tall); *diffusion/filtration *diffusion/filtration Cuboidal = same height Cuboidal and width (cubes); *secretion/absorption *secretion/absorption Columnar = tall cells Columnar (more tall than wide); *secretion/absorption *secretion/absorption Shape of nucleus Shape matches cell type matches Simple Squamous Simple Single layer of flat Single cells cells Occurs wherever Occurs molecules need to pass through quickly quickly Two special types Endothelium • Internal surface of BV Mesothelium • Internal wall and Internal organ covering (slick) organ Simple Cuboidal Simple Single layer of cubelike cells Walls of small ducts Walls of glands, tubules of kidneys kidneys Functions are the Functions same as simple columnar columnar Simple Columnar Simple Single layer of tall Single cells cells Lines digestive tract Lines (stomach to anal canal) canal) Molecule movement Absorption, ion Absorption, transport, secretion transport, Some have cilia: Some cilia assists with movement Ex Uterine tube Ex moving ovum moving Pseudostratified Columnar Pseudostratified Single layer but cells Single are different heights (only the tallest cells reach apical surface) reach Secretion/absorption Similar to simple Similar columnar columnar Ex: respiratory tubes Ex: with ciliated type with Stratified Squamous Stratified Many layers – surface Many are squamous are Lower levels are Lower cuboidal or columnar cuboidal Thickest; best Thickest; protection – epidermis of skin (special case = keratinized ch. 5) keratinized Stratified Cuboidal/Columnar Stratified Rare Ducts of glands (ex. Sweat, salivary) Transitional Transitional Similar to stratified Similar squamous and stratified cuboidal stratified Specific to hollow Specific urinary organs (bladder) (bladder) Stretches to Stretches different cell layer thickness thickness Glandular Epithelial Tissue Glandular Product is water-based fluid with proteins Secretion: process by which glands obtain Secretion: substances from blood and transform them into product for discharge into Exocrine (external) or endocrine (internal) Protein made in rough ER, packaged by Golgi, Protein released from cell by exocytosis released Difference in where the product is secreted Unicellular or multicellular Commonly found organelles: rough ER, Commonly Golgi Golgi Exocrine Glands Exocrine Secrete onto body surfaces or into Secrete cavities (multicellular have ducts to carry to surface) carry Local activity (Secreted near Local production) production) Exocrine Glands Exocrine Ex. glands of skin, Ex. salivary glands, pancreas, liver pancreas, Unicellular Goblet cell • Lining of intestines, Lining respiratory tubes, b/w columnar cells columnar • Produce mucin: Produce mucin glycoprotein that dissolves in water; mucin + water = mucus mucus Multicellular Exocrine Glands Multicellular 2 parts: duct and secretory unit parts: (secretory epithelium) (secretory Most are surrounded by connective Most tissue tissue Classified by duct structure: simple or Classified compound (branches) AND secretory unit: tubular or alveolar (spherical sacs) – tubuloalveolar also exist sacs) Endocrine Glands Endocrine Ductless Secrete into tissue fluid Produce hormones, which travel Produce through bloodstream to target organs (which can be a far distance) (which Ex. Endocrine cells in the intestines Ex. secrete hormones to signal for the pancreas to release enzymes to aid digestion digestion Connective Tissue (CT) Connective Most diverse and abundant class Most Major functions: Bind and support other tissues in body Protection and nourishment (maintenance of Protection other tissues) other Common features of MOST CT subclasses Highly vascular (except for cartilage) MOST can regenerate but slower than epithelial More matrix than cells (cells NOT tightly packed) Immune function (circulating WBCs) Most storage occurs in CT Derive from mesenchyme Major CT Classes •Defined by matrix (ground substance + fibers) properties •3 types of protein fibers (collagen, reticular, elastic) Matrix Matrix Fibers Cells CT proper Gel-like All 3 (not in All ALL subtypes) ALL Fibrocytes, Fibrocytes, -blasts, fat, defense cells defense Cartilage Gel-like Collagen, some Chondrocytes, Collagen, Chondrocytes, elastin -blasts elastin -blasts Bone Rigid Collagen Osteocytes, Osteocytes, -blasts -blasts Blood Fluid Fluid (plasma) (plasma) None Blood cells Embryonic (Mesenchyme) Embryonic All CT types originate from this All (mesenchyme = undifferentiated tissue) (mesenchyme Has gel-like matrix Usually develops into some type of Usually tissue somewhere, but doesn’t always differentiate differentiate Some continues to develop into and Some through adulthood in order to repair/ replace damaged CT replace CT Proper CT Most complex- has two sub-classes (loose Most and dense) and many subtypes Forms stoma (supportive framework) of Forms organs organs Common features: Matrix = ground substance Cells = mostly fibroblasts (fibro = fibers, which Cells are proteins- common organelles are ribosomes, ER, Golgi) ribosomes, The fibers give structural support and strength The to matrix and produce 3 types of fibers: to • • • Collagen – Strongest, resist tension (pulling) Elastic – Composed of elastin, rubber band like Reticular - Network of collagen fibrils, allow more give Subclasses of CT Proper Subclasses Differentiated by density of fibers Loose Areolar Adipose Reticular Dense Irregular Regular Elastic Areolar (Loose) CT Areolar Common type of CT proper Found in: Hypodermis (deepest skin Hypodermis layer), Fascia (surrounding Fascia muscles) muscles) Surrounding nerves and Surrounding blood vessels blood Loosely arranged fibers, Loosely widely spaced cells widely Functions: cushioning, cushioning, support and binding, defense against infection, storing nutrients as fat storing Areolar (Loose) CT Areolar GOOD blood supply, GOOD highly vascular highly Cells mostly fibroblasts Cells (produce protein fibers) (produce Some mast cells: react to Some mast react injury- produce heparin, which is anticoagulantalso produce histamine, which is vasodilator which Common organelle: Common lysosomes- many macrophages: engage in macrophages engage phagocytosis, eat damaged cells damaged Adipose (Loose) CT Adipose Lots of cells- few fibers and little matrix Cell - adipocytes (arise from fibroblasts) Adipocytes have FEW organelles Adipocytes Some mitochondria, few ribosomes/rough ER/Golgi Mostly smooth ER and nucleus pushed to side VERY vascular! Allows the high metabolic activity of adipocytes Removal of lipids from blood after meals to be released Removal later when necessary later Adipose (Loose) CT Adipose Functions: Location: Energy fuel storage Thermal insulation Padding for protection Throughout body in hypodermis (subcutaneous) and Throughout around kidneys, heart, joints, bone marrow, mesenteries around Typical adipose tissue is white, but there is another Typical type that is brown (produces heat, consumes nutrients) nutrients) Thought to only be found in infants, but has now be found Thought in adults in the center of the back, on the neck, and anterior abdominal wall abdominal Reticular (Loose) CT Reticular Gives rise to vascular tissue Matrix: softer, more jellylike Fibers: ONLY reticular fibers, form network Cells: reticulocytes specialized for Cells: phagocytosis phagocytosis Function: blood cell production, degrade Function: worn out cell parts worn Organelles: lysosomes, peroxisomes Location: bone marrow, lymph nodes, Location: spleen, liver spleen, Irregular (Dense) CT Irregular Thicker and more plentiful collagen fibers Thicker than loose CT tissue than Fibers run in different planes or different Fibers directions (Resists several tensions) directions Cells and matrix are same as areolar Function: Function: Protection from stretching Location Dermis of skin, surrounds kidneys (fibrous Dermis capsule), lymph nodes, bone capsule), Regular (Dense) CT Regular Lots of collagen – positioned in same Lots direction direction Function: provide strong support and Function: flexibility flexibility Relatively poorly vascularized compared to Relatively other types, so it’s slow to heal other Cells: fibroblasts (which produce collagen) Location: tendons (M-B), ligaments (B-B), Location: fascia (around mm), sclera of eye, dermis of skin skin Common organelles: those affiliated with Common protein- ribosomes, ER, Golgi protein- Elastic (Dense) CT Elastic Mostly the same as regular (Dense) CT Elastic fibers in irregular arrangement Stretches but returns to original size Found in large artery walls, larynx, Found trachea, bronchial tubes trachea, Cartilage Cartilage Matrix = lots of fibers and proteoglycans Matrix (type of fiber with protein and CHO, very complex and takes a long time to build themthis is why it takes cartilage a long time to heal) and lots of water heal) Cells = chondrocytes Blood supply = none (another reason it’s Blood slow to heal) – also no nerves slow Functions: protection, cushioning, shock protection, absorption (resist compression) absorption Location: nose, ears, trachea, joints Types of Cartilage Types Hyaline (Gr. Hyalos = Hyaline glass) glass) Looks like frosted glass Looks (THIN fibers) (THIN Weakest type of cartilage Weakest BUT most abundant BUT Surrounded by a capsule Surrounded of dense fibrous CT of Perichondrium = outer Perichondrium layer around cartilage (but not at articular surfaces of bones) bones) Function: framework, framework, structure structure EX: ribs attached to EX: sternum by costal cartilage, which is hyaline cartilage, Types of Cartilage Fibrocartilage Densely packed fibers Densely (TOUGH- strongest type of cartilage) of Doesn’t have Doesn’t perichondrium perichondrium Chondrocytes are Chondrocytes arranged in rows with collagen fibers in between between Function: structure, structure, framework, compression resistance (protection) is main function main Location: inside some inside joints EX: symphysis pubis, EX: intervertebral disks, menisci menisci Types of Cartilage Types Elastic cartilage Similar to hyaline but Similar has elastin fibers has Location: external external ear, eustachian tube (ear to throat), epiglottis epiglottis Function: stretch/strength, repeated bending repeated Bone Bone Cells: osteoblasts (build and mature into osteocytes) osteocytes) osteoclasts (break down, remodel bone) Matrix: rigid due to deposit of mineral salts rigid (calcium, phosphorus), also lots of collagen (provides some flexibility) (provides Vascularity: HIGH, very metabolically active HIGH, (remodeling, hematopoiesis) (remodeling, Bone Bone Subtypes of bone tissue Cancellous (aka trabecular, spongy, medullary) • • • • • Where hematopoiesis occurs Found on inside lining- spongy Structural unit = trabeculum Location = inner cavity of long bones (medullary cavity) Softer, more vascular, lots of empty spaces Compact (aka dense, cortical) • • • Hard and dense, lots of mineral salts Location: outer layer outer Structural unit = osteon, has central canal with Structural concentric rings concentric • Can determine human bone from non-human animal Can bone bone Vascular (Blood) Vascular Atypical CT (no binding or support) Why is vascular tissue classified as CT? Why Origin is fibroblasts (made in bone marrow), Origin function is nutrient delivery function Develops from mesenchyme Has cells and matrix Cells: blood cells (leukocytes-WBCs, blood erythrocytes-RBCs, thrombocytes-platelets) erythrocytes-RBCs, Matrix: fluid (plasma) Coverings and Linings Coverings Membranes that cover areas in the body – Membranes made up of an epithelial sheet and underlying layer of CT proper underlying Cutaneous: skin (dry membrane) Mucous: lines organs that open to outside of Mucous: body (moist) – many (but not all) secrete mucus body • Lamina propria: loose CT (underlying layer) Serous: lines cavities • Simple squamous epithelial layer on top of areolar CT – Simple serous fluid serous Muscle Tissue Muscle Cells: myocytes (long, thin fibers) that myocytes contain myofilaments contain Sarcolemma = cytolemma of muscle cell Sarcoplasm = cytoplasm of muscle cell Sarcoplasmic reticulum = ER of muscle cell Matrix: very little (densely packed cells) Vascularity: HIGH (due to how high metabolic HIGH rate needs to get) rate Function: contraction, movement 3 types: skeletal, cardiac, smooth Skeletal Muscle Skeletal Multinucleated High metabolic rate (lots of High mitochondria) mitochondria) Highly vascular Lots of fibrous proteins Striations (regular alignment Striations of actin, myosin) of Connected to bone by Connected tendons tendons Function: movement of Function: skeleton, posture (“voluntary” control) (“voluntary” Sarcomere = unit of skeletal Sarcomere muscle contraction muscle Cardiac Muscle Cardiac Located in walls of Located heart heart Striated (has Striated sarcomeres) sarcomeres) HIGHLY vascular Differs from Differs skeletal: skeletal: Short, branched, Short, MONOnucleated cells cells Intercalated discs Smooth Muscle Smooth NOT striated Has ability to regenerate Has actin and myosin, but Has not regularly arranged (no sarcomeres) sarcomeres) Cells are mononucleated Not as vascular as other 2 Not types types Found in bladder, uterus, Found stomach, tube circumference, etc. (“involuntary” control) (“involuntary” Nervous Tissue Nervous Function: nerve impulse transmission Function: (communication) (communication) Composed of nerve cells and support tissue Location: brain, spinal cord, nerves Cells = neurons (aka nerve fibers) 3 components: axon, body, dendrites long fiber (axon)- can be as long as muscle fibers, but only long one nucleus- signal transmission one body (aka perikaryon) dendrites- sense signal (receive impulses) Neuroglia Support tissue for neurons – nourishment More abundant than neurons Insulate and protect neurons Tissue Injury and Repair Tissue Injury Inflammation • Non-specific, local, acute • Heat, redness, swelling, pain Immune response • Highly specific, takes a while to develop Repair Regeneration • Replacement of tissue by same kind Fibrosis • Creation of fibrous CT (scar tissue) Tissue Throughout Life Tissue Stem cells Undifferentiated cells that continuously renew and produce Undifferentiated new cells when necessary new Found mostly in rapidly replacing tissues (e.g., epidermis), Found but are in other tissues too (e.g., brain) but 3 types: embryonic, embryonic germ, adult • Embryonic: human embryo, 5 days • Embryonic germ: 5-9 weeks – less research on these, but appear Embryonic more limited more • Adult: found in bone marrow, skin, blood, brain Umbilical cord and placenta are also being explored Treatment of neurological disorders Ethical issues • Stem cell line: mass of cells descending from original cell ...
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