Human Anatomy and Physiology

Chapter 3 –Cells and Tissues

Part I-Cells

• Identified by _______________first as he looked at dead cork cells

• Cell Theory:• Basic structural and functional unit of life• Activity of an organism depends on collective activity of cells• ___________________________________-Biochemical activities

of cells are dictated by their relative # of their specific subcellular structures

• Continuity of life has a cellular basis

Robert Hooke

Principle of Complementarity

• Made of primarily 4 elements---_____________/other elements include Ca, I, Na, K..Some of these in water solution carry a charge ,at which point they are called_______________...Ca is used for blood clotting ,Fe to make hemoblobin, and I for Thyroid hormone

C,H,O,N

Electrolyte/ion

• ~60% water/cells are in a dilute water solution called________________ (dilute saltwater solution),,derived from blood-HERE IS WHERE EXCHANGES BETWEEN CELLS & BLOOD TAKE PLACE!

• Size ranges—2 micrometers-~1 meter• Overall structure may be related to

function

Interstitial fluid

ANATOMY of GENERALIZED CELL-

• -nucleus,cytoplasm,plasma membrane• 1) Nucleus-____________centered---contains DNA

which has info for making proteins-/necessity for cell reproduction/shape usually conforms to shape of cell

• ___________or___________ fluid –filled space with nuclear pores penetrate through envelope-Contain jellylike nucleoplasm-other Nuclear elements suspended

• _________-makes ribosomes• Chromatin-DNA and chromatin that constitute dense

chromosomes during cell division

Control centerNuclear envelope OR membrane

nucleoli

2)Plasma Membrane(cell membrane)

• Contains a phospholipids bilayer-“tail-to-tail” and proteins floating amidst this.-some having attached sugars---as channels to allow particles in and carb tags to specify what molecules are admitted/some proteins act as carriers to move something out membrane

• Fluid mosaic model• Also contains cholesterol-helps keep the

membrane fluid• Proteins may be enzymes or hormone receptors

Plasma membrane cont’d

• Polar heads of bilayer are Hydrophilic-______________________

• Nonpolar tails are Hyrdrophobic-avoid water• General properties allows membrane to reseal easily

Attracted to water

• The “sugar proteins” are _____________________ producing the sugar rich or(sticky) known as Glycocalyx—-one of the many functions is to determine blood type,or as receptors for bacteria,viruses and toxins---some function as enzymes---see cancer connection p.102-103---``````````````, most functions are for transport

Glycoproteins

Cell Membrane specializations:

»Microvilli-Projections to increase surface area so absorption occurs more quickly

>>Membrane junctions

• : may be 1-glycoproteins acting as glue or adhesive,2-wavy contours from membranes of adjacent cells fit together in a tongue-and groove manner Or 3-special membrane junctions/structurally depending on roles

>>Membrane junctions

A-________________-impermeable and bind to prevent leakage between cells(acts like a “zipper”)

B-____________anchoring junctions that prevent mechanical stress(eg.skin cells)-prevent being pulled apart—thickenings_PLAQUES-of adjacent cell membrane-by protein filaments-”guy wires”

TIGHT junctions Desmosomes

Membrane Junctions cont’d

• C---______________________-(in heart and between embryonic cells)—function for communication----place where chemicals pass----connect to neighboring cell by CONNEXONS(hallow cylinders composed of proteins to span width between cell)

Gap Junctions

CYTOPLASM-material outside nucleus and inside cell membrane

1)cytosol fluid;2)organelles 3) inclusions-chemicals possibly present,depending on cell type—usually stored nutrients of cell products-eg.pigment or glycogen. lipid droplets common in fat cells, mucus, or crystals.

ORGANELLES:

• Most membrane bound-allows unique internal environment separate from cytosol

• _______________-changes shape and has a double membrane-Inner cristae composed of enzymes and as well as dissolved in fluid-CARRY OUT CELLULAR RESPIRATION from which we get ATP-energy----many found in liver and muscle----in more busy cells,enzymes dissolved in fluids and cristae

mitochondria

• ____________-have rRNA and protein ,HERE mRNA is read -tRNA-brings appropriate amino acid in to make PROTEINS…..some free in cytoplasm and some attached to ER

• ER-endoplasmic reticulum-has fluid filled cisterns or coils

ribosomes

Er cont’d

– Rough-has ribosomes and sends proteins out as their intricate folding occurs to area of cell in transport vesicles or for export (protein products)

– Smooth-used in lipid metabolism and detox of drugs etc.,(many in liver)• ___________-stack of membranous sacs and

exports proteins in SECRETORY VESICLES,then to plasma membrane-eg-digestive enzymes made by pancreas

GOLGI

• ______________________-membranous bags w/ digestive enzymes-for worn out cell structures

lysosomes

• Perioxisomes-membranous sacs w/ oxidase enzymes that use O2 to detox poisons-like alcohol- and formaldehyde---also to convert FREE RADICALS to H2O2 and this is catalyzed to water….(What are Free radicals?-reactive chemicals w/unpr’ed electrons that can scramble proteins and nucleic acids….many in liver and kidney)/peroxisomes convert peroxide to H2O2/enzyme ctalase converts peroxide to H2O

• Cytoskeleton—network of protein structures,inc:– Intermediate filaments-help desmosomes– microfilaments-involved in motility and shape-

eg.actin and myosin– microtubules-give shape and for cell divisions

• Cytoskeleton—network of protein structures,inc:

– Intermediate filaments-help desmosomes– microfilaments-involved in motility and

shape-eg.actin and myosin– microtubules-give shape and for cell

divisions

• Centrioles-near nucleus-role in cell division• Cilia-on some cells to move things-as in

respiratory tract• Flagella-whiplike---in sperm• microvilli

Cell extensions

CELL DIVERSITY-Trillions of human cells spell about 200 different cell

types.Below are some of the specializations--shape reflects function

--– 1) Cells that connect body parts:

• ____________-elongated shape;secretes cable –like fibers;much rough ER and large Golgi to secrete proteins

• ____________(RBC)carries O2 in blood;concave shape gives surface area for O2 uptake,yet streamlined for flow-absent of other organelles so can carry much O2

Fibroblast Erythrocyte

– 2)Cell that covers and lines body organs:– _______________________hexagonal shape-

allows packing together in a sheet;filaments present to resist tearing

– 3) Cells that move organs and body parts:

– Skeletal and smooth muscle-long and filled w/ contractile filaments-to move bones or change size of internal organs.

epithelial

– 4) Cell that stores nutrients– ____-large spherical shape-from large lipid

droplet in cytoplasm– 5) Cell that fights diseases:– ________________________-phagocytic-sends

pseudopods to reach infection and infection digested by lysosomes

fat Macrophage

• 6)Cell that gathers info and controls body functions:• ______________-(neuron)-long extensions for

receiving messages and transmiting;extensive plasma membrane/plenty rough ER for making membrane components

• 7) Cells of Reproduction:• __________female-largest cell in body,several

copies of all organelles• __________male-long and flagellated

Nerve Oocyte and

sperm

III. CELL PHYSIOLOGY--for metabolism,digestion,waste

disposal,reproduction,growth,movement,and irritability

• ---MEMBRANE TRANSPORT• Solution basics-

– __________=homogeneous mixture of 2 or more substances

– _______________-does dissolving– _______________-gets dissolved

solution solvent solute

• __________________-nucleoplasm and cytyosol---containing sm amounts gases(O2 and CO2),nutrients,and salts in water solution

• _____________-continously washes exterior of cells---many components,inc. amino acids,sugars,fatty acids ,vitamins/regulatory hormones and neurotransmitters,as well as salts and waste.CELL MUST OBTAIN THAT WHICH IT NEEDS FROM HERE AND REJECT REST.

Intracellular fluid

Interstitial fluid

• Plasma Membrane is ___________________________________-choosy in what is allowed in and kept out….also certain substance smust remain in cell

Selectively permeable

Movement in 2 ways:– 1) PASSIVE TRANSPORT—pass w/o energy– ________________molecules move AWAY from

areas where more concentrated;move down concentration gradient-; greater the difference in concentration of 2 areas,the faster the movement-also the smaller the particle,the faster it moves--hydrophobic portion of membranes resists barrier, ;hydrophobic portion of membranes resists-barrier

diffusion

• ----WILL MOVE THROUGH DUE TO ANY OF THE FOLLOWING:-1)small molecules 2)lipid soluble molecules and 3)assisted by membrane carrier- diffusion,-particles small enough will go through pores-in MEMBRANE PROTEINS-This is simple diffusion-either they are small enough or lipid soluble

• _____________-water diffuses through selectively permeable membrane-water resisted through nonpolar lipid core—BUT assisted by pores called____________-made by membrane proteins

osmosis

aquaporins

– Facilitated diffusion-needed substance-eg.glucose-lipid insoluble and too big for pores protein membrane channel is used-transport vehicle

– ____________-water and solutes forced through a membrane-or capillary wall by FLUID_HYDROSTATIC PRESSURE---usually by blood-is w/ a gradient,but the gradient actually MOVES the solution.The gradient is called a PRESURE GRADIENT-actually pushes solute through….also used in kidney function/usually just blood and membrane proteins held back

Filtration

– 2) ACTIVE TRANSPORT PROCESSES-uses ATP-particles may be against gradient,too large,or lack a helper protein

– Active Transport-solute pump-ATP energizes protein carriers(solute pump)-carries amino acids,sugars ,and most ions----Sodium potassium pump vital to nerve transmission{excess Na ions outside and excess K on inside

– ______________________-w/ use of ATP moves large masses in or out(w/o crossing plasma membrane)

• __________________- moves large masses out-package by golgi into vesicles and ruptures outward-Secretion of hormones,mucus…Transmembrane Proteins on vesicles (v_SNARES) /v=vesicle-recognize Plasma Proteins (t-SNARES)/t=target-causes membranes to corkscrew together and fuse

• __________________-moves the same IN—engulfs certain substances into a vesicle-sends to lysosome…..Phagocytosis—engulfs larger things/eats bacteria and dead cell bodies-protective,not nutritive

• Pinocytosis(cell drinking)—pinches in liquids/frequent occurrence as in absorption in small intestine

• Receptor mediated endocytosis-plasma membrane receptors target certain molecules

Vesicular transport exocytosis

endocytosis

CELL DIVISION-cell reproduces

During interphase,cell must duplicate DNADNA REPLICATION/enzyme regulated—remember A_T

and C_G

• MITOSIS--( may take 5 minutes-several hrs.)number of chromosomes you start with—diploid is same at end,then followed by cytoplasm division-____________________

• PROPHASE-chromatin coils and shortens-CHROMOSOMES;centrioles move to opposite poles and mitotic spindle form to form a railway for chromosome movement

cytokinesis

• Metaphase-chromosomes line up at center• Anaphase-chromatids split and go to opposite

poles• Telophase-chromosomes become thin

again,spindles break down and 2 new nuclei• CYTOKINESIS separation occurs at

_________________maybe a multinucleated cell w/o cytokinesis.

Cleavage furrow

Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings

Stages of Mitosis

Figure 3.15(cont)

PROTEIN SYNTHESIS-

• _________________-DNA segment with info for one protein(polypeptide chain)

• DNA is stuck in nucleus so copies some of info onto mRNA—mRNA forms a RNA version of DNA template(note U replaces T----so A-U and C-G

• This is decoded or interpreted by rRNA-at ribosome

gene

• tRNA brings in appropriate amino acids to assemble protein at ribosome

• ___________________-transfer of DNA base sequence into complementary mRNA segment-each 3 amino acids are a triplet and complement on mRNA is called a_____________________

Transcriptionanticodon

DNA mRNAA UA UT AC GG C

T___________AT__________AC__________G

G___________C

• Translation-DNA info translated into amino acids----tRNA brings in a anticodon to complement codon and this brings in correct amino acid

Part II –BODY TISSUES

• _________________cells in a group that are similar in structure and function

• Basically 4 types and functions:– covering(epithelial)– movement(muscle)– support(connective)– control(nervous)

tissue

Epithelial Tissue

• This is the lining ,covering(cover free body surfaces and _____________________of the body,covering various glands

• Function in protection,absorption,filtration and secretion

glands

SPECIAL CHARACTERISTICS OF EPITHELIUM

– fit together closely to form continuous sheets(except glandular)-bound by tight junctions and desmosomes

– Always has one free unattached edge-_____________________-exposed to body’s exterior or cavity of an organ

apical

– lower surface rests on a ____________-structure-less material secreted by both epithelial and connective tissue that is abut the epithelium

– no blood supply of own--__________________-and depend on diffusion from capillaries-from underlying connective tissue for food and oxygen normally regenerate easily

Basement membrane avascular

• CLASSSIFICATION OF EPITHELIUM -1st name indicates basic # of cell layers

– ___________________________-1 layer of cells– ____________________________-> 1 cell layer

simple

stratified

CLASSSIFICATION OF EPITHELIUM -2nd name indicates shape of cells

• _______________________-flattened like fish scales(squam= scale)

• cuboidal-shaped like dice

• columnar-like columns

• (stratified epithleial named for cells at free surface,not those on basement layer)

squamous

SIMPLE EPTHELIA—apsortion,secretion,and filtration-not protection

• Simple Squamous Epithelium-rests on basement membrane,fit closely,usually forms membranes for for filtration or diffusion

• ---found in lungs(air sacs),walls of capillaries –nutrients and gases pass

• ----also found in ___________________________-slick membranes in ventral body cavity and organs

Serous membranes--serosae

Simple Cuboidal Epithelium-also fit closely together on basement membrane--in glands and ducts,walls of kidney tubules and

surface of ovaries

Simple Columnar Epithelium-also close together--_______________make a lubricating mucus-entire

digestive tract---called __________if line body cavities open to

exterior

Goblet cells

Mucosae or mucous membranes

• Pseudostratified Columnar Epithelium• --on basement membrane• Some cells shorter than others and nuclei give

impression of different heights—false impression--- that its stratified

• - Pseudostratified Ciliated Columnar Epithelium- in respiratory tract –goblet cells help trap dust

nonciliated is found in male reproductive system

STRATIFIED EPITHELIA—durable and protect

• Stratified Squamous Epithelium-most stratified Epithelium/most common epithelium---several layers

• -squamous at free edge and more columnar or cuboidal close to basement

• -sites that receive abuse like-____________________

Esophagus,mouth or skin

• Stratified Cuboidal –typically 2 cell layers and stratified Columnar Epithelium-basal cells vary in size and shape----both types rare in body-mostly in ducts of large glands

• Transitional Epithelium-modified stratified squamous in lining of a few organs(bladder,ureters and urethra---which are all subject to stretching)

• -basal layer cuboidal or columnar;at free surface vary)eg. When not stretched has many layers

• -ability to slide past each other and change of shape yields function

Glandular Epithelium-

• -product called __________________(also refers to verb)-usually protein in water

• _______________glands-lose connection to surface and called (often ductless)________________-secrete hormones into blood-eg.thyroid,pituitary and adrenals

• ______________glands keep ducts and secrete to epithelial surface-eg sweat and oil glands,liver and pancreas

secretionEndocrine/ ductless

exocrine

II.Connective Tissue-connects body parts-mostly involved in protecting,supporting,and binding/most

abundant and widely distributed

1. Variations in blood supply-most well vascularized(except tendons and ligaments-poor blood supply/cartilage is avascular-thus heal slowly)

• 2)__________nonliving material– Produced by connective tissue and secreted to its

exterior has 1)structureless ground fibers w/some adhesion proteins(like a glue attaching cells to matrix fibers in ground substance) and large polysaccharides(trap water as they intertwine---varies to gel-like to rock hard-a water reservoir)

– Fibers—inc. collagen(white)-strong , elastic(yellow)-stretches and recoils,____________________-fine collagen inside soft organs-like spleen……

– Building blocks made by connective tissue cells and secreted into ground substance in extracellular space

– Matrix allows it to form soft packing,weight and withstand abuse

Extracellular

MatrixReticular fibers

VARIATION:1)in fat mostly cells and matrix soft/ 2)opposite extreme is bone w/few cells and hard

TYPES Of CONNECTIVE TISSUE:all living cells surrounded by matrix

• Bone-_bone cells=osteocytes/_________________tissue-bone cells in cavities called ______________________(“pits”) surrounded by hard matrix w/Ca salts and collagen-PROTECTS

osseus lacunae

• Cartilage-less hard and more flexible/major cell type=chondrocytes

– 1)________________________most common-abundant collagen w/rubbery matrix-blue-white—in larynx,attaching ribs to sternum and covers end of many bones to form joints(fetal skeleton mostly hyaline)

hyaline

• ___________________-compressible-in cushion-like discs between vertebrae

fibrocartilage

– 3)Elastic cartilage-eg.external ear

• Dense Connective tissue-or dense fibrous collagen crowded between rows of fibroblasts-fiber forming cell----tendons(muscle to bones and ligaments that connect ___________________________

bones

Loose connective Tissue-softer w/ more cells and less fibers than any other (except blood)

• ____________________soft,pliable-cobweblike that protects body organs---lamina propria(soft) underlies all mucous membranes-fluid w/loose fibers of all types in matrix (Areola=small open space)---much water and salts-“tissue fluid”----subjected to _______________-swelling-often fill w/phagocytes

areolar

edema

• _________________-fat-areolar tissue in which fat cells predominate(signet ring cells) the fat displaces nucleus to one side-------makes up subcutaneous tissue-insulates and protects from exterior and protects some organs(eg.eyes and kidneys)

adipose

Reticular Connective tissue- reticular fibers in delicate network and cells(reticular cells) that look like fibroblasts-make stroma or bed for free blood cells in lymph organs-spleen,nodes,and bone

marrow

Blood-vascular tissue-matrix is blood plasma-fibers are soluble proteins---covered in ch 10

III. MUSCLE TISSUE-movement

• Skeletal-packed connective tissue sheets

• voluntary-flesh

• ---cells long,cylindrical and multinucleate w/striations---muscle fibers

• Cardiac-in heart-pumps blood-has striations,but uninucleate,short,branching cells

• ---W/______________________where branches fit together by gap junctions-to allow ions to pass-giving electrical impulse---INVOLUNTARY

Intercalated disks

___________________-(or visceral)-no striations visible,single nucleus and spindle shaped cells-contract and expand for organs(relaxation-enlarges)----contract more slowly

Smooth muscle

• ---_______________________________-wavelike motion that moves food in small intestine

peristalsis

IV.Nervous Tissue-contains __________________

• Neurons receive and transmit electrochemical impulses

• _________________________-insulate-protect

neurons Supporting cells

TISSUE REPAIR-

– by Regeneration-replace w. same type of cells– fibrosis-repair by dense connective tissue---scar

tissue-depends on damage and severity• Capillaries become permeable-income clotting

proteins and other material(clot exposed to air becomes a scab)

• ____________________tissue forms-delicate pink tissue made of new capillaries that grow into damaged area-fragile

• Surface epithelium regenerates-beneath scab• Scar tissue usually poor on function

granulation

DEVELOPMENTAL ASPECTS OF CELLS AND TISSUES

• Importance of cell division(except neurons)• At adulthood only certain cells regenerate-

epithelial,liver only for tissue replacement/heart and nerves become mostly amitotic-

• Aging process begins once maturity is reached—possibly net effect of “chemical insults”;some think influenced by radiation;and some think it is genetically programmed

• List some tissue changes of aging-see p.104

• ___________________abnormal mass of dividing cells-benign or malignant

• Hyperplasia-growth due to hormone or irritant• Dysplasia-Abnormal development or growth of tissues,

organs, or cells

neoplasm

Atrophy-decrease in size—if loss normal stimulation-eg. with unused muscle