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Unit 2- cells and tissues

Warm-up #1Write down 5 things that you remember about cells from bio 1.

Changes to Calendar TOC

Part 1: Biology Review• Objectives:• Identify cell organelles and briefly discuss the function of

each.• Explain the function of cell differentiation.• Discuss the structure and function of the cell membrane.• Explain how transport processes function to move substances

across the plasma membrane.• Differentiate between passive and active transport.• Give examples of passive and active transport.• Describe the process of mitosis and explain the importance of

mitotic cell division. (regulation of cell cycle)• Discuss neoplasms and distinguish between benign and

malignant neoplasms.

Cells and Tissues• Carry out all chemical activities

needed to sustain life• Cells are the building blocks of all

living things.• Tissues are groups of cells that are

similar in structure and function.

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Anatomy of the Cell• Cells are not all the same.• All cells share general structures.• All human cells have three main

regionso Nucleuso Cytoplasm (cytosol and organelles)o Plasma membrane

Found in ALL CELLS

Organelles- vary based on cell functions Name the structure and function.

Variety of cells- differentiationCell membrane

• flexible boundary• facilitates contact with other cells and

environment• receptor sites - hormones, enzymes,

neurotransmitters, nutrients, antibodies• selectively permeable - mediates entrance

and exit of material into and out of cello Based on:

• size of molecules• solubility in lipids• charge on ions• presence of carrier molecules

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Membrane structureCellular Projections

• Not found in all cellso Cilia move materials across the cell surface

• EX: respiratory system to move mucus o Flagella propel the cell

• Only human cell= spermo Microvilli are tiny, fingerlike extensions of the

plasma membrane• Increase surface area for absorption• EX: small intestines

Quick Check1. What is the function of the plasma membrane?2. What are 3 structures that all cells have?3. What is the function of the mitochondria?4. What kind of cell might have the most

mitochondria?

Solutions and Transport• Solution—homogeneous mixture of two or

more componentso Solvent—dissolving medium (water)o Solutes—components in smaller quantities within a solution

• Intracellular fluid—Fluid found in living cells.

• Interstitial fluid—fluid on the exterior of the cell (between cells)

Movement Across the Plasma Membrane

• Passive Processeso no energy expenditureo moves down a concentration gradiento high ---> low concentration

• Active Processeso requires energy expenditureo moves against a concentration gradiento low ---> high concentrationo may utilize 40% of cells ATP supply

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Passive Processes

• Types of diffusiono Simple diffusionoOsmosiso Facilitated diffusion

• Filtration

Passive Processes• Diffusion

o Particles tend to distribute themselves evenly within a solution

oMovement is from high concentration to low concentration, or down a concentration gradient

Passive Processes

• FiltrationoWater and solutes are forced through a

membrane by fluid, or hydrostatic pressureoA pressure gradient must exist

• Solute-containing fluid is pushed from a high-pressure area to a lower pressure area.

Active Processes• Substances are transported that are

unable to pass by diffusion o too largeo solubilityo against a concentration gradient

• ATP is used for transport (ENERGY)• Two common types

o Active transport (solute pumping)o Vesicular transport

• Exocytosis (out of cell)• Endocytosis (into cell)o Phagocytosiso Pinocytosis

Na+/K+ Pump Quick Check1. What is the main difference between passive and

active transport?2. Give examples of active transport used in the

body.3. Give examples of passive transport used in the

body.

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Cell Life Cycle• Cells have two major periods

o Interphase• Cell grows• Cell carries on metabolic processes

o Cell division (mitosis)• Cell replicates itself• Function is to produce more cells for growth and

repair processes.• Varies depending on cell type.• Body (somatic) cells.

o *Remember* - gametes are made by meiosis

Cell Cycle

Centrioles Chromatin

Formingmitoticspindle

Centrioles

Chromosome,consisting of twosister chromatids

Nuclearenvelope

Plasmamembrane

Interphase

Metaphaseplate

Nucleolus

Early prophase

Fragments ofnuclear envelope

Late prophase

Nucleolusforming

Spindlepole

Cleavagefurrow

Nuclearenvelopeforming

Telophase and cytokinesis

Daughterchromosomes

Anaphase

Sisterchromatids

Spindle

Metaphase

Spindlemicrotubules

Centromere

Centromere

Figure 3.15

Neoplasms• Uncontrolled cell division (loss of natural

cell cycle regulation)

• An abnormal cell mass= a neoplasm

Neoplasms• Benign = stays at the original site,

encapsulated. (noncancerous)• Malignant = nonencapsulated, metastasize,

or break away. (cancerous)

More on Cancer• Cancer can occur any time in your life.• Carcinogens are substances known to promote

cancer• It is NOT CONTAGIOUS• YOU CAN INHERIT MUTATED DNA WHICH INCREASES

CHANCE OF CANCER

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Quick Check• What are the four phases of mitosis?• Where does mitosis occur in the body?• Why is cell cycle regulation so important?• What is the difference between benign and

malignant?

Active Closure• Snowstorm:• On a scratch piece of paper develop and write

one question from the notes today.• When cued, crumple up the question and toss it in

the air.• Pick up a piece of paper and be ready to share the

question and a answer.

Part 2: Tissues• Objectives:• Explain the four major tissue type’s function and

determine the chief locations of each.

Warm-up #2• Describe the function of a sponge.

How does its structure allow for its function?

Body Tissues• Tissues

o Groups of cells with similar structure and functiono Four primary types

• Epithelial tissue (epithelium)• Connective tissue• Muscle tissue• Nervous tissue

• Structure based on function!

Epithelial Tissues

• Locationso Body coveringso Body liningso Glandular tissue

• Functionso Protectiono Absorptiono Filtrationo Secretion

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Epithelium Characteristics• Cells fit closely together and often form

sheets• free surface of the tissue= apical surface• basement membrane= lowest surface• Avascular (no blood supply)• Regenerate easily if well nourished• Classification based on cell layers and

shape:o Simple—one layero Stratified—more than one layer

Apical surface

Apical surface

Classification of Epithelia

• Shape of cellso Squamous

• flattenedo Cuboidal

• cube-shapedo Columnar

• column-like

Simple Epithelia

• Simple squamouso Single layer of flat cellso Location - usually forms membranes

• Lines body cavities• Lines lungs and capillaries• (little wear and tear)

o Functions • Diffusion• filtration• secretion in membranes

Simple Epithelia

• Simple cuboidalo Single layer of cube-like cellso Locations

• Common in glands and their ducts• Forms walls of kidney tubules• Covers the ovaries

o Functions • secretion and absorption• ciliated types propel mucus or reproductive

cells

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Simple Epithelia

• Simple columnaro Single layer of tall cellsoOften includes mucus-producing goblet

cellso Location - lines digestive tracto Functions

• secretion and absorption• ciliated types propel mucus

Stratified Epithelia

• Stratified squamouso Cells at the apical surface are flattened, lower

layers cuboidal.o Basal layers- continuous mitosiso Functions as a protective covering where friction

is commono Locations - lining of the:

• Skin• Mouth• Esophagus

Glandular Epithelium• Gland

o One or more cells responsible for secreting a particular product

o Secretions contain protein molecules in an aqueous (water-based) fluid

• Two major gland typeso Endocrine gland

• Ductless since secretions diffuse into blood vessels• All secretions are hormones

o Exocrine gland• Secretions empty through ducts to the epithelial surface• Include sweat and oil glands

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Nervous Tissue• Composed of neurons and nerve

support cells• Function is to send impulses to other

areas of the bodyo Irritabilityo Conductivity

• Support cells called neuroglia insulate, protect, and support neurons

Do you understand?• Classification of epithelium is based on

what?• What are the two types of glands?• Where would you find stratified squamous

epithelium?• What kind of epithelium would you find in

digestive tract?

Active Closure1. I am found covering the ovaries.

2. I am a single layer of tall cells.

3. I often contain goblet cells.

4. I am found in high friction areas, such as the

esophagus and skin.

5. I am responsible for secreting specific hormones.

6. I form the walls of the kidney tubules.

7. My main functions are diffusion and filtration.

Part 3: Tissues• Objectives:• Explain the four major tissue type’s function and

determine the chief locations of each.

Warm- up #3

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Connective Tissue• Found everywhere in the body (most

abundant tissue)• Variations in blood supply

o Mostly vascularizedo Some avascular (cartilage)

• Derived from cells called fibroblasts (produce ECM)

• Extracellular matrix (ECM)o Non-living material that surrounds living cellso Mostly water and some fibers produced by cells.

• Functionso Binds body tissues togethero Supports the bodyo Provides protection

Connective Tissue Types1. Bone (osseous tissue)

o Composed of• Bone cells in lacunae

(cavities)• Hard matrix of calcium

salts• Large numbers of

collagen fiberso Functions to protect and

support the body

Connective Tissue Types2. Cartilage:

Avascular (slow healing), strong• Types

• Hyaline cartilageo Most common type of cartilageo Composed of

• Abundant collagen fibers• Rubbery matrix

o Locations• Larynx, nose• Entire fetal skeleton prior to birth• Ends of long bones

Figure 3.19b

Chondrocyte(Cartilage cell)

Lacunae

(b) Diagram: Hyaline cartilage Photomicrograph: Hyaline cartilagefrom the trachea (500×).

Matrix

Chondrocytein lacuna

Connective Tissue Types• Cartilage types con’t…

o Elastic cartilage• Structural cartilage• Provides elasticity, shape, rigidity• Location

oSupports the external ear, tracheao Fibrocartilage

• Highly compressible (shock absorption)• Location

oForms cushion-like discs between vertebrae, pubic symphysis

Connective Tissue Types

3. Dense connective tissue (fibrous)o Main matrix element is collagen fibero Usually occurs in sheetso Locations

• Tendons• Ligaments

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Connective Tissue Types4. Loose connective tissue types

A. Areolar tissue• Most widely distributed

connective tissue• Soft, pliable tissue like “cobwebs”• Functions as a packing tissue• Contains all fiber types• Can soak up excess fluid (causes

edema)• helps hold internal organs

together and in proper position

Connective Tissue Types4. Loose connective tissue types

B. Adipose tissue• FAT• Functions

o Insulates the bodyo Protects some

organso Serves as a site of

fuel storage

Connective Tissue Types5. Blood (vascular tissue)

o Blood cells surrounded by fluid matrix called blood plasma

o RBC, WBC, plateletso Fibers are visible during

clottingo Functions as the

transport vehicle for materials

Do you understand?• Name the five types of connective tissue?• What is adipose tissue and tell me one funtion?• What is the function of connective tissue?• What are the three types of cartilage?• What type of cartilage is found in the larynx?

Muscle Tissue• Function is to produce movement• Can convert chemical energy to

mechanical energy.• Three types

o Skeletal muscleo Cardiac muscleo Smooth muscle

Muscle Tissue Types• Skeletal muscle

o voluntary o Contracts to pull on

bones or skino Produces gross body

movements or facial expressions

o Characteristics • Striated• Multinucleate (more

than one nucleus)• Long, cylindrical cells

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Muscle Tissue Types• Cardiac muscle

o involuntary o Heart onlyo Function = pump

bloodo Characteristics:

• Striated• One nucleus • Intercalated discs• Amitotic at

maturity

Muscle Tissue Types• Smooth muscle

o involuntary o Found in walls of hollow

organs such as stomach, uterus, and blood vessels

o Characteristics of smooth muscle cells• No visible striations• One nucleus per cell• Spindle-shaped cells

Tissue Repair (Wound Healing)

• Regenerationo Replacement of destroyed tissue by the same kind of cells

• Fibrosiso Repair by dense (fibrous) connective tissue (scar tissue)

• Whether regeneration or fibrosis occurs depends on:o Type of tissue damagedo Severity of the injury

Events in Tissue Repair• Inflammation

o Capillaries become very permeableo Clotting proteins migrate into the area from the blood

streamo A clot walls off the injured area

• Granulation tissue formso Growth of new capillarieso Rebuild collagen fibers

• Regeneration of surface epitheliumo Scab detaches

Regeneration of Tissues• Tissues that regenerate easily

o Epithelial tissue (skin and mucous membranes)o Fibrous connective tissues and bone

• Tissues that regenerate poorlyo Skeletal muscle

• Tissues that are replaced largely with scar tissue (because they are amitotic)

o Cardiac muscleo Nervous tissue within the brain and spinal cord

Do you understand?• What are the three types of muscle tissue?• Where do you find Nervous tissue?• What causes scaring?• What is the last step to tissue repair?

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Active closure• Summarize today’s lesson in 5 words or

less.

Warm- up #4• 1. ID the specific tissue

type.• 2. How did you ID the

tissue? (what characteristics did you use?)

• 3. Where might you find this tissue in your body?

• 4. What is one function of this tissue?

Active Closure• Using the information from today’s lab, write

a question using one of the following beginnings:oWhat is the relationship between….?oWhat ideas justify…..?oCan you propose an alternative to…?oHow can you distinguish between…..?

• Be ready to answer one another’s questions.

TEST DAY!• Get your unit 2 notebook packet in order. • You may have 5 minutes to look over your

notes and worksheets.• After the 5 minutes, then place the stapled

notebook packet at the front, grab an answer sheet.

• Phones and electronic devices are off and placed in book bags.

• Bags are at the front of the room…UNTIL ALL ARE FINISHED WITH THE TEST!!