powerpoint to accompany hole’s human anatomy and … · 2014-07-15 · 22 3.2 clinical...

1 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Chapter 03

*Lecture Outline

*See separate Image PowerPoint slides for all

figures and tables pre-inserted into

PowerPoint without notes.

2

3.1: Introduction

• The basic organizational structure of the human body is the

cell.

• There are about 75 trillion cells in the human body.

• Cell size is measured in micrometers.

• Differentiation is when cells specialize.

• As a result of differentiation, cells vary in size and shape

due to their unique function.

3

3.2: A Composite Cell

• Also called a ‘typical’

cell

• Major parts include:

• Nucleus

• Cytoplasm

• Cell membrane

Microtubules

Flagellum

Nuclear envelope

Basal body

Chromatin Ribosomes

Cell membrane

Mitochondrion

Cilia

Microtubules

Microtubule

Centrioles

Microvilli

L ysosomes

Nucleolus

Nucleus

Phospholipid bilayer

Smooth

Endoplasmic

reticulum

Rough

Endoplasmic

reticulum

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Golgi apparatus

Secretory

vesicles

The nucleus is usually innermost and is enclosed by the

nuclear envelope. It contains DNA which directs the

cells functions.

The cytoplasm includes the organells that provide specific

functions such as extracting energy from nutrients,

dismantling debris, or packaging secretions.

The cell membrane(also called a plasma membrane),

mainly composed of lipids and proteins, contains the

cytoplasm which surrounds the nucleus.

It is self sealing but if extensively damaged the cell dies.

4

5

Cell Membrane

(aka Plasma Membrane) • Outer limit of the cell

• Controls what moves in and out of the cell

• Selectively permeable—it decides what goes through or not

• Phospholipid bilayer • Water-soluble “heads” form surfaces (hydrophilic)

• Water-insoluble “tails” form interior (hydrophobic)

• Permeable to lipid-soluble substances--

• Cholesterol stabilizes the membrane

• Proteins: • Receptors

• Pores, channels and carriers

• Enzymes

• CAMS

• Self-markers

6

Cell Membrane

Cell membrane

Cell membrane (b) (a)

“Heads” of

phospholipid

“Tails” of

phospholipid


a: © Biophoto Associates/Photo Researchers, Inc.

Fibrous protein Carbohydrate Glycolipid

Glycoprotein

Extracellular side

of membrane

Cytoplasmic side

of membrane

Cholesterol

molecules Globular

protein

Double

layer of

Phospholipid

molecules

Hydrophobic

fatty acid

“tail”

Hydrophilic

Phosphate

“head”


Table 3.1

Fig. 3.7


Double

layer of

phospholipid

molecules

Fibrous protein

Extracellular side

of membrane

Glycolipid Carbohydrate

Glycoprotein

Hydrophobic

fatty acid

“tail”

Hydrophilic

phosphate

“head”

Globular

protein

Cytoplasmic side

of membrane

Cholesterol

molecules

9

3.1 Clinical Application

Faulty ion channels cause disease

0 in your book describes how

pain intensity, irregular heartbeats,

and cystic fibrosis have something in

common.

11

Cell Adhesion Molecules

(CAMs)

• Guide cells on the move

•Helps cells get where they need to

• Integrin – guides white blood

cells through capillary walls

• Important for growth of

embryonic tissue

• Important for growth of nerve

cells

Adhesion

White blood cell

Integrin

Selectin

Exit

Splinter

Attachment

(rolling)

Blood vessel

lining cell

Carbohydrates

on capillary wall

Adhesion

receptor proteins



White blood cell

Attachment

(rolling)

Adhesion

Integrin

Blood vessel

lining cell Exit

Splinter

Adhesion

receptor proteins

Carbohydrates

on capillary wall

Selectin

13

Cytoplasm

• Cytoplasm = networks of membranes and organelles

suspended in the cytosol

•Activities of the cells occur mainly in the cytoplasm

•Cytoskeleton= forms supportive framework and is

made of protein rods and tubules

•The following slide are cytoplasmic organelles and their

functions

14

Organelles

Endoplasmic Reticulum (ER)

• Connected, membrane-bound

sacs, canals, and vesicles

• Transport system

• Rough ER • Studded with ribosomes

• Smooth ER • Lipid synthesis

• Added to proteins

arriving from rough ER

• Break down of drugs Ribosomes

• Free floating or connected to ER

• Provide structural support and enzyme activity

to amino acids to form protein

Membranes

Ribosomes

Membranes

(b) (c)


ER membrane

Ribosomes

(a)

(a): © Don W. Fawcett/Photo Researchers, Inc.

Golgi apparatus

• Stack of flattened,

membranous sacs

• Modifies, packages

and delivers proteins

Vesicles

• Membranous sacs

• Store substances

15

Organelles Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Nuclear

envelope

Nucleus

Cytosol

Rough

endoplasmic

reticulum

Golgi

apparatus

Secretion

Transport

vesicle

Cell membrane (a) (b)

a: © Gordon Leedale/Biophoto Associates

16

Organelles

Inner membrane

Outer membrane

Cristae

(a) (b)

a: © Bill Longcore/Photo Researchers, Inc.

Mitochondria

• Membranous

sacs which

captures and

transfers energy

into ATP

• Generate energy

The Mitochondria uses cellular

respiration . It is a chemical reaction that

releases energy from glucose and other

nutrients. It captures and transfers this

newly released energy into special

chemical bonds of the molecule

adenosine triphosphate( ATP)

17

Fig. 3.11


1

2

3

4

5

6

7

Lysosome Lipids are

synthesized

in the smooth

endoplasmic

reticulum (ER).

Mitochondrion

Cell membrane

Carbohydrates

Nuclear pore

Nuclear envelope

Milk protein genes are

transcribed into mRNA.

mRNA exits through

nuclear pores.

Most proteins are synthesized

on ribosomes associated with

membranes of the rough ER,

using amino acids in the cytosol.

Sugars are synthesized in the

smooth ER and Golgi apparatus

and may be attached to proteins

or secreted in vesicles.

Proteins are secreted from

vesicles that bud off of the

Golgi apparatus.

Fat droplets pick up a layer of

lipid from the cell membrane

as they exit the cell.

Milk

protein mRNA

Milk

protein

in Golgi

vesicle

19

Organelles

Lysosomes

• Enzyme-containing

sacs

• Digest worn out cell

parts or unwanted

substances

Peroxisomes

• Enzyme-containing

sacs

• Break down organic

molecules

Centrosome

• Two rod-like centrioles

• Used to produce cilia and

flagella

• Distributes chromosomes

during cell division

(a) (b)

)

a

20

Organelles

Cilia---motile extensions—fringe the

free surfaces of some epithelial

cells—propels mucus over the lining

of the respiratory tract

• Short hair-like projections

• Propel substances on cell

surface

Flagellum

• Long tail-like projection

• Provides motility to sperm

(a)


a: © Oliver Meckes/Photo Researchers, Inc.

© Colin Anderson/Brand X/CORBIS

21

Microfilaments and microtubules

• Thin rods and tubules

• Support cytoplasm

• Allows for movement of

organelles

Organelles Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Nucleus Mitochondrion Vesicle

Rough

endoplasmic

reticulum

Cell membrane

(a) Microfilaments Microtubules Ribosome

(b) b: © K.G. Murti/Visuals Unlimited

22

3.2 Clinical Application

Disease at the Organelle Level p. 95

If mitochondria cannot synthesize proteins required

to carry out energy reactions.

Krabbe disease is a lsysosomal storage disease. It

results when one of the organelle’s enzymes is not

present within a certain concentration range.

ALD decrease in enzyme normally manufactured in

peroxisomes. The enzyme controls breakdown of a

type of fatty acid. Death comes in a few years.

1992 film Lorenzo’s oils told the story.

23

Cell Nucleus

•Control center of the cell

• Nuclear envelope

• Porous double membrane

• Separates nucleoplasm from

cytoplasm

• Nucleolus

• Dense collection of RNA and

proteins

• Site of ribosome production

• Chromatin

• Consists of all the cell’s 46

chromosomes, each containing DNA

wound around proteins

• Fibers of DNA and proteins

• Stores information for synthesis of

proteins


Nucleus

Nucleolus

Chromatin

(a)

Nuclear

pores

Nuclear

envelope

24

3.3: Movements Into

and Out of the Cell

Physical (Passive) Processes

• Require no cellular

energy and include:

• Simple diffusion

• Facilitated diffusion

• Osmosis

• Filtration

Physiological (Active) Processes

• Require cellular energy and

include:

• Active transport

• Endocytosis

• Exocytosis

• Transcytosis

25

Simple Diffusion

• Movement of substances from regions of higher concentration to

regions of lower concentration---the concentration gradient

• Oxygen, carbon dioxide and lipid-soluble substances

T ime

Solute molecule

W ater molecule

A B A B

(2) (3)

Permeable

membrane

A B

(1)


26

Facilitated Diffusion

• Diffusion across a membrane with the help of a channel or carrier

molecule

• Glucose and amino acids

•Think “revolving door”

But only down a concen-

tration gradient and is

specific for a particular

Solute– if the concentration

Inside is too high it will not

transfer

Region of higher

concentration

Transported

substance

Region of lower

concentration Protein carrier

molecule

Cell

membrane


27

Osmosis

• Movement of water through a selectively permeable

membrane from regions of higher concentration to

regions of lower concentration

• Water moves toward a higher concentration of solutes

T ime

Protein molecule

W ater molecule

A

B

A B

(1) (2)

Selectively

permeable

membrane


28

Osmosis and Osmotic Pressure

• Osmotic Pressure – ability of osmosis to generate

enough pressure to move a volume of water

Osmotic pressure increases as the concentration

of nonpermeable solutes increases.

• Isotonic – same osmotic pressure

•Cells placed in isotonic have no net gain or loss

of water.

• Hypertonic – higher osmotic pressure (water loss)

•Cells placed in hypertonic solution lose water.

• Hypotonic – lower osmotic pressure (water gain)

•Cells placed in hypotonic solution gain water.


© David M. Phillips/Visuals Unlimited

(b)

(a)

(c)

What is a hypotonic solution?

the solution has a lower solute concentration than the cell so

water moves into the cell causing plant cells to swell and

animal cells to swell and burst

what is isotonic solutuin?

The concentration of solutes is equal inside and outside the cell

so water moves across the membrane in both directions

maintaining cell size

What is hypertonic solution?

The solution has a higher solute concentration than the cell so

water moves out of the cell and into the solution causing the

cell to plasmolyze

(following slide shows) examples

29

Solutions

30

0.9% NaCl (normal saline) isotonic

0.25% NaCl hypotonic—lower

solute concentration

0.45% NaCl hypotonic

2.5% dextrose hypotonic

Lactated Ringer's solution isotonic

D5W (acts as a hypotonic solution

in body) isotonic

D5 NaCl hypertonic

D5 in Lactated Ringer's hypertonic

D5 0.45% NaCl hypertonic

31

Filtration

• Smaller molecules are forced through porous membranes

• Hydrostatic pressure important in the body—think kidneys and low B/P

• Molecules leaving blood capillaries Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Capillary wall

Larger molecules

Smaller molecules

Blood

pressure Blood

flow

Tissue fluid

32

Active Transport

• Carrier molecules transport substances across a membrane from regions of

lower concentration to regions of higher concentration

• Requires energy

• Sugars, amino acids, sodium ions, potassium ions, etc. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Carrier protein Binding site

(a)

(b)

Cell m

em

bra

ne

Carrier protein

with altered shape

Phospholipid

molecules Transported

particle

Cellular

energy

Region of higher

concentration

Region of lower

concentration

33

Active Transport:

Sodium-Potassium Pump

• Active transport mechanism

• Creates balance by “pumping” three (3) sodium

(Na+) OUT and two (2) potassium (K+) INTO

the cell

• 3:2 ratio

34

Endocytosis

• Cell engulfs a substance by forming a vesicle around the

substance does not actually cross the cell membrane

• Three types:

• Pinocytosis – substance is mostly water

• Phagocytosis – substance is a solid

• Receptor-mediated endocytosis – requires the substance

to bind to a membrane-bound receptor

Nucleus Nucleolus

V esicle Cell

membrane


35 Cytoplasm

V esicle

(a) (b) (c) (d)

Receptor

protein

Cell

membrane

Molecules

outside cell

Cell

membrane

indenting

Receptor-ligand

combination

Particle

Phagocytized

particle

Cell

membrane


•Receptor-mediated endocytosis – requires the

substance to bind to a membrane-bound receptor

36

Exocytosis

• Reverse of endocytosis

• Substances in a vesicle fuse with cell membrane

• Contents released outside the cell

• Release of neurotransmitters from nerve cells

Nucleus

Endoplasmic

reticulum

Golgi

apparatus


37

Transcytosis

• Endocytosis followed by exocytosis

• Transports a substance rapidly through a cell

• HIV crossing a cell layer

V iruses bud

HIV

Exocytosis

Receptor-mediated endocytosis

HIV-infected

white blood cells Anal or

vaginal canal

Lining of anus

or vagina

(epithelial cells)

Virus infects

white blood cells on

other side of lining

Receptor-mediated

endocytosis


Cell

membrane

38

3.4: The Cell Cycle

• Series of changes a cell

undergoes from the time it

forms until the time it divide

• Stages:

• Interphase

• Mitosis

• Cytokinesis

Apoptosis

G2 phase

Cytokinesis

Restriction

checkpoint

Remain

specialized

Proceed

to division

S phase:

genetic

material

replicates

G1 phase

cell growth


39

Interphase

• Very active period

• Cell grows

• Cell maintains routine functions

• Cell replicates genetic material to prepare for nuclear division

• Cell synthesizes new organelles to prepare for cytoplasmic

division

• Phases:

• G phases – cell grows and synthesizes structures other than

DNA

• S phase – cell replicates DNA

40

Mitotic Cell Division

• Produces two daughter cells from an original (non sex) somatic

cell-each with 46 chromosomes.

• Nucleus divides – mitosis

• Cytoplasm divides – cytokinesis

• Phases of mitosis:

• Prophase – chromosomes form; nuclear envelope disappears

• Metaphase – chromosomes align midway between

centrioles

• Anaphase – chromosomes separate and move to centrioles

• Telophase – chromatin forms; nuclear envelope forms

41

Mitosis

Telophase and Cytokinesis

o cells. Nuclear envelopes begin to

reassemble around two daughter

nuclei. Chromosomes decondense.

Spindle disappears. Division of

the cytoplasm into two

Anaphase

Sister chromatids separate to

opposite poles of cell. Events

begin which lead to cytokinesis. Metaphase

Chromosomes align along

equator, or metaphase plate

of cell.

Prophase

Chromosomes condense and

become visible. Nuclear

envelope and nucleolus

disperse. Spindle apparatus

forms.

Late Interphase

Cell has passed the

restriction checkpoint

and completed DNA

replication, as well as

replication of centrioles

and mitochondria, and

synthesis of extra

membrane.

Early Interphase

of daughter cells—

a time of normal cell

growth and function.

Cleavage

furrow

Nuclear

envelopes

Nuclear envelope Chromatin

fibers

Chromosomes

Spindle fiber

Centromere

Aster

Centrioles

Late prophase

Sister

chromatids

Microtubules

Mitosis

Cytokinesis

S phase

G1 phase

Interphase

Restriction

checkpoint

(a)

(b)

(c) (d)

(e)


© Ed Reschke

G2 phase

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42

Mitosis is a continual process of --

prophase—

metaphase—

anaphase---

telophase

See box at bottom of page 109

43

Cytoplasmic Division

• Also known as cytokinesis

• Begins during anaphase

• Continues through telophase

• Contractile ring pinches cytoplasm in half

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44

3.5: Control of Cell Division

• Cell division capacities vary greatly among cell types • Skin and blood cells divide often and continually

• Neuron cells divide a specific number of times then cease

• Chromosome tips (telomeres) that shorten with each mitosis

provide a mitotic clock

• Cells divide to provide a more favorable surface area to

volume relationship

• Growth factors and hormones stimulate cell division—page 112 • Hormones stimulate mitosis of smooth muscle cells in uterus

• Epidermal growth factor stimulates growth of new skin

• Tumors are the consequence of a loss of cell cycle control

• Contact (density dependent) inhibition

45

Tumors

• Two types of tumors:

• Benign – usually remains

localized

• Malignant – invasive and can

metastasize; cancerous

• Two major types of genes

cause cancer:

• Oncogenes – activate other

genes that increase cell division

• Tumor suppressor genes –

normally regulate mitosis; if

inactivated they are unable to

regulate mitosis

• Cells are now known as

“immortal”

Normal cells

(with hairlike cilia)

Cancer cells


© Tony Brain/Photo Researchers, Inc.;

46

3.6: Stem and Progenitor Cells

• Differentiation: specialization of cells

• Stem cell:--retain the ability to divide repeatedly

• Can divide to form two new stem cells

• Self-renewal

• Can divide to form a stem cell and a progenitor cell

• Totipotent – can give rise to every cell type

• Pluripotent – can give rise to a restricted number of cell types

• Progenitor cell:--intermediate between a stem cell and differentiated cell

• Committed cell

• Can divide to become any of a restricted number of cells

• Pluripotent vs. totipotent p. 113-114

47

Stem and Progenitor Cells

one or more steps

Sperm

Egg

Fertilized

egg

Stem cell

Stem cell

Progenitor cell

Progenitor

cell

Progenitor

cell

Blood cells and platelets

Fibroblasts (a connective tissue cells)

Bone cells

Progenitor

cell

Astrocyte

Neuron

Skin cell

Sebaceous

gland cell

produces another stem cell

(self-renewal)

Progenitor

cell

Progenitor

cell

Progenitor

cell

Progenitor

cell

Progenitor

cell

Progenitor

cell


48

3.1 From Science to Technology

Stem cells to Study and Treat Diseases

Page 116

49

3.7: Cell Death

Apoptosis:

• Programmed cell death

• Acts as a protective mechanism

• Is a continuous process

page 117 and bullets on page 114

Blebs

Cell fragments

Phagocyte attacks

and engulfs cell

remnants. Cell

components are

degraded.

Caspases destroy various

proteins and other cell components.

Cell becomes deformed.

Death receptor on doomed cell

binds signal molecule. Caspases

are activated within.


© Peter Skinner/Photo Researchers, Inc.

50

Important Points in Chapter 3: Outcomes to be Assessed

3.3: Movements Into and Out of the Cell

Explain how substances move into and out of cells.

3.4: The Cell Cycle

Describe the cell cycle.

Explain how a cell divides.

3.5: Control of Cell Division

Describe several controls of cell division.

powerpoint to accompany hole’s human anatomy and … · 2014-07-15 · 22 3.2 clinical...

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