summer 2009 college of san mateo instructor: theresa martin

PowerPoint® Lecture Slides prepared by Janice Meeking, Mount Royal College

C H A P T E R

Copyright © 2010 Pearson Education, Inc.

Summer 2009

College of San Mateo

Instructor: Theresa Martin

Human Anatomy


Student Learning Objectives

• Identify the structures of the body by systems.

• Relate the structure to the function of anatomic structures.

• Manipulate cadaver dissections and other lab specimens to understand structural relationships in the body.

• Learn the aspects of normal functioning in order to relate to clinical issues.


The Language of Anatomy

• Originally from Latin and Greek

• Word roots have specific meanings

• Osteo-

• Cyte-


Principle of Complementarity

• Anatomy and physiology are inseparable.

• Every structure has a function

• What a structure can do depends on its specific form


C H A P T E R


1

The Human Body: An Orientation


Levels of Body Organization• Chemicals• Cells• Tissues• Organs• Organ Systems• Organism


Cardiovascularsystem

OrganelleMoleculeAtoms

Chemical levelAtoms combine to form molecules.

Cellular levelCells are made up ofmolecules.

Tissue levelTissues consist of similartypes of cells.

Organ levelOrgans are made up of different typesof tissues.

Organ system levelOrgan systems consist of differentorgans that work together closely.

Organismal levelThe human organism is made upof many organ systems.

Smooth muscle cell

Smooth muscle tissue

Connective tissue

Blood vessel (organ)

HeartBloodvessels

Epithelialtissue


12

3

4

56

Figure 1.1


MoleculeAtoms

Chemical levelAtoms combine to form molecules.1

Figure 1.1, step 1





Smooth muscle cell

12

Figure 1.1, step 2






Smooth muscle cell


12

3

Figure 1.1, step 3







Smooth muscle cell


Connective tissue


Epithelialtissue


12

3

4

Figure 1.1, step 4









Smooth muscle cell


Connective tissue


HeartBloodvessels

Epithelialtissue


12

3

4

5

Figure 1.1, step 5









Organismal levelThe human organism is made upof many organ systems.

Smooth muscle cell


Connective tissue


HeartBloodvessels

Epithelialtissue


12

3

4

56

Figure 1.1, step 6


What are the organ systemsof the human body?

What organs are in each system?

What does each organ system do?

Homework


Organ Systems Interrelationships

• All cells depend on organ systems to meet their survival needs

• Organ systems work together to perform necessary life functions

Copyright © 2010 Pearson Education, Inc. Figure 1.2

Digestive system Takes in nutrients, breaks them down, and eliminates unabsorbed matter (feces)

Respiratory systemTakes in oxygen and eliminates carbon dioxide

Food O2 CO2

Cardiovascular systemVia the blood, distributes oxygen and nutrients to all body cells and delivers wastes and carbon dioxide to disposal organs

Interstitial fluid

Nutrients

Urinary systemEliminates nitrogenouswastes andexcess ions

Nutrients and wastes pass between blood and cells via the interstitial fluid

Integumentary system Protects the body as a whole from the external environment

Blood

Heart

Feces Urine

CO2

O2


C H A P T E R


3

Cells: The Living Units


Cell Theory

• The cell is the smallest unit of life


Cell Diversity

• Over 200 different types of human cells

• Types differ in size, shape, intracellular components, and functions


Fibroblasts

Erythrocytes

Epithelial cells

(d) Cell that fights disease

Nerve cell

Fat cell

Sperm

(a) Cells that connect body parts, form linings, or transport gases

(c) Cell that storesnutrients

(b) Cells that move organs and body parts

(e) Cell that gathers information and control body functions

(f) Cell of reproduction

SkeletalMusclecell

Smoothmuscle cells

Macrophage

Figure 3.1


Generalized Cell

• All cells have some common structures and functions

• Human cells have three basic parts:

• Plasma membrane—flexible outer boundary

• Cytoplasm—intracellular fluid containing organelles

• Nucleus—control center


Secretion beingreleased from cellby exocytosis

Peroxisome

Ribosomes

Roughendoplasmicreticulum

Nucleus

Nuclear envelopeChromatin

Golgi apparatus

Nucleolus

Smooth endoplasmicreticulum

Cytosol

Lysosome

Mitochondrion

CentriolesCentrosomematrix

Cytoskeletalelements• Microtubule• Intermediate filaments

Plasmamembrane


Plasma Membrane

• Bilayer of lipids and proteins in a constantly changing fluid mosaic

• Separates intracellular fluid (ICF) from extracellular fluid (ECF)

• Interstitial fluid (IF) = ECF that surrounds cells


Integralproteins

Extracellular fluid(watery environment)

Cytoplasm(watery environment)

Polar head ofphospholipid molecule

Glycolipid

Cholesterol

Peripheralproteins

Bimolecularlipid layercontainingproteins

Inward-facinglayer ofphospholipids

Outward-facinglayer ofphospholipids

Carbohydrate of glycocalyx

Glycoprotein

Filament of cytoskeleton

Nonpolar tail of phospholipid molecule


Membrane Lipids

• 75% phospholipids (lipid bilayer)

• 5% glycolipids

• 20% cholesterol


Integralproteins




Glycolipid

Cholesterol

Peripheralproteins





Glycoprotein




Membrane Proteins

• Integral proteins

• Firmly inserted into the membrane (most are transmembrane)

• Functions:

• Transport proteins (channels and carriers), enzymes, or receptors


Membrane Proteins

• Peripheral proteins

• Loosely attached to integral proteins

• Include filaments on intracellular surface and glycoproteins on extracellular surface

• Functions:

• Enzymes, motor proteins, cell-to-cell links, provide support on intracellular surface, and form part of glycocalyx

Animation: Structural ProteinsPLAYPLAY

Animation: Receptor ProteinsPLAYPLAY


Integralproteins




Glycolipid

Cholesterol

Peripheralproteins





Glycoprotein




Functions of Membrane Proteins

1. Transport

2. Receptors for signal transduction

3. Attachment to cytoskeleton and extracellular matrix

Copyright © 2010 Pearson Education, Inc. Figure 3.4a

A protein (left) that spans the membrane may provide a hydrophilic channel across the membrane that is selective for a particular solute. Some transport proteins (right) hydrolyze ATP as an energy source to actively pump substances across the membrane.

(a) Transport

Copyright © 2010 Pearson Education, Inc. Figure 3.4b

A membrane protein exposed to the outside of the cell may have a binding site with a specific shape that fits the shape of a chemical messenger, such as a hormone. The external signal may cause a change in shape in the protein that initiates a chain of chemical reactions in the cell.

(b) Receptors for signal transductionSignal

Receptor

Copyright © 2010 Pearson Education, Inc. Figure 3.4c

Elements of the cytoskeleton (cell’s internal supports) and the extracellular matrix (fibers and other substances outside the cell) may be anchored to membrane proteins, which help maintain cell shape and fix the location of certain membrane proteins. Others play a role in cell movement or bind adjacent cells together.

(c) Attachment to the cytoskeleton and extracellular matrix (ECM)


Functions of Membrane Proteins

4. Enzymatic activity

5. Intercellular joining

6. Cell-cell recognition

Copyright © 2010 Pearson Education, Inc. Figure 3.4d

A protein built into the membrane may be an enzyme with its active site exposed to substances in the adjacent solution. In some cases, several enzymes in a membrane act as a team that catalyzes sequential steps of a metabolic pathway as indicated (left to right) here.

(d) Enzymatic activity

Enzymes

Copyright © 2010 Pearson Education, Inc. Figure 3.4e

Membrane proteins of adjacent cells may be hooked together in various kinds of intercellular junctions. Some membrane proteins (CAMs) of this group provide temporary binding sites that guide cell migration and other cell-to-cell interactions.

CAMs

(e) Intercellular joining

Copyright © 2010 Pearson Education, Inc. Figure 3.4f

Some glycoproteins (proteins bonded to short chains of sugars) serve as identification tags that are specifically recognized by other cells.

(f) Cell-cell recognition

Glycoprotein


Membrane Junctions

• Three types:

• Tight junction

• Desmosome

• Gap junction


Interlockingjunctional proteins

Intercellularspace

Plasma membranesof adjacent cells

Microvilli

Intercellularspace

Basement membrane

(a) Tight junctions: Impermeable junctions prevent molecules from passing through the intercellular space.


Membrane Junctions: Tight Junctions

• Prevent fluids and most molecules from moving between cells

• Where might these be useful in the body?


Intercellular space


Microvilli

Intercellularspace

Plaque

Linker glycoproteins(cadherins)

Intermediatefilament (keratin)

(b) Desmosomes: Anchoring junctions bind adjacent cells together and help form an internal tension-reducing network of fibers.

Basement membrane


Membrane Junctions: Desmosomes

• “Rivets” or “spot-welds” that anchor cells together

• Where might these be useful in the body?



Microvilli

Intercellularspace

Intercellularspace

Channelbetween cells(connexon)

(c) Gap junctions: Communicating junctions allow ions and small molecules to pass from one cell to the next for intercellular communication.

Basement membrane


Membrane Junctions: Gap Junctions

• Transmembrane proteins form pores that allow small molecules to pass from cell to cell

• For spread of ions between cardiac or smooth muscle cells


Membrane Transport

• Plasma membranes are selectively permeable

• Some molecules easily pass through the membrane; others do not


Types of Membrane Transport

• Passive processes

• No cellular energy (ATP) required

• Substance moves down its concentration gradient

• Active processes

• Energy (ATP) required

• Occurs only in living cell membranes


Passive Processes

• What determines whether or not a substance can passively permeate a membrane?

1. Lipid solubility of substance

2. Channels of appropriate size

3. Carrier proteins

PLAYPLAY Animation: Membrane Permeability


Passive Processes

• Simple diffusion

• Carrier-mediated facilitated diffusion

• Channel-mediated facilitated diffusion

• Osmosis


Passive Processes: Simple Diffusion

• Nonpolar lipid-soluble (hydrophobic) substances diffuse directly through the phospholipid bilayer

PLAYPLAY Animation: Diffusion


Extracellular fluid

Lipid-solublesolutes

Cytoplasm

(a) Simple diffusion of fat-soluble molecules directly through the phospholipid bilayer


Passive Processes: Facilitated Diffusion

• Certain hydrophilic molecules (e.g., glucose, amino acids, and ions) use carrier proteins or channel proteins.


Facilitated Diffusion Using Carrier Proteins

• Transmembrane proteins transport specific polar molecules (e.g., sugars and amino acids)

• Binding of substrate causes shape change in carrier


Lipid-insoluble solutes (such as sugars or amino acids)

(b) Carrier-mediated facilitated diffusion via a protein carrier specific for one chemical; binding of substrate causes shape change in transport protein


Facilitated Diffusion Using Channel Proteins

• Aqueous channels formed by transmembrane proteins selectively transport ions or water

• Two types:

• Leakage channels

• Gated channels


Small lipid-insoluble solutes

(c) Channel-mediated facilitated diffusion through a channel protein; mostly ions selected on basis of size and charge


Passive Processes: Osmosis

• Movement of solvent (water) across a selectively permeable membrane

• Water diffuses through plasma membranes:

• Through the lipid bilayer

• Through water channels called aquaporins (AQPs)

Copyright © 2010 Pearson Education, Inc. Figure 3.7d

Watermolecules

Lipidbillayer

Aquaporin

(d) Osmosis, diffusion of a solvent such as water through a specific channel protein (aquaporin) or through the lipid bilayer


Importance of Osmosis

• When osmosis occurs, water enters or leaves a cell

• Change in cell volume disrupts cell function

PLAYPLAY Animation: Osmosis


Membrane Transport: Active Processes

• Two types of active processes:

• Active transport

• Vesicular transport

• Both use ATP to move solutes across a living plasma membrane


Active Transport

• Requires carrier proteins (pump)

• Moves solutes against a concentration gradient

• Types of active transport:

• Primary active transport

• Secondary active transport


Primary Active Transport

• Energy from hydrolysis of ATP causes shape change in transport protein so that bound solutes (ions) are “pumped” across the membrane


Extracellular fluid

K+ is released from the pump proteinand Na+ sites are ready to bind Na+ again.The cycle repeats.

Binding of Na+ promotesphosphorylation of the protein by ATP.

Cytoplasmic Na+ binds to pump protein.

Na+

Na+-K+ pump

K+ released

ATP-binding siteNa+ bound

Cytoplasm

ATPADP

P

K+

K+ binding triggers release of thephosphate. Pump protein returns to itsoriginal conformation.

Phosphorylation causes the protein tochange shape, expelling Na+ to the outside.

Extracellular K+ binds to pump protein.

Na+ released

K+ bound

P

K+

PPi

1

2

3

4

5

6


Primary Active Transport

• Sodium-potassium pump (Na+-K+ ATPase)

• Located in all plasma membranes

• Involved in primary and secondary active transport of nutrients and ions

• Maintains electrochemical gradients essential for functions of muscle and nerve tissues


Secondary Active Transport

• Depends on an ion gradient created by primary active transport

• Energy stored in ionic gradients is used indirectly to drive transport of other solutes


Secondary Active Transport

• Cotransport—always transports more than one substance at a time

• Symport system: Two substances transported in same direction

• Antiport system: Two substances transported in opposite directions


The ATP-driven Na+-K+ pump stores energy by creating a steep concentration gradient for Na+ entry into the cell.

As Na+ diffuses back across the membrane through a membrane cotransporter protein, it drives glucose against its concentration gradientinto the cell. (ECF = extracellular fluid)

Na+-glucosesymporttransporterloadingglucose fromECF

Na+-glucosesymport transporterreleasing glucoseinto the cytoplasm

Glucose

Na+-K+

pump

Cytoplasm

Extracellular fluid

1 2


Vesicular Transport

• Transport of large particles, macromolecules, and fluids across plasma membranes

• Requires cellular energy (e.g., ATP)


Vesicular Transport

• Functions:

• Exocytosis—transport out of cell

• Endocytosis—transport into cell

• Transcytosis—transport into, across, and then out of cell

• Substance (vesicular) trafficking—transport from one area or organelle in cell to another


Endocytosis and Transcytosis

• Involve formation of protein-coated vesicles

• Often receptor mediated, therefore very selective


Phagosome

(a) PhagocytosisThe cell engulfs a large particle by forming pro-jecting pseudopods (“false feet”) around it and en-closing it within a membrane sac called a phagosome. The phagosome is combined with a lysosome. Undigested contents remain in the vesicle (now called a residual body) or are ejected by exocytosis. Vesicle may or may not be protein-coated but has receptors capable of binding to microorganisms or solid particles.


Vesicle

(b) PinocytosisThe cell “gulps” drops of extracellular fluid containing solutes into tiny vesicles. No receptors are used, so the process is nonspecific. Most vesicles are protein-coated.


Exocytosis

• Examples:

• Hormone secretion

• Neurotransmitter release

• Mucus secretion

• Ejection of wastes


1 The membrane-bound vesicle migrates to the plasma membrane.

2 There, proteinsat the vesicle surface (v-SNAREs) bind with t-SNAREs (plasma membrane proteins).

The process of exocytosisExtracellular

fluid

Plasma membraneSNARE (t-SNARE)

Secretoryvesicle

VesicleSNARE(v-SNARE)

Molecule tobe secretedCytoplasm

Fusedv- and

t-SNAREs

3 The vesicleand plasma membrane fuse and a pore opens up.

4 Vesiclecontents are released to the cell exterior.

Fusion pore formed


Summary of Active Processes

• Also see Table 3.2

Process Energy Source Example

Primary active transport ATP Pumping of ions across membranes

Secondary active transport

Ion gradient Movement of polar or charged solutes across membranes

Exocytosis ATP Secretion of hormones and neurotransmitters

Phagocytosis ATP White blood cell phagocytosis

Pinocytosis ATP Absorption by intestinal cells

Receptor-mediated endocytosis

ATP Hormone and cholesterol uptake


Membrane Potential

• Separation of oppositely charged particles (ions) across a membrane creates a membrane potential (potential energy measured as voltage)

• Resting membrane potential (RMP): Voltage measured in resting state in all cells

• Ranges from –50 to –100 mV in different cells

• Results from diffusion and active transport of ions (mainly K+)


1

2

3

K+ diffuse down their steep concentration gradient (out of the cell) via leakage channels. Loss of K+ results in a negative charge on the inner plasma membrane face.

K+ also move into the cell because they are attracted to the negative charge established on the inner plasma membrane face.

A negative membrane potential(–90 mV) is established when the movement of K+ out of the cell equals K+ movement into the cell. At this point, the concentration gradient promoting K+ exit exactly opposes the electrical gradient for K+ entry.

Potassiumleakagechannels

Protein anion (unable tofollow K+ through themembrane)Cytoplasm

Extracellular fluid


Cell-Environment Interactions

• Involves glycoproteins and proteins of glycocalyx

• Cell adhesion molecules (CAMs)

• Membrane receptors


Roles of Cell Adhesion Molecules

• Anchor cells to extracellular matrix or to each other

• Assist in movement of cells past one another

• CAMs of blood vessel lining attract white blood cells to injured or infected areas

• Stimulate synthesis or degradation of adhesive membrane junctions

• Transmit intracellular signals to direct cell migration, proliferation, and specialization


Roles of Membrane Receptors

• Contact signaling—touching and recognition of cells; e.g., in normal development and immunity

• Chemical signaling—interaction between receptors and ligands (neurotransmitters, hormones and paracrines) to alter activity of cell proteins (e.g., enzymes or chemically gated ion channels)

• G protein–linked receptors—ligand binding activates a G protein, affecting an ion channel or enzyme or causing the release of an internal second messenger, such as cyclic AMP

summer 2009 college of san mateo instructor: theresa martin

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