
CHAPTER 1
-All specific functions (physiology) and performed by specific structures
(anatomy)
Gross anatomy , or macroscopic anatomy, examines large, visible structures
Microscopic anatomy examines cells and molecules
• Cytology: study of cells and their structures
• Histology: study of tissues and their structures
-Homeostasis
• All body systems working together to maintain a stable internal environment
-Autoregulation (intrinsic)
• Automatic response in a
cell, tissue, or organ to some environmental change
Extrinsic Regulation

Responses controlled by nervous and endocrine system
 Homeostatic regulatory mechanisms (how to keep things “just right”) consist of 3 components
1. Receptor
• Receives/senses the stimulus  “measures” the environment, collects information
2. Control Center
• Processes information and sends instructions
3. Effector (gland/muscle tissue)
• Carries out instructions, causes a change
*The Role of Negative Feedback (generate maintenance of normal range)
• The effector moves a parameter in the opposite direction from the stimulus (i.e., up/down)
• Body is brought back into homeostasis (near set point)
• Normal range is maintained
• Most effectors use negative feedback
• Example is regulation of body temperature
*The Role of Positive Feedback (deviate; responds to hazardous situations w/in the body)
• The effector moves a parameter in the same direction as the stimulus
(i.e., up —up)
• Body is moved farther and farther away from homeostasis  speeds up processes
• Normal range is lost
• Blood clotting
*CHAPTER 3
Functions of the Plasma Membrane
1. Physical isolation  barrier between cell interior and surrounding extracellular fluid (a.k.a. interstitial fluid)
2. Regulation of exchange with the environment
• Ions and nutrients enter

• Waste and cellular products released
3. Sensitivity to the environment  facilitates communication, receives information about the cell’s surroundings
• Extracellular fluid composition, chemical signals
4. Structural support  anchors cells and tissues
Phospholipid bilayer  creates a barrier to ions, water, and large or polar molecules
•
Hydrophilic heads

exposed to the aqueous environment on both sides
(extracellular fluid, cytosol)
• Hydrophobic fatty-acid tails  buried inside membrane
-Integral proteins  embedded within the membrane
-Peripheral proteins  bound to inner or outer surface of the membrane
Membrane Protein Functions
1. Anchoring Proteins (stabilizers)

attach to other structures, can attach inside or outside of cell
2. Recognition Proteins (identifiers)  label cells as normal or abnormal
3. Enzymes

catalyze reactions
4. Receptors  bind and respond to ligands (ions, hormones)
5. Carriers  transport specific substances across membrane
6. Channels

create a pore for water and solute transport
Membrane Carbohydrates  Proteoglycans, glycoproteins , and glycolipids
• Extend outside cell membrane and form sticky “sugar coat” ( glycocalyx )
Functions of the glycocalyx
• Lubrication and Protection
• Anchoring and Locomotion
• Specificity in binding (receptors)
• Recognition (immune response)
** KNOW 3-2 AND 3-3**
Membrane Transport
• The cell membrane is a barrier, however nutrients must get in and products/wastes must get out
• Permeability determines what moves in and out of a cell
• Impermeable  nothing passes
•
Freely permeable

everything passes
• Selectively permeable  some materials pass freely, others do not ( PLASMA MEMBRANE )
How can membrane transport be characterized?
• By energy requirements:
• Active (requiring energy and ATP)
• Passive (no energy required)
• By mechanism:
• Diffusion (passive)
• Carrier-mediated transport (passive or active)
•
Vesicular transport (active)

*Diffusion is the movement of a substance from an area of higher concentration to an area of lower concentration
• Occurs spontaneously
• No energy is required  passive
Factors Influencing Diffusion
• Distance  shorter is faster
• Molecule Size  smaller is faster
•
Temperature

hotter is faster
• Concentration Gradient  larger difference is faster
• The difference between high and low concentrations
Diffusion across Plasma Membranes
• Simple diffusion  move directly across phospholipid bilayer
• Channel mediated (facilitated diffusion)  move through a protein to cross the membrane
•
Simple = hydrophobic
• alcohols, fatty acids, steroids, O
2
, CO
2
• Channel = hydrophilic
•
Simple sugars, ions
• Size, charge, interaction with channel protein
Osmosis  a special case of diffusion
• Osmosis is the diffusion of water across the cell membrane
• More solute molecules  lower concentration of water molecules
• Membrane must be freely permeable to H
2
O, selectively permeable to solutes
Volume increased
Applied force
Volume decreased
Original level
Volumes equal
Water molecules
Solute molecules
Selectively permeable membrane
• Osmolarity (osmotic concentration) is the total solute concentration in an aqueous solution
• Tonicity describes how a solution affects a cell
Isotonic  surrounding solution has same solute concentration
• Water neither flows into or out of a cell
Hypotonic  surrounding solution has less solutes
• Water flows into cell
Hypertonic  surrounding solution has more solutes
• Water flows out of cell
*Carrier-Mediated Transport
• Hydrophillic substances  ions and organic substrates
• Specificity

one transport protein, one set of substrates
Number of molecules & direction of transport
• Cotransport  two substances move in the same direction at the same time

• Countertransport
 two substances move in opposite directions at the same time
Passive Transport (aka facilitated diffusion )
• From [high] to [low]
• With concentration gradient
• Carrier proteins transport molecules too large to fit through channel proteins (glucose, amino acids)
Active Transport
• From [low] to [high]
• Against concentration gradient
• Requires energy, such as ATP
• Ion pumps move ions (Na + , K + , Ca 2+ , Mg 2+ )
• Exchange pumps countertransport two ions
How is energy provided to fuel active transport?
Primary active transport requires a direct input of energy = ATP hydrolysis
• Ex: Sodium –potassium exchange pump
• 1 ATP moves 3 Na + and 2 K +
•
Sodium ions (Na + ) out, potassium ions (K + ) in
Secondary active transport requires an indirect input of energy = potential energy stored in an ion gradient
• Ex: Sodium
–glucose cotransporter
• Na + concentration gradient drives glucose transport
• ATP energy pumps Na + back out
Vesicular Transport (Bulk Transport)
•
Materials move into or out of the cell in vesicles
• All vesicular transport is active = requires input of energy
• Exocytosis  use vesicles to transport materials out of the cell
• Endocytosis

use vesicles to transport materials into the cell
• Pinocytosis  “drinking”  bring in extracellular fluid
• Phagocytosis  bring in large substances
• Use pseudopodia
• Exocytosis  materials are released from the cell
Bacterium
PHAGOCYTOSIS
Lysosome
Phagosome fuses with a lysosome
Secondary lysosome
Golgi apparatus
EXOCYTOSIS
*CHAPTER 4
Epithelial tissue includes epithelia and glands
• Epithelia are layers of cells covering internal or external surfaces

•
Glands are structures that produce secretions
Functions of Epithelial Tissue
1. Provide physical protection  cover exposed surfaces
2. Control permeability  all substances that enter/leave the body cross an epithelium
3. Provide sensation  specialized epithelia facilitate smell, taste, sight, equilibrium, hearing
4. Produce specialized secretions ( glandular epithelium )

sweat, mucus, oil, milk, hormones
Characteristics of Epithelium
1. Cellularity

cell junctions
2. Polarity  apical and basal surfaces
3. Attachment  basement membrane or basal lamina
4. Avascularity  lack blood vessels
5. Regeneration

stem cells divide to replace lost cells
Maintaining the Integrity of Epithelia
1. Intercellular connections
• Transmembrane proteins called CAMs (cell adhesion molecules) can connect adjacent membranes at cell junctions
2. Attachment to the basement membrane
• Hemidesmosome 
connects cytoskeleton of cell to the basement membrane
3. Epithelial maintenance and repair
• Cells are replaced by division of germinative cells (stem cells) near the basement membrane
Intercellular Connections
1. Tight junction  seals plasma membranes between cells, prevents passage of water and solutes
2. Gap junction  connects cytoplasm of adjacent cells, allows rapid communication
3. Desmosome

connects cytoskeleton of adjacent cells, allows bending and twisting
Classification of Epithelia
1. Based on cell shape
•
Squamous epithelia

thin and flat
• Cuboidal epithelia  square shaped
• Columnar epithelia  tall, slender rectangles
2. Based on number of cell layers
• Simple epithelium  single layer of cells
• Stratified epithelium  several layers of cells
Squamous Epithelia
Simple squamous epithelium  absorption and diffusion
• Mesothelium lines body cavities
• Endothelium lines heart and blood vessels
Stratified squamous epithelium
• Protects against physical and chemical wear and tear

•
Keratin protein adds strength and water resistance to exposed body surfaces like the skin
Cuboidal Epithelia
Simple cuboidal epithelium
• Secretion and absorption
Stratified cuboidal epithelia
• Sweat ducts and mammary ducts
Transitional Epithelium
• Tolerates repeated cycles of stretching and recoiling and returns to its previous shape without damage
• Appearance changes as stretching occurs
• Located in regions of the urinary system (ex: urinary bladder)
*Columnar Epithelia
Simple columnar epithelium
• Absorption and secretion
Pseudostratified columnar epithelium
• Often have cilia  fluid movement
Stratified columnar epithelium
• Protection
*Glandular Epithelia
Endocrine glands
• Release hormones into interstitial fluid
• No ducts
Exocrine glands
• Release secretions onto epithelial surfaces
• Through ducts
Exocrine Glands - Modes of Secretion
1. Merocrine secretion
 product released in vesicles (exocytosis) most common, ex: sweat glands
2. Apocrine secretion  product released by shedding cytoplasm, ex: mammary glands
3. Holocrine secretion  product released by cell bursting (killing gland cells), ex: sebaceous glands
Classifying Glandular Epithelia
• Gland Structure
• Unicellular glands
• Mucous (goblet) cells are the only unicellular exocrine glands
• Scattered among epithelia ex: in intestinal lining
• Multicellular glands
• Further classified by duct structure and shape
Muscle Tissue is specialized for contraction  produces all body movement
Three types of muscle tissue
1. Skeletal muscle tissue
• Large body muscles responsible for movement
2. Cardiac muscle tissue
• Found only in the heart

3. Smooth muscle tissue
• Found in walls of hollow organs (blood vessels; urinary bladder; respiratory, digestive, and reproductive tracts)
Skeletal Muscle Cells
• Long (up to 1 ft) and thin  usually called muscle fibers
• Multinucleate (several hundred)
• Do not divide  new fibers produced by stem cells (myosatellite cells)
• Regulated by nerves 
also known as striated voluntary muscle
Cardiac Muscle Cells
• Called cardiocytes
• Limited ability for cell division and repair
• Form branching networks connected at intercalated discs
• Regulated by pacemaker cells  striated involuntary muscle
Smooth Muscle Cells
• Small and tapered with single nucleus
• Can divide and regenerate
• No striations  nonstriated involuntary muscle
Neural Tissue
Two Types of Neural Cells
1. Neurons (nerve cells)
• Perform electrical communication
2. Neuroglia  supporting cells
• Repair and supply nutrients to neurons
Neuron cell structure
•
Cell body

contains the nucleus and nucleolus
• Dendrites  short branches extending from the cell body
• Receive incoming signals
•
Axon (nerve fiber)

long, thin extension of the cell body
• Carries outgoing electrical signals to their destination
*CHAPTER 5