A & P I Chap 3

Front 1

Cytology-

Back 1

The study of cell structure and function

Front 2

Cell Shapes-

Back 2

--Squamous- thin, flat and have angular contours (line esophagus and cover skin)
--Polygonal- irregularly angular shapes with 4,5, or more sides
--Stellate- cells with multiple extensions; starlike shape (nerve cells)
--Cuboidal- squarish and about as tall as they are wide (liver cells)
--Columnar- taller than they are wide (lines the intestines)
--Spheroid to Ovoid- round to oval (egg cells and fat cells)
--Discoid- disc-shaped (RBC's)
--Fusiform- thick in middle, tapered at ends (smooth muscle)
--Fibrous- threadlike (skeletal muscle)

Front 3

General Cell Structure-

Back 3

Filled with cytoplasm (fluid btw nucleus and cell membrane). Also known as the cytosol or Intracellular fluid (ICF)
--Outer surface- plasma (cell) membrane (phospholipid bilayer)
--contains several organelles and has a support framework (cytoskeleton)
--Space outside the cell- extracellular fluid (ECF)

Front 4

Plasma Membrane-

Back 4

Membrane of the cell surface, defines the boundaries of the cell
--Controls interactions with other cell, controls the pasage of materials into and out of the cell

Front 5

Membrane Lipids-

Back 5

98% of molecules in the membrane
--75% are phospholipids, which are amphiphilic and form a bilayer (with hydrophobic end facing each other and hydrophilic ends facing outward)
--Cholesterol makes up 20% of membrane lipids, which holds phospholipids still and stiffen membrane
--Remaining 5% is glycolipids- help form glycocalyx, a carb coating for cell
--

Front 6

Membrane Proteins-

Back 6

2% of the molecules in the cell membrane (50% of weight)
--Integral (transmembrane) proteins- pass thru membrane; most are glycoproteins
--Peripheral proteins- adhere to intracellular surface of membrane; tend to be associated with a integral protein
--Tend to functions as: receptors, second-messenger systems, enzymes, channell proteins, carriers, molecular motors, cell-identity makers and cell-adhesion molecules

Front 7

Microvilli-

Back 7

Extension from the cell membrane
--Serve to increase the cell's surface area (best in cell for absorption)
--ex. on taste buds and inner ear, serve as sensory organ

Front 8

Cilia-

Back 8

Hairlike processes
--Nearly on every human cell has a single, nonmotile primary cilium (function: sensory)
--In inner ear- sense of balance; in retina- light absorption; in kidneys- monitor fluid flow

--Motile cilia, mainly in respiratory tract and fallopian tudes
--Function: sweep across surface, pushing mucus and other matter along

Front 9

Flagella-

Back 9

Whiplike structure
--Only functional flagella is in the tail of the sperm cell

Front 10

Cell Membrane-

Back 10

Barrier and gateway btw cytoplasm and ECF
--Selectively Permeable- controls what substances enter and leave the cell
--Substances can be moved into or out of the cell by: passive or active means, or by carrier-mediated means or not
--Passive- no ATP (fiiltration or diffusion)
--Active- requires ATP (active transport and vesicular transport)
--Carrier-mediated- use membrane proteins to moves substances (facilitated diffusion)

Front 11

Filtration-

Back 11

Process in which particles go through a selective membrane by hydrostatic pressure (force exerted by water on the membrane)
--ex. coffee making w/ a filter
--Water and dissolved particles go through, large particle stay on opposite side
--Common on blood capillaries

Front 12

Simple Diffusion-

Back 12

the net movement of particles from a place of high concentration to a place of low concentration
--High -> Low
--Down concentration gradient

Front 13

Factors that affect rate of diffusion-

Back 13

Temp- Temp is a measure of kinetic energy. The warmer the more rapid the diffusion

Molecular Wt- Heavy molecules move slower and diffuse slowly; small molecules pass thru membrane pores easily

Steepness of concentration gradient- steepness= concentration difference btw 2 points; The greater the difference, the more rapidly the particle diffuse

Membrane surface area- the more membrane surface area available allows more particles to diffuse.

Membrane permeability- diffusion depends on how permeable it is to particles; non-polar molecules diffuse thru cell membrane directly; small, charged molecules diffuse through channel proteins (can't mix with lipids)

Front 14

Osmosis-

Back 14

Diffusion of water thru a permeable membrane, from more watery to less watery
--Move thru membrane by way of aquaporins (channel proteins)
--Move from more dilute (more water, less solutes) to less dilute (less water, more solutes)
--Osmotic Pressure- the pressure the water places on the membrane that stops osmosis

Front 15

Tonicity-

Back 15

The ability of a solution to affect the fluid volume and pressure in a cell
-- 3 types:

Hypotonic- lower concentration of solutes than ICF (pulls water in)

Hypertonic- higher concentration of solutes than ICF (pushes water out)

Isotonic- total concentrationis the same as ICF (no change)

Front 16

Carrier-Mediated Transport-

Back 16

The use of transport proteins to move particles thru membrane
--Ligand binds to a receptor on carrier (specificity)
--As the concentration rises, rate of transport increase (saturation)
--3 types:

Uniport- one solute at a time

Symport- 2 or more solutes at the same time in the same direction (or cotransport)

Antiport- 2 or more solutes at the same time, in opposite directions (or countertransport)

Front 17

Facilitated Diffusion-

Back 17

Carrier-mediated transport of a solute down its concentration gradient
--Passive transport (0 ATP)
--Transports solutes that could not otherwise get thru a membrane unaided

Front 18

Active Transport-

Back 18

Carrier-mediated transport of solute thru a membrane up it concentration gradient
--Uses ATP
--enables cells to absorb amino acids that are already more concentrated in the cytoplasm

Front 19

Sodium-Potassium Pump-

Back 19

Active transport system, pumps 3 Na out the cell, while pumping 2 K into the cell
--The carrier is an enzyme that hydrolyzes ATP
--Each cycle uses 1 ATP
--Keeps K concentrations high in cell and Na lower in cell

Front 20

Functions of Na/K pump-

Back 20

Regulation of cell volume- part of a negative feedback loop that reduce ion concentration, osmolarity and cellular swelling

Secondary active transport- creates a steep concentration gradient of Na and K btw the 2 sides of the membrane; gradient has high potential energy that can drive processes

Heat Production- Na/K pumps use ATP, they release heat

Maintenance of membrane potential- the difference in charge in inside and outside the membrane, causing a membrane potential, which is key for nerve and muscle cells

Front 21

Vesicular Transport-

Back 21

Moves large particles, droplets of fluid or numerous molecules at once through the membrane, contained in vesicles
--Endocytosis- bringing matter into cell
--Exocytosis- releasing matter out of cell

Front 22

Endocytosis-

Back 22

Bringing matter into cell
--2 basic forms:

Phagocytosis- "cell eating" the process of engulfing particles (used in neutrophils)

Pinocytosis- "cell drinking" taking in droplets of ECF into cell (occurs in all cells)

Front 23

Receptor-mediated Endocytosis-

Back 23

More selective form of phagocytosis or pinocytosis
--Allows cell to take in certain molecules from ECF by binding to receptors on membrane
--Receptors clluster together, creating a pit coated with clathrin

Front 24

Transcytosis-

Back 24

Transport of a substance across the cell, which is captured on one side and released on the other side of the membrane

Front 25

Exocytosis-

Back 25

Discharging material from the cell
--Vesicle fuses with membrean, membrane pulls inward and creating a dimple which eventually fuses with vesicle and allows the release
--Used in releasing insulin, expressing milk, releasing hormones, sperm penetrating the egg
--Purpose- to replace membrane removed by endocytosis and damaged or worn out

Front 26

The Cytoplasm-

Back 26

The center of the cell, containing the organelles, the nucleus, the cytoskeleton and inclusion (everything inbedded in cytosol

Front 27

Organelles-

Back 27

Internal structures within a cell that carry out specific functions
--Some have a 1-2 layer membrane- mitochondria, lysosomes, perioxisomes, endoplasmic reticulum, and Golgi complex
--Some have no membrane- ribosome, centrisome, centrioles, and basal bodies

Front 28

The Nucleus-

Back 28

Largest Organelle
--Most cell have at least 1, mature RBC have none (anuclear), and some have many (multinucleated)
--Has a 2 layer membrane (nuclear envelope), which has pores (holds layers together and monitors traffic in and out)
--Pores allow materials for making DNA and RNA, enzymes and hormones into the cell, and allows RNA to leave the cell
--Material within the nucleus (nucleoplasm) includes chromatin (genetic material), 1 or more nucleoli (site of ribosome production)

Front 29

Endoplasmic Reticulum-

Back 29

A system of interconnect cisternae inside a unit membrane
--Made of rough and smooth ER
--Rough ER- cisternae are flattened sac, covered in ribosomes, attached to outer membrane of nuclear envelope
--Smooth ER- Lacks ribosomes, attached to