A&P Chapter 3

The state of solute equilibrium because

the cell membrane is freely permeable to water.

Osmosis

the diffusion of water across a membrane.

Water molecules tend to flow across a membrane toward the solution that contains _____________. p. 66

the higher solute concentration.

Diffusion

the net movement of molecules from an area of relatively high concentration (of many collisions) to an area of relatively low concentration (of fewer collisions). -often described as proceeding "down a concentration gradient" or "downhill".

Membrane Transport: permeability

the property that determines precisely with substances can enter or leave the cytoplasm.

Cytology

the study of the structure of the cell.

hydrophobic

water fearing. insoluble in water. tails on the inside.

hydrophilic

water loving. soluble in water. heads are on the outside.

Extracellular fluid

watery medium surrounding the cell

Membrane Transport: impermeable

when nothing can cross the membrane.

Solutions of various solute concentrations are descried as ____________, ___________, or __________ in regard to their effects cell membrane

isotonic, hypotonic, or hypertonic

Most of the body's osmosis occurs in the:

kidneys

The membrane contains:

lipids, proteins, and carbohydrates

The cell Membrane contains ______________, ____________, and ________________.

lipids, proteins, and carbohydrates.

Cytoplasm

surrounds the nucleus.

Membrane Transport: Freely permeable

Any substance can cross without difficulty

What are the building blocks of molecules?

Atoms

Anchoring Proteins

Attach the cell membrane to other structures an stabilize its position Example: Inside the cell, anchor proteins bind to the cytoskeleton. Outside the cell, anchor proteins attach the cell to extracellular protein fibers or to another cell

Interstitial Fluid

Extracellular fluid between the cells and outside the vascular bed. (i.e. connective tissue, cartilage, and bone)

Hydrophobic

Fatty substances; insoluble in water; positioned on the inside; tails will not associate with water or charged molecules which enables the cell membrane to act as a selective physical barrier.

Carbohydrates

Form complex molecules with proteins and lipids on the outer surface of membrane -Function as cell lubricants and adhesives -Act as receptors for the extracellular compounds -Form part of a recognition system that keeps the immune system from attacking the body's own cells

Hydrophilic

H20 core and glycerol; soluble in water; positioned on the outside

Recognition (Identifier)Proteins

Identify a cell as self or non-self, normal or abnormal, to the immune system Example: One group of such recognition proteins is the major histocompatibility complex (MHC) (Lymphocytes)

Cell Structure: Organelles

Intracellular structures of a cell

Cell Structure: Cytosol

Liquid division of a cell

Tonicity

Measurement/rat used for effective osmolarity Refers to blood

Membrane Transport: Passive Processes

Move ions or molecules across the cell membrane without energy expenditure by the cell (Diffusion and Osmosis)

Membrane Transport: Osmosis

Net movement of H2O through a semi-permeable membrane(Water specific diffusion) -Osmosis occurs across a selectively permeable membrane that is freely permeable to water but is not freely permeable to solutes. -In osmosis, water flows across a membrane toward the solution that has the higher concentration of solutes, because that is where the concentration of water is lower. -Most of the body's osmosis occurs in the kidney

Membrane Transport: Impermeable

Nothing can cross a membrane

Movement across the membrane can be ____________ or __________.

Passive or active

Membrane Transport: Selectively permeable

Permits free passage of some substances and restricts the passage of other. -Based on size, electrical charge, molecular shape, lipid solubility, or a combination of these factors. -Can be passive or active movement

_____________ are a major component of a cell membrane.

Phospholipids

Albumin

Protein produced by the liver that determines the blood's osmotic pressure

Active processes:

Require that the cell expend energy usually in the form of ATP

Active Processes

Require that the cell expend energy, usually in the energy form of ATP.

Receptor Proteins

Sensitive to specific extracellular materials that bind to them and trigger a change in a cell's activity Example: Binding of the hormone insulin to a membrane receptors increases the rate of glucose absorption by the cell

Cell Membrane

Separates the cell's contents from extracellular fluid.

Solutes

Solutions that contain a variety of dissolved materials. Solutes can be found in both intracellular and extracellular fluids.

The extracellular fluid in most tissues is called __________________.

interstitial fluid

Isotonic

iso-equal tonos-tension -solution is one that does not cause a net movement of water into or out of the cell.

Transmission electron micrographs (TEMs)

photographs of very thin sections, and they can reveal fine details of cell membranes and intracellular structures.

Scanning electron Micrographs ( SEMs)

provide less magnification but reveal the 3-D nature of cell structures. -provide a surface view of a cell, a portion of a cell, or extracellular structures rather than a detailed sectional view.

The Cell Membrane: Structural Support

Specialized connections between cell membranes, or between membranes and extracellular materials, give tissues a stable structure.

The Cell Membrane: Regulation of exchange with the environment

The cell membrane controls the entry of ions and nutrients, the elimination of wastes, and the release of secretions.

The Cell Membrane: Physical Isolation

The cell membrane is a physical barrier that seperates the inside of the cell from the surrounding extracellular fluid.

The Cell Membrane: Sensitivity

The cell membrane is the first part of the cell affected by changes in the extracellular fluid.

Cell Structure: Nucleus

The control center of the cell. Contains genetic material and directs cell activities. -Surrounded by the nuclear envelope -Communicates with the cytosol by was of nuclear pores

Membrane Transport: Concentration Gradient

The difference between high and low concentrations.

Partial Pressure

The driving force of osmosis involving gases.

Intracellular Fluid

The fluid found inside all body cells

Extracellular Fluid

The fluid found outside the cells

Osmotic Pressure

The force/flow of water movement into a solution as a result of the solute concentration.

Cell Structure: Plasma/Cell membrane

The outer boundary of a cell and has four general functions

Membrane Transport: freely permeable membrane

any substance can cross without difficulty

The outer boundary of the cells is formed by a:

cell membrane or plasma membrane

Membrane Transport: selectively permeable

cell membrane permits the free passage of some materials and restricts the passage of others.

Concentration gradient

difference between the high and low concentrations

*solutes

dissolved materials

Our model body cell is surrounded by a watery medium known as _______________.

extracellular fluid

****hypotonic

hypo-below when a cell swells up like a balloon due

Osmotic Pressure of a solution

indication of the force of water movement into that solution increases, so does it's osmotic pressure.

Isotonic to blood plasma

-Normal Saline -Lactated Ringers

Membrane Transport: Diffusion

-Proceeding "down concentration gradient" or "downhill" -Net movement of molecules from an area of relatively high concentration to an area of relatively low concentration to affect equilibrium. -Passive process -In extracellular fluids of the body, Water and dissolved solutes diffuse freely -Some substances can pass through easily, whereas others cannot penetrate the membrane at all

Normal Saline=

0.9% NaCL (gm/100ml=900mg of NaCL/100ml)

An ion or molecule can in diffuse across the lipid portion of the membrane in one of two ways:

1. By moving across the lipid portion of the membrane 2. By passing through a channel protein in the membrane.

Cell theory has four basic concepts:

1. Cells are the building blocks of all plants and animals. 2. Cells are the smallest functioning units of life. 3. Cells are produced through the division of pre-existing cells. 4. Each cell maintains homeostasis.

Two Types of Passive Processes:

1. Diffusion 2. Filtration

Two most common methods used to study cell and tissue structures

1. Light microscopy 2. Electron microscopy

Three chacteristics of osmosis are important to remember:

1. Osmosis is the diffusion of the water molecules across a membrane. 2. Osmosis occurs across a selecvively permeable membrane that is freely permeable to water but not freely permeable to solutes. 3. In Osmosis, water flows across a membrane toward the solution that has higher concentration of solutes, because that is where the concentration of water is lower.

General functions of the Cell Membrane:

1. Physical Isolation 2. Regulation of exchange with the environment. 3. Sensitivity 4. Structural Support

The phospholipids in a cell membrane lie in two distinct layers:

1. hydrophilic 2. hydrophobic

Whether or not a substance can cross the cell membrane is based off what 5 factors?

1. size 2. electrical charge 3. molecular shape 4. lipid solubility 5. some combination of these (above) factors

Cell Theory includes the following four concepts:

1.Cells are the building blocks of all plants and animals 2. Cells are the smallest functioning unit of life 3. Cells are produced through the division of pre-existing cells 4. Each cell maintains homeostasis

Phospholipids: Lie in two distinctive layers

1.Hydrophilic: H20 core and glycerol; soluble in water; positioned on the outside 2.Hydrophobic: Fatty substances; insoluble in water; positioned on the inside; tails will not associate with water or charged molecules which enables the cell membrane to act as a selective physical barrier.

Cell Structure: The 4 General Functions:

1.Physical isolation: physical barrier that separates the inside of the cell from the surrounding extracellular fluids. 2.Regulation of exchange with the environment: Controls the entry of ions and nutrients, the elimination of wastes and the release of secretions. 3.Sensitivity: First part of the cell affected by changes in the extracelular fluid through a variety of receptors. 4.Structural support: Specialized connections between cell membrane, or between membranes and extracellular materials, give tissues a stable structure

5 Factors that determine the rate of diffusion:

1.Relative concentration 2.Barriers or decreased permeability (membrane involvement) 3.Speed or energy of motion 4.Heat-(expands) 5.Size of particle

D5W=

5gm/100ml=5gm dextrose/100ml water

The cell membrane is thin and delicate, and ranges from ____nm to ____nm in thickness

6-10nm

The cell membrane is extremely thin and delicate and ranges from ______nm-______nm in thickness.

6nm-10nm

Carrier Proteins

Bind and transport solutes across the cell membrane This process may or may not require energy Example: Carrier proteins bring glucose into cytoplasm and also transport sodium, Potassium, and calcium ions into and out of the cell

Hemolysis

Bursting of a RBC

Proteins

Can cross over the surface or in the membrane -Function to assist the chemical activities that occur withing the cytoplasm -Uptake of environment -Transport out of the cell -Cell identifiers-related to blood type

Enzymes

Catalyze reactions in the extracellular fluid or within the cell Example: Dipeptides are broken down into amino acids by enzymes on the exposed membranes of cells that line the intestinal tract

What are the building blocks of the human body?

Cells

Cells= _______ water; _____ dissolved materials(_____Saline); 99% of fluid is reabsorbed, remaining _____ in tissues return through Lymphatic system

Cells= 91.5% water; 8.5% dissolved materials (0.9% Saline); 99% of fluid is reabsorbed, remaining 1% in tissues return through Lymphatic system

Channel Proteins

Central pore, or channel, permits water, ions, and other solutes to bypass lipid portion of cell membrane Example: Calcium ion movement through channels is crucial to muscle contraction and the conduction of nerve impulses

Cell Structure: Cytoplasm

Contents of the cell, Fluid and sub cellular parts that surrounds the nucleus.

Isotonic Solution

Does not cause a net movement of water into or out of a cell. Equilibrium exists; cells will survive.

Membrane Transport: Permeability

The property of the cell membrane that determines precisely which substances can enter or leave the cytoplasm.

Hydrostatic Pressure

The pushing against a fluid that prevents the entry of a water molecule

Crenation

The shrinking of a red blood cell

Cytology: The study of the structure and function of cells.

The study of the structure and function of cells.

Hypotonic Solution

Water flows into a cell which causes it to swell up like a balloon. Cell may eventually burst, or lyse

Hypertonic Solution

Water flows out of a cell Shrivel and dehydrate

Electron microscopy

a technique that replaced light with a focused beam of electrons.

Nucleus

control center for cellular operations.

Passive processes

move ions or molecules across the cell membrane without any energy expenditure by the cell.