A&P LECTURES 1-3

anatomy

study of the structure of the body parts and their relationship to one another

physiology

study of the function of body parts; how they work to carry out life-sustaining activities

integumentary system

forms external body covering (skin)

protects deeper tissues from injury

synthesizes vitamin D

houses cutaneous receptors and sweat/oil glands

nervous system

fast-acting control system of the body

responds to internal and external changes by activating appropriate muscles and glands

muscular system

allows manipulation of the environment, locomotion and facial expression

maintains posture and produces heat

skeletal system

protects and supports body organs

provides framework for muscles

blood cells formed within bones

bones store minerals (calcium)

cardiovascular system

heart pumps blood

blood vessels transport blood, carrying oxygen, carbon dioxide, nutrients, wastes, etc.

lymphatic system

picks up fluid leaked from blood vessels and returns it to blood

disposes of debris

houses white blood cells involved in immunity

mounts the attack against foreign substances within the body

respiratory system

keeps blood constantly supplied with oxygen and removes carbon dioxide

gaseous exchange occur through the walls of the air sacs of the lungs

endocrine system

glad secrete hormones that regulate processes such as growth, reproduction, and metabolism

digestive system

breaks down food into absorbable units that enter the blood for distribution to body cells

indigestible foodstuffs are eliminated as feces

urinary system

eliminates nitrogenous wastes from the body

regulates water, electrolyte and acid-base balance of the blood

female reproduction system

production of offspring

ovaries produce eggs and female sex hormones

sites for fertilization and development of fetus

mammary glands of female breasts produce milk to nourish the newborn

male reproductive system

production of offspring

testes produce sperm and male sex hormones

male ducts and glands aid in delivery of sperm to the female reproductive tract

negative feedback mechanism

response reduces or shuts off original stimulus

ex: regulation of body temp. and blood glucose by insulin

positive feedback mechanism

response enhances or exaggerates the original stimulus

ex: enhancement of labor contractions by oxytocin, blood clotting

Most common elements in body (macronutrients):

oxygen, carbon, hydrogen, nitrogen

Micronutrients in body:

calcium, phosphorus, potassium, sodium, iron

synthesis reaction

involve the combining of atoms or molecules to form a larger, more complex molecule and requires energy

decomposition reaction

involve the breaking down of a molecule into smaller molecules or its constituent atoms (releases energy)

exchange reaction

involving both synthesis and decomposition (reordering)

dehydration synthesis

release of water molecule in polymer formation

monomers joined by removal of OH from one and H from other

anabolic

hydrolysis reaction

water molecule added to bonds that are broken

polymers are broken apart by adding OH to one momoner and H to the other

releases energy

anabolic reactions

requires energy

catabolic reactions

release energy

organic compounds

contain carbon, are usually large and covalently bonded

carbohydrates, lipids, proteins and nucleic acids

inorganic compounds

do not contain carbon

water, salts, and many acids/bases

carbohydrates

contain carbon, hydrogen and oxygen (H and O are 2:1 ratio)

monosaccharides, disaccharides and polysaccharides

lipids

insoluble in water

contain carbon, hydrogen and oxygen (less O than in carbohydrates)

triglycerides, phospholipids, steroids, eicosanoids

triglycerides

3 fatty acids bonded to glycerol molecule

fats when solid (saturated) and oils when liquids (unsaturated)

energy storage, insulation and protection

phospholipids

glycerol, 2 fatty acids plus a phosphorous-containing group

head is polar and hydrophilic (-)

tails are non-polar and hydrophobic (uncharged)

cell membrane structure

steroids

consist of four interlocking ring structures

ex: cholesterol, vitamin D, steroid hormones and bile salts

cholesterol is building block for other examples and important in cell plasma membrane structure

eicosanoids

derived ffrom 20-carbon fatty acid found in cell membranes

ex: prostaglandins- play a role in blood clotting, control of BP, inflammation and labor contractions

proteins

contain carbon, hydrogen, oxygen, nitrogen and sometimes phosphorus, and sulfur

polymers of amino acid monomers held together by peptide bonds

4 levels of protein structure

primary, secondary, tertiary, quartenary

primary structure

sequence of amino acids form the polypeptide chain

secondary structure

primary chain forms alpha-helics and beta-sheets

tertiary structure

alpha-helics and beta-sheets are folded up to forma a compact globular molecule held together by intramolecular bonds

quaternary structure

two or more polypeptide chains, each with its own tertiary structure combine to form a functional protein

fibrous (structural) proteins

strand-like, hydrophobic and stable

most have tertiary or quaternary structure (3-D)

provide mechanical support and tensile strength

in connective tissues

globular (functional) proteins

compact, spherical, hydrophilic and sensitive to environmental changes

tertiary or quaternary structure (3-D)

specific functional regions (active sites)

enzymes

lower activation energy needed to initiate reaction, speeding up the reaction

nucleic acids

composed of carbon, hydrogen, oxygen, nitrogen and phosphorus

deoxyribonucleic acids (DNA) and ribonucleic acids (RNA)

polymers are made up of nucleic monomers

nitrogen bases in DNA:

thymine, adenine, guanine, cytosine

nitrogen bases in RNA:

adenine, guanine, cytosine, uracil

ATP

directly powers chemical reactions in cells

adenine-containing RNA nucleotide with 2 additional phosphate groups

fibroblasts and erythrocytes

cells that connect body parts, form linings, or transport gases

fat cell

cell that stores nutrients

macrophage

cell that fights disease

sperm

cell of reproduction

skeletal muscle cell and smooth muscle cells

cells that move organs and body parts

nerve cell

cell that gathers information and controls body functions

plasma membrane

flexible selective permeable outer membrane

cytoplasm

intracellular fluid containing organelles

composted of cytosol and organelles

nucleus

DNA containing control center

only in eukaryotic cells

integral proteins

firmly inserted into membrane

have both hydrophobic and hydrophilic regions

peripheral proteins

loosely attached to integral proteins

include filaments on intacellular surface used for plasma membrane support

function as enzymes and cell-to-cell connections

tight juctions

integral proteins on adjacent cells fuse to form an impermable junction that encircles whole cell

interlocking

prevents fluids and most molecules from moving in between cells

desmosomes

rivet-like cell junction formed when linker proteins of neighboring cells interlock like the teeth of zipper

allow “give” between cells, reducing possibility of tearing under tension

uses calcium to hold together like velcro

gap junctions

transmembrane proteins form tunnels that allow small molecules to pass from cell to cell

used to spread ions, simple sugars, or other small molecules between cells

allows electrical signals to be passed quickly from one cell to next cell

passive processes

no energy (ATP) required

simple, facilitated, osmosis

filtration

usually occurs across capillary walls

active processes

energy (ATP) required

diffusion

movement of molecules from high concentration to low concentration

concentration gradient

higher temp = faster diffusion

simple diffusion

non-polar and lipid-soluble (hydrophobic) substances diffuse directly through the lipid bilayer

facilitated diffusion

certain hydrophilic molecules are transported passively down their concentration gradient by carrier-meditated facilitated diffusion and channel-meditated facilitated diffusion

carrier-mediated facilitated diffusion

substances bind to protein carriers

channel-mediated facilitated diffusion

substance move through water-filled channels

leakage channels (always open) and gated channels (controlled by chemical or electrical signals)so

osmosis

movement of solvent across a selectively permeable membrane

high to low concentration

isotonic solutions

cells retain normal size because solute/water concentration is same as interior of cell

hypertonic solutions

water lose water and shrink because there is a higher concentration of solutes outside of the cell than inside the cell

hypotonic solutions

cells become bloated and burst because there is a higher concentration of solutes inside the cell compared the exterior of the cell

active membrane transport

requires ATP to move solutes across a membrane against concentration gradient

active transport and vesicular transport

sodium-potassium pump

pumps Na+ out of cell and K+ back into cell against concentration gradients

maintains electrochemical gradients

vesicular transport includes:

endocytosis, exocytosis, transcytosis, vesicular trafficking

cytosol

gel-like solution made up of water and soluble molecules such as proteins, salts, sugars etc.

mitochondria

produces most of cell’s energy molecules via aerobic cellular respiration

double membrane

contains DNA, RNA and ribosomes

ribosomes

site of protein synthesis

non-membranous organelles

made up of protein and ribosomal RNA (rRNA)

free ribosomes and membrane-bound ribosomes

endoplasmic reticulum

consists of series of parallel, interconnected cisterns

ER is continuous with outer nuclear membrane

rough ER and smooth ER

rough ER

studded with attached ribosomes

site of synthesis of proteins that will be secreted from cell

site of synthesis of many plasma membrane proteins and phospholipids

smooth ER

network of looped tubules continuous with rough ER

enzymes within its membrane function in lipid metabolism

golgi apparatus

modifies, concentrates, packages proteins and lipids received from rough ER

lysosomes

membranous bags containing digestive enzymes (acid hydrolases)

digest ingested bacteria, viruses and toxins

metabolic functions

peroxisomes

detoxify harmful substances and neutralize free radicals

numerous in liver and kidneys

cytoskeleton

elaborate network of rods that run through cytosol

act as cells “bones, ligaments, and msucles”

microfilaments, intermediate filaments, microtubules

flagella

aid in movement of cell (sperm)

cilia

aid in the movement of materials across the surface of the cell (cells of respiratory tract)

microvilli

fingerlike projections that extend from the surface of the cell to increase surface area for absorption (intestinal and kidney tubule cells)

nuclear envelope

double-membrane barrier that encloses the nuceloplasm

nucleolus

contains DNA codes for rRNA

involved in rRNA synthesis and ribosome subunit assembly

chromatin

supramolecular structure that packs genetic material

protein synthesis steps:

transcription and translation

transcription

DNA information coded in mRNA

translation

mRNA decoded to assemble polypeptides

codon

three-base sequence on mRNA

free ribosomes

site of protein synthesis that function in cytosol or other organelles

free radicals

reactive atoms that are natural by-products of cellular metabolism

glycocalyx

glycolipids and proteins sticking out of cell surface

used for cell to cell interaction and recognition