Human Anatomy and Physiology Exam 1 [Ch. 1-3] *only parts of ch. 3

Matter

Matter

Anything that has mass and takes up space.

Chemical Element

The simplest form of matter, elements are made up of all the same atoms—cannot be broken down by any chemical means.

Atom

The smallest unit of matter that enters chemical reactions.

Proton

Positively charged particle in the nucleus of the atom.

Neutron

Non-charged particle in the nucleus.

• Isotopes: of the same element have different numbers of neutrons.

• Radioisotopes: decompose spontaneously into more stable forms giving off radiation.

Electron

Negatively charged particle that orbits the nucleus — sometimes may be gained or lost from an atom or molecule to conform to a stable number in the outer shell — usually 2 or 8.

Ion

An atom or molecule with an unequal number of protons and electrons — therefore has some charge — and is formed by the gain or loss of electrons

Electrolytes

Forms an ion in water [H₂O].

Free Radicals

Highly reactive electron in the outer shell (eg. superoxide).

Anatomy

The study of body structure. Ana: "apart" Tome: "cut"

Physiology Subdivisions

Based on organ systems. Begins at molecular and cellular level. The body's abilities depend on chemical reactions in body cells.

Subdivision Examples of Anatomy

Gross: visible Microscope: too small to see with naked eye (microscope) Developmental: traces structural changes that occur in the body throughout the life span

To Study Anatomy Clinically:

Observation: looking Manipulation: moving Palpation: touching Auscultation: listening

Physiology

The study of body function. Physis: "nature/life" Logos: "study of/discourse"

Conceptual Knowledge in Physiology

Focus at many levels: chemical --> organism Basic physical principles: electricity, molecular movements Basic chemical principles: chemical RxNs

Homestasis

The essential concept of physiology: to maintain relatively stable internal conditions even though the outside worlds world changes continuously.

Homeostatic Control Mechanisms

Monitor change (variable) and respond. Communication; e.g. nervous and endocrine systems Three Interdependent Components:

1. Receptor - sensor that monitors the environment and responds to stimuli

2. Control Center - which determines the set point [maintained condition], analyzes the input it receives and then determines the appropriate response or course of action.

3. Effector - response (output) to the stimulus. [Need to do to maintain homeostasis]

Negative Feedback Mechanism

Keeps body conditions relatively constant.

• Most feedback mechanisms in body (maintains homeostasis)

• Response reduces or shuts off original stimulus

Negative Feedback Examples

body temperature (nervous) , blood pressure, glucose regulation (endocrine)

Positive Feedback Mechanism

The response enhances or exaggerates the original stimulus; exhibits an amplifying effect; usually controls infrequent events.

Positive Feedback Examples

Childbirth and blood clotting [makes a change]

Anatomical Position

The common reference standard:

• Body upright and palms forward

• Always use directional term as if body is in a anatomical position

• Right vs. Left [subjects point of view]

Sagittal Plane

Vertical division of the body into right and left portions.

• Midsagittal (median) Plane: equal right and left

• Parasaggital Plane: unequal right and left

Frontal (Coronal) Plane

Vertical plane dividing the body or structure into anterior and posterior portions.

Transverse (Horizontal) Plane

Divides the body into superior and inferior parts.

• Cross Section: across the length

• Oblique Section: at an angle

Superior (Cranial)

Higher on the body, nearer to the head.

Inferior (Caudal)

Away from the head end or toward the lower part of a structure or the body; below.

Ventral (Anterior)

Toward or at the front of the body; in front of.

Dorsal (Posterior)

Toward or at the back of the body; behind.

Medial

Toward the midline of the body.

Lateral

Away from the midline of the body.

Intermediate

Between a more medial and a more lateral structure.

Proximal

Closer to the origin of the body part or the point of attachment of a limb to the body trunk.

Distal

farther from the origin of a body part or the point of attachment of a limb to the body trunk.

Superficial (External)

toward or at the body surface.

Deep (Internal)

Away from the body surface; more internal.

Dorsal Body Cavity

Protects the fragile nervous system organs, has two subdivisions:

1. Cranial Cavity - in the skull, encases the brain

2. Vertebral Cavity - runs within the bony vertebral column, encloses the spinal cord.

Ventral Body Cavities

The more anterior and larger of the closed body cavities, two sub divisions:

1. Thoracic Cavity - surrounded by the ribs and and muscles of the chest. Further divided into three components. [Pleural cavities (lungs), Mediastinum cavities (lungs), Pericardial cavities (heart)]

2. Abdominopelvic Cavity - Below diaphragm, two parts. [Abdominal cavity, Pelvic cavity]

Nine Abdominopelvic Regions

Major : central portions [epigastric, umbilical, hypogastric] Right + Left [hypochondriac, lumbar, iliac (inguinal)]

Membranes in Ventral Body Cavity

Serous membrane (serosae) = "watery" membrane

• parietal membrane: lines cavity walls

• visceral membrane: covering surface of organs

• Serous fluid: between parietal and visceral membrane

Other Body Cavities

Oral and digestive, nasal, orbital, middle ear, synovial.

Chemical Bonds

The attractive forces that hold atoms together.

Covalent Bonds

Bonds created by sharing electrons with other atoms.

• Two or more atoms together = molecule

Non-Polar Covalent Bond

A covalent bond in which the bonding electrons are shared equally by the bonded atoms, resulting in a balanced distribution of electrical charge.

Polar Covalent Bond

A covalent bond in which electrons are not shared equally.

Ionic Bonds

Formed when one or more electrons are transferred from one atom to another.

• Negatively Charged Ions: anions

• Positively Charged Ions: cations

• Ionic Compound: SALT

Hydrogen Bonds

Very weak bonds; occurs when a hydrogen atom in one molecule is attracted to the electrostatic atom in another molecule.

Van der Waal Forces

Non-polar regions of molecules are attracted to each other.

• Weak force

• Important in lipid molecule interaction (e.g. cell membrane)

Solution

Homogenous mixtures of components that may be gases, liquids, or solids. Mixture at a molecular level (molecule) ex. mineral water

• Solvent: Substance present in the greatest amount.

• Solute: Substance present in smaller amount.

"can see through"

Colloid

Also called emulsions, are heterogeneous mixtures that often appear translucent or milky. Permanent mix of "chunks" not molecules. [e.g. milk --> chunks of fat and protein]

"can not see through"

Suspensions

Heterogeneous mixtures with large, often visible solutes that tend to settle out. Mix of "chunks" --> in time will settle out [e.g. blood]

Solutions in the Body

Main solvent is water (H₂O) which accounts for the majority of our body weight. [60 % +]

• Intracellular: 2/3

• Extracellular: 1/3

Characteristics of Water

1. Polarity: gives water its solvency and cohesion (liquid at room/body temp)

• Some molecules are hydrophilic (easily dissolved in H₂O)

• Some molecules are hydrophobic (not easily dissolved in H₂O)

2. Thermal Stability

• Heat capacity (stores heat)

• Heat of vaporization (increase of energy to H₂O liquid --> gas)

3. Chemical Reactivity

• Hydrolysis (add water to break apart macromolecules)

• Hydro "water" + Lysis "to break"

• Dehydration synthesis (condensation) (remove water to build macromolecules)

Solutes in the Body

1. Electrolytes: ions ionize in H₂O Na+, Cl-, K+, Ca++, PO₄---, some amino acids

2. Non-electrolytes: not ionize in H₂O Gases (O₂, N₂, CO₂), glucose, some amino acids

Acids/Bases

Acids are proton (H+) donors:

• Increase [H+] in water. H+Cl- ---> H+ + CL-

Bases are proton acceptors:

• Decrease [H+] in water Na+OH- ---> Na+ +. OH-

pH = 1/log10 [H+]

Anabolic Reactions (Synthesis)

Always involves bond formation. A + B --> AB

• Building larger molecules from smaller molecules

• Generally requires energy input

• Protein synthesis is one example

Catabolic Reactions (Decomposition)

AB --> A + B

• Breakdown larger molecules into smaller molecules

• Generally releases energy

• Examples: Glucose + O₂ --> CO₂ +H₂O + ENERGY

Exchange Reactions

Involves both synthesis and decomposition; bonds are both made and broken. AB + C --> AC + B

Oxidation

When molecules give up electrons (or H) so they release energy.

Reduction

When molecules accept electrons (or H) so they gain energy.

Characteristics of Chemical Reactions

• Chemical reactions may be reversible: AB + C --> AC + B

• The rate of a chemical reaction is dependent on many factors: concentration, temperature, an the presence of a catalyst (biological catalyst are called enzymes)

• Metabolism + Anabolism + Catabolism

Carbon Chemistry Overview

There are two major categories of molecules:

• inorganic (do not have carbon)

• organic (carbon + some hydrogen)

Four biological important macromolecules:

• Carbohydrates

• Lipids/fats

• Proteins

• Nitrogenous base molecules/DNA + RNA

Most of these are polymers made from monomers through dehydration synthesis.

Carbohydrates

• Composed of Carbon (C), Hydrogen (H), and Oxygen (O) in a ratio of 1C2H1O

• World's supply of carbohydrates is formed by photosynthesis (plants & algae)

• Example: sugars, starches, non-digestible fiber (e.g. cellulose)

Three Types of Carbohydrates

1. Monosaccharides: 3-7 carbons in a molecule. Example (glucose, the main form of energy delivered to our body'd cell) "one sugar"

2. Disaccharides: two monosaccharides joined together. Example [Sucrose (table sugars) = Glucose + Fructose] [Maltose] "two sugars"

3. Polysaccharides: Many monosaccharides together — may be a large molecule. Example [Glycogen, chain of glucose] [plant fiber + plant starches]

Lipids

• Mainly composed of C, H, and O (with less oxygen than found in carbohydrates therefore less oxidized, more energy, more calories per gram)

• Energy source, protection and insulation

Four Types of Lipids

1. Fatty Acids: long chains of C with a Carboxyl group (COOH) at one end

• Saturated have NO double bonds (solid at room temp)

• Unsaturated have some (one or more) double bonds between carbons.

2. Neutral Fats: most important in humans are the Triglycerides. Made up of Glycerol (a three carbon modified sugar alcohol) and three long chains of fatty acids. Fats are unsaturated, saturated, or polyunsaturated depending on their fatty acids.

3. Phospholipids: Made up of Glycerol, two long fatty acid chains (non-polar, hydrophobic) and a molecule containing phosphate ion (polar; hydrophilic). Important part of the cell membrane as well as the fatty sheaths around the nerve cells.

4. Steroids: Made up of four interconnected rings of carbon atoms with various carbon chains attached. Examples [cholesterol, vitamin D, male and female hormones]

Proteins

• "of first importance"

• Building blocks of all proteins are molecules called amino acids

• Amino acids are made up of C, H, O, and Nitrogen, with occasional phosphorous and sulfur. There are 20 different amino acids in humans — all with the same basic structures.

• directs cell function

Peptide Bonds

Proteins are amino acids bonded together in a long chain by covalent bonds. Bond between Carbon and Nitrogen.

• Dipeptide "two"

• Tripeptide "three"

• Polypeptide "many Protein is usually amino acids in chains of thousands

Four Primary Protein Shapes

1. Primary Structure: sequence of amino acids

2. Secondary Structure (the initial shape): H-bonds; Alpha = helix (spiral), Beta = pleated

3. Tertiary Structure: 3D shape

4. Quaternary Structure: Two or more 3D shapes together.

Conformation vs. Denaturation

• Normal shape vs. Not normal shape (heat, change in pH, radiation)

Protein Function

Functions of protein are many because they can have such diverse structure:

• Globular Proteins: functional proteins; water soluble. "round, small"

• Enzymes: speed up chemical reactions

• Hemoglobin: carries gasses

• Antibodies: fight infections

• Receptors: bind to other molecules

• Fibrous Proteins: structural proteins; water insoluble. "round, large"

• Connective tissue: body support

• Muscle contractile proteins: movement

Enzymes

Globular proteins that act as biological catalysts.

• Protein

• Act to regulate chemical reactions in the body:

• Substrate: what enzymes works on

• Enzymes align substrates so they can interact

• lowers activation energy required for a RxN

Properties of Enzymes

• Enzymes speed up chemical reactions or allow them to occur at lower temperatures. (They don't cause a reaction that would never otherwise occur)

• In reversible reactions, one enzyme may enable a reaction to go in either direction. [The direction is determined by the Law of Mass Action (concentration of reactants and products)]

AB + C <---> AC + B Lots of AB + C ---> <--- Lots of AC + B

• Structures of Enzymes:

• Globular proteins: soluble

• Active sites: where substrates bind

• Enzyme-substrate specificity: work for one RxN

• Enzymes names use "ase" endings: Lactase, sucrase

• Factors that affect enzymes:

• Temperature

• pH

• Cofactors: metal ions act to carry e- in enzyme reactions

• Coenzymes: organic molecule acts to carry e- in enzyme reactions

Adenosine Triphosphate (ATP)

The major energy carrying molecule. Structure is similar to a nucleotide found in DNA and RNA, ATP is made up of:

• Adenine (nitrogenous base)

• Ribose (monosaccharide sugar)

• Three phosphate molecules — hence the word TRIphosphate

Function: Immediate energy source [INSIDE THE CELL} for chemical reactions

• ATP --> ADP (adenosine diphosphate) + Phosphate + Energy

• Phosphorylation: adding phosphate to another molecule to give energy

Nucleic Acids

Involved in cell control and heredity. Function = genetic coding, energy currency

Deoxyribonucleic Acid (DNA)

• Double Stranded HELIX (think of a twisted ladder)

• Each section of the helix is made up of NUCLEOTIDES which are:

• Deoxyribose (a monosaccharide sugar)

• Phosphate

• Nitrogenous base

• Purine bases: Adenine, Guanine (double ring)

• Pyrimadine: Thymine, Cystosine (single ring)

• Twisted ladder shape: rungs on the ladder are bases, uprights of the ladder are sugar chains (deoxyribose) and phosphates

• Complimentary base pairings: Adenine with thymine, and Guanine with cytosine. Held by hydrogen bonds.

Ribonucleic Acid (RNA)

• Single stranded

• Instead of thymine, uses the base known as Uracil

• Sugar on backbone is ribose

Cell Theory

Three main concepts:

1. Cell is structural + functional unit

2. All life is cellular

3. Cells came from preexisting cells

Plasma Membrane

A selectively-permeable phospholipid bilayer forming the boundary of the cells. Properties of the membrane:

• Protein: Most weight of the membrane

• Integral: all the way through

• Peripheral: on the edge

• Many functions:

• Transport

• Receptor

• Attachment

• Enzyme

• Joining the cell

• Recognition

• Carbohydrates

• Glycoproteins (attached to proteins)

• Glycolipids (attached to fats)

• Full layer on outside = Glycocalyx

Cell Junctions

• Tight Junctions: a fusion of two cells' membrane proteins, prevents movement between cells

• Desmosome: a fusion of protein plates — anchored into cell. Acts to hold cells together. "joining body" D-somes break down --> shed skin cells

• Gap Junction: made of a large group of channels (connexons):

• Line up up connexons with adjacent cells

• electrochemically couples cells

Surface Modifications

• Microvilli are finger like extensions: increase surface area (e.g. GI tract).

• Cilia provide motion in order to move, mucus.

What does selectively permeable mean?

Only allows certain materials to pass through.

Passive Mechanisms To Cross Membrane

No energy used by the cell itself.

• Filtration — Hydrostatic Pressure (fluid pressure)

• Diffusion

• Channel/Carrier-Mediated Diffusion

• Channel-Mediated Diffusion

• Osmosis

• Dialysis

• Tonicity

Diffusion

Movement of molecules from an area of higher concentration to an area of lower concentration.

• Why? Kinetic energy of molecules = molecules in constant motion

• Factors affecting rate of diffusion:

• Temperature (increase)

• Concentration gradient (increase)

• Solubility (increase)

• Molecular size/weight (decrease)

• Simple diffusion across membrane

• Lipid soluble solutes: O₂, CO₂, Alcohol

• Facilitated/Carrier-Mediated Diffusion:

• Carrier Proteins: Glucose + certain amino acids

• Channel-Mediated Diffusion:

• Specific Protein Channels: Na+, K+, Cl-, Ca+, ion

Osmosis

Diffusion of H₂O through selectively permeable membrane.

"water follows solute"

Dialysis

Diffusion of solute through selectively permeable membrane.

Tonicity of Solution

What does the cell do in various of solutions?

• Isotonic ("same tension/tone")

• Hypertonic ("more"): Crenation

• Hypotonic ("less"): swell, may burst

Active Transport To Cross Membrane

Requires energy in form of ATP.

Primary Active Transport

Active transport that relies directly on the hydrolysis of ATP.

• Most investigated example: sodium-potassium pump [BIGGEST USER OF ENERGY IN THE BODY] -Solute (ion) against concentration gradient

• What happens?

• Solute binds: to membrane protein

• ATP: Phosphorylates enzyme

• Protein changes shape: ion pumped

• Na+K+ ATP Pump:

• 1 ATP pumps: 3 Na+ out and 2 K+ into cell

• Sets up: concentration gradient across all cell membranes

Secondary Active Transport

Form of active transport which does not use ATP as an energy source; rather, transport is coupled to ion diffusion down a concentration gradient established by primary active transport.

Bulk Transport

Endocytosis: "into cell movement"

• Phagocytosis: "cell eating" solids

• Pinocytosis: "cell drinking" Liquids

• Receptor: Mediated Endocytosis will use specific protein receptors on cell surface to engulf specific substances

Exocytosis: Secretion/add/change membrane "out of the cell movement"

• Vesicles, using snare proteins, attach to membrane surface: secrete substances or add/change membrane. "fluid sac"

Role of Membrane Receptors

Ligand-Gated Ion Channel:

• Ligand is a chemical that binds to protein

• Binds and opens ion channel to cause ions to diffuse across membranes.

G-Protein Receptor

• Makes 2nd messenger inside the cell -Ligand binds to receptor

• G protein stimulated (uses energy molecule GTP)

• Effector protein stimulated

• 2nd messenger created inside cell

• Most common is cAMP, made from ATP, creates the effects inside cell

• Cyclic Adenosine Monophosphate

Electro-Chemical Gradient

The diffusion gradient of an ion, representing a type of potential energy that accounts for both the concentration difference of the ion across a membrane and its tendency to move relative to the membrane potential.

Set up by Na+ K+ ATP Pump. Membrane potential voltage. Charge INSIDE cell is negative. More Na+ outside, more K+ inside.

Aquaporins

Water channel proteins

Cytoplasm

Everything inside the membrane but the nucleus.

Cytosol

Fluid portion of cytoplasm. "cell solution" ---> H₂O + solutes

Inclusions

Chemical substances such as stored nutrients or cell products.

Organelles

A tiny cell structure that carries out a specific function within the cell.

Mitochondria

• Threadlike or sausage-shaped membraneous organelles.

• Enclosed by two membranes: inner (folds inwards, cristae) and outer (smooth).

• Contain their own DNA and RNA and are able to reproduce themselves.

• Similar to a group of Bacteria

• Function: "power plant" = convert energy

food + O₂ ---> CO₂ + H₂O + Energy

Endoplasmic Reticulum (ER)

Extensive system of interconnected tubes and parallel membranes enclosing fluid filled cavities that coil or twist through cytosol.

Two types:

1. Smooth ER: Less common, no ribosomes

• fat metabolism, making membrane for cell

• Ca++ stores in muscle

• Liver detoxing enzymes

2. Rough ER: Common, ribosomes attached

• ribosomes: make protein

• Proteins usually exported from cell

"network within cytoplasm"

Ribosomes

Small, dark staining granules composed of proteins and a variety of RNA called ribosomal RNA.

• Protein synthesis

• Two subunits: large and small

• Two types of ribosomes:

• Bound (on rough ER): proteins usually for export/secreted from cells

• Free/ Not bound to the ER, usually makes proteins for cell use.