Physiology Exam 1
Terms
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- Physiology
- Study of normal body functions
- Primary tissues
-
1. Muscle- contraction, generation of force
2. Nerve- initiate, transmit electrical impulses
3. Epithelial- barrier between body and external environment; exchange
4. Connective- connect, anchor, support - Organs
- collection of 2 or more types of tissues put together into structure that performs specific function
- Organ Systems
- collection of organs that work together to accomplish a particular task
- Body fluid compartments
-
1. Total body water= 70% BW
2. Intracellular fluid = 2/3 TBW
3. Extracellular fluid = 1/3 TBW
4. Plasma = 1/5 ECF
5. Interstitial fluid - Negative feedback control in homeostasis
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-Primary mechanism for maintaining homeostasis (aka homeostatic control mech.)
-3 basic components: sensors (nerve receptors), control center (brain/spinal cord), effectors (muscles/glands)
-Mechanisms: set point, sensors send input to integrating center which compares to set point then error signal goes to IC which sends output to brings level back to set point
-inhibitory, i.e. final corrective action is opposite to the initial deviation from the normal value (or condition). - Positive feedback
-
-loops cause rapid change (ex: ovulation)
-ex: upstroke of action potential in nerve and muscle
-body uses it to bring a physiological process to a quick completion (ex: childbirth, ovulation)
-does not lead to stability or regulation, but the opposite: a progressive change in one direction. - Feedforward control
- Term referring to an animal's ability to predict an upcoming disturbance to the homeostatic state, and to take the necessary corrective action. It is anticipatory- does not require error signals. Learned responses to known cues.
- Homeothermic
- of birds and mammals; having constant and relatively high body temp. (aka: warm-blooded)
- Poikilothermic
- of animals except birds and mammals; having body temp that varies with the environment (aka cold-blooded)
- Hypothermia
- subnormal body temp
- Hyperthermia
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abnormally high body temp (fever)
above 41 C (105.8 F), dangerous
above 43 C (109.4 F), deadly - Mechanisms of heat transfer between body and external environment
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-radiation- thermal energy as electromagnetic waves
-conduction- thermal energy through direct contact
-evaporation- heat loss through evaporation of water (insensible water loss, sweating)
-convection- heat transfer by movement of fluid or air - Fever
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-accompanies infections
-MOs and WBCs secrete pyrogens
-body temp set point increases (fever does NOT result from a failure of the thermoregulatory system)
-due to the resetting of the set point in the body's thermostat (hypothalamus)
-low fever enhances immune response; but fever that is too high and occurs too fast is dangerous - Pyrogens
- fever-inducing agents produced by bacteria, viruses, molds, and yeasts, or produced endogenously by WBC/macrophages
- Heat stroke
- an acute hyperthermia resulting from excessive exposure to heat, natural or artificial. The temp regulatory mechanisms become overwhelmed and unable to effectively deal with the heat, and body temp climbs uncontrollably
- Symptoms of heat stroke
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dry skin
vertigo
headache
thirst
nausea
muscular cramps
body temp may be subnormal - Heat exhaustion
- effect of excessive exposure to heat, occurring among workers in hot places (i.e. furnaces, sun's heat, foundries)
- Symptoms of heat exhaustion
-
normal/subnormal temp
dizziness
headache
nausea
weakness
profuse sweating
sometimes delirium or collapse - Thermoneutral zone
- range of ambient temp over which the organism is able to maintain a constant body temp without the use of metabolically demanding mechanisms (such as more fat burning, more muscle contractions, more sweating, etc.)
- Pathology
-
study of diseases;
branch of medical science that studies the causes, nature and effects of diseases and esp of the structural and functional changes produced by them - Symptoms
- subjective abnormalities felt by the patients
- Signs
- objective abnormalities perceptible to the examining physician
- Syndrome
- collection of symptoms and signs
- Etiology
- study or theory of all factors that cause disease and the method of their introduction to the host; the causes or origin of a disease or disorder
- Remission
- a diminution or abatement of the symptoms of a disease; also the period during which such diminution occurs
- Relapse
- the return of a disease after its apparent cessation
- Epidemiology
- the study of diseases (occurrence, distribution, and transmission) in populations
- Endemic diseases
- disease in population that is restricted to a local region
- Epidemic disease
- it has spread to many individuals at the same time in a larger region
- Pandemic disease
- an epidemic that is geographically widespread; occurring throughout a very large region, a continent, or even throughout the world
- Properties of water
-
-high heat capacity
-high heat of vaporization
-solvent
-molecules are cohesive and adhesive (high surface tension and capillary action)
-pure water freezes at 0 C but is most dense at 4 C. That is, solid water (ice) is less dense than cold liquid water
-polar molecules dissolve in water - Acids and bases
-
-An acid is a proton donor and a base is a proton acceptor
-strong acids dissociate totally, and the anions formed (like Cl- from HCl) are not bases because they do not associate with protons in solution. Only weak acids, mostly organic, dissociate partially. - pK' of an acid
- the pH at which the acid is half dissociated, when [A-]=[HA]
- Buffer system
-
-simply a mixture of a weak acid (e.g. acetic acid) and its conjugate base (e.g. acetate ion, an anion) or a weak base (e.g. ammonia, NH3) and its conjugate acid (NH4+, a cation)
-works by reacting with any added acid or base to control the pH, as the strong acid or base is changed to a weak one - Definition of buffering
- ability of a solution to resist a change in pH when acid or base is added
- More effective buffer:
- make sure that the concentration of the buffering agents is large in comparison to the added acid or base
- Biomolecules
-
Carbon-based (organic) molecules synthesized by living organisms.
Including carbohydrates, lipids, proteins/amino acids, and nucleic acids/nucleotides - Atoms
- an atom is the smallest part of an element which can take part in a chemical reaction; they are the basic building blocks of ordinary matter and can join together to form molecules
- Element
- substance made entirely from one type of atom
- Which 4 elements make up 98% of atoms in the body?
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H, O, C, N
(other 2%: P and S, etc.) - Common functional groups in biomolecules
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hydroxyl
sulfhydryl
phosphate
carboxyl
amino - Carbohydrates (sugars)
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C,H,O in proportion of 1:2:1
Cn(H2O)n = (CH2O)n - Monosaccharides
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glucose, fructose, galactose, ribose, 2-deoxyribose
notice hydroxyl groups which make carbs polar - Disaccharides
-
sucrose, lactose
formed by dehydration synth. from monosaccharides
(sucrose = glucose + fructose)
joined by glycosidic linkage - Sweetest carb?
- fructose
- Polysaccharides
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starch (from plants)
glycogen (animal starch) - Lipids
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composed of primarily hydrogen and carbon atoms
non-polar/hydrophobic (poor solubility in water) - Classes of Lipids
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Triglycerides
Phospholipids
Eicosanoids
Steroids - Triglycerides
- glycerol + 3 fatty acids
- What makes triglycerides hydrophobic?
- Fatty acid chains
- Triglyceride is produced by
- dehydration synthesis from glycerol and fatty acids
- Phospholipids
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one -OH of glycerol linked to phosphate
amphipathic (amphiphilic) molecules
phosphatidyl choline = lecithin - Amphipathic (Amphiphilic) means
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polar (hydrophilic)- phosphate group (Head)
nonpolar (hydrophobic)- FA chains (Tails) - Eicosanoids
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group of 20-C fatty acids with a cyclopentane ring
(prostaglandine, thromboxanes, leukotrienes) - Steroids
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Ring structure made of 4 C rings derived from cholesterol
Hydrophobic (NOT water soluble) - Sex steroids
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estradiol
testosterone
progesterone - Adrenal steroids
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cortisol
aldosterone - Proteins/Amino acids
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proteins = polymers of amino acids
20 aa's are building blocks of proteins
macromolecules of thousands of atoms
function as receptors, enzymes, ion channels, antibodies, etc. - Basic structure of aa's
-
R = side chain that can vary in property (polar, nonpolar, ionized)
20 diff aa's due to 20 diff R's. - peptide bond
- covalent bond between carboxyl group of one aa and amino group of another aa
- peptides
- generally 2-50 aa's (smaller)
- proteins
- greater than 50 aa's (huge)
- How are peptide bonds produced?
- dehydration synthesis
- Primary protein structure
- sequence of aa's
- Secondary protein structure
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H-bonding between amino hydrogen of 1 aa and carboxyl oxygen of another aa
(alpha helixes and beta pleated sheets) - Tertiary protein structure
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formation of bends and loops in polypeptide chain due to interactions between R groups
*overall shape (folding) of protein* - Interactions causing tertiary structure
-
-electrostatic interactions (ionic bonds)
-van der waals forces
-hydrogen bonds
-covalent bonds (disulfide bridge) - Quaternary protein structure
- formation of proteins with more than one polypeptide (2 or more chains/subunits) linked by disulfide bonds
- glycoproteins
- contains sugar units, i.e. FSH
- lipoproteins
- contains lipids, i.e. LDL, HDL
- Nucleic acids/nucleotides
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Functions: storage, expression, and transmission of genetic info
basic subunit = nucleotide = sugar + phosphate + nitrogenous base - Purines (double rings)
- A and G
- Pyrimidines (single ring)
- C, T, and U
- ATP and ADP
-
-high energy phosphate bonds
-major molecules for transferring energy
-muscle contraction
-active transport across membranes
-synth. of organic molecules - what are cAMP and cGMP?
- messengers
- what are NAD and FAD?
- other energy-transferring nucleotides
- A-T or A-U
- two H-bonds
- G-C
- three H-bonds