Bisc 162 Exam 2

Question 1

what do gas exchange systems consist of?

Answer 1

1. specialized body surface areas where gas move b/w body & environment
2. ventilation mechanisms that move air/water over environmental sides of surfaces
3. perfusion mechanisms that circulate ECF on internal sides

Question 2

what is partial pressure?

Answer 2

concentrations of different gases in mixture

Question 3

what are the variables of Q=DA(P1-P2/L)?

Answer 3

Q is rate at which gas diffuses b/w 2 locations
D is diffusion coefficient (combination of diffusing substance, medium & temp)
A is area across which gas diffusing
P1 & P2 is partial pressure gradient
L is distance between 2 locations

Question 4

why is oxygen obtained more in air?

Answer 4

1. O2 content in air is higher
2. O2 diffuses 8000 times quicker in air
3. animals have less work to ventilate gas exchange in air

Question 5

what is the tracheal system of insects?

Answer 5

communicate with environment through spiracle (gated openings) -> spiracle open to tubes (tracheae) -> open to tracheal (actual gas exchange surface)

Question 6

what is the water flow in fish?

Answer 6

water flows unidirectionally into fishes mouth, over gills, and out opercular flaps, maximizing PO2 on external gill surfaces & minimizes PO2 inside b/c it’s swept away

Question 7

how does the gill allow gas exchange?

Answer 7

each gill filament has lamellae (actual gas exchange surface) -> blood vessels flow in opposite direction so countercurrent flow maximizes transfer O2 from water to blood b/c always gradient
- afferent brings deoxygenated & efferent brings oxygenated away

Question 8

what is the air flow in birds?

Answer 8

trachea (air enters & leaves) -> 2 primary bronchi -> posterior air sacs -> secondary bronchi -> parabronchi branching off air capillaries -> anterior air sac -> trachea
- a single breath remains in system for 2 breathing cycles

Question 9

what is the air flow in mammals?

Answer 9

oral/nasal cavity -> pharynx -> larynx -> bronchi -> bronchioles -> alveoli

Question 10

what is difference between ventilation and perfusion?

Answer 10

ventilation delivers O2 and sweeps away CO2
perfusion sweeps away O2 and delivers CO2

Question 11

what does inhalation and exhalation do?

Answer 11

inhalation: diaphragm contract (pull down), pulling plural membrane, which pulls on lungs to increase volume and decrease alveoli pressure so air rush in
exhalation: diaphragm relax, which cause lung recoil to pull diaphragm up & air out

Question 12

what is the hemoglobin/oxygen binding & dissociation curve?

Answer 12

reflects interactions b/w the 4 subunits of Hgb molecule
- at low PO2, only one subunit will bind O2 molecule- causing shape to change & allow greater affinity of O2
- once 3rd O2 bound, it needs larger increase in PO2 to become 100% saturated b/c less likely to have place to bind

Question 13

what do muscles have for O2 biding?

Answer 13

they have their own O2 binding molecules (myoglobin with one subunit but greater affinity)

Question 14

what are the 3 factors that can affect Hgb binding properties?

Answer 14

1. chemical composition of Hgb
2. presence of 2,3 BPG
3. pH

Question 15

what is an example of chemical composition of Hgb affecting the binding curve?

Answer 15

Fetal humans have a greater affinity for O2 b/c their Hgb has y-globin chains instead of B-chains

Question 16

what is an example of pH affecting the binding curve?

Answer 16

Bohr effect: the influence of pH on Hgb
- as blood passes metabolically active tissue, it picks up acidic components (Carbonic acid) -> decreases pH -> shifts curve to right (decreases affinity) -> Hgb release more O2 where pH low

Question 17

what is an example of 2,3 BPG affecting the binding curve?

Answer 17

2,3 BPG decreases the affinity to O2 -> Hgb release more O2
- 2,3 BPG is a byproduct of glycolysis so it indicates metabolically active tissue

Question 18

what is the Haldane effect?

Answer 18

oxygenation of Hgb decreases affinity for CO2

Question 19

how does CO2 get transported as bicarbonate?

Answer 19

carbonic anhydrase speeds up conversion of CO2 to H2CO3, which dissociate into H+ & HCO3- -> HCO3- leaves plasma in exchange of Cl- ion -> keeps PCO2 low to alveoli where it diffuses in

Question 20

how does the spinal cord affect breathing?

Answer 20

breathing irregular if cut above medulla and below pons
breathing stopped if spinal cord in neck area severed

Question 21

what are the sensors that affect breathing?

Answer 21

chemical sensors in medulla sensitive to change in PCO2 & pH of cerebrospinal fluid -> change in PCO2 cause large increase in ventilation
chemosensory on carotid bodies & aortic bodies sensitive to O2 availability

Question 22

what is an open circulatory system?

Answer 22

ECF is the same as fluid in the system (hemolymph)

Question 23

what happens in an open circulatory system?

Answer 23

Heart moves hemolymph through vessels leading to different regions of body -> fluid leaves vessels to filter through tissue before returning to heart
- in arthropods, fluid returns to heart though openings called Ostia (valves that allow hemolymph to returned to relaxed heart but prevent flow in opposite)

Question 24

what happens in a closed circulatory system (earthworm)?

Answer 24

large ventral blood vessel carries from anterior to posterior -> smaller vessels branch -> even smaller vessels -> larger vessels that lead to large muscular dorsal vessel from posterior to anterior
- 5 pairs of vessels connect to large dorsal & ventral vessels that serve as heart

Question 25

what are the advantages of closed circulatory system?

Answer 25

1. fluid flow more rapidly 2. control flow of blood 3. specialized cells & molecules kept in

Question 26

what is the blood flow in mammals?

Answer 26

heart -> arteries -> arterioles -> capillaries -> venules -> veins -> heart

Question 27

what is the blood flow in fish?

Answer 27

sinus venosus -> atrium -> ventricle -> bulbus arteriosus (highly elastic) -> gills -> aorta - blood leaving gills & entering aorta under low pressure - limit capacity to supply tissue w/ nutrients b/c pressure from ventricle dissipated as resistance to flow in gill lamellae

Question 28

what is the blood flow in lungfish?

Answer 28

they have posterior gills to pick up oxygen & anterior gills that deliver oxygenated to dorsal aorta - posterior gills -> dorsal aorta (high O2)/pulmonary artery to lungs (low O2) -> atrium (separated from deoxygenated & oxygenated) -> bulbus arteriosus -> anterior gills -> dorsal aorta

Question 29

what is blood flow in amphibians?

Answer 29

single ventricle pumps blood to lungs and body -> 2 atriums -> could lead to some mixing but not much - advantage b/c allow blood to sidestep large pressure drop - partial separation of systemic & pulmonary circulation

Question 30

what is the blood flow in reptiles (not crocs)?

Answer 30

breathing: pump to lungs/ body not breathing: bypass pulmonary circuit & pump blood to body - have 2 atriums & partially divided ventricle. left aorta receive oxygenated blood from left ventricle & right aorta receive blood from right/left ventricle

Question 31

what is blood flow in crocodiles?

Answer 31

breathing: blood flow to pulmonary circuit not breathing: right ventricle to right aorta - have connection b/w 2 aortas so they alter amount of blood going to pulmonary & systemic circuit

Question 32

what is the difference between systole and diastole and lub-dub?

Answer 32

systole (ventricle contract) & diastole (ventricle relax) - lub-dub b/c of valves - lub because of AV valves close; dub because of semilunar valves close

Question 33

what are pacemaker cells?

Answer 33

cardiac muscle cells that initiate AP without stimulation through gap junctions from nervous system

Question 34

what is the sinoatrial node?

Answer 34

primary pacemaker located at junction of superior vena cava & right atrium

Question 35

what are the features of sinoatrial node?

Answer 35

slower to rise; broader; slower to return to resting potential - AP due to voltage-gated Ca2+ channels b/c they open & close slower than Na+ channels

Question 36

what is the AP phase in sinoatrial node?

Answer 36

rise in AP followed by opening of voltage-gated K+ channels -> causes unique voltage-gated Na+ channels open -> opening of Na+ & closing K+ cause membrane potential increase -> gradual rise in potential cause Na+ to close and transient (T) Ca2+ channels open -> long-lasting (L) Ca2+ channels open (generates AP)

Question 37

what is the pathway of electric signal in heart?

Answer 37

sinoatrial node -> AV node -> Bundle of HIS -> purkinje fibers (ventricles contract)

Question 38

how does the autonomic nervous system control heartbeat?

Answer 38

norepinephrine increase heartbeat b/c more permeability to Na+ & Ca2+ acetylcholine decrease heartbeat b/c more permeability to K+ & less to Ca2+

Question 39

what are the stages of the EKG?

Answer 39

P=depolarization of atrial muscle; Q, R, S= depolarization & contraction of ventricles/repolarization of atria; T=repolarization & relaxation of ventricles

Question 40

how does the exposure of blood vessels to collagen initiate a cascade?

Answer 40

prothrombin -> thrombin/fibrinogen -> fibrin - fibrin threads form meshwork that bind platelets, seal vessels, and provide scaffold for scar tissue

Question 41

what are arterioles and veins also called?

Answer 41

arterioles also called resistance vessels b/c resistance can vary blood flow to specific tissue veins called capacitance vessels b/c of ability to stretch and store blood

Question 42

what is blood volume maintained by?

Answer 42

Starling's force: 1. blood hydrostatic pressure increase squeezes water & small solute out artery end of capillaries 2. blood osmotic pressure decrease pulls water back into capillaries at venule end

Question 43

what is blood osmotic pressure maintained by?

Answer 43

large protein molecules that can't leave capillaries - HCO3- may also pull water back into cells b/c osmotic pressure at venule end higher than arterial end

Question 44

how does blood flow through veins?

Answer 44

below heart is squeezing of veins by contraction of surrounding skeletal muscle - veins compressed and blood squeezed through them - one way valves in veins of extremities prevent back flow of blood

Question 45

what is the pathway of lymphatic vessels?

Answer 45

interstitial fluid enters lymphatic vessels called lymph -> right and left lymphatic ducts -> left called thoracic duct carries lymph from lower part of body -> lymph nodes (major site of lymphocyte production & action to remove microorganisms & foreign material) - lymphs have valves too

Question 46

how does arteriosclerosis/atherosclerosis start?

Answer 46

damaged endothelial cells attract WBCs -> joined by smooth muscle -> lipid (cholesterol) join -> fibrous connective tissue + calcium make arteries more hard - plaque deposits narrow artery & platelets stick to plaque make thrombus

Question 47

what are the risk factors of arteriosclerosis/atherosclerosis?

Answer 47

genetic predisposition; age; high fat; high cholesterol; smoking; sedentary lifestyle; obesity; hypertension; smoking

Question 48

what do the negative feedback of baroreceptors and ADH do?

Answer 48

1. baroreceptors- change in BP in large arteries to brain (aorta/carotid); stretch response - increase BP cause increase Baro -> inhibit sympathetic & increase parasympathetic (heart slow & peripheral arteries dilate) - decrease BP -> stimulate sympathetic & reduce para (heart faster & constriction) 2. ADH to increase BP; vice versa

Question 49

what is the difference between osmoconformers/osmoregulators?

Answer 49

conformers: saltwater invertebrates that conform to osmotic concentration of environment over fairly wide range of saltiness regulators: constant osmolarity of ECF as osmolarity of environment change - seawater diluted, hypertonic regulation/saline, hypotonic regulation

Question 50

what are the different types of nitrogen waste?

Answer 50

Ammonia: urea/uric acid is excreted by diffusion (aquatic invertebrate/bony fish) Urea excreting is ureotelic (mammals, amphibians, cartilaginous fish) Uric acid excreting is uricotelic (birds)- forms colloid suspension

Question 51

how do protonephridia excrete waste?

Answer 51

by tubules ending in flame cells b/c each cell has tuft of cilia projecting into tubule - ECF enters tubule by filtration through slits in flame cell -> beating of cilia cause neg. pressure & movement of animal cause pos. pressure -> pressure difference cause ECF to be filtered -> filtrate flows toward animals excretory pore & alone way, cells of tubule modify composition by reabsorb & secrete

Question 52

how do annelids excrete waste?

Answer 52

fluid-filled body cavity called coelom with coelomic fluid filtered through meanephridia - each opening of nephrostome -> cells of tubule secrete & reabsorb -> nephridiopore to outside world

Question 53

how do insects excrete waste?

Answer 53

use Malpighian tubes using active transport - cells of tubule transport uric acid, Na+, K+ into tubule (water follows) -> Na+ & K+ active transport back to ECF (water follows) -> as concentration increase, uric acid creates colloidal suspension with waste excrete

Question 54

what do frogs do?

Answer 54

enter estivation & before, they fill bladder with diluted urine to serve as water reservoir - estivation: state of very low metabolic activity & water turnover

Question 55

what are the 3 processes of renal system?

Answer 55

1. filtration (glomerulus): permeable to water, ions, & small molecules; BP drives movement of water & small solutes out of glomerular capillaries 2. tubular reabsorption: in renal tubule where it modifies filtrate by reabsorbing & leaving behind 3. tubular secretion: filtrate modified more by tubule cells transporting substances into tubule, which need to be excreted

Question 56

what does the proximal convoluted tubule do?

Answer 56

most glomerular filtrate reabsorbed by it: actively transport Na+ (w/ Cl- following), glucose, & amino acids out and into ECF; water follows

Question 57

what does the loop of Henle do?

Answer 57

creates solute concentration gradient in medulla b/c ascending impermeable to water & permeable to solute transport while thin descending is opposite

Question 58

how does the loop of Henle create a solute concentration gradient?

Answer 58

thick ascending loop actively transport Na+/Cl- out of tubular fluid, raising concentration of interstitial fluid -> water draw from descending limb as concentration increase (fluid in descending become more concentrated at U-turn)

Question 59

what does the distal convoluted tubule do?

Answer 59

fine-tunes composition of urine with lots of ion transporters

Question 60

what does the collecting ducts do?

Answer 60

urine concentrated as it loses water to interstitial fluid as it flows down b/c urea main solute - tubule fluid entering duct is same solute concentration as blood plasma but different solute composition

Question 61

how does the kidneys control pH?

Answer 61

for each H+ secreted into tubular fluid, a HCO3- released into blood - Na+ & HCO3- filtered into glomerulus -> renal tubule cells secrete out H+ in exchange of Na+ (in) -> CO2 formed by reaction of HCO3- & H+ & CO2 + H2O diffused into tubule cells -> Co2 converted back to HCO3- in tubule cells -> Na+/HCO3- symporter carries them across membrane

Question 62

what is the renin cycle?

Answer 62

kidney release renin to convert angiotensionogen to angiotensin I -> angiotensin-converting enzyme (ACE) in lungs converts to angiotensin II

Question 63

what does angiotensin do?

Answer 63

1. constrict efferent blood vessels, raising resistnace 2. constrict all peripheral blood vessels 3. stimulate release of aldosterone 4. stimulate thirst

Question 64

what are the 2 different types of defense mechanism?

Answer 64

1. innate: also called nonspecific; provide 1st line of defense (skin, toxic molecules, & phagocytosis) 2. adaptive: aimed at specific pathogens & activated by cells of immune -> make antibodies that recognize, bind, & aid in destruction

Question 65

what are the examples of adaptive:

Answer 65

barrier, defensive cells, & defensive mechanism

Question 66

what are the 3 types of WBC?

Answer 66

Granulocytes (basophils, eosinophils, neutrophils, & mast cells); monocyte-derived (monocytes, macrophages, & dendritic); lymphocytes (B, T, and natural killer)

Question 67

what are examples of immune system proteins?

Answer 67

antibodies; major histocompatibility complex (MHC); T cell receptors; & cytokines

Question 68

what do the first line of defense include?

Answer 68

physical barrier, presence of mucus, presence of lysozyme, presence of defensins, presence of extreme conditions, & presence of normal flora

Question 69

what is the complement system job?

Answer 69

1. attach to specific component on surface of microbe/antibody that help phagocytes recognize 2. activate inflammatory to attract phagocytes 3. lyse invading cells

Question 70

what do interferons?

Answer 70

class of cytokines that are signaling protein that increase resistance of neighboring cells to infection - signaling pathway that inhibit virus reproduction; hydrolyze bacterial/virus protein to peptides

Question 71

what do mast cells release?

Answer 71

1. tumor necrosis factor: cytokine that kills target cells & activate immune 2. prostaglandin: fatty acid that widens blood vessels & interact with nerve ending (pain) 3. histamine: amino acid that leads to dilation & leakiness of blood vessels

Question 72

what is an example of damage to blood vessels leading to infection?

Answer 72

damage to tissue cause mast cells to release histamine -> histamine cause dilation & leakiness; complement leave vessel & attract phagocytes -> blood plasma & phagocytes move into infected tissue

Question 73

what are the key factors of the adaptive immune?

Answer 73

1. ability to distinguish self from non self 2. diversity 3. immunological memory 4. specificity: sites of antigens that immune know is antigenic determinant/epitopes

Question 74

what are B and T cells a part of?

Answer 74

B cells (antibodies) part of humoral immune response and cytotoxic T (Tc) cells part of cellular immune response

Question 75

what is clonal selection for the adaptive immune system?

Answer 75

adaptive triggered via antigen on antigen-presenting cell (dendritic) -> triggers proliferation of B & T cells that's specific for that antigen (clonal selection)

Question 76

what are antibodies?

Answer 76

immunoglobulins with 2 heavy & 2 light chains -> held together by disulfide bonds - constant region determine destination & function (class)/ variable region (antigen-antibody is non covalent: held together by hydrogen, ionic, hydrophobic, & van der Waals

Question 77

what are the 5 classes of antibodies?

Answer 77

IgG (monomer), IgM (pentamer), IgD (monomer), IgA (dimer), & IgE (monomer)

Question 78

what is immunoglobin diversity made by?

Answer 78

results from DNA arrangement & other mutations - Variable region made by 1 variable gene, 1 diversity gene, & 1 joining gene

Question 79

what are the other mechanisms that promote immunoglobin diversity?

Answer 79

1. higher spontaneous mutation 2. terminal transferase make insertion mutation 3. imprecise recombination make codon deletion, insertion, & frame-shift

Question 80

what are T-cell receptor?

Answer 80

glycoprotein made of 2 polypeptide chains with constant & variable region - can have error-prone & terminal transferase but no hyper somatic mutation - Can only bind to antigen displayed by MHC protein on antigen-presenting/target cell

Question 81

what are the different classes of MHC protein?

Answer 81

class I: present on surface of every nucleated cell that binds to Tc using CD8 class II: present on monocyte-derived & B cells and binds to T-helper using CD4

Question 82

what does regulatory T (Tregs) do?

Answer 82

ensures immune system doesn't attack self cells & molecules indiscriminately - secrete cytokines that block T cells that are bound to same antigen-presenting cell

Question 83

what happens during allergic reaction?

Answer 83

allergen binds to surface antibody on B cell -> cause plasma cell clones to release IgE -> IgE binds to receptors on mast/basophils -> allergen binds to IgE on mast, releasing histamine (dilation, inflammation, & difficulty breathing)

Question 84

what is difference between immediate and delayed hypersensitivity?

Answer 84

immediate happens when allegoric individual is exposed to allergen in environment delayed doesn't begin until hours after exposure (poison ivy)