BIOL 1720 TEST 2

Large network of alveoli in lung tissue

Extensive tracheal system

Tiny branching tubes that penetrate the body

1. Nasal cavity and pharynx

2. Trachea

3. Bronchi

4. Bronchioles

5. Alveoli (site of gas exchange)

The volume of the air inhaled and exhaled during a normal breath

The maximum volume of air that can be inhaled and exchaled

air remaining after full exhalation (incomplete removal)

Pulls air into the lungs

Forces air down the trachea

Mammals, birds, reptiles

MY BLOODY RALENTINE

Amphibians, fish

Negative feedback loop

PCO2 increases --> pH of blood and cerebrospinal fluid decreases --> ventilation increases by blowing off CO2

Chemosensors in the aorta and carotid arteries (which signals the breathing control centers)

8-9

By functioning as bellows that keep the air flowing through the lungs; have parabronchi (air tubes) instead of bronchi

-Air passes in one direction only

-Fresh air does not mix

Favors diffusion of O2 into the blood and CO2 into the air

AI

Favors diffusion of O2 out of the blood and CO2 into the blood

CO

4 (2 alpha and 2 beta)

4

Allosteric cooperation

CO2 produced during cellular respiration lowers blood pH and decreases the affinity of hemoglobin for O2, causing a rightward shift and facilitating the offloading of oxygen

HCO3- ions in the plasma

There is less O2 available in water than in air

Offsets low O2 content in water by minimizing diffusive distance

Countercurrent exchange

long fibers

myofibrils

Thick filaments and thin filaments

Staggered arrays of myosin molecules

Consist of 2 strands of actin and 2 strands of a regulatory protein

Sarcomere

Z lines

M lines

Myosin heads split ATP and become reoriented/energized

Ca2+ binds to troponin so that the binding site is uncovered; Head of the myosin molecule binds to an actin filament, forming a cross-bridge

Myosin head rotates towards the center of the sacromere (Power stroke); thin filament moves toward the center of the sarcomere.

binds to actin strands on thin filaments, preventing actin and myosin from interacting

Calcium ions (Ca2+)

stimulus leading to contraction of a muscle fiber

The synaptic terminal of the motor neuron releases the neurotransmitter acetylcholine (Ach)

Acetylcholine depolarizes the muscle, causing it to produce an action potential, which travels to the interior of the muscle fiber along transverse (T) tubules

The action potential causes the sarcoplasmic reticulum (SR) to release Ca2+

Ca2+ binds to the troponin complex on the thin filaments, exposing myosin-binding sites (allowing the cross-bridge cycle to proceed)

When motor neuron input stops, the muscle cell relaxes; Transport proteins in the SR pump Ca2+ out of the cytosol and regulatory proteins shift back to the myosin-binding sites

Conformational change in troponin

Varying the number and varying the rate

A state of smooth, sustained contraction when the rate is so high the muscle fiber cannot relax between stimuli

-Rely mostly on aerobic respiration to generate ATP

-Many mitochondria

-Rich blood supply

-Large amount of myoglobin

-Dark meat

-Uses glycolysis (anaerobic) as their primary source of ATP

-Less myoglobin; tires more easily

-Light meat

-Contracts slowly

-Sustains longer contractions

-ALL oxidative

-Contracts rapidly

-Sustains shorter contractions

-Glycolytic or oxidative

-Slow concentration speed

-Aerobic respiration

-Slow rate of fatigue

-Many mitochondria

-High myoglobin content

-Fast concentration speed

-Aerobic respiration

-Intermediate rate of fatigue

-Many mitochondria

-High myoglobin content

-Fast concentration speed

-Glycolysis

-Fast rate of fatigue

-Few mitochondria

-Low myoglobin content

Concentration of a dissolved substance

Concentration of all solutes that contribute to the osmotic pressure of a solution (depends on the number of dissolved particles); determines the movement of water across a selectively permeable membrane

Same concentration of solutes

Lower relative concentration of solutes

Higher relative concentration of solutes

Isosmotic with their surroundings and do not regulate their osmolarity; consists only of some marine animals

Expends energy to control water uptake and loss in a hyper/hyposmotic environment

Animals that cannot tolerate substantial changes in external osmolarity (most animals)

Animals that can survive large fluctuations in external osmolarity (common in estuaries and tidal pools)

They constantly lose salts and gain water by diffusion from their hyposmotic environment

By excreting large amounts of dilute urine and replacing salts by active uptake across the gills and diet

They constantly lose water by osmosis and gain salt by diffusion

By drinking seawater and excreting salts across gills, excreting salts and retaining water by kidneys, and diet

A solution that contains more solute than the cell which is placed in it (withered cells)

A solution in which the same amount of solute and solution is available inside of the cell and outside of the cell

A solution that contains less solute than the cell which is placed in it (fat cells)

Ammonia (NH3), Urea, Uric Acid

-Most Toxic

-Freely diffuses across the whole body surface or through gills

-Need access to lots of water

-Fish/Aquatic animals

-Less toxic, requires energy

-NH3 converted to urea in liver, then excreted by kidneys

-Requires less water

-Amphibians, sharks, mammals

-Least toxic, most expensive

-Does not dissolve readily in water

-Can be secreted as a paste with little water loss

-Insects, birds, reptiles

Filtration, Reabsorption, Secretion, Excretion

(Farting Rats Scream Excitedly.)

Filtration: blood pressure forces water and small solutes through capillary bed into excretory tubule; cells and large molecules remain in the blood

Reabsorption: Valuable solutes actively reclaimed back into the blood (glucose, amino acids, etc.); wastes and non-essential solutes remain

Secretion: Nonessential solutes and wastes are added to the filtrate (toxins, excess ions)

Excretion: Processed filtrate containing nitrogenous wastes is released

Located on either side of the vertebreal column; connected to a ureter; consists of a renal vein/artery, medulla, cortex, and renal pelvis

In the renal pyramid among the cortex and medulla

Stepwise processing of blood filtrate

Salts, glucose, amino acids, vitamins, nitrogenous wastes, and other small molecules

NaCl and Urea

Salts and nutrients are actively reabsorbed; water follows passively by osmosis; as the filtrate passes through the proximal tubule, materials to be excreted become concentrated as water is being reabsorbed in the capillaries

Freely permeable to water through channels formed by aquaporin proteins, but very low permeability for NaCl and other small solutes. Water moves out freely by osmosis; filtrate becomes increasingly concentrated

Ascending loop of Henle is impermeable to H2O, but permeable to NaCl so NaCal initially passes into interstitial fluid freely by diffusion

Gradient becomes unfavorable for passive diffusion of NaCl --> active transport required; movement of NaCl along ascending limb helps maintain osmolarity of medulla; filtrate becomes increasingly dilute as NaCl is reabsorbed

Reabsorption of NaCl and H2O

Secretion of h+ and reabsorption of HCO3- ions

Aquaporin channels allowed water to be reabsorbed; impermeable to salts; solutes become increasingly concentrated; in the inner medulla, high concentration of urea drives passive reabsorption that helps to maintain high osmolarity of interstitial fluid in this region

Aquaporin channels are absent; impermeable to water; salts actively reabsorbed; hormones control absorption of water in collecting ducts by regulating aquaporin channels

Prevents water loss by regulating water retention by making the collecting duct epithelium more permeable to water

increases

decreases

Helps reabsorb water and some solutes across the plasma membrane

Primarily eats plants and algae

Primarily eats other animals

Regularly consume animals as well as plants or algae