Final

Gastrovascular Cavity

1-opening

\-for digestion and circulation

\-acts as hydrostatic skeleton-support, movement

\-cellular exchange through diffusion

\-ex cnidarian and platyhelminthes

hemolymph

functionally blood + interstitial fluid

Open circulatory system

hemolymph pumped through open-ended vessels & flow among cells

\-circulation aided by muscle contraction

\-fluid returns to heart through pores

\-valves prevent backflow

Closed circulatory system

blood remains in vessels

Interstitial fluid

fluid surrounding cells

System that all Arthropods have

Open circulatory system

Insect gas exchange: Tracheal system

\-tubes branch into tracheoles which supply cells

\-gases diffuse across epithelial tissue to cells

\-circulatory system not involved

\-muscle contractions can help ventilate

Crustaceans exchange gas through

gills

\-distribute through open circ system

Molluscs have

open circ system, gas exchange through gills

\-lining of the mantle cavity functions for gas function

Cephalopods

only molluscs with closed circulatory system

Annelids have

closed circulatory system

\-earthworms through thin, moist skin

\-marine annelids through parapodia

vertebrates

closed circulatory system

Gills

dissolved O2

4-12ppm in oxygenated water, 21% in air

\-large surface area, efficient gas exchange

\-as water increases in temp. and salinity, O2 availability decreases

\-high viscosity of water (relative to air) more energy to ventilate

countercurrent exchange

fish can remove >80% of dissolved O2 from water

Atrium

receives blood from veins

Ventricle

pumps blood to arteries

Single circulation

blood pumped once through body

heart → gills → body → heart

\-fish, sharks, rays

Class Amphibia

\-exchange gas through lungs, and/or skin

\-closed circulatory system with double circulation

Blood pumped twice too

once to pulmonary circuit (pulmocutaneous in amphibians) and once to systematic circuit-rest of body

3 chambered heart

2 atria, 1 ventricle

\-some blood mixing

Class reptilia

\-Gas exchange-lungs

\-skin, dry & scaly

Non-bird reptiles

\-2 atria, 1 ventricle

\-crocodilians are 4 chambered

Circulation and gas exchange: Birds and mammals

4-chambered heart

\-2 atria, 1 ventricle

\-oxygenate/ deoxygenated kept separate

\-arteries, arterioles, capillaries, venules, veins

Arteries

away from heart

\-not always oxygenated

arterioles

small arteries

capillaries

b/w arteries and veins

venules

small veins

veins

towards heart

\-doesn’t always mean deoxygenated

Gas exchange and circulation: Birds

\-one-way air flow-through lungs

\-air sacs function as bellows

\-lungs contain parabronchi (parallel tubes) instead of alveoli

\-Lung size and complexity related to metabolic rate

Cardiac cycle

0\.8 seconds

systole, diastole, atrioventricular (AV) valves, semilunar valves

Systole

chambers pumps

Diastole

Chamber relaxed

Atrioventricular (AV) valves

prevent backflow from ventricles to atria

Semilunar Valves

Prevent backflow into ventricles

Capillaries

wall is single layer of epithelial cells

\-diffuse with interstitial fluid

Veins and Arteries

\-Elastic connective tissue

\-smooth muscle

\-help regulate blood flow

\-nerves/ hormones control dilation/ constriction

\-Arteries thicker than veins

\-Veins have valves to prevent backflow

Blood pressure

force exerted to pump blood

pulse

rhythmic stretching of arteries as ventricles pump

Systolic pressure

pressure w/ ventricle contractions

Diastolic pressure

elastic contraction of arteries after ventricle pumping-maintains pressure and flow

capillary exchange

gases, small non-polar molecules diffuse

\-larger molecules pass through endocytosis & exocytosis

\-small pores in capillary walls allow leaking (water, sugar, salts)

\-Osmatic pressure (dissolved protein) helps capillaries retain water

Blood

\-pH 7.4

\-55% plasma, mostly water + dissolved material

\-45% red blood cells (O2), white blood cells (immune system), platelets (clotting)

\-Blood pressure results in net loss of fluid from blood in capillaries

Lymphatic system

\-returns fluid to circulatory system (valves prevent backflow)

\-Lymph similar to interstitial fluid but has less O2 and fewer nutrients

Contraction of diaphragm and rib muscle generate

negative pressure to inhale

Nose

air filtered by, hair, warmed, humidified

Pharynx

junction

Glottis

opening to trachea, covered by epiglottis when swallowing

Larynx

voice box

Human: Trachea

\-rings of cartilage

\-ciliated epithelial cells with mucus help trap dust, etc

\-sweap up to pharynx

\-forks into 2 bronchi

Bronchus branches into

bronchioles

Bronchioles end in

alveoli air sacs

\-millions per lung

\-surface area -100 m2

medulla oblongata

brain stem

\-detects increases (CO2) by decreasing blood and cerebrospinal fluid pH

\-increases breathing rate

Gases move by ________ their concentration gradients (two words)

diffusion down

Humans extract ___ % of inhaled O2

25

Oxygen Transport

\-O2 is not very soluble in water

\-Each hemoglobin molecule in red blood cells transports 4 O2 molecules.

\-hemoglobin protein has 4 hem groups, each associated with 1 Fe atom

Myoglobin

O2 storing protein in muscle of vertebrates

\-enables extended dives in marine mammals

Carbon Dioxide Transport

CO2 diffuse from cell to interstitial fluid into capillary

\-10% CO2 in plasma solution

\-20% CO2 binds to hemoglobin

\-70% CO2 as bicarbonate (HCO3) in plasma

\-Hemoglobin binds to H+

\-Reaction reverse at lungs to release CO2

Osmosis

Water moves from hypotonic to a hypertonic solution across a semipermeable membrane

Excretion

\-removal of metabolic waste

\-largely nitrogenous from proteins an nucleic acids

\-important for cell integrity, enzyme functioning, etc

Osmoconformer

organisms is isoosmotic with surroundings

Osmoregulator

Organism controls internal solute concentration and hydration

\-regulating solutes affects hydration by osmosis

Osmoregulation and excretion- prokaryotes

Largely osmoconformers

\-diffusion and active transport to remove waste and maintain slightly hyperosmotic condition

\-change membrane proteins by transcription/translation

hyperosmotic

plump with water

cell walls help prevent __

in _______ solution.

lysing (bursting), hypoosmotic

Capsule

polysaccharides/ protein protects from dehydration

\-some form endospores when water is unavailable

endospores

durable, inert structure containing chromosome

Halophilic archaea

can pump K+ into cell to become isoosmotic

“salt loving”

Osmoregulators- Fungi

\-use diffusion and active transport of solute + osmosis

\-modify membrane proteins

\-cell wall helps to protect from lysing

Osmoregulation and excretion- Plants

Water balance largely regulated by guard cells

\-open and close through \[K+\] and osmosis

\-Plant cells generally hyperosmotic to remain turgid

\-water is stored in the central vacuole

Plants have limited _____

metabolic waste

\-some stored in vacuoles, shed w/ leaves, gas exchange, etc.

Secondary metabolites

not healed from growth, reproduction or development

\-can have numerous other ecological benefits

Osmoregulation and Excretion- Animals

* Most marine invertebrates are Osmoconformers

\-Have balanced osmolarity with sea, but with different solute concentrations

Aquatic Osmoregulators

Marine Fish, Fresh Water Fish, terrestrial

Marine Fish

\-Lose water through gills

\-drink sea water

\-excrete excess salts

\-concentrated Urine

Fresh water fish

\-Gain water through gills

\-Produce dilute urine

Terrestrial

\-Gain water from food and drinking

\-Lose water from urine, feces, gas exchange, evaporation from skin

\-Humans -60% water by mass

Adaptations to reduce water loss

\-Insects exoskeletons

\-Human skin -outer layer of dead cells

\-Amniotic egg

Nitrogenous Wastes

From proteins and nucleic acids

Ammonia

most aquatic organisms

\-very toxic, cant be stored, diffuses readily into water

Urea

mammals, amphibians, some bony fish

\-less toxic than NH3, but requires energy to produce

\-produced in liver, to blood, to kidneys for excretion

\-moderate water loss

Uric acid

birds, reptiles, insects

\-little water loss

\-more energy to produce, helps conserve water

Steps to Excretion

1. Filtration- of wastes, water, and small solutes from blood, hemolymph, or coelomic fluid
2. Reabsorption- of water, glucose, amino acids, vitamins, hormones, etc. through active transport
3. Secretion- active transport of waste too big for filtering
4. Excretion- of filtrate (urine)

Methods of excretion

Protonephridia, metanephridia, Malpighian tubules

Protonephridia

empty outside body

\-flatworms, rotifers, some annelids

Metanephridia

to bladder first

\-earthworms

Malpighian tubules

empties to rectum

\-insects and other terrestrial arthropods

Osmoregulation and Excretion- Human

Kidney, Nephron

Human- Kidney

filtration of 1,100-2,000L blood/ day (cycling -5L)

\-excrete -1.5 L urine/day

\-adults require -2.6-3.8L water/ day

Blood enters kidney through ______

leaves through _______

renal artery, renal vein

Urine goes from _____ to __________

leaves body through ______

Ureter, Urinary bladder, urethra

Nephron

functional unit of kidney

\-filtrate from blood enters nephron at Bowmans capsule

Bowmans capsule

cup-shapes swelling

glomerules

ball of capillaries within Bowmans capsule

Filtrate refined in

proximal in proximal tubule, loop of Henle, and distal tubule

Urine leaves distal tubule and nephron through ____ __leading to__ ______

collecting duct, renal pelvis

____ % of water beginning as filtrate is absorbed into capillaries

99

Osmotic gradient largely from

NaCl and urea

Urine can be up to _____ greater osmolarity than blood

4x

\-1,200 and 300 mOsm/L, repectivley

Antidiuretic hormone (ADH or vasopressin)

helps to regulate body state concentrations

\-increased ADH increases water reabsorption

\-Alcohol inhibits ADH → greater urination and dehydration

Diuresis

increased urination