Unit 7
Gas Exchange with Animals (Ch. 42) Read 915-920
Necessary for oxygen: respiratory surface and surface area (more = more oxygen)
Alveoli: surface area for the oxygen, oxygen and carbon dioxide goes in and out of the bloodstream
Frogs: have lung but tiny BC the fronts can breathe through their skin and blood vessel
Grasshopopers don't need a respiratory system. They have one holes throughout the body. Trachea system
Counter Current Exchange system: gas exchange in gills, advantage: maximizes the oxygen of inhalation
Inhalation: diaphragm contracts (moves down)
Exhalation: diaphragm relaxes (moves up)
CO2 + H2O = H2CO3 (Carbonic acid) ➡ H + HCO3 (bicarbonate)
Key Points interaction of organs and systems
Maintaining homeostasis
Common ancestry
Timing and coordination of physiological events
Responding to environmental cues
Feedback mechanisms
Disruption to homeostasis
Environment I flue des expressin of genotype
Gas Exchange with Plants (776-779)
Guard Cells are openings where gas can enter the plant leaf. Gases need to get to the upper epidermis to produce sugar.
Opening of the guard cells is called a stomate (somata); more on the bottom side of the plant.
When water is low, the stamata close and strink so gases can't enter.
Photosythesis: Co2 + H2O ➡ C6H12O6 + O2
If the stomata are on the top of the plant, the water will evaporate more. On the bottom for the leaf for water conservation
Transport (Animals-p893-903)
Transport/Circulation
Gastrovascular Cavity: Connected area with mouth and anus as one, cell to cell diffusion
Open circ. system: insects, heart acts as a pump which sloshes around this blood like fluid (hemolymph)
Closed Circ. System: humans, blood is always carried around in some tube like system, enclosed, single loop/fish
Double loop/amphibian with the oxygenated/deoxygenated blood (2 chambered heart)
Double loop System w/ four chambered heart

Atrium = receiving chamber
Ventricle = pumping chamber
Arteries: carries blood away from the heart
Vein: carries blood to the heart
Sino-Artial node
Atrio-ventricular node
When blood enters the capillaries, the pressure decreases. The movement changes gases and nutrients.
Interstitial Fluid: movement and swelling
Lymphatic System: carries body fluid, plasma, etc.
Homeostatic control: Carbonic Acid (breath more), pH sensors in the aorta and brain stem
Transport (Plants-p772-776)
Gas exchange on both ends, water at the roots
Surface Area: major surface areas and little hairs to get more water
Mycorrhizae: relationship between fungi and plants, 80%, on roots
Xylem cells: transport water, long dead cylinder hallow tubes, vessel elements, trachieds
Phloem: carries glucose, tubes of cytoplasm, sieve-tube elements, companion/nurse cell
Apoplastic: water diffuses in through the cell wall, casparian strip (wax) pathway, little membrane
Symplastic: diffuses directly through the cytoplasm, openings connect to other cell walls, endodermis (filter, cell wall)
Transpirational pull: evaporation of water out of the leaves, sucks water through the entire plant,adhesion and cohesion
Cotransport happens by the membranes.
Source-to-Sink: Water moves back to and from the xylem and phloem
Digestion in Animals/Humans
Food is used for energy and biosynthesis. Nutrients are needed to do biosynthesis which requires energy to make energy.
Food for Energy carbs (glucose, glycogen)
Fats
Proteins
Undernourishment: not getting enough calories
Essential Nutrients four Classes of Essential Nutrients
-Amino acids (8/20)
-Essential fatty acids (linoleic acid)
-vitamins (13)
-Minerals

Malnourishment: lack of essential nutrients
Larger the organism : larger the BMR or metabolic rate
Smaller the organism : more energy it takes to maintain life
Digestive Mechanisms food vacuoles (protists)
Gastrovascular cavity (mouth is mouth and anus)
Alimentary canal (mou and anus)
With cecums
Excretion
Excretion: process of removing waste