UNIT 3: GAS EXCHANGE AND CIRCULATION IN ANIMALS
What are the three main types of vessels?
Arteries, Veins, and capillaries
What are the 3 phases of gas exchange in humans and other animals with lungs?
Breathing, transport of gases by the circulatory system, and exchange of gases with body cells
What happens in exhalation?
CO2 is expelled and alveolar air pressure forces air up the breathing tubes and out of the body
What characteristic of the respiratory system allows O2 to diffuse in circulatory system/bodily tissues and CO2 to diffuse out?
They are thin and moist
Why do most aquatic animals have gills?
They are used to promote gas exchange
Why are hemoglobin important?
They transport O2 and CO2 and buffers blood (carbonic acids forms from CO2 in blood cells)
How must an animal sustain life?
acquire nutrients & deliver them to cells, exchange gases & deliver them to/from cells, dispose of waste products
What is the type of ventilation in the human lungs?
Negative pressure breathing
Is the circulatory system used in insects for gas exchange?
No
What happens in the alveoli?
O2 diffuses into the blood and CO2 diffuses out of the blood
What are sufactants?
Secretions that keep the walls of the small alveoli from sticking shut from the surface tension of their moist surface
What are alveoli patrolled by?
White blood cells
Is breathing under automatic control?
Yes
What do an open circulatory systems consist of?
A tubular heart, open ended vessels, and blood that directly bathes the cells and functions as fluid
What are the two big advantages of using air to breathe?
Air contains a higher concentration of O2 than water and it is lighter and easier to move than water
Where are open circulatory systems found in?
All anthropods
What happens in the lungs?
Blood gains O2 and loses CO2
What happens in the body tissues?
Blood loses O2 and gains CO2
What does a closed circulatory system consist of?
Blood that is confined to vessels, keeping blood distinct from the fluid
How do body tissues help with gas exchange?
Body tissues take up oxygen and then release carbon dioxide
What is the function of the arteries?
Carries blood away from the heart to body, organs, and tissues
What is the structure of hemoglobin?
Four polypeptide chains that are different types in which each polypeptide has an iron atom that binds to one O2 molecule
What system bring resources close enough to cells for DIFFUSION to be effective?
Internal transport system
What is the function of capillaries?
It conveys blood between arteries and veins within the tissue
How does breathing in air in mammals work?
It is inhaled through the nostrils into the nasal cavity, filtered by hairs and mucous surfaces, warmed and humidified, and sampled for odors
What is the function of the veins?
It returns blood to the heart
What is exhalation?
It reverses the pressure gradient
What is the diaphragm?
It separates the abdominal cavity from the thoracic cavity and helps ventilate the lungs
How does continual movement of air affect the respiratory surface?
It will maintain high O2 and low CO2 concentrations
What is the main problem of air breathing animals?
Loss of water to the air by evaporation
What are the body systems that work together to facilitate these exchanges?
Respiratory and circulatory
What is gas exchange?
Respiratory and circulatory systems in servicing your body's cells
How is breathing automatically controlled?
The breathing control center keeps breathing in tune with what the body needs, sensing and responding to the CO2 level in the blood
How does inhalation occur in humans?
The ribs will contract moving it up and out, the diaphragm moves downward, the thoracic cavity expands in volume, the pressure around the lungs decreased, and air is pulled into the respiratory tract
What two regions does the heart pump blood to?
The right side (OXYGEN POOR) to the lungs and the left side (OXYGEN RICH) to the body
Why do animals have adaptations in regards to gas exchange?
To improve ventilation over the respiratory surface
Why do insects have tracheal systems?
To promote gas exchange
Why do terrestrial vertebrates have lungs?
To promote gas exchange
Why do insect tracheal systems use tiny branching tubes?
To reduce water loss and to deliver air directly to cells
How is air passed through the nasal cavity?
To the pharynx, larynx then vocal chords, then trachea by Cartlidge rings, into the bronchi then bronchioles
T OR F: Alveoli are sensitive to airborne contaminants
True
T OR F: The skin can be used to help gas exchange in animals that are WET AND SMALL
True
What is breathing?
Ventilation of the lungs through alternating inhalation and exhalation
Where are closed circulatory systems founded?
Vertebrates (humans), earthworms, squids, and octopuses
