Animals - Chapter 10 Flashcards
Importance of a respiratory system
aerobic cellular respiration
cells use oxygen to produce the energy needed to grow, repair, divide, and conduct cellular functions
energy is released in a cell when glucose reacts with oxygen to form carbon dioxide and water
this energy is used to add a phosphate group to a molecule of ADP, resulting in ATP
Physical activity and oxygen
physical activity depends on the energy released during aerobic cellular respiration, which depends on the oxygen available and how quickly it can be supplied to the cells
VO2 = rate at which oxygen is used, function of the amount of oxygen delivered to the body in a given time
VO2 max = maximum amount of oxygen an individual can use during sustained hard exercise
Respiration
all processes that supply oxygen to the cells of the body for the breakdown of glucose
all the processes by which wastes are transported to the lungs for exhalation
Ventilation
movement of gases between the external environment and the location where they can enter/leave the body
as animals increase in size, more oxygen is required, so respiratory membranes must have an increased surface area
respiratory membranes must be moist to facilitate dissolution of oxygen and carbon dioxide, which is why lungs are located within the body cavity
Types of respiration in animals
earthworm = outer skin absorption
fish = gills
insects = tracheal system
land animals = lungs
Fish
fish gill filaments are red as they are full of blood that is available to take in oxygen
countercurrent flow to ensure the greatest concentration gradient throughout the entire gill
Pleural membrane
surrounds lungs and lines chest cavity
filled with fluid that reduces friction during inhalation
attaches to inner sides of ribs
Breathing movements
the body uses muscles to change the volume of the thoracic cavity, which alters in pressure inside the lungs
an increase in volume = decrease in pressure
respiratory muscles = diaphragm, intercostal muscles
Inspiration
diaphragm contracts and flattens
external intercostal muscles contract and move ribcage upwards
pleural membrane pulls on lungs
lungs volume in increased, pressure inside the lungs decreased, air moves in
Expiration
diaphragm relaxes and returns to dome shape
external intercostal muscles relax, inner intercostal muscles contract and move ribcage downwards
pleural membrane no longer pulling on lungs
lung volume decreased, pressure inside the lungs increases, air moves out
Lung capacities
the full capacity of your lungs is not used in normal conditions
a spirometer is used to measure lung capacities and produces a spirograph
Control of breathing
levels of carbon dioxide control our rate of breathing, not oxygen levels
physical activity leads to more cellular respiration which creates carbon dioxide as a waste product
carbon dioxide is carried in the blood to the lungs
after gas exchange, remaining carbon dioxide in blood is carried to brain, which senses the concentration of carbon dioxide
the brain increases or decreases the respiration rate by sending nerve impulses to respiratory muscles
Transport of carbon dioxide in blood
carbon dioxide is transported in 3 different ways
dissolved in plasma, attached to hemoglobin, reacts with water to form carbonic acid, which dissociates into hydrogen and bicarbonate
hemoglobin helps by binding many of the hydrogen ions and enables the transport of oxygen around the body
brain senses carbon dioxide levels by detecting a drop in the pH of blood
Partial pressures
composition of air = 20 percent oxygen, and 0.04 percent carbon dioxide
total pressure of a mixture of gases is the sum of the partial pressures of its component gases
Gas diffusion
the greater the concentration gradient, the higher the rate of diffusion
explains the diffusion of oxygen into the bloodstream and then into cells, and the diffusion of carbon dioxide out of cells and then into lungs
