Flashcards in Chapter 36 Flashcards Deck (59):
What is Respiration?
The physiological process by which an animal exchanges oxygen and carbon dioxide with its environment.
What is Respiration dependant on?
It depends on the tendency of gaseous oxygen and carbon dioxide to diffuse down their concentration gradients between the external and internal environments.
True or False: More O2 dissolves in cooler, fast flowing water than in warm, still water.
What is a Respiratory Surface?
A moistened layer thin enough for gases to diffuse across, this is where gases enter and exit an internal environment. Gases diffuse only across small distances, and only if dissolved in liquid.
What three factors affect diffusion rates?
1. Surface to Volume Ratio - more molecules diffuse across a large respiratory surface than a small one. 2. Ventilation - moving air or water past a respiratory surface keeps the pressure gradient across the surface high and thus increases the rate of gas exchange.3. Respiratory Proteins - they help maintain a steep partial pressure gradient for oxygen between the cells and blood.
What are Respiratory Proteins?
Proteins that house one or more metal ions that bind oxygen atoms when oxygen levels are high and release them when oxygen levels fall.
List the two Respiratory Proteins.
1. Hemoglobin - an iron-containing respiratory protein that occurs in vertebrate red blood cells and circles freely in other organisms. Hemerythrin (iron) or hemocyanin (copper) is used in other invertebrates.2. Myoglobin - a heme-containing protein in muscle of vertebrates and some invertebrates that helps stabilize the oxygen level inside cells.
What is Integumentary Exchange?
A mode of respiration that occurs in small-bodied invertebrates of aquatic or continually moist habitats where gases just diffuse across the body surface covering (the integument). This is the simplest form of respiration.
What do many aquatic invertebrates call their thin-walled, moist respiratory organs?
Gills. Extensively folded gill walls increase the respiratory surface area and gas exchange rates between body fluids and the outside.
What is a Tracheal System?
An internal respiratory surface that consists of repeatedly branching, air-filled tubes. They have no need for respiratory proteins to carry gases.
What are Book Lungs and what can they be found in?
They can be found in spiders; book lungs are respiratory organs where the air and blood flow through spaces separated only by thin sheets of tissue. Hemocyanin is used.
What is a defining trait of chordates?
Gill Slits (openings across a pharynx).
True or False: Most adult fish have external gills.
False, most adult fish have internal gills located inside a slit or a pouch that opens to the body surface.
What is Countercurrent Exchange? (Happens in fish)
A process where two fluids flow in opposite directions and exchange substances. It boosts the oxygen uptake from water.
What is this? A saclike respiratory organ located inside a body cavity and connected by airways to the outside air.
True or False: Reptiles, birds, and mammals have waterproof skin and no gills as adults and exchange gases in two well-developed lungs.
True, chest muscles draw the air inward. The respiratory surface area is large and serviced by many blood capillaries.
True or False: Birds exchange gas at the ends of the smallest airways.
False. In reptiles and mammals gas exchange occurs at the ends of the smallest airways, but in birds there are no "dead ends" and instead there are tiny tubes that convey air through the lungs to air sacs that serve as the respiratory surface.
What role does the rib cage have in respiration?
Their rhythmic contraction and relaxation cause air to move into and out of the paired lungs.
List some of the additional roles of the respiratory system.
The human respiratory system functions in gas exchange. It also has roles in sense of smell, voice production, body defenses, acid–base balance, and temperature regulation.
What is the Oral Cavity?
The mouth, supplemental airway when breathing is laboured.
What is the Nasal Cavity?
Chamber in which air is moistened, warmed, and filtered, and in which sounds resonate.
What is the Pharynx?
The throat, an airway connecting nasal cavity and mouth with larynx; enhances sounds; also connects with esophagus.
What is the Epiglottis?
Closes off larynx during swallowing.
What is the Pleural Membrane?
Double layer membrane that separates lungs from other organs; the narrow, fluid-filled space between its two layers has roles in breathing.
What is the Larynx?
The voice box, airway where sound is produced; closed off during swallowing.
What is the Trachea?
The windpipe, airway connects larynx with two bronchi that lead into the lungs.
What are the Intercostal Muscles?
At rib cage, skeletal muscles with roles in breathing. There are two sets of intercostal muscles (external and internal).
What are the Lungs?
Lobed, elastic organ of breathing; enhances gas exchange between internal environment and outside air. Cone shaped and located in the thoracic cavity on either side of the heart.
What is the Diaphragm?
A Muscle sheet between the chest cavity and abdominal cavity with roles in breathing. It can be controlled voluntarily.
What is the Bronchial Tree?
Increasingly branched airways starting with two bronchi and ending at air sacs (alveoli [where gas is exchange]) of lung tissue.
What are Vocal Cords?
A skeletal muscle with a cover of mucus-secreting epithelium.
What is the Glottis?
The gap between the vocal cord that changes size when the vocal cords contract. An open glottis lets air flow through with no sound, as it narrows the vocal cords vibrate and the larynx's position changes, letting sound happen.
What is Laryngitis?
Overuse or infection has inflamed the vocal cords; the swollen cords cannot vibrate as they should, making speaking difficult.
True or False: Air enters through the nose or mouth. It flows through the pharynx (throat) and larynx (voicebox) to a trachea that branches into two bronchioles, one to each lung.
Where do gases diffuse between an alveolus and a pulmonary capillary?
At the lung's respiratory membrane, a thin membrane made up of alveolar epithelium, capillary endothelium, and fused basement membranes of the alveolus and capillary. Secretions keep the alveolus moist so gases can diffuse.
What does the hemoglobin molecule consist of?
Four polypeptide chains, each with one heme group that has one iron atom (this reversibly binds O2).
What is hemoglobin with oxygen bonded to it called?
Oxyhemoglobin, or HbO2.
Which holds onto oxygen more tightly: Hemoglobin or Myoglobin?
Myoglobin, the O2 given up by the hemoglobin diffuses through cardiac muscle cels and binds to myoglobin. This O2 is released when blood flow cannot keep up with a cell's O2 needs.
True or False: Carbon dioxide diffuses into blood capillaries in any tissue where its partial pressure is higher than it is in blood.
What three forms is Carbon dioxide transported to the lungs in?
10% remains dissolved in plasma, 30% binds to hemoglobin to form carbaminohemoglobin (HbCO2), 60% is transported back as bicarbonate (HCO3-).
What enzyme speeds the formation of HCO3-?
Carbonic anhydrase, an enzyme inside red blood cells.
What happens when CO builds in the air?
It fills O2 binding sites on hemoglobin, preventing the transport of O2 and causing carbon monoxide poisoning.
What is a respiratory cycle?
One breath in and one breath out. Inhalation is always active, and muscle contractions drive it.
True or False: Exhalation is usually aggressive.
False, exhalation is usually passive. When the muscles that caused inhalation relax, the lungs passively recoil and lung volume decreases. This compresses alveolar sacs, causing the air pressure inside them to increase above atmospheric pressure. Air moves down the pressure gradient, out of the lungs.
True or False: Exhalation is active only when you exercise vigorously or consciously attempt to expel more air.
True. During active exhalation, muscles of the abdominal wall contract, increasing the pressure and exerting an upwards directed force on the diaphragm. Internal intercostal muscles contract at the same time.
Define Vital Capacity.
The maximum volume of air that the lungs can hold (averages 5.7L in a heathy adult).
What is the term for the volume that moves into and out of lungs during a respiratory cycle?
Tidal volume, it averages about 0.5 L.
What controls the rate and depth of breathing?
Respiratory centres in the the brain stem. A respiratory pacemaker establishes the initial rhythm, which is adjusted in response to changes in activity levels.
True or False: Inhalation is always an active, energy-requiring process.
True. It primarily requires contractions of the diaphragm and the external intercostal muscles.
What is apnea?
A disorder where breathing repeatedly stops and restarts spontaneously, especially during sleep. SIDS occurs when an infant does not wake from an apneic episode.
True or False: Each time breathing stops, blood pressure soars.
True, this leads to an increase in risk for heart attacks and strokes.
What is Mycobacterium tuberculosis?
The cause of tuberculosis, one third of the human population is infected by it. About 10% of them will develop the disease.
What is Pneumonia?
A general term for lung inflammation.
True or False: Human's hemoglobin binds oxygen more efficiently than llamas.
False. Llamas are able to live at high altitudes because their hemoglobin binds oxygen more efficiently, and because their hearts and lungs are unusually large relative to their body size.
Hypoxia is the result of what?
Also called cellular oxygen deficiency, occurs when people ascend too fast to high altitudes. The brain will command the heart and respiratory muscles to work faster, and people begin to breathe faster and more deeply. They hyperventilate, causing CO2 to be exhaled faster than it forms.
True or False: People who grow up at low elevations develop more alveoli and blood vessels in their lungs.
False, people who grow up at high altitudes develop more alveoli and blood vessels. The heart develops larger ventricles and pumps greater volumes of blood.
How can people adapt to higher altitudes?
Through acclimatization, the acute compensatory response that the body made to a markedly different environment slowly gives way to adjustments in cardiac output, the rhythmic pattern of breathing, and the magnitude of breathing. Acclimatization causes more red blood cells to form, which thickens the blood and can increase the risk of heart attacks.
What is erythropoietin?
A hormone secreted by kidney cells that induces stem cells in bone marrow to divide repeatedly, and induces the descendant cells to develop as red blood cells. When hypoxia causes more to be secreted, the formation of red blood cells can be multiplied by six.