Chapter 8: Respiratory Systems in Humans and Animals Flashcards
Exchange of gases occurs at ______ ______ of the respiratory structures.
- respiratory surfaces
What are the four main adaptations of respiratory surfaces for gaseous exchange?
- large total surface area of the respiratory surface
- moist respiratory surface
- thin wall of the respiratory surface
- a network of blood capillaries on the respiratory surfaces
Explain the adaptations of respiratory surfaces for gaseous exchange.
Large total surface area
- respiratory surfaces are branched, folded or numerous to increase the surface area
- small in size to increase the total surface to volume ratio
Moist respiratory surface
- to dissolve the gases so they can diffuse easily and rapidly across the surface
Thin wall
- one cell thick to facilitate the diffusion of gases
A network of blood capillaries
- increase the rate of diffusion and transportation of oxygen and CO2
The respiratory structure in insect is the _____ _____ which consists of _____, tracheae, and _____.
- tracheal system
- spiracles
- tracheoles
Explain spiracles.
- small pores through which air enters and leaves
- has valves to control the opening and closing
Explain trachea.
- a network of air tubes that open to the outside through spiracles
- supported by rings of chitin to prevent it from collapsing
- branches into fine tubes to form tracheoles
Explain tracheoles.
- thin and have moist walls
- surrounded by fluid to facilitate the diffusion of gases
- diffusion of gases occur directly
Fish has four pairs of _____ covered by an _____.
- gills
- operculum
What does gill consist of?
- gill rakers
- gill arch
- gill filament
What is the purpose of gill rakers and gill filaments?
Gill rakers - filter the water that flows through it Gill filaments - respiratory surface - has many thin and flat projections called lamellae
What are the adaptations of gill filaments gaseous exchange?
- numerous gill filaments and lamellae
- thin epithelial walls
- moist surface
- a network of blood capillaries
- countercurrent flow of water and blood over the gill filaments to maximize the rate of oxygen diffusion
The respiratory structures of amphibians such as frogs are the ____ and _____.
- skin
- lungs
What are the adaptations of skin for gaseous exchange ( frogs)?
- thin - allows gases to diffuse easily
- moist
- network of blood capillaries underneath
What are the adaptations of lungs ( frog )?
- inner walls are folded to increase total surface area
- thin walls
- a layer of moisture
- a network of blood capillaries
What are the adaptations of the alveolus for the exchange of gases ( humans )?
- numerous and small
- thin wall
- moist wall
- a network of blood capillaries
What are the similarities in the respiratory structures in humans and animals?
- all have a large total surface area to volume ratio
- have a thin wall
- a layer of moisture
Breathing is the process of moving air in and out of lungs to _____ the ____ supply and remove _____ _____.
- replenish
- oxygen
- carbon dioxide
The breathing mechanisms in insects involve ______ and _____ of muscles in the abdomen which causes air to move in and out through the _____.
- contraction
- relaxation
- spiracles
Explain inhalation and exhalation in insects.
Inhalation
- abdominal muscles relax - valves of spiracles open - pressure in trachea decreases - air forced into the tracheal system through the spiracles
Exhalation
- opposite of inhalation
The breathing mechanism in fish involves the movement of the _____ and the ___ __ __ ____ to create the flow of water into the _____ cavity and out through the operculum opening.
- operculum
- floor of the mouth
- buccal
Explain the inhalation and exhalation in fish.
Inhalation
- mouth opens - floor of buccal cavity lowers - volume in it increases as pressure decreases - high outside pressure presses operculum and closes it - water enters the mouth
Exhalation
- mouth closes - floor of buccal cavity raises - volume in it decreases as pressure increases - operculum opens - water flows through gills over the filaments - gaseous exchange occurs
The breathing mechanism of frogs involves the _____ __ __ ____ of the ______ cavity and the ____ of the lungs.
- movement of the floor
- buccopharyngeal
- elasticity
Explain the inhalation and exhalation in frogs.
When the mouth and glottis are closed, the floor of the buccopharyngeal cavity is lowered. Air pressure in the mouth cavity decreased caused the air from outside enters the nostrils into the buccopharyngeal cavity.
When the glottis is opened, the nostrils are closed while the floor of buccopharyngeal cavity is raised.
Air pressure inside the mouth cavity increased caused the air inside the buccopharyngeal cavity enters the lungs and gaseous exchange occurs. When the lungs contracted, air is expelled out from the lungs. Some air is expelled through nostrils while some air mixed with the air inside the buccopharyngeal cavity
The breathing mechanism in humans involves the action of _____ muscles and _____ muscles.
- intercostal
- diaphragm
Explain the inhalation and exhalation in humans.
Inhalation
- external intercostal contracts as internal intercostal relax
- ribcage moves upwards and outwards
- diaphragm muscles contract and flattens
- increase the volume of the thoracic cavity
- air pressure in the thoracic cavity decreases
- air in the atmosphere enters the lungs
Exhalation
- opposite of inhalation
Gaseous exchange occurs by the process of _____ and involves _____ and carbon dioxide.
- diffusion
- oxygen
Explain the gas exchange at the alveolus.
- inhaled air contains more O2 and less CO2
- hence the partial pressure of O2 is higher in the alveolus compared to in the blood capillaries
- O2 diffuses out from the alveolus into the blood capillaries down the partial pressure gradient of oxygen
- during respiration, CO2 produced
- partial pressure of CO2 is higher in the blood capillaries than in the alveolus which causes it diffuses out into the alveolus
Explain the partial pressure for the air in the alveolus, blood from the alveolus to the pulmonary vein, and the blood from the pulmonary artery entering the alveolus.
Air in the alveolus
- high ( O2 ) low ( CO2 )
Blood from the alveolus to the pulmonary vein
- high ( O2 ) low ( CO2 )
Blood from the pulmonary artery entering the alveolus
- high ( CO2 ) low ( O2 )
In the blood capillaries surrounding the alveolus, oxygen diffuses into the red blood cells and combines with ______ to form ________.
- haemoglobin
- oxyhaemoglobin
Explain the diffusion of oxygen from the blood capillary into the body cells.
- oxyhaemoglobin is not stable
- it breaks down as the cells lack oxygen
- oxygen is released and diffuses into the plasma of the blood capillaries
- the partial pressure of oxygen is higher than in the body cells
- hence, it diffuses out of the blood capillary into the body cells
Explain the diffusion of carbon dioxide from body cells into the blood capillary.
- cellular respiration releases CO2
- body cells contain a high concentration of CO2
- hence the partial pressure of CO2 in the body cells is higher
- CO2 diffuses out of the body cells into the blood capillary
Explain the transport of CO2 from the body cells to the alveolus.
- 70% of CO2 is carried through plasma in the form of bicarbonate ions
- some diffuse into the RBC and combine with haemoglobin to form carbaminohaemoglobin
- some dissolve to form carbonic acid
- at the alveolus, bicarbonate ions, carbaminohaemoglobin, and carbonic acid break down to release CO2 into the plasma
- higher partial pressure of CO2 causes it to diffuse into the alveolus and be expelled during exhalation
What are some issues related to the human respiratory system?
- Chronic Obstructive Pulmonary Disease ( COPD ) includes asthma, chronic bronchitis, and emphysema
Explain COPD.
- a chronic respiratory disease that obstructs airflow to the lungs and interferes with normal breathing
- dust, air pollutants, and irritants enter the lungs
- stimulates the secretion of viscous mucus by the goblet cells
- inhibits movement of cilia of the epithelial lining
- carcinogenic substances accumulate in bronchioles
- results in inflammation
- elasticity is lost in the alveolus
What are chronic bronchitis, asthma, and emphysema?
Chronic bronchitis
- inflamed bronchial tubes produce a lot of mucus
Asthma
- wall of the bronchiole swells and thickens
Emphysema
- breaking down of the alveoli wall which reduces the total surface area
List out the symptoms of the diseases.
Chronic bronchitis - shortness of breath - cough with phlegm - wheezing Asthma - difficulty in breathing - chest tightness - wheezing Emphysema - exhausted - shortness of breath
