Moduel 3 : Adaptations For Gas Exchange Flashcards
What is the surface area?
The surface area refers to the total area of the organism that is exposed to the external environment.
What is the volume?
The volume refers to the total internal volume of the organism (total amount of space inside the organism).
What happens that will cause the surface - area-to-volume ratio to decrease?
As the surface area and volume of an organism increases the natio decreases. This is because volume increases much more rapidly than surface area as size increases.
What are the steps to investigating sa:v ratio with agar method?
- Cut coloured agar into cubes or required dimensions.
2.calculate the surface area, volume and sa:v
Of each cube.
3. Place the agar cubes into boiling tubes containing the diffusions solution.
4. Measure the time taken for the agar cubes to go colourless
What is the structure of the leaf?
1.waterproof cuticle
2. Upper epidermis - layer of tightly packed cells.
3. Palisade mesophyl -layer of elongated lens containing chloroplasts.
4.spongy mesophyl - layer of cells that contains an extensive network of air spaces.
5.stomata - pores (usually) on the underside of the leaf which allows air to enter.
6.guard cens-pairs of cans that control the opening and closing of the stroma.
7. Lower epidermis - layer of tightly packed cells.
What are the mechanisms of a leaf?
- When guard cans are turgid (full of water) the stroma remains open allowing air to enter the leaf.
- the air spaces within the spongy mesophyll layer allus carbon dioxide to rapidly diffuse into cells.
-the carbon dioxide is quickly used up in photosynthesis by cells containing chloroplasts - maintaining the concentration gradient. - No active vertiation is required as the thinness of the plant tissues and the presence of stomata helps to create a short diffusion pathway.
What adaptations do plants have that have a plentiful supply of water?
- leaves with a short diffusion distance, through the stomata and a larger surface area provided by the air spaces in the spongy mesophyll.
- however, this makes them venerable to water loss.
What adaptations might a plant have that has a limited supply of fresh water?
- Very few stroma
- sunken stomata
- hairs surrounding sterna
- needle-shaped or small leaves
- waxy cuticle.
- plants with these adaptations are described as xerophytic.
What does the large surface Area of single - called organisms allow for?
The maximum abscrbtion of nutrients and gases and secretion of waste products.
How does gas exchange happen in single celled organisms?
Single celled organisms have a high sa:v ratio which Allans for the exchange of substances to occur via simple diffusion.
What is a definition of simple diffusion ?
Diffusion from high to low concentration den the concentration gradient.
Why do organisms require a a supply of oxygen?
Organisms require ATP in order to carry out the biochemical processes required for survival. The majority of ATP is produced through aerobic respiration which requires oxygen.
Why do organisms require the removal of Carbon dioxide?
Carbon dioxide is a toxic waste product of aerobic respiration.it it accumulates in cells/tissues it alters the pH.
What is the metabolic rate?
The metabolic vale ofan organism is the amount of energy expended by that organism within a given period of time.
What is the basal metabolic rate (BMR)?
The basal metabolic rate is the metabolic rate of an organism when at rest. The basal metabolic role is significantly lower than when an organism is actively moving.
How can the metabolic rate be measured?
- oxygen consumption
- carbon dioxide production
- read production
What do effective exchange surfaces in organisms have?
- A large surface area.
- short diffusion distance.
- concentration gradient maintained.
How does gas exchange happen in terrestrial insects?
Insects have evolved a breathing system that delivers oxygen directly to all the organs and tissues of their bodies, via holes in the exoskeleton called spiracles.
How do spiracles help gas exchange in terrestrial insects?
They have valves that allow them to open and close.
- it allows air to enter the insect and flow into the system of tracrece.
- most of the time, the spiracle is closed to reduce water loss.
What are tracheae and new have they adapted for efficient gas exchange in terrestrial insects?
Tracheae are tubes within the insects breathing system which leads to tracheoles (narrow tubes).
-the tracheae walls have reinforcements that keeps them open as the air pressure inside them fluctuates.
How does the gas move from the tracheae to muscle fibers in terrestrial insects?
- A large number of tracheoles run between cells and into the muscle fibers - the site of gas exchange.
How is a concentration gradient created in terrestrial insects?
A concentration gradient is created as oxygen is used by respiring tissues allowing more to more in through the spiritless by diffusion.
- carbon dioxide produced by the respiring tissues moves out through the spiracles Devon a concentration gradient.
How do very active, flying terrestrial insects get a more rapid supply of oxygen?
Very active, flying insects need more rapid supply/intake of oxygen. They create mass flow of air into the tracheal system by: closing the spiracles and using muscles to create a pumping movement for ventilation.
What is lactate and what does it ao in the gas exchange in terrestrial insects?
During flight the production of lactate in the respiring muscles, lowers the water potential of muscle cells.
- water found at the narrow ends of the trachooles is thendrewn into the respiring muscle by osmosis.
- this allows gases to diffuse across more quickly.
How do terrestrial insects prevent water loss?
-Insects possess a waterproof exoskeleton that prevents water loss.
- The waterproof waxy coating of the exoskeleton mares gas exchange by diffusion very difficult.
- as a result, insects move evolved a breathing system (the tracheal system) which consists of many tubes that carry oxygen directly to all tissues and cans of the body.
- spires are openings in the exoskeleton of insects that are connected to the tracheal system.
How is oxygen present in water?
Oxygen dissolves less readily in water. Air contains box more oxygen then water. Fish extract oxygen directly from water.
What is the structure of fish gills in bony fish?
-Fish gills are comprised of gill arches, each with two stacks of filaments.
- filaments are covered with Neros of lamenae, which are thin, place like structures.
- The lamellar contain a dense reswerse of capillaries.
What are the mechanisms of gas exchange in a fish?
- Capillary system in lamellae ensures blood flows in the opposite direction to water flow (counter-current system).
- counter-current system maintains concentration gradient along the capillary.
- water with lowest oxygen concentration is adjacent to the most deoxygenated blood.
How does the counter-current system maintain the concentration gradient in a fish?
1.The counter current flow ensures that the concentration gradient of oxygen is maintained along the entire length of filament.
2. Water with a higher oxygen concentration always meats blood with a lower oxygen concentration, facilitating continuous diffusion of oxygen into the blood.
How does the counter-current system maximize oxygen uptake in fish?
- By maintaining the concentration gradient, the counter-currents system allus for more efficient oxygen uptake.
2.fish can extract up to 80 - 90% of the oxygen from the water passing over their gills.
How does the counter current system allow for efficient gas exchange in fish?
- the counter-current system also facilitates the removal of carbon dioxide form the blood into the water.
- this efficient gas exchange is crucial for the fish’s respiration and overall ,metabolic process.
how does the air pass through the human respiratory system?
- air enters the respiratory system through the nasal cavity, where it is filtered, warmed, and humidified.
- it then passes through the pharynx, a muscular tube that connects the nasal cavity to the larynx.
- the larynx, also known as the voice box, is located at the top of the trachea and contains the vocal cords.
- from the larynx, air moves into the trachea, a large tube that extends down into the chest cavity.
- the trachea divides into two bronchi, each leading to one lung. within the lungs, the bronchi further divide into smaller tubes called bronchioles.
these bronchioles continue to branch out and end in tiny air sacks called alveoli. the alveoli are surrounded by a network of capillaries, where gas exchange occurs. - oxygen from the air diffuses into the blood, and carbon dioxide from the blood diffuses into the alveoli to be exhaled.
what are tracheal rings and how do they help in gas exchange in humans?
they are made of cartilage (a strong flexible tissue). they help to support the trachea and ensure it stays open, while allowing it to move and flex while we breath.
what is ciliated epithelium and how is it useful in gas exchange in humans?
it is a specialized tissue found along the trachea down to the bronchi. each cell has small projections of cilia which sweep mucus, dust and bacteria upwards and away from the lungs and the epithelium itself.
What are goblet cells andwhat is there role in the respiratory system of humans?
They are mucus producing cells that secrete mucus which traps dust, bacteria and other microorganisms and prevents them form reaching the lungs. They are located scattered throughout the ciliates epithelium in the trachea. The mucus produced is then swept along by the cilia of the ciliates epithelium upwards and is swallowed. The mucus and any microorganisms will then by destroyed by the acid in the stomach.
How does smooth muscle make gas exchange more efficient in humans?
It can be found throughout the walls of the bronchi and bronchioles. It helps to regulate the flow of air into the lungs by dilating when more air is needed and constricting when less air is needed.
How does the extensive network of capillaries help provide humans with efficient gas exchange?
Carbon dioxide diffuses out of the capillaries and into the alveoli to be exhaled, while oxygen diffuses the other way from alveoli and into the capillaries to be carried around the body.
How is gas’s exchange from the alveoli into the blood in humans?
Oxygen and carbon dioxide are exchanged in a process of simple diffusion. The air in the alveoli contain a high concentration of oxygen, this can diffuse from the alveoli and into the blood capillaries before being carried away to the rest of the body for aerobic respiration. The blood in the capillaries has a relatively low concentration of oxygen and a height concentration of carbon dioxide. The carbon dioxide diffuses from the blood and into the alveoli and is then exhaled.
How does the large number of alveoli allow for efficient gas exchange in humans?
The average human adult has about 480-500 million alveoli in their lungs. This equals a surface area of 40-75m^2. The large number of alveoli increases the surface area available for oxygen and carbon dioxide to diffuse across.
How do thin walls allow for efficient gas exchange in humans?
The walls of the alveoli are only one cell thunk and these cells are flattened. This means that gases have a very short diffusion distance so gas exchange is quick and efficient.
How does the extensive capillary network allow for efficient gas exchange in humans?
The walls of the capillaries are only one cell thick and these cells are flattened, keeping the diffusion distance fr gases short. The constant flow of blood through the capillaries means that oxygenated blood is brought away from the alveoli and deoxygenated blood is brought to them. This maintains the concentration gradient necessary for gas exchange to occur.
What mechanisms are required in inhalation in the human respiratory system?
- external intercostal muscles contract.
- rib cage moves up and out.
- diaphragm contracts and flattens.
- volume of thorax decreases.
- air is drawn in.
What mechanisms are required for exhalation in the human respiratory system?
-external intercostal muscles relax.
- recoil of elastic fibres surrounding the alveoli cause air to be forced out.
- internal intercostal muscles contract.
- abdominal muscles contract.
Rib cage moves down and in.
Diaphragm relaxes and becomes dome shaped.
- volume of thorax increases.
-air is forced out.
How can breathing be effected by activity?
When at rest, breathing is shallow and steady.
When exercising, breathing is deeper and more frequent.
What is the tidal volume?
The volume of air inspired per breath when at rest.
What is the breathing rate?
The number of breaths taken per minute.
How can you show volume changes in the lungs?
Using the results from a spirometer.
What is the Pulmonary Ventilation Rate (PVR) ?
The volume of air breathed (in or out) in one minute.
How do you calculate the PVR?
PVR= tidal volume x breathing rate
How does cancer effect the normal workings of the lungs?
Tumours develop if mutations occur in oncogenes or tumour-suppressor genes of the bronchial epithelial cells.
If the tumour becomes large because it has no method of programmed cell death, it survives by developing its own blood supply.
The tumour interfears with the normal working of the longs, such as by squeezing against blood vessels or cancer cells entering the lymphatic system.
Symptoms include coughing up blood, a persistent cough, increased mucus, back or shoulder pain, wheezing, breathing difficultly and sudden weight loss.
What is COPD and what is its key symptoms?
Chronic bronchitis and emphysema.
Symptoms: shortness of breath, chronic cough, crest tightness, wheezing, and difficulty breathingduring physical activity.
What does COPD stand for?
chronic Obstructive Pulmonary Disease.
What happens to the lungs in COPD?
Enlarged goblet cells produce mere mucus, destroying cilia the in trachea and preventing them from sweeping mucus away from the lungs.
Much blocks narrow bronchioles, causing coughing, scar tissue und infection.
How can COPD affect the alveoli?
Infection attract phagocytes, which release elastase, damaging the elasticity of the alveolar walls.
Without enough elastin, alveoli breaking down, creating large air spaces and causing wheezing and breathlessness.
Advanced COPD may require a constant supply of oxygen.
What chemicals are found in cigarettes?
Tar - a carcinogen (a substance that causes cancer)
Nicotine-an addictive substance which narrows blood vessels
Carbon monoxide - reduces the oxygen carrying capacity of the blood.
How does tar effect air passage?
Tar destroys the cilia (which carry dust and microbes trapped by mucus away from the lungs), causing the buildup of mucus and potentially leading to bronchitis as the lining of the bronchi become irritated.
How does tar effect the alveoli?
It contributes to the break down of the alveoli, causing them to merge together.
This creates an insufficient SA:V ratio, allowing less gas exchange.
This reduces the efficiency of gas exchange, causing emphysema where less oxygen is carried in blood.
Tar can also build up and form a layer on top of the alveolar cells which can increase the diffusion distance for gas exchange.
What is forced expiratory volume (FEV)?
The volume of air that can be forcibly exhaled from the lungs after taking the deepest breath possible.
What is Forced Expiratory Volume in 1 second (FEV1)?
The maximum volume of air that can be forcibly exhaled in one second. In a healthy version, this is usually 80% or higher.
Why is FEV1 important?
It is a key indicator of lung function and is used to diagnose and monitor respiratory conditions such as asthma, COPD, and emphysema.
How does smoking effect FEV1?
Long term smoking can cause a significant decrease in FEV1, making it harder to breath out quickly and forcefully.
Regular measurements of FEV1 can help monitor the progression of lung diseases and the impact of smoking cessation.
