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Biology > Respiration in Humans > Flashcards

Respiration in Humans Flashcards

1
Q

What is the order in which air flows through the respiratory system?

A

Nostrils, nasal passages, pharynx, larynx, trachea, bronchi, bronchioles, alveoli

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2
Q

What is the pleural cavity?

A

Each lung lies in a pleural cavity. Each pleual cavity is lined by two transparent elastic membranes known as pleura

The inner pleura covers the lungs and the outer pleura touches the wall or the thorax and diaphragm.

Pleural fluid lies between the layers

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3
Q

What are the advantages of breathing through the nose?

A
  1. Dust and foreign particles, including bacteria are trapped by hairs in the nostril and mucus on the mucous membrane
  2. When air passes through the nasal passages, it is warmed and moistened before entering the lungs
  3. Harmful chemicals can also be detected by smell sensory cells in the mucous membrane
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4
Q

How are foreign particles removed from the respiratory system?

A
  • The thinner walls of the trachea and bronchi are lined by epithelium bearing cilia
  • Gland cells in the epithelium secrete mucus to trap dust and foreign particles
  • Cilia help to sweep these particles up trachea and bronchi and into the pharynx
  • From here they are swallowed into the oesophagus
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5
Q

Describe

The structure of the trachea

A
  1. In front of the oesophagus
  2. Suppoted by C shaped cartilages
  3. Branch into 2 bronchi
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6
Q

Describe

The structure of bronchi

A
  1. Divide into many fine bronchioles
  2. Each bronchiole leads to a cluster of alveoli
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7
Q

Describe the process of inspiration

A
  1. Diaphragm contracts and flattens
  2. Internal intercostal muscles relax , external intercostal muscles contract (RICE)
  3. Ribs move upwards and outwards
  4. Thoracic volume increases
  5. Air pressure in thorax decreases
  6. Air flows into lungs
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8
Q

Describe the process of expiration

A
  1. Diaphragm relaxes and arches upwards
  2. External intercostal muscles relax, internal intercostal muscles contract (ERIC)
  3. Ribs move downwards and inwards
  4. Thoracic volume decreases
  5. Air pressure in thorax increases
  6. Air flows out of lungs
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9
Q

How are the lungs adapted for gaseous exchange?

4 adaptations

A
  1. Numerous alveoli in the lungs give a large surface area for exchange
  2. Walls of alveoli are one cell thick; shorter distance –> greater rate of diffusion
  3. Thin layer of moisture covers the surface of alveolus; allows oxygen to dissolve in it
  4. Walls of alveoli are richly supplied with blood; flow of blood maintains steep concentration gradient
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10
Q

Describe

How gaseous exchange takes place in the alveoli

A
  • Takes place by diffusion
  • Blood entering the lungs have a higher conc. of CO2 but lower conc. of O2 compared to atmosphere
  • A concentration gradient is set up between blood and alveolar air
  • Oxygen diffuses from alveolar air into blood
  • Carbon dioxide diffuses from blood into alveolus
  • The concentration gradient is maintained by constant breathing and continuous flow of blood in capiliaries
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11
Q

How is oxygen absorbed in your lungs?

A
  • One cell thick wall is permeable to O2 and CO2
  • As alveolar air has a higher conc. of O2 than blood, O2 dissolves into moisture lining the walls of the alveoli and diffuses into the blood capiliaries
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12
Q

What is tidal air?

A

The volume of air entering and leaving the lungs (500cm3) in a normal, quiet breathing cycle

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13
Q

What is complemental air?

A

The extra volume of air (1500 cm3) that can be taken in during a deep breath

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14
Q

What is supplemental air?

A

The extra volume of air that can be forced out (1500 cm3) during a depp expiration

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15
Q

What is the vital capacity of the lungs?

A

Vital capacity= tidal air+complementary air+supplementary air

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16
Q

What is residual air?

A

The air (1500 cm3) that is left behind in the lungs no matter how hard a person tries to force all the air out of the lungs

17
Q

Define

Cellular respiration

A

A sequence of enzyme controlled steps by which chemical potential energy ‘locked up’ in organic molecules such as carbohydrates, proteins and fats are released by oxidation and harvested in the form of ATP

18
Q

Define

Aerobic respiration

A

Aerobic respiration is the oxidation of glucose in the presence of oxygen, with the release of a large amount of energy

Carbon dioxide and water are released as waste products

19
Q

What is the equation for aerobic respiration?

A

Oxygen+glucose–> Carbon dioxide+water+energy

20
Q

Define

Anaerobic respiration

A

Anaerobic respiration is the release of energy by the breakdown of glucose in the absence of oxygen

21
Q

Where does aerobic and anaerobic respiration take place?

A

Aerobic: Mitochondrion
Anaerobic: Cytoplasm

22
Q

Compare the amount of energy produced by aerobic and anaerobic respiration

A

Aerobic respiration produces much more energy

23
Q

Why do humans require anaerobic respiration in some cases?

A

When muscle contractions are vigourous over a period of time, maximum aerobic respiration does not release enough energy to meet the demand. Muscle cells then carry out anaerobic respiration to release extra energy to meet the demand. The energy produced by both is enough to meet the demand

24
Q

What is the equation for anaerobic respiration in humans?

A

Glucose–> lactic acid+energy

25
What is the equation for anaerobic respiration in microorganisms during alcohol fermentation?
Glucose--> ethanol+carbon dioxide+energy
26
# Define Oxygen debt
Oxygen debt is the amount of oxygen required to remove lactic acid
27
How does lactic acid affect the body?
When lactic acid concentrations build up slowly in the muscles, they can cause fatigue and muscular pains
28
How can oxygen debt be removed?
- After exertion, the breathing rate remains high to provide sufficient oxygen to remove the lactic acid from the muscles and transport it to the liver - The heart rate also remains high to quickly transport lactic acid to the liver and oxygen from the lungs to the liver - In the liver, some of the lactic acid is oxidised to release energy, and this energy is used to convert the remaining lactic acid to glucose, which is then transported back to the muscles - When the lactic acid is removed and used up, the oxygen debt is repaid
29
What are some harmful chemicals in tobacco smoke? ## Footnote 3 substances
1. Nicotine 2. Carbon monoxide 3. Tar
30
What is the effect of nicotine on the body? ## Footnote 5 effects
1. Increase heart rate and pressure 2. Increased risk of blood clots in arteries (thrombosis) and thus risk of coronary heart disease 3. Increased risk of arteries to narrow 4. Causes the release of adrenaline 5. Causes addiction as it is highly addictive
31
What are the effects of carbon monoxide on the body? ## Footnote 3 effects
1. Decreased ability of RBCs to carry oxygen; CO permanently binds to haemoglobin 2. Increased rate of fatty deposits (atherosclerosis) 3. Damage of lining of blood vessel 2 and 3 increase risk of coronary heart disease
32
What are the effects of tar on the body? ## Footnote 2 effects
1. Increased risk of lung cancer; tar is a carcinogen 2. Increased risk of chronic bronchitis and emphysema; dust particles trapped by mucus cannot be removed --> tar paralyses cilia
33
What are diseases caused by tobacco smoke?
1. Chronic bronchitis 2. Emphysema 3. Lung cancer
34
What is chronic bronchitis?
- Caused by prolonged exposure to irritant particles found in tobacco smoke - Epithelium lining of air passages become inflamed - Excessive mucus is secreted - Cilia on epithelium are paralysed; mucus cannot be removed--> increased risk of lung infections - Air passages blocked, making it harder to breathe--> persistant coughing to remove mucus to clear air passages
35
What is emphysema?
- Caused by persistant and violent coughing due to chronic bronchitis - Partition walls between alveoli break down - Decreased surface area for gaseous exchange - Lungs lose elasticity and become inflated with air - Breathing becomes difficult--> wheezing and breathlessness
36
# True or false In all organisms, lactic acid is produced in anaerobic respiration
False. In alcohol fermentation, ethanol and carbon dioxide are produced
37
# True or false Glucose is the only substrate that can be used in respiration
False. Galactose and fructose can be used as well
38
# True or false Our lungs contain muscles that aid in inhalation and expiration
False. The muscles are outside the lungs themselves

Biology (10 decks)

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