Breathing, Gaseous Exchange, & Cellular Respiration Flashcards
Respiratory system is responsible for
Supplying the body’s cells with oxygen and for removing carbon dioxide
Animal examples + respiratory system
- Fish: gills
- Frogs: skin & lungs
- Bird: air sacs
- Insects: spiracles
Processes collectively referred to as metabolism:
- Living cells grow
- Living cells divide
- Living cells make substances
All organisms are made of living cells
_______ is released during ______
Chemical energy
Cellular respiration
All metabolic activities takes place in cells require
Chemical energy
Chemical energy is stored in
Bonds of organic compounds
Organic compounds are made by
Autotrophic organisms during process of photosynthesis: absorbs sun’s energy and change it into chemical energy
Organic compounds supply
Cells of an autotroph with energy needed to function
Compounds that are not used
Stored in the form in starch
When an animal eats a plant…
It consumes stored compounds and thus stored energy. Stored energy is absorbed into the blood which takes them to the cells of the body
ATP
Heat energy
In the presence of ______
Oxygen
Respiration is most efficient
During cellular respiration:
- Energy is released (is useful to the body)
- CO2 is released (a waste)
Cellular respiration occurs in
Mitochondria of all living cells
Cellular respiration formula
Glucose + Oxygen + = Energy (ATP/Heat energy) + CO2 + Water
Cellular respiration is opposite of
Photosynthesis
Photosynthesis
Radiant energy converted into chemical energy
Photosynthesis formula
CO2 + Water ➡️ Glucose + Oxygen
(light energy) = ➡️
Respiratory system is responsible for
- Providing oxygen needed by the body
- Removing carbon dioxide produced by the body
How oxygen is obtained in plants
- Diffusion through stomata
- Photosynthesis
How oxygen is obtained in animals
- Breathing
- Gaseous exchange
- Diffusion into the blood
Respiration takes place
In cells to release energy when oxygen is combined with glucose and other nutrients
Inhalation/inspiration
- Air is breathed to get oxygen
- Increased volume, decreased pressure
- Active process
Exhalation/expiration
- Carbon dioxide is produced during cellular respiration and is toxic. Needs to be breathed out
- Decreased volume and increased pressure
- Passive process
Gases are exchanged at the
Surface of the lungs & alveolus
Respiratory system consists of
- Air passages
- Two elastic lungs
- Diaphragm
- Intercostal muscles between ribs
Inhaled air travels to the lungs
Beginning in the nose and mouth ➡️ throat ➡️ larynx/“voice box” ➡️ trachea ➡️ lungs
Nasal Cavity
- Well supplied with blood capillaries, mucus glands and cells with tiny hairs called cilia
Cool dry air breathed in must be
- Moistened by mucus
- Warmed by blood capillaries
- Filtered and cleaned by cilia
Cells lining nasal cavities and trachea make slimy mucus to:
Trap dust and germs
Cilia beat rhythmically to
- Remove/sweep mucus and dirt/foreign objects from nasal cavity & lungs
Larynx
- Contains vocal cords
- When air blows over these, sounds are made
Trachea
- Runs from larynx to lungs branching into bronchioles
- Kept open by c-shaped rings of cartilage: allows trachea to squash a little as food passes down the oesophagus
- Oesophagus lies directly behind trachea
Bronchi
- Branch into a network of fine tubes: bronchioles
- Bronchioles divide into millions of air sacs: alveoli
- Bronchioles function: carry air, which contains oxygen to the different areas of the lungs
Lungs physical characteristics:
- Spongey, elastic organs made up of millions of air spaces: alveoli
- Pink colour: richly supplied with blood vessels
- Left lung 2 lobes; right lungs 3 lobes: heart sits between lungs and slanted more left so left lung is smaller to accommodate it
Alveolus
Very thin wall and surrounded by blood capillaries
Role of pleural membrane
- Protect and cushion lungs
- Reduce any friction which may develop between the lungs, rib cage and chest cavity
Fluid between lungs and pleural membrane
Pleural fluid
Function of pleural fluid
- Acts as a protective layer
- Fluid lubricates the lungs as they move in and out (inflate and deflate)
Diaphragm
Very important structure in whole breathing process: movements of diaphragm controls breathing
Intercostal muscles
- Muscle between ribs
- Play important role in breathing process: movement of intercostal muscles controls breathing
- Function: pulls ribs downwards causing elastic lungs to spring back to squeeze air out (requires no energy) and air is forced out of lungs
Ciliated glandular columnar epithelium
- Trachea, bronchi and nasal passages are lined with ciliated glandular columnar epithelium
- Goblet cells secrete sticky substance called mucus
Squamous epithelium
- Tissues consist of very thin, flat cells that are 1 cell thick
- Forms walls of alveoli and blood capillaries
- Oxygen flows through 2 cells to go through capillaries (lining of alveoli + lining of blood capillaries): makes distance for gases to diffuse more shorter, efficient and effective
Primary function of lungs
Gaseous exchange
Each alveoli
Has a network of capillaries that carry deoxygenated blood, needing to get oxygen from lungs
Gaseous exchange in lungs
- Oxygen moves from alveolar space (high concentration of O2) into red blood cells (low concentration of O2) by diffusion
- CO2 is in blood cells of capillaries
- Carbon dioxide moves from blood (high concentration of CO2) into alveoli (low concentration of CO2) by diffusion
Diffusion happens very quickly because
- Surface area of alveoli is huge
- Membranes separating lungs from red blood cells are very thin
Oxygen must
Dissolve into the moisture lining the alveolus before it diffuses
Blood that leaves lungs
- Blood circulating around the body will be oxygenated by absorbing oxygen from alveoli
- Cells absorb oxygen for use during respiration
- CO2 produced during cellular respiration diffuses out of cells into blood
- Blood that is deoxygenated returns to lungs
To respire aerobically
Muscles need glucose and oxygen which is delivered to the muscles by blood system
During vigorous exercise
Heart and lungs cannot get enough oxygen to muscles quickly enough: muscles then start to carry out anaerobic respiration
Anaerobic respiration
- Glucose is only partly broken down to lactic acid (waste product) which slowly starts to poison muscles causing pain and stiffness of muscles
- Breathing is faster & deeper to get extra oxygen
Waste product produced in plants during anaerobic respiration
Ethanol
Extra oxygen after anaerobic respiration
Breaks down lactic acid and is called oxygen debt
Anaerobic respiration differs from aerobic respiration:
- Does not need oxygen
- Does not produce as much ATP
- Lasts from a short amount of time
Anaerobic respiration formula
Glucose ➡️ Lactic acid + Energy
Anaerobic respiration: Plants formula
Glucose ➡️ Ethanol + Carbon Dioxide + Energy
Smoking
- Tar & nicotine in cigarette smoke irritate lung tissue & contain several cancer causing agents
- Smoker’s air passages become coated with sticky tar
- Tar paralyses cilia: cilia can no longer sweep tar away from lungs
- Tar builds up (over years): changing surface cells of passages (cells increase: lung cancer appears)
- Nicotine makes heart beat faster = heart disease
Smoking causes
Damages health: heart and lung diseases
Emphysema
- Most common cause: smoking
- Walls of air sacs weakened by chemicals in tobacco smoke
- Coughing can burst air sacs, damaging lung tissue (creates larger spaces)
- Alveolar walls damaged causing loss of elasticity & decrease in surface area for gaseous exchange
- Damaged alveoli joint & tidal volume decreased
Emphysema: when lungs cant take in enough oxygen
- Result is breathlessness in patient
- Hard to breathe in & out - must work to exhale air
Emphysema symptoms
- Coughing
- Wheezing
- Breathless
- Fatigué
- Coughing up phlegm
- Bronchitis
Tuberculosis
- Caused by type of bacteria
- Spread when a person breathes in small particles of mucus which carry bacteria
Symptoms of tuberculosis
- Continuous cough
- Loss of weight
- Loss of appetite
- Coughing up blood
- Breathlessness
Usual treatment for TB
- 2 antibiotics (isoniazid & rifampicin) 6 months
- after taking antibiotics for 2 weeks: most people are no longer infectious & feel better
Bronchitis
- Inflammation of bronchi and bronchioles: caused by bacteria
- Produce a lot of thick mucus called phlegm (when infected) making breathing difficult
Asthma
- Occurs when people are allergic to substances e.g. pollen, dust and breathe them in
- Body reacts by constricting the bronchiole (making them narrower) making breathing difficult
