Gaseous Exchange and Respiration in Plants

Gaseous Exchange in Plants

• Plants do not require respiratory systems like lungs or gills found in animals.
• Large surface areas facilitate gaseous exchange through diffusion.
• Millions of leaves, each containing numerous stomata, aid in gas exchange.
• Stomata are small pores facilitate gaseous exchange
• Aquatic plants obtain dissolved oxygen from water via diffusion.
• Land plants obtain oxygen from the surrounding air through stomata in leaves and young stems.

Respiration vs. Breathing

• Respiration is an energy-releasing process at the cellular level where food is broken down whereas breathing involves inhalation and exhalation for oxygen intake and carbon dioxide expulsion.
• Respiration involves breaking complex substances like glucose into simpler compounds, such as carbon dioxide and water, releasing energy, while breathing provides fresh air to respiratory surfaces like lungs for gaseous exchange.
• In higher animals, lungs are the organs of breathing.

Surface Area Importance

• Gaseous exchange, vital for survival and metabolism in plants and animals, occurs through available surface area.
• Increased surface area enhances the effectiveness of gas exchange.
• Stomata in leaves facilitate gas exchange in plants.
• Photosynthesis and respiration are main processes needing gaseous exchange.
• Photosynthesis and respiration occur during the day, only respiration occurs at night and oxygen from photosynthesis is released through stomata during the day.

Cartilage Function in Trachea and Bronchi

• Cartilage, a flexible connective tissue, bends with resistance to stretching; found in joints, ribcages, ears, noses, throats, and between back bones
• Trachea contains 16-20 C-shaped cartilaginous rings.
• Bronchi have cartilaginous rings smaller than those in the trachea.
• Cartilage provides support and prevents collapsing of the trachea and bronchi.
• Connects bones, provides a base for bone formation and protects bone interaction spots.

Diaphragm in Breathing

• The diaphragm, a muscular structure, is a dome-shaped sheet of skeletal muscles located below the lungs
• Diaphragm muscle contractions and relaxations facilitate gaseous exchange during breathing.
• During inspiration, the diaphragm contracts, flattening its shape.
• Expiration sees the diaphragm muscles relaxing, returning to a dome shape.
• Diaphragm contraction lowers, enlarging the chest cavity to reduce lung pressure, causing air to enter.
• Diaphragm relaxation raises, decreases the chest cavity; lung elasticity and chest wall pushes out air.

Carcinogens

• Carcinogens are cancer-causing chemicals, with over 69 identified in tobacco smoke.
• Nicotine increases heart rate, blood pressure, constricts blood vessels, damages muscles, and disrupts hormonal systems and metabolism, plus increases platelet stickiness, leading to potential blockages and coronary diseases.
• Carbon monoxide, created when cigarettes burn, combines with red blood cells, preventing oxygen transport, causes inflammation, impairs lung functions, and heightens lung cancer risk.

Air Composition Comparison

• Inhaled air has 21% oxygen versus 16% in exhaled air.
• Inhaled air has 0.04% carbon dioxide versus 4% in exhaled air.
• Water vapor content varies in inhaled air; exhaled air is saturated at 6.2%.
• Temperature varies in inhaled air; exhaled air is 38%.

Gaseous Exchange in Plants: Definition

• It is the exchange of oxygen and carbon dioxide between organisms and their environment.

Types of Gaseous Exchange in Plants

• Through the epidermis.
• Through stomata.
• Through lenticels.

Mechanisms of Gaseous Exchange in Plants

• During the day plants perform photosynthesis, utilizing carbon dioxide produced in respiration and additional carbon dioxide absorbed from atmosphere while the respiration uses oxygen produced during photosynthesis.
• During respiration, carbon dioxide is released and used by the plant. During night respiration occurs, extracting oxygen from the environment and releasing carbon dioxide.
• In plants, gaseous exchange occurs between the body and the environment via the surface epidermis which allows gas exchange but may have a cuticle presence that can also assist.
• Epidermis in leaves and young stems has stomata for air movement
• Woody stems have bark with lenticels to allow gaseous exchange with environment

Breathing

• The definition is the inhalation and exhalation of air for the intake of O2 and the giving out of CO2.
• Breathing involves inspiration (inhaling air) and expiration (exhaling air).
• These processes occur continuously

Inspiration

• Chest cavity volume increases, decreasing lung pressure due to diaphragm muscle contraction and intercostal muscle contraction that expands the ribcage.

Expiration

• Rib and diaphragm muscles relax which decreases the chest cavity and increases pressure on the lungs to expel air.

Human Air Passageways Parts

• Nostrils, nasal cavities, pharynx, larynx, trachea, bronchi, & bronchioles.
• Nostrils are two openings allowing air from outside to enter the nasal cavities.

Human Air Passageways Functions

• The inhaled air passes through the nose into the nasal cavities where the air is warmed, moistened and dust freed by the cilia (hairs) and the mucus membrane.
• Nasal cavities lead into the pharynx, that traps micro organisms, contains tonsils and adenoids which filter them out.
• Air moves from the pharynx into the larynx, that surrounds the upper part of the trachea
• Larynx is known as the voice box, or sound box.
• The epiglottis, in larynx’s cavity closes the esophagus to prevent food entry when inhaling.
• Larynx opens into the trachea, also known as the windpipe, it has 16-20 C shaped cartilaginous rings to prevent collapse and to maintain passage of air open
• Trachea divides into 2 branches called "bronchi" each bronchus enters the lungs

Bronchioles

• Smaller bronchi reaching one millimeter or less in diameter without cartilage and consisting of circularly arranged smooth muscles.

Air Sac

• Bronchioles split deep in lungs forming many air sacs that are the functional units resembling grape bunches.

Alveoli:

• They consist of microscopic structures, where alveoli form lung's inner surface, blood capillaries network supports gaseous exchange.

Bronchitis

• Lining of the bronchi/bronchioles inflames due to infection, reduces airflow, and causes mucus.
• Commonly caused by viruses, bacteria, and irritants.
• Treatment is short term and resolves within 2 weeks or requires medicines like antibiotics or anti-virals or coughing removes irritants from bronchi.

Pneumonia

• Pneumonia: Lung infection caused by viruses, bacteria, and fungi and transmits via small droplet inhalation.

Severe Pneumonia

• A person with another disease may have from severe pneumonia.
• People with viral infections, lung/heart problems, are more likely to have pneumonia.
• Symptoms: Cold, high fever (i.e. 104°F), shivering, and sputum cough.

Lung Cancer

• Lung cancer is a dangerous and fatal respiratory disease from uncontrolled cell division, which is more common in men than women due to: smoking, industrial carcinogens, air pollution, and tar.
• It is recognized by cough with sputum, pleural chest pain, and breathlessness.

Tilling (Tillage)

• A farming technique for soil softening by hoeing/ploughing, improves soil aeration, water drainage, recycling nutrients, better gases exchange, also reduce plant related problems

Photosynthesis vs. Respiration

• Photosynthesis stores energy while respiration releases energy.
• Photosynthesis uses sunlight captured by chlorophyll and converts it to chemical energy by producing organic material
• Respiration can occur around the clock without sunlight while photosynthesis happens during the day with sunlight.
• Photosynthesis uses carbon dioxide and creates oxygen
• Respiration creates carbon dioxide and requires oxygen

Human Lungs

• The lungs are located in the chest cavity
• Lungs are covered with pleura membrane, a dual layered sac with thin fluid between for easy movement. connected via the trachea through chest to the nose

Gaseous exchange

• Gaseous exchange occurs in alveoli, supplied with blood capillaries, thin walls aid the capillaries providing gas exchange.
• R.B.C transfers from the lungs to the body

Breathing Advice

• Breathing through the noise advised for overall health

Lungs sizes

• Lungs the size depends on the organism's body

Smoking Consequences

• Smoking causes negative biological effects.

Tar, from smoking

• It is composed of particulate metals from the smoke's tar.
• Tar contains harmful organic chemicals which act as carcinogens and tumor maker, stains body parts, increases mucus/phlegm.

Nicotine, from smoking

• It increases heart heat rate/blood pressure, constricts blood vessels, damages muscles, and is a harmful substance affecting hormonal system, while increasing platelet stickiness and possibly leading to blockages and coronary diseases.

Carbon Monoxide

• Gas produced when a cigarette is lit is linked to heart disease
• It stops cleaning airways, and other cigarette toxins which can cause inflammation, impairing lung and is a factor causing lung disease.

Nitrogen Oxide

• Found in high doses in cigarette smokers causing lung damage that leads to emphysema.

Hydrogen Cyanide

• It destroys the cilia which is used to destroy the lungs. By damaging the the lungs it causes many diseases

Metals

• 30 different metals have been found in cigarette

Carcinogens

• Substances causes lung cancer, some metals and radioactive compounds are found in cigarettes:
  • Polonium
  • Pyrene
  • Nephtyl amin
  • Cadmium

Smoking Social Negatives

• Most non-smokers have an allergy to cigarette smoke that lead to an irritation to the nose and throat
• Breathing smoke around smokers is called passive smokers, may cause cancer
• Government have made laws against smoking which have allocated area which are allowed for smoking

breathing increase on exercising

• Rate of breathing increase due the amount of oxygen required to maintain oxidation of molecules
• The brain sends and receives this response to help increase breathing rate

Cigarette components

• Ammonia
• Toilet cleaner
• Toluene (industrial solvent)
• Stearic acid (candle wax)
• Methanol (rocket fluid)
• Carbon monoxide( pollution )
• Hexamine (barbeque lighter)
• Formaldehyde
• Butane( lighter fluid)
• Cadmium (batteries)
• Arsenic (poison)
• Acetic acid ( vinegar)
• Nicotine ( insecticides)
• Paint
• Methane (sewer gas

Importance of home ventilation

• System used to remove stale air
• Proper ventilation can provide human comfort

Emphysema

• Lung disease damaging the alveoli, commonly caused by environmental pollution and/or cigarette smoke

Asthma

• Way of the airways in which air has a narrow passing
• Causes
  • Animals
  • Dust change
  • Certain Chemicals
  • Mold and Pollens.

Artificial Ventilators

• Mechanical ventilator is a form of artificial respiration that uses a breathing machine
• Used to help patients
• Controller: Used breath adjust sizes
• Humidifier: Warm and moisten the lungs.
• Tubing and trap used air to pass out and get rid by getting rid of moisture.
• Help with breathing

fuel exhaust

• Irritations: Suffocation when in contact with heavy traffic
• Contains a lot of harm full toxins
• Gasoline helps produce, monoxide,nitrogen, formaldehyde , and root
• This increase the risk of cancer and asthma.