biology-respiratory system

• what is respiration

  the chemical breakdown of complex organic substances that takes place in cells and tissues during which carbon dioxide is produced and energy is produced in the form of ATP
• how many parts does the circulatory system have

  the pulmonary circulaion(the lungs)

  the coronary circulation(the heart)

  the systemic circulation(the rest of the body)
• what is the circulatory system responsible for

  performs functions that help to maintain constant internal conditions

  • exchanges neutrients with intestitial fluid to control the chemical balance of fluid
• what way does deoxygenated blood flow

  deoxygenated

  • vena cava
  • right atrium to tricuspid valve
  • right venticle to pulmonary valve
  • pulmonary artery
• what way does oxygenated blood flow

  gets oxygenated in the lungs

  • left atrium
  • left ventricle
  • aorta
  • rest of body
• describe the systematic

  • starts with aorta carrying oxygenated blood from the left ventricle
  • arteries go from the aorta to each specific organ
• what is the pulmonary circulation

  • deoxygenated blood flows down the pulmonary trunk to the pulmonary arteries and into the lungs
  • the blood then gets oxygenated and 4 pulmonary veins carry the blod to the left atrium
• what would happen if you stopped breathing for a few minutes

  -withoutoxygen no respiration occurs so metabolic reactions cannot occur

  -no ATP produced

  -no steady flow of oxygen for working cells
• what is a respiratory surface

  a surface covered with a single layer of living cells tha is thin enough and moist enough to allow rapid diffusion between the body and the environment
• how do earthworms breath

  -use their outer skin as a respiratory surface

  -moist skin and gases diffuse across its general surface

  -resulting in the exchange of O2 and CO2 between the environment anda network of capillaries below the skin
• how do aquatic animals breath

  -respiratory surfaces are found in extensions of the body called gills

  -the rspiratory areahas a large surface area

  -as water passes over the gills and gases diffuse between the blood and water. the blood then carries oxygen to the rest of the body
• how do insects breath

  -breathe using the tracheae

  -the o2 travels down to the spiracles

  -no circulatory system required to transport O2 as the body cells are within a short distance from the resiratory surface
• how do humans breathe

  • Lungs are the most common respiratory surface.
  • All mammals,terrestrial vertebrates such as amphibians,

  birds and other reptiles have lungs.

  • In contrast to the tracheae of insects, lungs are located

  in only one part of the body.
• what is the first step of gas exchange

  • The first step of gas exchange is breathing.

  • When an animal with lungs breathes, a large, moist

  internal surface is exposed to air.

  • Oxygen diffuses across the cells lining the lungs and into

  the surrounding blood vessels. Simultaneously, CO2

  passes out of the blood, into the lungs, and is exhaled.
• what is the secon step of the gas exchange

  • The second step in gas exchange is the transport of O2

  from the lungs to the rest of the body via the circulatory

  system. The blood also carries CO2from the tissues back to the lungs

  • The final step is for cells to take up O2 from the blood and release co2 into the blood

  • The circulatory system transports the CO2

  back to the lungs, where it is exhaled and released from the body.
• describe the lungs

  
• how do we breathe

  • Air enters through the nasal cavity

  and mouth.

  • In the nasal cavity, the air is filtered

  by hairs, warmed, humidified, and

  sampled by smell receptors.

  • The air passes to the pharynx,

  • From the pharynx, air is inhaled

  into the larynx (voice box)

  • The wall of the larynx is reinforced

  with cartilage

  • From the larynx air passes into the

  trachea (windpipe).

  • Rings of cartilage (shaped like the

  letter C) maintain the shape of the

  trachea
• why is the trachea covered in cartilage rings

  to prevent it from collapsing
• what does the trachea divide into

  2 bronchi one leading into each lung
• describe the bronchioles

  they end in structures known as alveoli that lok like grapelike clusters
• what is the alveoli

  • High surface area to maximise gas exchange

  • rate of diffusion proportional to surface

  area

  • Specialized cells of alveolar lining secrete

  chemicals.

  • reduce “surface tension” – prevents fluid

  from beading up on alveolar surface.

  • Thinner layer of fluid makes gas diffusion

  easier.

  • Alveoli contain lots of phagocytic cells:

  ALVEOLAR MACROPHAGES.

  • Ingest and destroy microorganisms and

  other foreign substances (from breathing

  them in)
• what is the role of the pleural membranes

  -surrounds and protects the lungs

  -keeps the lungs against the diaphram and the chest wall

  -permits smooth moving of the lungs
• what is the role of the ribs

  they are a protective layer of bones around the heart and lungs
• what is the role of the diaphragm

  contraction is responsible for drawing air into the lungs
• what do the internal intercoastal muscle do

  contract during forced breathing out during expiration
• what do the external intercoastals do

  contract to breathe in inspiration
• describe the goblet cells

  -found in the nose

  -they clean particles from inhaled air

  -the cilia trap debris in mucus

  -the debris is expelled by coughing and sneezing
• what is the bronchus wall

  -lined with cilia and goblet cells that

  - clean and warm the air

  -cartilage supports the structure as air pressure changes during the proces of inspiration and expiration
• what are terminal bronchioles

  -the folds present give the brochiole a large surface area

  -the muscle allows for expansion and contraction during breathing
• what part of the brain regulates breathing

  -the autonomic control centres

  -nerves from the brain signal the diaphram and rib muscles to contract foucing us to inhale

  -when at rest the brin sends signals that keep our respiratory rate at 10-14 inhalations per minute
• what is the role of carbon dioxide in the process of breathing

  -increasing levels of co2 will increase the breathing rate as more co2 needs to be expelled

  -an increase in co2 levels in blod stimulate the medulla which then sends signals to the breathing muscles

  -causing the diaphragm and external intercostal muscles to contract so we inhale

  -feedback from the alveoli causes the medulla to stop sending signals

  -this stops inhalation and the lungs recoil causing expiration

  -exersise also increase the levels of co2 so causing an increase in breathing rate
• what is the effect of exercise on our breathing

  -the breathing control centre in our brain increase or decrease the rate of our breathing depending on the level of co2 in the blood

  -exercise stimulate respiration producing more ATP and raising the amount of CO2 in the blood

  -this is sensed by the brain causing the brain to send signals to increase breathing rate and depth

  -this expels more co2 and inhales more o2 for working muscles
• what is inspiration

  • An active process because it involves muscle contraction.

  • The diaphragm and external intercostal muscles contract. (relaxation of internal)

  • The contracting diaphragm flattens and stretches the elastic lungs downward.

  • The contracting intercostals pull the ribcage up and out causing the elastic lungs to

  stretch.

  • The expansion of air causes a drop in air pressure in the lungs.

  • Air in the lungs is at a lower pressure than the air outside, so air enters the lungs.
• what is expiration

  • A passive process because it does not involve muscle contraction.

  • The diaphragm relaxes, and the external intercostal muscles relax

  • The lungs recoil elastically reducing their volume – a passive process.

  • The volume of air in the lungs decreases causing an increase in the air

  pressure.

  • Air flows from higher to lower pressure so the air flows out of the lungs.
• what would happen if you breathed in too much oxygen over a long period of time

  -leads to oxygen toxcity

  -where the prolonged exposure to oxygen causes damage to cell membranes

  -it can also cause the alveoli to collapse

  -symptoms are seizures and retinal detachment
• what is the circulatory system

  • The respiratory system exchanges gases through inhalation and exhalation, but it relies on the circulatory system to bring these gases to body cells.

  • The O2-rich blood is then sent to body tissue capillaries via the heart. In the body tissues, O2 enters the tissue cells and CO2 leaves the tissue cells and enters the blood. The O2-poor blood is circulated back to the heart, then to the lungs.
• what is the role of haemoglobin in the blood

  -to help the oxygen bind to the blood

  -the haemoglobin pivks up o2 at the lungs and carres it to the bodys cells where it i released

  -each haemoglobin molecule can carry up to 4 molecules of O2

  -as it binds to oxygen it changes the colour from dark red to bright red
• what is the co-operative binding method

  -the binding of 1 oxygen molecule cause the haemoglobin molecul to change shape increasing the attraction for o2 as it is easier for them to bind

  -when it rleases te o2 the haemoglobin changes shape again lowering the attraction to o2
• how is co2 transported in the blood

  -dissolved in the blood plasma as a bicarbonate ion

  -at the lungd there is a lower pressure of co2, this allows the co2 to diffuse out of the blood into the lungs
• what happens when carbon monoxide bind to haemoglobin instread of oxygen

  -it binds to the haemoglobin even tighter than oxygen

  -causing less respiration to occur

  -less ATP produced