Respiration System

Function of respiration

• oxygen carries out cellular respiration

• releases energy from glucose

• produces carbon dioxide as waste

Respiration

• bring oxygen into body

• makes oxygen available to cells

• eliminates carbon dioxide

stages:

1. breathing

2. external respiration

3. internal respiration

4. cellular respiration

Inspiration

breathing in or inhaling oxygen into lungs

expiration

breathing out or exhaling air from lungs outside of body

external respiration

• exchange oxygen and carbon dioxide between inspired air and blood

• preforms function for gas exchange

Gas exchange

• primary function of lungs

• delivery of oxygen from lungs to blood

• eliminates carbon dioxide from blood to lungs

Limitations of gas exchange

• single-celled organisms rely on diffusion however organisms with more than a few cells thick beed specialized systems

• body is complex for some meaning body surface cannot dedicate self to gas exchange

internal respiration

• exchange of oxygen and carbon dioxide between blood and tissue cells of body

cellular respiration

• releases energy needed to drive cell functions

• cell requires oxygen and produces carbon dioxide as waste

• in mitochondria

Efficiency of respiration

• organisms use ventilation

• moves oxygen with medium (water/air) over respiratory surface

respiratory surface

• area of animals body where gases are exchanged with the environment

• every organism has different systems

respiratory requirements

• respiratory surface must be large enough for gas exchange to occur at a rate that meets metabolic needs

• must be in moist environment so gases dissolve in water

Skin respiration

• use outer skin

• oxygen diffuses to thin network of thin welled capillaries below skin

• high ratio of respiratory surface : body volume

• must live-in damp/water to keep skin moist

Gills

• fish and aquatic invertebrates exchange gases through gills

• folds in body that increase surface area

• feathery tissue structures with numerous branches

• gases exchange across gill membranes

• oxygen diffuses across gill surfaces into capillaries

• carbon dioxide diffuses out into water

gills Pt2

• aquatic environments contain oxygen in form of dissolved gas in water

• physical adaptations that allow gas exchange in water

• fish exchange gas by taking water in mouth and ventilating it over gills, carbon diffuses from blood, across gill tissue and into water

Gill Gas exchange

• blood flows through gills in opposite directions to flow of oxygen containing water (counter-current flow)

• oxygen is diffused from water into blood

• counter-current flow provides better diffusion of oxygen from water into bloodstream

tracheal respiratory system

• internal respiratory system consisting of external pores called spiracles

• spiracles lead to internal respiratory tubes called tracheae

• gas exchange through pores and moves through tracheae

• gas exchange by diffusion

• no need for circulatory system

Lungs

• mammals, birds, reptiles, and amphibians exchange gases through internal system consisting of trachea branching into lungs

• sacs filled with moist epithelium

• folds in lung lining increase surface area for diffusion

Characteristics of lung systems

1. moist respiratory surface

2. forcibly bringing air into contact with lung surface (ventilation)

3. circulatory system to carry gases between lungs and other body cells

Nose

Structure:

• 2 nostrils

• separated by cartilage and bone

Function:

• air breathed in is warmed by heat in capillaries

• dampens air when passes over mucus lining

• cleans air by cilia sweeping dirt into mucus

• nose hair filters air removing large particles

Pharynx (throat)

Structure:

• muscular tube

Function:

• breathing: pharynx connects nasal passages into larynx that leads to trachea

• maintains air pressure: eustachian tube in middle ear opens pharynx to equalize pressure in ear with atmospheric pressure

• swallowing: soft palate rises ti block nose opening and covers entrance to trachea using epiglottis

Larynx

Structure:

• first part of trachea

• contains tight stretched cords (vocal cords)

• lie against wall when breathing (move forward for speaking)

Function:

• forces air over cords vibrating them allowing speech

• loudness = how hard breathe out

• pitch = how tight cords are

• quality = amplifiers (mouth, nose, lungs)

Trachea

Structure:

• 10 cm rube from larynx to bronchi

• held open by C-shaped rings of cartilage preventing collapsing

Function:

• passageway for air

Bronchi

Structure:

• base of trachea divides into 2 tubes

• each bronchus goes into a left and right lung

• inside lung bronchi branch into bronchioles all over lungs

Function:

• passageway for air

Alveoli

Structure:

• clusters at end of bronchioles

• allows surface area

• surrounded by blood capillaries

• covered in film of moisture

Function:

• oxygen in air that enters alveoli during inhalation dissolving in moisture diffusing in capillaries

• hemoglobin (protein in red blood cells) absorbs oxygen and transports it to heart

• Carbon dioxide passes capillaries into alveoli be breathed out

Lungs Structure and Function

Structure:

• 2 large spongy organs

• fill thoracic cavity (chest)

• 2 lobes on left, 3 on right

• contain bronchi, bronchioles, alveoli, capillaries

Function:

• Fill and contract to fill up with gas

Pleura

Structure:

• Membrane that covers lungs

• between pleura and lungs fluid lubricant

Functions:

• applies pressure equally ti all parts of lungs allowing inhalation and exhalation

Pleurisy

• Inflammation of pleura causing pain when breathing or coughing

• smooth lining of lungs becomes rough

pleural effusion

• fluid collection around lungs

• results from TB infection

Brain's influence on breathing

• brain is respiratory control centre

• coordinates breathing movements and regulates breathing rates

• monitors volume of air in lungs and gas levels of blood

Mechanics of breathing

• ventilation is from pressure difference between thoracic cavity and atmosphere

• pressure is created by changing volume in thoracic cavity

• muscular diaphragm and rub muscles control air pressure

• air pressure changes due to air moving in and out

• diaphragm = dome shaped separation with thoracic cavity and abdominal cavity

Intercostal Muscles

• rib muscles

• found between rubs and below surface of rib cage

• works with diaphragm to move air out of lungs

Inhalation process

1. intercostal muscles and diaphragm contract

2. ribcage moves upward and outward

3. diaphragm moves down flattening

4. lungs expand

5. air rushes in

inhalation pt2

• chest is air tight increasing volume when air inside

• gas molecules exert less outward pressure decreasing pressure in thoracic cavity

• lungs suspended in the air as they are sensitive to air pressure changes

inhalation pt3

• air pressure cavity decrease drawing lungs outward and expanding

• air pressure in lungs is lower than our of body

• air rushes to region of higher pressure to lower

• air enters lungs to stabilize pressure difference between external atmosphere and internal lung compartments

Exhalation

1. muscle movements expel air from lungs

2. intercostal muscles and diaphragm relax

3. ribcage moves down and in

4. lungs contract

5. air moves out

6. volume of chest cavity decreases

7. air pressure inside lung increases

8. change in air pressure causes air to move to lower pressure area

Exhalation Expiration

• passive

• intercostal muscles relax decrease volume

• pressure exceeds atmospheric pressure

• air expelled from lungs

Respiratory volumes

• breathing does not use full capacity of lungs

• if body needs more oxygen volume of air drawn into lungs increases

spirograph

• amount of air moves in and out if lungs with each breath

• measured with spirometer

tidal volume (TV)

• volume of air inhaled and exhaled in normally at rest

inspiratory reserve volume (IRV)

• volume of air forcefully taken into lungs beyond regular or tidal inhalation

expiatory reserve volume (ERV)

• volume of air expelled or forced out of lungs beyond regular/tidal exhalation

Residual volume (RV)

• amount of gas left in lungs after forced max exhalation

total lung capacity (TLC)

• amount of gas in lungs after max inhalation

• TLC = IRV + TV + ERV + RV

vital capacity (VC)

• max volume if gas that can be exhaled voluntarily after max inhalation

• max volume of air moved in and out of lungs during a breath

• VC = IRV + TV + ERV

inspiratory capacity (IC)

• max amount of gas inhaled after normal exhalation

• IC = IRV + TV

functional residual capacity (FRC)

• amount of gas left in lungs after normal exhalation

• FRC = ERV + RV