Chapter 22 - Respiratory System

Major function is to supply the body with __ and remove __. Can divide the respiratory system into: 1)______ portion - passageways that conduct air 2)______ portion - actual site of gas exchange

02, CO2 conducting respiratory

O2 in alveolar air (___mmHg) moves to blood of pulmonary capillaries (__mmHg). CO2 in blood of pulmonary capillaries (__mmHg) moves to alveolar air (__mmHg)

105, 40 45, 40

Bronchi and subdivisions - remaining airways branch about __ times → bronchial tree - primary bronchus - to R. and L. lungs - secondary bronchus - to lung ____ - tertiary bronchus - to lung _____ - become smaller and smaller bronchi - passages smaller than _ mm in diameter are _______

23 lobes segments 1, bronchioles

Peripheral chemoreceptors in aortic and carotid bodies - sensitive to changes in pCO2, pO2, H+ concentration - arterial pO2 must decrease from 100 to __ mmHg before chemoreceptors are stimulated

60

Transport of Respiratory Gases Oxygen - about __% of O2 is transported bound to the iron in the heme group of hemoglobin - remainder of O2 is transported dissolved in _____ Hb + O2 ↔ HbO2 (_______) - binding to Hb is reversible - binding is a function of pO2 and results in a _____ curve due to "subunit cooperativity"

98 plasma oxohemoglobin sigmoid

Pulmonary Ventilation: ______ Pressure - Pressure exerted by air (gases) on the surface of the body (at sea level = 760 mmHg = 1 atm) _________ Pressure - Air pressure within the _____ (changes with the phases of breathing)

Atmospheric Intrapulmonary alveoli

P value of a gas is an indication of its concentration of that gas within a mixture Can calculate P in atmospheric air as follows: Eg: pO2 = 20.9% X 760 mmHg = 159mmHg pCO2 = 0.04% = 760 mmHg = 0.30mmHg Add all mmHg values and should equal 760mmHg, this is _____ law.

Dalton's

Dalton's Law States that atmospheric pressure is equal to the sum of the pressure exerted by each individual gas pN2 + pO2 + pCO2 + pH2O + p(other gases) = atmospheric pressure _____ Law States that a gas in contact with a liquid will dissolve in the liquid in proportion to its partial pressure A gas diffuses from an area where its partial pressure is ____ to the area where its partial pressure is _____ - The greater the partial pressure of a gas in a mixture, more and faster it enters the liquid solution (CO2 is 20X more soluble in plasma and alveolar fluid than O2)

Henry's higher, lower

5 Factors that Influence the Rate and Depth of Breathing

Higher brain inputs Pulmonary irritants Inflation reflex (Hering-Breur) Proprioceptor stimulation Chemical factors

_____ connects pharynx to trachea - _ pieces of cartilage connected by membranes and ligaments - _______ covers opening of larynx (glottis) when swallowing - ____ vocal cords involved in voice production

Larynx 9 epiglottis true

Composition of Air Air is composed of a mixture of gases: 78.6% __ 20.9% __ 0.04% ___ 0.06% other gases 0.40% water vapor = 100% Total Each individual gas in this mixture exerts its own pressure - pressure of a specific gas is called its ____ _____

N2 O2 CO2 partial pressure

p__ main sensors are in peripheral chemoreceptors: -Has to drastically decrease before pO2 is sensed -Huge reserves of O2 bound to hemoglobin - rarely gets low (hypoxic) -if pO2 is less than 60mmHg, triggers reflex increase in resp rate

O2 increase

Intrapleural Pressure Pressure within the ____ cavity (between the pleurae) and is about _ mmHg less than atmospheric pressure ____ Gas Law States that under constant temperature, the pressure exerted by a gas varies inversely with volume i.e. if ↑ volume, then ↓ pressure if ↓ volume, then ↑ pressure

Pleural 4 Boyle's

_____ respiratory area modifies the activity of medullary neurons and helps coordinate the transition between inspiration and expiration - fine tunes breathing during _____, ____ and _____

Pontine speaking, sleep, excercise

Respiratory Physiology: Involves Four Events: 1. ______ Ventilation - mechanics of breathing 2. _____ Respiration - pulmonary  gas exchange 3. _____ Respiration - capillary gas  exchange at tissues 4. Transport of Respiratory ____ -  O2 and CO2 transport in the blood

Pulmonary External Internal Gases

in systemic capillaries, CO2 enters ___ CA CO2 + H2O ↔ H2CO3 ↔ H+ + HCO3- (carbonic acid) (bicarbonate ion) - Hb binds H+ (important buffer system) - HCO3- is exchanged for plasma chloride "chloride shift" - all of these processes are reversed in lungs to allow removal of CO2

RBC

Alveoli: Walls composed primarily of ____ _____ epithelial cells called: Type I alveolar cells Outer surface of alveoli is covered by pulmonary _______ Respiratory = _____ + ______ + _______ (exam) membrane Gas exchange occurs across the ______ _______

Simple squamous Capillaries respiratory membrane Type I alveolar cell, fused basement membrane and endothelial cell of pulmonary capillary

pO2 = 105mmHg pCO2 = 40mmHg Why does it differ? Humidification of air as contacts mucous membrane in conduction passageways - pH2O increases 10X Gas exchanges of O2 from alveoli and CO2 from the blood occurs Mixing of freshly inspired air with air from previous breath - tends to dilute O2 and CO2 levels ____ volume: the normal amount of air your inspire/expire when normal breathing occurs -Normally about ___mL - About ___mL of this air fills the conducting passageways - (aka anatomic deadspace) -About ___mL reach alveoli for gas exchange

Tidal 500 150 350

Control of Respiration: Need to match respiration to the metabolic requirements for O2 Respiratory centre consists of neurons in the _____ and ____ ______ respiratory area controls breathing rhythm (____ area) and integrates peripheral sensory input  (____ area) - cyclic on/off activity of inspiratory and expiratory neurons produce a resp rate of __-__ breaths/min

_medulla, pons medullary ventral. dorsal 12-15

Inspiration is an ____ process - involves muscle contraction When diaphragm contracts it _____ and increases length of thoracic cavity Air movement into lungs as long as a pressure ____ exists Forced inspiration: use scalenes, sternocleidomastoid, pectoralis minor, straighten spine

active flattens gradient

Scattered throughout the alveolar epithelium are Type II alveolar cells which secrete _____ ____ - keeps surfaces moist - contains ______ Phagocytic alveolar _______ wander the inner alveolar surfaces to remove dust and other foreign particles Fine ____ fibers surround the bronchial tree and alveoli

alveolar fluid surfactant macrophages elastic

External resp: external air is at lung _____ Internal resp: exchange at ____ cells

alveoli tissue

Gas exchange occurs between the atmospheric air and the _____ of the lungs. At Rest: - just before inspiration, ____ pressure = _______ pressure (760 mmHg) - diaphragm is relaxed (___-shaped) **Diaphragm is skeletal muscle - but NOT consciously controlled

alveoli alveolar, atmospheric dome

External (Pulmonary) Respiration: - Gas exchange between the ____ and blood in pulmonary capillaries Gas exchange is aided by: - _____ of respiratory membrane - extensive _____ ___ of alveoli - numerous small pulmonary ___ When inspire, atmospheric air enters the lungs and gets _____' (less O2 and more CO2)

alveoli, capillaries thinness surface area caps modified

Trachea - ______ to esophagus - 10-12 cm long and 2 cm diameter - lined by ________ epithelium - has 16-20 C-shaped rings of _____ cartilage - open part of ring against esophagus where ______ muscle connects rings - trachealis muscle can _____ tracheal diameter to adjust air flow

anterior pseudostratified hyaline trachealis decrease

Carbon dioxide - about 70% of CO2 is transported as _______ ions (HCO3-) in the blood plasma - about 23% is transported by Hb (____ portion) in RBCs as carbaminohemoglobin - about 7% is dissolved in the blood ____

bicarbonate globin plasma

c) Inflation (Hering-Breuer) reflex  - stretch receptors found in walls of ____ and ______ - keep lungs from over-______ d) Proprioceptor stimulation - monitor movement of ____ and _____ - stimulate the medullary area to ______ respiratory rate

bronchi, bronchioles inflating joints, muscles increase

Note ** ______ do NOT have hyaline cartilage (test q) - Also, bronchioles change thickness of epithelium & have less ciliated cells as near alveolar sac Losing: cartilage, thickness of epithelium, cilia, goblet cells as approach alveolar sac

bronchioles

e) Chemical factors - chemoreceptors monitor levels of CO2, O2 and H+ and provide input to respiratory centre  - are ____ chemoreceptors in medulla oblongata - most sensitive to changes in __ concentration CO2 + H2O ↔ H2CO3 ↔ H+ + HCO3- - an increase in p___ will ↑ H+ - lower pH in medulla will ______ RR

central H+ CO2 increase

C shaped rings prevent _______ of trachea when inspire/expire (due to pressure changes) Trachialis muscle - contracts diameter of trachea to expel air more forcefully Pseudostratified epithelium creates a "____ escalator" - mucous overlies surface of cilia - cilia takes stuff away from lungs and up towards throat

collapsing mucous

Pressure = force per unit area Increase altitude - ______ Atm P Intrapulmonary pressure eventually equalizes with Atm P

decrease

Epiglottis is _____ cartilage - ___ way flap over trachea (exam q) -In males thyroid cartilage thickens due to male hormones in puberty Vocal cords are upper folds of mucous membrane - help close the glottis when swallow True vocal cords - elastic fibers that make sound, lower folds of mucous membrane Vary pitch due to tension on cords and loudness due to amount of air flow over cords

elastic, one

Respiratory system other functions: Produces speech, song Removes some water and heat as you respire First line of defense against inhaled pathogens -Sense of smell in nasal area Conducting part: (Nostrils - bronchioles) Moisten, heat, filters (cleanse) incoming air Respiratory part: (From respiratory bronchioles to alveoli) Only site of ___ _____ Page 801 fig 22.1

gas exchange

Nasal conchae increase surface area and air turbulance Pseudostratified epithelium produced mucous, mucous contains lyzozomes (an antibacterial enzyme) Endothelial cells produce defensin antibodies that destroy bacteria Nasal cavity has sensory endings - irritants trigger a sneeze reflex ___ palate: between oral and nasal cavities (palatine and maxilla) ___ palate: unsupported muscular portion Cleft palate: nasal and mouth cavity do not separate properly Sinuses are spaces in the skull and lighten weight of bone

hard soft

- in lungs, pO2 is ___, O2 loads - in tissues, pO2 is ___, O2 unloads - can unload more O2 as tissue needs change

high low

Inspiration - - diaphragm and external intercostals contract - thoracic cavity _____ in size - lungs ____ - pressure in lungs decreases from ___ to ___ mmHg

increases expand 760 to 758

- inspiratory neurons fire to stimulate contraction of diaphragm and external _____ muscles - expiratory neurons fire and passive relaxation of inspir muscles occurs - inspiration lasts _ secs/expiration _ sec - other neurons modify rhythm by integrating sensory input from _____ receptors and ____-receptors

intercostal 2, 3 stretch, chemo

Intrapleural pressure will increase/decrease as you breathe but it's always less than ________ pressure - it is considered to be negative with respect to intrapulmonary pressure ______ pressure + surface tension of fluids in pleural space hold lungs against thoracic wall If intrapleural pressure = intrapulmonary pressure then the lungs collapse (atelectasis) happens if have chest wound - air enters pleural cavity and alveoli are drawn inward The ____ forces exceed the _____ forces Inward forces: elastic fibers, surface tension of alveolar fluid Outward forces: intrapleural pressure, sticking together of pleurae What happens if have equal pressures - question in lab Know laws for exam - Boyle, Henry If V is halved, increase P by 2X

intrapulmonary intrapleural inward, outward

Surfactant: -Mixture of ____ and ____ (detergent like substance) -Fct: acts to decrease _____ _____ and prevent collapse of alveoli when _____ Molecules of fluid lining alveoli are more attracted to each other than to the molecules of air, which is what produces surface tension When you breathe, you need to overcome surface tension - surfactant decreases hydrogen bonding among water molecules Premature babies - _____ _____ syndrome (lack of surfactant so many alveoli collapse with each breath) - give surfactant spray

lipids, proteins surface tension, exhale respiratory distress

Chemical: one of most important factors that determines respiratory rate Chemoreceptors are in 2 places: 1) Central chemoreceptors in _____ (know this location) - CO2 can readily cross blood brain barrier - CO2 reacts with water in cerebrospinal fluid 2) ____ chemoreceptors in aortic arch and carotid arteries (locale for baroreceptors) (know this location) No buffers in CSF, so any change in H+ will decrease pH So stimulate central chemoreceptors in medulla will increase nerve impulses to resp center - increase resp rate and depth of breathing (Breath faster will decrease CO2 and H2O) Moment to moment control of respiration is via central chemoreceptors & that maintains brain CO2 levels and pH - O2 goes along for ride If ___ levels are too low you get periods of apnea - no respiration If you hyperventilate (breathe fast) before doing something, you lower your CO2 and can not breathe for a longer period (swimmers)

medulla, peripheral CO2

Nose - air enters via nostrils (___) - vestibule area lined with ___ - nasal cavity lined with ____ ____ ______ - roof of cavity contains olfactory _______ - functions of nose include: - warms, moistens, cleanses air - produces _____ - sense of smell

nares skin pseudo stratified epithelium receptors mucous

Pharynx has 3 regions: - _______ - pseudostratified epithelium (air only) - ______ + _________ - stratified squamous epithelium (air + food) Oro and laryngopharynx get wear and tear bc both food and air - therefore have a stratified squamous epithelium to replace cells and protect.

nasopharynx oropharynx and laryngopharynx

Expiration is ______ process - does not take muscle work Forced expiration: use abdominal muscles and internal intercostals

passive

Expiration - - diaphragm and external intercostals ____ - thoracic cavity _____ in size - lungs ____ - pressure in lungs increases from 760 to ___ mmHg

relax decreases recoil 762

Internal (tissue) respiration: Gas exchange between the blood in _____ capillaries and ____ cells Tissue cells are _____ oxygen and are ______ carbon dioxide during _____ ______

systemic, tissue consuming, producing cellular respiration

- mucus-producing cells and cilia are sparse in bronchioles - _____ bronchioles feed into _____ bronchioles which lead into winding ______ ___ - alveolar ducts lead into clusters of many alveoli (alveolar sacs) ~ ___ million alveoli provide a large surface area for gas exchange - surface area is approx 70m2

terminal, respiratory, alveolar ducts 300

Lungs: Paired lungs are located in the ____ cavity (pleural) Each lung is cone-shaped; point up and broad base rests on diaphragm R lung has _ lobes; L lung _ lobes _____ pleura lines the inner surface of the thoracic cavity _____ pleura covers the external surface of each lung Space between is the pleural cavity

thoracic 3, 2 Parietal Visceral

a) Higher brain inputs - cerebral cortex - ____ control eg. limited breath holding, speech - _______ - emotional state b) Pulmonary irritants - presence of dust, smoke, noxious fumes ______ respiration

voluntary hypothalamus decrease