4.Respiratory system Flashcards
How does cilia work
hair like projections (cilia) lines the respiratory tract and traps then moves inhaled foreign particles up and out of the respiratory tract by exhalation as part of the mucocilliary escalator
Function of the respiratory system
provides gas exchange between the blood and external environment, for example oxygen is absorbed form the atmosphere (inhalation) and carbon dioxide is expelled from the body (exhalation)
How is the respiratory tract divided
split into the upper and lower respiratory tract
List components of upper respiratory tract
nose(nostrils), nasal cavity, mouth, oral cavity, pharynx, larynx
List components of lower respiratory tract
trachea, bronchus, bronchioles, alveoli and diaphragm
Describe the structure of the nose
-large irregular cavity
-divided into two equal parts by septum
-is a mucous membrane
-contains sinuses
Function of nose/nasal cavity
Main route of entry for air and hence warms, moistens, and filters air entering the respiratory system
What is the common name for pharynx
throat
Describe the structure of the pharynx
-12 to 14 cm tube
-consists of mucous membrane, submucosa and smooth muscle tissues
-3 parts
Function of pharynx
-provide passageway for food, air
-warm, moistens and protects from infection
-assist with speech and is involved with hearing
Outline 3 parts of pharynx
nasopharynx -superior
oropharynx -middle
laryngeal pharynx -inferior
Describe location of pharynx in relation to larynx
Pharynx is posterior to larynx
*superior also but (only the nasopharynx and oropharnyx)
Structure of larynx
VOICE BOX between the pharynx and trachea
-flexible
-thyroid, cricoid and arytenoid cartilage
Function of larynx
1.Respiratory: To allow air to pass through to the trachea whilst stopping food (bolus) and liquid from entering the respiratory tract
2.Speech: Houses the vocal cords, which manipulate pitch and volume essential for speech
What is Pulmonary aspiration
A condition which food, liquids, saliva or vomit are breathed into the airways
How does the larynx prevent aspiration
1.Larynx lifts up to the level of the epiglottis
2.Epiglottis closes over the opening to the larynx
3.Food boluses pass into the oesophagus
What are the vocal cords
2 layer of smooth muscle in the larynx
How do vocal cords work
They vibrate as air passes through them (exhalation) to produce sound
-length and tension of cords controls pitch
Describe the location of larynx in relation to oesophagus
the larynx is anterior/ventral to the oesophagus
pathway of air in respiratory system
nose (nostrils) or mouth , pharynx, larynx, trachea, bronchus, bronchioles, alveoli
Structure of Trachea
The windpipe that travels to the 5th thoracic vertebra then divides into L/R bronchi
-comprises 3 layers of tissue
Outline the three layers of trachea
Outermost-elastic and fibrous tissue which encloses cartilage
middle-cartilage with bands of smooth muscle
inner-columnar epithelium that is ciliated with mucous secreting cells present
Function of trachea
provide a pathway for air between larynx and bronchus
Structure of bronchi
large airways that branch of trachea
RIGHT BRONCHUS is shorter and wider than left bronchus
Function of bronchi
To provide a pathway for air between trachea and bronchioles
Structure of bronchioles
smaller branches of the bronchi that connect to alveoli
-3 bronchioles (3 lobes) on right side
-2 bronchioles (2 lobes) on left
Function of bronchioles
provides a pathway for air between bronchus and alveoli
Structure of alveoli
-tiny balloon shaped air sacs at end of respiratory tract
-single cell thick and surrounded by capillary network
Function of alveoli
To exchange O2 and CO2 molecules to and from the blood stream as part of pulmonary diffusion
Why are alveoli single cell thick
increase efficiency of diffusion
Why are alveoli surrounded by an extensive capillary network
increase capacity of diffusion
what cavity and membrane are the lungs located
thoracic cavity and pleura (serous) membrane
what cavity and membrane is the heart located in
Mediastinum cavity and pericardial membrane
How many lobes on each lung
3 on R and 2 on L
Structure of lungs
cone shaped, have an apex, base, tip and coastal and medial surface
Function of lungs
provide gas exchange between blood and external environment
Structure of pleura
Thin layer that covers lungs
Visceral and Parietal pleura membrane (PIC & VOO)
What is visceral pleura
covers the lungs and each fissure/lobe
What is parietal pleura
covers inner chest wall of thoracic surface of the diaphragm
Function of pleura
Provides lubrication, reduces friction during the movement of lungs in breathing
Aerobic cellular respiration equation
glucose + oxygen –> carbon dioxide + water + 30-32 ATP
How is gas exchange efficiency increased
thin walls–> reduce diffusion pathway
good blood supply–> maintains concentration gradient
Large SA:V
Moist surfaces–> gasses diffuse in solution
oxygen concentration in lungs during inspiration
high
CO2 concentration in lungs during inspiration
low
oxygen concentration in body tissues during inspiration
low
CO2 concentration in body tissues during inspiration
high
what gas moves into tissues (inspiration)
Oxygen
what gas moves into lugs (inspiration)
CO2
what direction do gases move
from high to low concentration (down a concentration gradient)
Features of inspiration in order
diaphragm contracts and flattens
intercostal muscles contract
ribcage moves up and out
lungs expand
air moves INTO lungs
LOW intrathoracic pressure (increased thoracic volume)
Intrathoracic pressure is the same as
intrapulmonary pressure
Features of expiration in order
Diaphragm relaxes (dome like)
intercostal muscles relax
rib cage moves down and in
lungs relax (tissue recoils)
air pushed OUT of lungs
HIGH intrathoracic pressure (decreased thoracic volume)
shape of diaphragm in inspiration
flattens
shape of diaphragm in expiration
dome like
what controls CO2 levels in body
chemoreceptors
How do chemoreceptors work
If increased CO2 levels, an increase in RR is triggered to blow off extra CO2
and vice versa
Describe COPD
a number of lung diseases that prevent proper breathing
-limitation in airflow into and out of the body
Examples of COPD
emphysema
chronic bronchitis
chronic asthma
briefly describe chronic bronchitis
long term inflammation of airways and mucous hyper secretion
list 5 symptoms of COPD
SOB
wheezing
chest tightness
chronic cough
sputum production (increase)
reduced exercise tolerance
frequent respiratory infections
Whats sputum
saliva and mucous
Briefly describe emphysema
-air becomes trapped in air sacs and bronchioles making breathing difficult
-decreased elasticity of lung tissue
-mucous accumulation
list 4 risk factors of COPD
smoking
air pollution
chemical fumes
dusts
genetics
co morbidities eg asthma
How to maintain a healthy respiratory system
stop smoking –> decreased damage to lung tissue (cancers) increased capacity for respiratory organs to function
regular exercise–> increased capacity of lungs to take in air and increased removal of mucous
Avoid areas of high pollution–> decreased risk of irritating lungs or aggravating other conditions
Wash hands-less likely that pathogens enter respiratory tract
Vitamin rich diet–> increased immunity to protect lungs
Rest and sleep–> time for growth and repair or maintenance of lungs
Briefly describe asthma
-difficulty breathing due to spasm of the bronchial tubes or swelling of mucos membrane lining
List two symptoms of asthma
SOB and wheezing
