Chapter - Respiratory System Flashcards
What is external respiration
Pulmonary respiration
What is the main function of the respiratory system
Supplies body cells with O2 and co2
What is internal respiration
Cellular respiration
What is pulmonary ventilation
Breathing
What is inspiration
Movement of air into lungs
What is expiration
Movement of air out of lungs
What is involved in pulmonary ventilation
- O2 and co2 exchange between lungs and capillaries
- O2 and co2 transported in blood
- O2 and co2 exchange between systemic capillaries and tissues
What is vocalization (phonation)
Vibration of vocal cords stretched across larynx
What is olfaction
Olfactory cells (chemoreceptors) bind molecules; nerve impulses are interpreted as smells by olfactory lobes of brain
What is thermoregulation
Warm air by entering respiratory tract; evaporative cooling at mucosa
What is the acid base balance in blood
Co2 amount dissolved in blood
Which structures are considered part of the upper respiratory tract
Nose, pharynx, larynx, trachea
What are the nares
Nostrils; external openings that lead into nasal passages
What is the nasal septum
Divides left + right side
What are turbinate bones
Increases surface area inside passage divide each passage into three smaller ones ; nasal meatus
What cell type is the nasal passage lined with
Ciliates pseudostratified columnar epithelium
What secrets mucus
Mucosa glands and goblet cells
What is the function of mucus
Warm and humidify and filter air
How does mucus work
Mucus escalator traps debris and moves it cranial u to pharynx to be swallowed
What does inflammation do to cilia
Reduces effectiveness
What are the sinuses
Spaces within skull out pockets of nasal passages. Lining continuous with that of nasal passages.
What are the sinuses named after
They are named after skull bones where they are located
What are the two sinuses
Frontal sinuses and maxillary sinuses
What is sinusitis
Inflammation of sinuses
What is sinusitis in dogs commonly caused by
Carnassial tooth abscesses
What is the pharynx
Common passage for digestive and respiratory tracts -> choking
Where are lymphatic tissues (tonsils) present
In naso and oropharynx
What is the larynx
The voice box. Composed of segments of hyaline cartilage. Supported by hyoid bone
What does the epiglottis cover
Opening to larynx (glottis) while swallowing
What are vocal chords
Connective tissue stretched against the glottis. Sounds produced by differences in tension and vibration
What is laryngeal paralysis in dogs
Inability to abduct vocal folds due to muscle or nerve problem. Either congenital or acquired. But often idiopathic
What are the signs of laryngeal paralysis in dogs
Coughing, distressful noises, exercise intolerance, thermal regulation problems
What is the treatment for laryngeal process and dogs
Surgical tieback of one vocal fold
What is roaring in horses
It is the laryngeal hemiplegia which is a half paralysis. Congenital degeneration of left laryngeal nerve which controls muscles to tighten left arytenoid cartilage
What is the treatment of laryngeal hemiplegia in horses
Surgery
What is the trachea
The windpipe
What is the windpipe composed of
Composed of C shaped rings of hyaline cartilage. C closed dorsally by smooth muscle and lined with ciliated mucosa
What does the trachea divide into
2 bronchi at base of heart which is called bifurcation
What is a tracheal collapse in dogs
Hyaline cartilage rings weaken and then flatten which causes dyspnea
What is ET tube intubation
The insertion of flexible tubes through the glottis and into the trachea. Provides open airway for artificial ventilation or administration of inhalant anesthetics. Reduce his risk of aspiration during anesthesia
Is it possible to intubate cows and horses
No
What is the laryngoscope
Using cats and dogs to visualize the glottis before ET tube insertion
What is special about cats in terms of ET tube intubation
Cats require local anesthetic due to sensitivity of glottis. Reflects causes laryngeal spasms
Describe the train of the lower respiratory tract
Bronchi to bronchioles to alveoli
What are the bronchi similar to in structure
The trachea
Describe bronchioles
No cartilage, fewer goblet cells and cilia
Why is there increased smooth muscle in the lower respiratory tract
Bronchodilation versus bronchoconstriction
What do terminal branches end in
Alveolar ducts
Describe Alveoli
Sacs of simple squamous epithelium. Microscopic, hundreds of millions of alveoli. Surrounded by Capillaries and elastic fibers which are the site of gas exchange. Produce surfactant to reduce the surface tension and pores equalize air pressure in the sacs.
What protects the alveoli from pathogens
Macrophages and antimicrobial proteins
How many layers do gases have to pass through in the Alveoli
2 simple squamous epithelial layers
What is asthma in cats
The lining of the bronchioles become irritated due to allergens cold temperatures and airborne chemicals. Causes increased mucus production and bronchial construction
Describe the symptoms of asthma in cats
Dyspnea cyanosis and wheezing
What is the treatment for asthma in cats
Removal of irritants, anti-inflammatories and bronchodilators
What is asthma in horses
Chronic obstructive respiratory disorder.
What are the signs of asthma in horses
Dyspnea cyanosis coughing mucus production and heave line on ventral surface. Most commonly seen in stabled horses due to increased exposure to dust. Treatment similar to cats
What are the lungs
In the thoracic cavity they surround the heart and the mediastinum.
Where does the base of the lung rest
The diaphragm
Where is the apex of the lungs
The cranial end
What is the Hilium
Concavity on mediastinal surface. It is the site for the entry and exit of blood vessels bronchi lymphatic vessels and nerves
How are the lobes of the lung divided
They’re divided into lobes based on the bronchi. The left has two lobes, the cranial and the caudal. The right has four lobes the cranial, middle, caudal and accessory
What is special about the lobes of the lung in the horse
Horses all have only one lobe per side except for the right side which also has an accessory lobe
Describe an upper respiratory tract infection
Involves infection of nasal passages, pharynx, larynx, trachea. Easier to expel excessive mucus by coughing and sneezing
Describe lower respiratory tract infection
Can be more life-threatening due to difficulty and expelling mucus. Airway obstruction more common
What is bronchitis
Infection of the bronchi epithelia
What is pneumonia
Infection of small bronchioles and alveoli
Prior to birth describe the lungs
Fetal lungs are nonfunctional and filled with amnionic fluid. Tissue consistency is like the liver. Reduced pulmonary circulation
Describe the lungs at birth
Alveoli filled with air in first breaths, spongy consistency. Surfactants produced late in gestation which prevent alveoli from collapsing
What is the pleurae
Thin, double layered serosa of simple squamous epithelium.
Where does the parietal pleura line
Lines thoracic walls, cranial aspect of diaphragm, around the heart and between the lungs
Where does the visceral pleura line
Covers external lungs surface. Plural fluid fills the slit-like pleural cavity which provides lubrication and surface tension which assists in expansion and recoil during breathing.
What is the diaphragm
Flat, dome shaped skeletal muscle which divides the thoracic and abdominal cavities. Attached to ribs and innervated by phrenic nerve.
What does contraction and relaxation of the diaphragm do
Changes the volume of the thorax which affects the pressure which causes ventilation
What is a diaphragmatic hernia
Tear or hole in diaphragm. Abdominal organs enter thorax. Congenital or caused by trauma and fixed by surgery
What is pneumothorax
collapsed lung. Accumulation of air in plural cavity prevents full inflation of lungs. Symptoms are dyspnea, tachypnea, tachycardia
What are the types of pneumothorax
Trumatic versus spontaneous. Open versus closed. Traumatic pneumothorax are usually open whereaa spontaneous are always closed and are usually due to lung disorders
What is pleural effusion
Accumulation of excess fluid in the plural cavity due to production and removal problem.
What are the causes of pleural effusion
Heart worms, liver disease, cardiac failure, cancer, pyothorax
What is the treatment for Pleural effusion
Thoracocentesis. Need to treat underlying problem. Examination of aspirate can help in diagnosis
What is exercised induced pulmonary hemorrhage
Bleeding in lungs. Hemorrhage of pulmonary capillaries. Common to race horses racing caramels, greyhounds and humans. Likely due to high pulmonary blood pressure or pounding on hard racing surfaces. Can affect performance and be fatal
What is epistaxis
Hemorrhage of nasal cavity vessels
What is the treatment for exercised induced pulmonary hemorrhage
Diuretic which reduces blood pressure. Illegal except for use in USA and Canada
What is intrapulmonary pressure
The pressure in alveoli. Which fluctuates with breathing. Eventually equalizes with atmospheric pressure during ventilation
What is intrapleural pressure
Pressure in plural cavity which also fluctuates with breathing. Always negative relative to others
Describe the partial vacuum in the thoracic cavity
Partial vacuum exists in thoracic cavity to keep the lungs inflated and pull out against thoracic wall so intrapulmonary volume fluctuates with thoracic cavity volume. Assists in Venous return of blood to the heart
What are the highs and lows of atmospheric pressure
0 MM HG to 760 MM HG
What are the highs and lows of intrapleural pressure
4 MM HG to 756 MM HG
What are the highs and lows of intrapulmonary pressure
0 MM HG to 760 MM HG
What is inspiration
Inhalation
What is expiration
Exhalation
What are inspiration and expiration considered
Mechanical processes that depend on volume changes in thoracic cavity
What happens when the volume changes in the thoracic cavity
Volume changes cause pressure changes in pressure changes cause gas flow to equalize pressure
What is Boyles law
Pressure and volume are inversely proportional
Describe inhalation
Diaphragm contracts. External intercostal muscles contract. Rib cage elevates. Increased thoracic cavity volume. Increased intrapulmonary volume. Decreased intrapulmonary pressure.
Describe exhalation
Diaphragm relaxes. External intercostal muscles relax and abdominals contract. Rib cage drops. Decrease in thoracic cavity volume. Decrease in intrapulmonary volume. Increase in intrapulmonary pressure.
What is the tidal volume
Volume of air inspired an expired in one breath. Varies with need
What is minute volume
Volume of air inspired and expired in one minute. Needs to match perfusion to alveolar capillaries.
What is perfusion
Blood flow
What is inspiratory reserve volume
Volume of air inspired above that in tidal volume
What is expiratory reserve volume
Volume of air expired above that in tidal volume
What is vital capacity
Tidal volume plus inspiratory reserve volume plus expiratory reserve volume
What is residual volume
Volume of air left after forcing expiration. The amount left in alveoli
What is the total lung capacity
Tidal volume plus inspiratory reserve volume plus expiratory reserve volume plus residual volume
What are the two things that diffusion of gases in Lungs and body tissues involve
Concentration gradients of gases. Physical properties of gases. Moves from high to low concentration
What is partial pressure
Pressure exerted by each gas in the mixture. Directly proportional to its percentage in the mixture
What is the total pressure exerted by mixture of gases
The sum of pressures exerted by each gas
When gas mixture comes in contact with liquid
Each gas dissolves into proportion to its partial pressure. At equilibrium, partial pressures into phases will be equal
What does the amount of gas that will be dissolved dependent on
The molecule. CO2 is 20 times more soluble in water then 02. Little n2 dissolves in water
Increasing pressure does what
Increases solubility
Describe the pressure gradient for 02 in lungs
Steep partial pressure gradient. oxygen diffuses down concentration gradient from alveoli to blood
What is the partial pressure of venous blood
40 mm Hg
What is the partial pressure in the alveolars
104 mm Hg
What happens when equilibrium is reached
No more net diffusion
Describe the partial pressure gradient for CO2 in lungs
Partial pressure gradient less steep. Though gradient is not as steep, CO2 diffuses in equal amounts with oxygen. CO2 is 20 times more soluble in plasma than oxygen.
What is the partial pressure gradient for co2 in venous blood
45 mm Hg
What is the partial pressure for co2 in alveolars
40 mm Hg
What percent of oxygen transport is dissolved in plasma
1.5%
What percent of oxygen transport is carried by hemoglobin in red blood cells
98.5%. Max of four o2 molecules per hemoglobin
What is oxygen saturation dependent on
The pressure of O2, temperatures, blood pH, pressure of CO2 and competing molecules
How is Co2 transported
7-10% in plasma
20% in hemoglobin
70% transported as bicarbonate ions in plasma and in red blood cells cytoplasm
Scribe the influence of CO2 on blood pH
Carbonic acid equals bicarbonate buffer system. Resist change in blood pH. If H+ concentration in blood rises, excess H+ is removed by combining with HC03. If H+ concentration begins to drop, H2CO3 this disassociates releasing H+
Changes in what affect blood pH
Respiratory rate and depth
With slow shallow breaths what happens to the amount of CO2 in blood and the blood pH
Increased concentration of CO2 in blood and decreased blood pH
In rapid deep breath what happens to amount of CO2 in blood and blood pH
Decreased number of CO2 in blood and increased pH
Describe the control of ventilation
Skeletal muscles are used in ventilation but conscious thought not required. Involuntary control can be overridden by voluntary control. Controlled by respiratory center in brainstem (Medulla and pons). Influenced by mechanical factors such as stretch receptors in lungs preventing over inflation.
Chemoreceptors allow for what
Monitoring of O2, CO2 and pH levels and blood
What are the aorta and carotid arteries sensitive to
Hypoxia
What is the medulla oblongata sensitive to
Sensitive to hypercapnia and acidemia. H+ binds to chemo receptors
What are short-term mechanisms to increase oxygenation
Increased respiration rate and depth. Increased heart rate. Increase core body temperature. Splenic contractions
What are long-term mechanisms to increase oxygenation
erythropoiesis
What is hyperventilation
Creased depth and rate of breathing that exceeds bodies need to remove CO2. Decreased blood CO2 levels which cause hypocapnia
What is apnea
Breathing cessation from abnormally low PCO2
