AP3 Final Study Guide Flashcards
Name the organs of the respiratory system. (upper & lower)
The Upper Respiratory System
- Nose,
- nasal cavity,
- pharynx, and associated structures
Lower Respiratory System
- Larynx,
- Trachea,
- Bronchi, and
- lungs
What are the conductive and respiratory zones?
Name the organs of each zone
Conducting Zone
- Series of interconnecting Cavities whose function is to filter, warm, and moisten air and conduct it into the lungs
- Nose, Nasal Cavity, Pharynx, Larynx ,Trachea, Bronchi, Bronchioles Terminal Bronchioles
Respiratory Zone
- Consists of tubes and tissues within the lungs where gas exchange occurs between the air and blood
- Respiratory Bronchioles, Alveolar Ducts, Alveolar Sacs, Alveoli
What are the bones forming the bony framework of the nose?
Name the cartilages of the nose?
What are the bones forming the nasal septum?
- The bony framework of the nose is formed by the frontal bone, nasal bones, and maxilla
- The cartilaginous framework consists of:
- septal cartilage
- lateral nasal cartilages
- alar cartilages
- Septum made up of cartilage and bones: vomer, ethmoid, maxilla, palatine
Define external nares and internal nares (Choanae).
- External Nares – Nostrils that open into the nose
- Internal Nares – Posterior opening of the nasal cavity, communication with the Pharynx
Name the paranasal sinuses.
What are the locations and functions of paranasal sinuses?
Paranasal sinuses are found in ethmoid, sphenoid, frontal & maxillary
Function is to lighten skull & resonate voice - they are also produce and are lined with mucus that is continuous with the mucus of the nasal cavity
What are the functions of nasal cavity?
- Warming, moistening, filtering
- Detect olfactory Stimuli
- Speech vibration, Resonance
Define conchae and meatuses. What are their functions?
Conchae - bony swellings
Meatuses - gaps between them
Increase surface area and prevents dehydration (keep air moist and warm)
What are the functions performed by the pharynx?
Passageway for food, water, air
What are the anatomic extensions of pharynx?
Nasopharynx - from choanae to soft palate
Oropharynx - from soft palate to Hyoid Bone
Laryngopharynx - from Hyoid to Cricoid cartilage of Larynx
What are the three regions of pharynx? What are the structures and openings related to each region?
Nasopharynx -
- Two choanae (internal nares) to soft palate
- Two openings of auditory (Eustachian) tubes) from middle ear that equalizes air pressure
- Opening into the oropharynx
- Posterior wall contains adenoids (aka pharyngeal tonsil)
- Passageway for air only
Oropharynx
- Extends from soft palate to the level of the Hyoid bone
- Fauces is the opening from mouth into oropharynx
- Palatine tonsils found in the side walls, lingual tonsil in the tongue
- Common passageway for food and air
Laryngopharynx
- Begins at the level of the Hyoid bone down to the cricoid cartilage
- Inferior end opens into esophagus posteriorly and larynx anteriorly
- Common passageway for food and air
Define larynx. What are the cartilages of the larynx? What are the locations of each cartilage?
Larynx aka Voice Box — Short passageway that connects the laryngopharynx with the trachea
9 Cartilages
- Epiglottis
- Thyroid Cartilage
- Cricoid Cartilage
Pairs:
- Arytenoid – most important because they influence changes in position and tension of the vocal folds (true vocal cords for speech)
- Cuneiform
- Corniculate Cartilages
What is the function of epiglottis?
Leaf like cartilage - Prevents food from entering the Larynx
What are the two pairs of vocal folds? What are the names of the spaces between each of them?
Ventricular folds or vestibular folds - Superior, aka false vocal cords
- It consists of vestibular ligament covered by mucous membrane
- Function in holding breath against pressure in thoracic cavity
- The space between the ventricular folds is called rima vestibuli
Vocal folds (true vocal cords) - Inferior, which produce sound.
- It consists of vocal ligament covered by mucous membrane
- The space between the vocal folds is called rima glottidis
To which cartilage, the true vocal cords are attached?
True vocal cords attach to arytenoid cartilages
What is the mechanism of voice production? What are the organs involved in speech production?
- Deep to the mucosa of vocal folds are bands of elastic ligaments (vocal ligament) stretched between the rigid cartilages of the larynx like the strings of a guitar.
- Intrinsic laryngeal muscles attach to both the rigid cartilages and the vocal folds
- When the laryngeal muscles contract, they move the cartilages which pulls the elastic ligaments tight, and this stretches the vocal folds out into the airways so that rima glottidis is narrowed
- Contraction and relaxation of muscles varies the tension in the vocal folds, much like loosening and tightening a guitar string.
- Air passing through the larynx vibrates the folds and produce sound.
What is the difference between male and female vocal folds?
The longer & thicker vocal cord in male produces a lower pitch of sound – Androgens make vocal folds thicker and longer causing slower vibration and lower pitch in males.
How the pitch of the sound is controlled? What are the other structures which modify the sound and how?
- The variation in the pitch of the sound is related to the tension in the vocal folds
- The tighter the folds, the higher is the pitch because the folds vibrate more rapidly.
- Relaxed vocal folds produce low pitches because the folds vibrate more slowly
- Other structures which modify the sound are – Pharynx, mouth, nasal cavity and paranasal sinuses – They all act as resonating chambers that give the voice its individual quality
- Vowel sounds are produced by the constriction and relaxation of muscles in the wall of the pharynx
- Muscles of the face, tongue and lips help enunciate words
Which organs are involved during whispering?
Whispering is forcing air through almost closed rima glottidis – oral cavity alone forms speech
How the trachea is made up of? What are the relations and extensions of trachea with vertebrae and esophagus?
Trachea - aka windpipe
16-20 C-shaped Cartilage Rings,
Smooth Muscle,
and pseudostratified ciliated columnar Epithelial Cells
The C-shaped rings allow for the esophogus to expand
What is carina? Name the generations of divisions of bronchial tree.
The point where the trachea divides into right and left primary bronchi is a ridge called carina
- Right Left Main/Primary Bronchi,
- Secondary/Lobar bronchi,
- Tertiary/Segmental bronchi,
- Bronchioles,
- Terminal Bronchioles
What is the difference in the structural component of bronchi and bronchioles?
Walls of bronchi contain rings of cartilage.
Walls of bronchioles contain smooth muscle
Why aspiration is more likely in the right primary bronchus?
Right primary bronchus is more vertical, shorter, and wider than the left.
Aspirated object is more likely to enter in the right than the left primary bronchus
What parts of the respiratory system are supplied by the primary, secondary, and tertiary bronchi?
- Primary bronchi supply each lung
- Secondary bronchi supply each lobe of the lungs (3 right + 2 left)
- Tertiary bronchi supply each bronchopulmonary segment
Name the pleural membranes. What is the location and attachment of each layer?
Visceral Pleura - is the inner layer, covering the lungs themselves
Parietal Pleura - is the outer layer which is attached to the wall of the thoracic cavity
Define pleural cavity. What is its content and functions?
Pleural cavity is potential space between ribs & lungs - Protects & lubricating fluid secreted by the membranes.
What is pneumothorax?
Pneumothorax •
Pleural cavities are sealed cavities not open to the outside
Injuries to the chest wall that let air enter the intrapleural space – causes a pneumothorax
What are the anatomic extensions of the lungs?
What are the fissures and lobes in the two lungs? Define cardiac notch.
Base, an apex (cupula), a costal surface, and a mediastinal surface
Right Lung (thicker, broader, shorter): Lobes Superior, Middle, Inferior Horizontal Fissure, Oblique Fissure
Left Lung (smaller): Lobes Superior, Inferior Oblique Fissure only
Cardiac Notch - medial left lung where the heart sits
What are the parts of the lungs? What are the locations and relations of each part?
- The apex lies superior to the medial third of the clavicle
- The anterior, posterior and lateral surfaces lie against the ribs
- The base extends from the sixth costal cartilage anteriorly to the spinous process of the 10th thoracic vertebra posteriorly
- The pleura extends about 5 cm below the base from the 6th costal cartilage anteriorly to the 12th ribs posteriorly.
- Surface of each lung has a hilum (Bronchi, Pulmonary blood vessels, Lymphatic vessels, Nerves) — These structures constitute the root of lungs
Define hilum of the lung. What are the structures passing through the hilum?
Indentation through which the following structures enter and exit being held together by pleura and connective tissue
- The bronchi
- Pulmonary blood vessels
- Lymphatic vessels
- Nerves
Define alveolus. What are the names and functions of the three cell types in alveoli? Name the layers of respiratory membranes.
An alveolus is a cup-shaped outpouching lined by simple squamous epithelium and supported by a thin elastic basement membrane
- Type I alveolar cells - simple squamous cells where gas exchange occurs
- Type II alveolar cells (septal cells) - free surface has microvilli Secrete alveolar fluid containing surfactant, keeps the alveolar cells moist
- Alveolar macrophages (dust cells) – Phagocytes that remove debris from alveolar spaces
What is the double blood supply to the lung?
Lungs receive blood supply from pulmonary arteries and bronchial arteries
- Deoxygenated from Pulmonary Arteries
- Oxygenated from the Aorta to the tissues
What is ventilation perfusion coupling?
A unique feature of pulmonary blood vessels is their constriction in response to low O2 levels thereby diverting pulmonary blood from poorly-ventilated areas of the lungs to well-ventilated regions.
aka: When there is more air, more blood will go there
What are the three basic steps of respiration? Define each step.
Pulmonary ventilation — (breathing) is the inhalation and exhalation of air between the atmosphere and the alveoli of the lungs
External respiration — exchange of gases between alveoli of the lungs and the blood in the pulmonary capillaries
Internal respiration — exchange of gases between blood in systemic capillaries & tissue cells
Describe the mechanism of breathing in relation to pressure changes in the intrapleural and alveolar spaces. Know the pressures of each area in different steps.
When alveolar (intropulmonic) pressure drops below atmospheric pressure (from 760 mm Hg to 758 mm Hg) air moves into the lungs.
Contraction of the diaphragm and external intercostal muscles increases the size of the thorax, thus decreasing the intrapleural (intrathoracic) pressure so that the lungs expand.
Expansion of the lungs decreases alveolar pressure so that air moves along the pressure gradient from the atmosphere into the lungs.
Which pressure is always negative and how does it help?
Intrapleural Pressures - Always ~ -4mmHg at rest
Helps keep parietal & visceral pleura stick together
What is the function of the surfactant? What are the cause and effects of its absence?
Surfactant lowers the surface tension of alveolar fluid, preventing the collapse of alveoli with each expiration (Produced by Type II Avelolar cells).
The surfactant is a mixture of phospholipids and lipoproteins
A deficiency of surfactant in premature babies causes respiratory distress syndrome, in which many alveoli collapse at the end of each exhalation
What are the muscles of inspiration and which one is most important? What are the accessory muscles of both inspiration and expiration?
Diaphragm and external intercostal muscles (Internal intercostal, expiration)
Accessory Muscles: Scalenes, Serratus Posterior Superior / Anterior, Latissimus dorsi, Pec Major/Minor, SCM
What muscle activity causes expiration? What are the two forces that contribute to the elastic recoil of the lungs during expiration?
Relaxation of the diaphragm and external intercostal muscles results in elastic recoil of the chest wall and lungs, which increases intrapleural pressure
Two forces contribute to the elastic recoil –
- recoil of elastic fibers that were stretched during inhalation
- inward pull of surface tension due to the film of alveolar fluid.
What is Anatomical dead space?
Anatomic dead space is the total volume of the conducting airways from the nose or mouth down to the level of the terminal bronchioles, and is about 150 ml on the average in humans. (Not participating in the exchange of gases)
Define the following Lung volumes and capacities (TV, RV, VC, IRV, FEV1) and normal values of each.
Tidal volume (TV) = amount of air inhaled and exhaled during quiet breathing; 500ml
Residual volume (RV) = the amount of air remaining in the lungs after forceful expiration; 1200 mL in males and 1100 ml in females
Vital capacity (VC)= the amount of air that can be forcefully exhaled after taking a forceful inspiration; sum of IRV, TV, and ERV; 4800 in males and 3100 in females
Inspiratory reserve volume (IRV)= amount of air you can breathe in forcibly above tidal volume; 3100 ml in males and 1900 ml in females
FEV1 - Forced expiratory volume in one second. Normal FEV1 is 3.8 L in males, and 2.8 L in females. Typically, Asthma and COPD greatly reduces FEV1 because COPD increases airway resistance
What is spirometer?
The apparatus commonly used to measure the volume of air exchanged during breathing is called spirometer
What are the factors on which the gaseous exchanges depend? Explain each.
- Partial pressure difference of gases; the rate of diffusion is faster when the pp difference is larger and vise versa
- Surface area available for gas exchange; emphysema reduces the surface area thereby slowing the pulmonary gas exchange
- Diffusion distance; pulmonary edema increases diffusion distance – size of the respiratory membrane
- Molecular weight and solubility of the gases; O2 has a lower molecular weight than CO2; solubility of CO2 is 24 times greater than that of O2; Taking both these factors into account, net outward CO2 diffusion occurs 20 times more rapidly than net O2 diffusion
In which forms oxygen is transported in the blood? Know the percentage in each form
- Dissolved in Plasma - 1.5% (Only dissolved portion can go to the tissue)
- Oxyhemoglobin (Carried by RBC) - 98.5%. (Reserve of oxygen)
What are the factors that affect the affinity of hemoglobin for oxygen? What are the effects of pH, temperature, pCO2 and type of hemoglobin on hemoglobin affinity for oxygen?
- PO2 (Partial Pressure of oxygen)
- pH - Right shift, a decrease in pH lowers the affinity, more O2 released (PCO2 increases acidity, lowers affinity)
- Temperature - Higher heat, lower affinity, more O2 released
- BPG - BPG decreases affinity
- Type of Hb - Fetal has a higher affinity because its structure binds BPG less strongly. BPG decreases affinity
What is Bohr effect?
As blood flows from the lungs toward the tissues, the increasing acidity (pH decreases) shifts the O2–Hb saturation curve “to the right”, enhancing unloading of O2 (which is just what we want to happen). This is called the Bohr effect.
How does carbon monoxide cause poisoning and what is its affinity to hemoglobin as compared to oxygen and carbon dioxide?
Strong attraction of carbon monoxide (CO) to hemoglobin, even small concentrations of CO will reduce the oxygen carrying capacity leading to hypoxia and carbon monoxide poisoning. It is treated by administering pure O2.
200x the affinity
In which forms carbon dioxide is transported in the blood? Know the percentage in each form.
- Dissolved CO2 in plasma (7%)
- Combined with the globin part of Hb molecule forming carbaminohemoglobin (23%)
- Bicarbonate ions (70%).
Name the respiratory centers with locations.
3 groups of neurons –
- medullary rhythmicity area - medulla oblongota
- pneumotaxic area - Pons
- apneustic area - Pons
What are the neurons and groups of the Medullary Rhythmicity area?
Medullary (Rythmicity Area) - basic rhythm of respiration
- Dorsal Respiratory Group - DRG, impulses to the diaphram via the Phrnic nerve and Intercostal Nerves
- Ventral Respiratory Group VRG - Rhythm generator similar to, and likely communicating with pacemaker cells, activated in forceful breathing sending signals to accessory muscles
What are the neurons and groups of Pontine area
- (PRG) Pneumotaxic, Apneustic - Modifies the rhythm by VRG for excercising, sleeping, speaking etc
- The pneumotaxic area and the apneustic area in the pons help coordinate the transition between inspiration and expiration.
- Apneustic area - sends stimulatory impulses to the inspiratory area that activate it and prolong inspiration, inhibiting expiration. This results in a long, deep inhalation
How do the cortical influences control the respiratory center?
Voluntary influence - allow the concious control of repsiration that may be needed to avoid inhaling noxious gases or water
What are the two groups of chemoreceptors? How does each group control the respiratory center? What are the nerves involved?
- Sensors - Central and Periphereal
- Central Chemoreceptors - medulla oblongata, central nervous system, respond to changes in H+ concentration (or PCO2) in cerebrospinal fluid
- Peripheral Chemoreceptors - aortic bodies and carotid bodies, sense changes in PO2, H+, and PCO2 in Blood, Aorta - Vagus Nerve, Carotid - Glossopharyngeal nerve
What is the effect of increased pCO2 (increase H+) and decreased pCO2 on respiratory rate?
- An increase in pCO2 (hypercapnia) will stimulate the DRG - increase the respiratory rate (hyperventilation, rapid and deep breathing, occurs. This allows the inhalation of more O2 and exhalation of more CO2, until pCO2 and H+ are lowered to normal.)
- Decrease in PCO2 (hypocapnia) will decrease the respiratory rate until CO2 accumulates
How the proprioceptors of joints and muscles influence the respiratory rate?
Monitor movement of joints, nerve impulses stimulate DRC and increases breathing
What is Hering-Breuer reflex? What is its function?
The inflation (Hering-Breuer) reflex detects lung expansion with stretch receptors and limits it depending on ventilatory need and prevention of damage. (Breathing then resumes back to normal)
What are the other influences on the respiratory rate?
blood pressure, temperature, pain, stretching the anal sphincter, and irritation to the respiratory mucosa.
Define hypoxia. What are its types? What are the causes of each?
Hypoxia refers to oxygen deficiency at the tissue level and is classified in several ways
Hypoxic hypoxia - low PO2 in arterial blood (high altitude, airway obstruction, fluid in lungs).
Anemic hypoxia,- too little functioning hemoglobin in the blood (hemorrhage, anemia, carbon monoxide poisoning). –
Stagnant hypoxia -inability of blood to carry oxygen to tissues fast enough to sustain their needs (heart failure, circulatory shock).
Histotoxic hypoxia- blood delivers adequate oxygen to the tissues, but the tissues are unable to use it properly (cyanide poisoning).
What are the organs and functions of the lymphatic system?
Organs:
Thymus, Spleen, Lymph (Vessels, Notes, Fluid), Red Bone Marrow (And more)
Functions:
- Drain excess interstitial fluid from tissue spaces and return to the blood
- Transport dietary lipids and lipid-soluble vitamins absorbed by GI tract
- Carry our immune responses against particular microbes or abnormal cells
What are the features of lymphatic vessels? What are the features of lymphatic capillaries?
Lymphatic vessels -
- Closed at one end, like veins but thinner with more valves
Lymphatic Capillaries -
- Allow lymph fluid to flow in but not out, slightly larger than blood capillaries, have anchoring filaments to stretch when fluid accumulates
What is chyle? Why its color is creamy-white?
Chyle is lymph with lipids that drains from the small intestines specialized capillaries called Lacteals; Lipids cause its color to be creamy-white
What are the five main lymph trunks and two main lymph channels?
Trunks:
- Lumbar,
- Intestinal,
- Broncomediastinal,
- Subclavian and
- Jugular
Channels:
- Thoracic Duct,
- Right Lymphatic Duct
How is thoracic duct formed? From which area and to which vessel does the thoracic duct drain lymph? From which area and to which vessel does the right lymphatic duct drain lymph?
The thoracic duct is formed beginning at the dilation called the Cisterna Chyli
Thoracic duct
- receives lymph from: left side of the head, neck, and chest, the left upper extremity, and the entire body below the ribs.
- It drains lymph into venous blood at the junction of the left internal jugular and left subclavian veins
The right lymphatic duct
- drains lymph from the upper right side of the body.
- It drains lymph into venous blood at the junction of the right internal jugular and right subclavian veins.
What are the primary lymphatic organs? What is their major function?
Primary Organs: Red Bone Marrow and Thymus
Sites where stem cells divide and become immunocompetent, capable of mounting an immune response
What is the location of the thymus? What are the component cells in outer cortex and inner medulla of the thymus?
The Thymus is located in the mediastinum between the sternum and the aorta
Component Cells of the Outer Cortex and Inner Medulla:
- Large number of T Cells
- Dendritic Cells
- Epithelial Cell
- Macrophages
Where and how self recognition and self tolerance of T cell happen?
In the Thymus is where the T Cells under go self recognition (OC) and self tolerance (IM) but only 2% survive
Immature T Cells migrate to Thymus, specialized epithelial cells educate for self-recognition through positive selection, specialized epithelial cells produce thymic hormones (Positive and Negative Selection)
What are the component parts of a lymph node? What are the functions of a lymph node?
Stroma - The Connective Parts
Parenchyma - Outer/Inner Cortex, Deep Medulla
Function as a filter Macrophages destroy foreign substances by phagocytosis Lymphocytes destroy foreign substances by immune responses
(double check this)
What are the component structures and cells in the outer cortex, inner cortex, and medulla of a lymph node?
- Outer Cortex - Groups of B cells called lymphatic nodules (follicles)
- Inner Cortex - T Cells and Dendritic Cells
- Inner Medulla - B cells, antibody-producing plasma cells from cortex, and macrophages
How the lymph flows through the lymph nodes?
Afferent Lymphatic Vessel -> directs lymph inward Subcapsular Sinus -> sinus / irregular channels Trabecular Sinus -> Medullary Sinus -> Efferent Lymphatic Vessel -> Conveys lymph antibodies, and activated T cells out of the node
