Biology Ch 6. The Respiratory System Flashcards
Breathing in path
Air is drawn in through the nares, then the nasal cavity and pharynx, where it is warmed and humidified, then it is filtered by vibrissae and mucous membranes, then it enters the larynx, then trachea, the trachea divides into the two mainstream bronchi, which divide into bronchioles, which divide until they reach the alveoli
Nares
External feature on the nose where air is breathed in through
Pharynx
Resides behind the nasal cavity at the back of the mouth, common pathway for both air and food
Vibrissae
Nasal hairs used for filtration
Larynx
Lies below the pharynx, air pathway only, opening is the glottis, covered by the epiglottis during swallowing
Trachea
Cartilaginous structure that divides into bronchi, contains ciliated epithelial cells for further filtration
Bronchi
The two major divisions of the trachea, contains ciliated epithelial cells for further filtration
Bronchioles
Further division of bronchi, within the lungs
Alveoli
Small sacs that interface with the pulmonary capillaries, allowing gases to diffuse across a one-cell-thick membrane, coated with surfactant, branching and size of alveoli allows for exchange surface area of 100m^2
Surfactant
In the alveoli, a deterrent that reduces surface tension at the liquid-gas interface, preventing collapse
Pleura
Covers the lungs and lines the chest wall, includes the visceral pleura, parietal pleura, and the intrapleural space between them
Visceral pleura
Lies adjacent to the lung itself
Pariental pleura
Lines the chest wall
Intrapleural space
Lies between these two layers and contains a thin layer of fluid that lubricates the two pleural surfaces
Diaphragm
A thin skeletal muscle that helps to create the pressure differential required for breathing, divides the thoracic cavity from the abdominal cavity, under somatic control
Inhalation
An active process, diaphragm and the external intercostal muscles expand the thoracic cavity, this increases the volume of the intrapleural space, decreasing intrapleural pressure, this pressure difference expands the lungs, drops the pressure from within, and draws air in from the environment, mechanism termed negative-pressure breathing
Exhalation
Can be passive or active
Passive exhalation
Relaxation of the muscles of inspiration and elastic reveal of the lungs allow the chest cavity to decrease in volume, reversing the pressure differentials seen in inhalation
Active exhalation
The internal intercostal muscles and abdominal muscles can be used to forcible decrease the volume of the thoracic cavity, pushing out air
Spirometer
Can be used to measure lung capacities and volumes
Total lung capacity
TLC - maximum volume of air in the lungs when one inhales completely
Residual volume
RV - volume of the air remaining in the lungs when one exhales compeltely
Vital capacity
VC - the difference between the minimum and maximum volume of air in the lungs
Tidal volume
TV - the volume of air inhaled or exhaled in a normal breath
Expiratory reserve volume
ERV - the volume of additional air that can be forcible exhaled after a normal exhalation
Inspiratory reserve volume
IRV - the volume of addition air that can be forcibly inhaled after a normal inhalation
Ventilation center
A collection of neurons in the medulla oblongata that regulates ventilation, uses chemoreceptors for CO2, increases respiratory rate if low blood oxygen concentration, can be consciously controlled through the cerebrum, although the medulla oblongata will override during extended periods of hypo- or hyper- ventilation
Chemoreceptors
Detect carbon dioxide and oxygen concentrations, increasing the respiratory rate when there’s a high concentration of carbon dioxide in the blood (hypercarbia or hypercapnia) or low oxygen (hypoxemia)
Hypercarbia/hypercapnia
High carbon dioxide concentration in the blood
Lung gas exchange
Occurs via simple diffusion across concentration gradients due to differences in partial pressure of oxygen, deoxygenated blood with a high carbon dioxide concentration is brought to the lungs via the pulmonary arteries, and oxygenated blood to the low carbon dioxide concentration leaves the lungs to be the pulmonary veins
Pulmonary arteries
Bring deoxygenated blood to the lungs
Pulmonary veins
Bring oxygenated blood away from the lungs
Vasodilation and vasoconstriction
Alters the capillary beds to assist in thermoregulation, constriction conserves more energy, dilation causes more energy to be dissipated
Respiratory system filters
Vibrissae, mucous membranes, mucociliary escalator, help filter the incoming air and trap particulate matter
Mucociliary escalator
The mechanism where cilia lining the internal airways propel mucus with trapped particulate matter up the respiratory tract to the oral cavity where it can be expelled or swallowed
Lysozyme respiratory system
Type of enzyme present within the nasal cavity (also in tears and saliva), attacks peptidoglycan cell walls of gram-positive bacteria
Macrophages respiratory system
Can engulf and digest pathogens and signal to the rest of the immune system that there is an invader
Mucosal surfaces respiratory system
Covered in IgA antibodies
Mast cells respiratory system
Have antibodies on their surface that when triggers can promote the release of inflammatory chemicals, often involved in allergic reactions also
Respiratory system and pH controls
When blood pH decreases, respiratory rate increases to compensate by blowing off carbon dioxide, this causes a left shift in the buffer equation reducing hydrogen ion concentration
When blood pH increases, respiratory rate decreases to compensate by trapping carbon dioxide, this causes a right shift in the buffer equation increasing hydrogen ion concentration
External intercostal muscles
One of the layers of muscles between the ribs, helps expend the thoracic cavity along with the diaphragm
Intrathoracic volume
The volume of the chest cavity
Internal intercostal muscles
Can speed up the exhalation process during active processes by actively decreasing the volume of the thoracic cavity
Hypoexemia
Low oxygen concentration in the blood, detected by chemoreceptors
Bicarbonate buffer system equation
CO2(g) + H2) (l) = H2CO3 (aq) = H+ (aq) + HCO3- (aq)
Acidemia
Blood too acidic, pH lower, hydrogen ion concentration higher
Alkalemia
Blood too basic, pH higher, hydrogen ion concentration lower
