Immunology & Respiratory Flashcards
pharynx:
- aka throat
- 3 regions: nasopharynx, oropharynx, laryngopharynx
nasopharynx region:
- most superior
- posterior to nasal cavity
- extends down to uvula
- passage for air only
- lined with pseudostratified ciliated columnar epithelium
- uvula moves up to close off nasopharynx
oropharynx region:
- posterior to oral cavity
- extends from uvula to epiglottis
- passage for food & air
- lined with stratified squamous epithelium for protection from friction
laryngopharynx region:
- posterior to opening of larynx
- extends from epiglottis to inferior edge of cricoid cartilage
- passage for food & air
- lined with stratified squamous epithelium for protection from friction
- continues inferiorly to become the esophagus
function of uvula:
- moves up to block nasopharynx during swallowing of food
larynx:
- aka voice box
- contains vocal folds that vibrate when speaking or singing
function of epiglottis:
- guards the superior opening of the larynx
- made of elastic cartilage
- closes down during swallowing to block larynx & trachea (so food doesn’t enter here == choking)
function of palate (hard & soft)
- both part of nasal cavity
- hard palate = anterior part; formed by maxillary & palatine bones
- soft palate = posterior part; soft tissue & skeletal muscle; ends @ uvula
hyoid bone:
- attaches structure for tongue & muscles in floor of oral cavity to larynx
- only free floating bone in the body
conducting zone regions:
- external nose & nasal cavity
- pharynx
- larynx
- trachea
- bronchi; bronchioles; terminal bronchioles
conducting zone purpose:
- thick walled passages that serve to:
- conduct air into lungs
- warm & humidify air
- remove dust, allergens, bacteria
- do not permit gas exchange
trachea:
- aka windpipe
- extends from larynx into mediastinum
- anterior to the esophagus
tracheal histology:
- inner lining of tracheal wall = mucosa
- lined with pseudostratified ciliated columnar epithelium mixed with goblet cells
- cilia beat to move mucus up to laryngopharynx to be swallowed
tracheal anatomy:
- outer layer of tracheal wall = an adventitia (tough layer of CT to give structural support
- adventitia encloses 16-20 rings of hyaline cartilage
- these rings are C shaped & open toward esophagus (posterior part of trachea)
- this allows the esophagus to expand during swallowing & peristalsis
bronchi:
- trachea extends inferiorly to divide into L&R primary bronchi (last section to contain this much cartilage (rings))
- right primary bronchi is wider & more vertical than left
- primary bronchi divide to become secondary (lobar) & tertiary (segmental) bronchi
bronchioles:
- smallest passages of conducting zone = terminal bronchioles still no gas exchange here
- contains smooth muscle layer
- site of control of air flow into alveoli
- bronchoconstriction/bronchodilation
cilia function:
- propel mucus to throat to be swallowed
- mucociliary escalator
- cleanses air before it reaches lungs
pulmonary ventilation:
- aka breathing
1. inspiration = gases flow into lungs (breathe in)
2. expiration = gases flow out of lungs (breathe out)
alveoli:
- site of gas exchange (gas-filled air space)
- 300 million alveoli per lung = large surface area
-intrapulmonary pressure changes with breathing - respiratory membrane = fused basement membranes of alveolus & capillary endothelium (alveolar epithelium)
vibrissae function:
- hair that blocks insects & debris from entering body openings (such as nose & ears)
gross anatomy of R&L lungs:
- right lung = shorter because liver rises higher on the right
- left lung = taller & narrower because of the tilt of the hear (cardiac notch)
alveoli cells:
- squamous (type I) alveolar cells = 95% of alveolar tissue
- cuboidal great (type II) alveolar cells = 5% of alveolar tissue; function to:
- repair alveolar epithelium when squamous cells are damaged
- secrete pulmonary surfactant (oily phospholipids & proteins that coat alveoli & smallest bronchioles, preventing them from collapsing during exhalation)
inspiration pressure relations:
- intrapulmonary pressure < atmospheric pressure
- lung volume increases = pressure inside lungs decreases
- pleural cavity pressure = more negative
inspiration steps in order:
- inspiratory muscles contract (diaphragm descends; rib cage rises)
- thoracic cavity volume increases
- lungs are stretched; lung volume increases
- intrapulmonary pressure decreases
- air flows into lungs
tension pneumothorax:
- punctured parietal pleura
- leads to ruptured visceral pleura
- causes air in pleural cavity (intrapleural pressure) to = atmospheric pressure
- results in collapsed lung
gas exchange:
- respiratory zone = site of gas exchange; allows O2 to enter blood & CO2 to leave blood & enter lungs
- pulmonary capillaries pick up O2 & unload CO2
Ohm’s Law:
- pressure & flow relation
- change in pressure = flow x resistance
- flow occurs passively from high to low pressure
nasal conchae:
- aka turbinates
- serve to create turbulence as air is directed into respiratory tract
- humidifies the air
- provides larger respiratory surface area
- 3 pairs of conchae (superior, middle, inferior)
- superior & middle conchae = features of ethmoid bone
- inferior conchae = feature of separate facial bone
external nose:
- begins @ vestibule just inside nostril
- lined with stratified squamous epithelium
- has vibrissae (hair) for protection
- made of hyaline cartilage
asthma:
- acute bronchial smooth muscle contraction (bronchoconstriction)
- narrows the airways in response to exposure to allergens or irritants
- causes dyspnea (tightening of chest & shortness of breath)
- treated/relieved w/ bronchodilators (relax muscle bands) also help clear mucus
principle respiratory muscles:
- contraction of breathing muscles = thoracic cavity changes volume
1. diaphragm
2. external intercostals
accessory respiratory muscles:
- sternocleidomastoid & scalene muscles
- erector spinae
- abdominal muscles
- pectoralis major & minor
- serratus anterior
pulmonary surfactant:
- secreted by cuboidal great (type II) alveolar cells
- oily secretion of phospholipids & proteins that coats alveoli & smallest bronchioles, preventing them from collapsing during exhalation
innate immunity:
- nonspecific defenses
- ready to defend against all foreign substances immediately
- 1st –> 2nd line of defense
- mucus membranes, skin, acidic environment, fluid dilution
- 2nd line: phagocytes, NK cells, inflammation, antimicrobial proteins, fever
dendritic cells:
- APCs = antigen-presenting cells
- patrol skin & mucus membranes
- long wispy extensions capture & phagocytize Ags = then carry them to lymph nodes
- present Ags to T cells
- CD4 cell gives T cells to “go ahead”
memory cells:
- produced by B cells = many give lifetime immunity
- occurs in active humoral immunity
arrival of white cells to injury cite:
- inflammation = phagocyte mobilization
1. leukocytosis: neutrophils enter blood from bone marrow
2. Margination: neutrophils cling to capillary wall
3. diapedesis: neutrophils flatten & squeeze out of capillaries
4. chemotaxis: neutrophils follow a chemical trail to injury site
plasma cells role in immunity:
- antibodies are proteins made by effector B cells (plasma cells)
- Abs don’t destroy invaders, they form complexes for destruction:
1. neutralization = coat a toxin/virus to prevent it from entering body cells
2. agglutination = complex w proteins on cell surfaces; cells clump
3. precipitation = Abs complex w soluble Ags; cause them to precipitate
Lines of defense:
- 1st = innate, nonspecific, immediate
- 2nd = internal, phagocytes, NK cells, inflammation, antimicrobial proteins, fever, immediate
- 3rd = adaptive; specific; includes: humoral (B cells) & cellular (T cells) immunity; memory created, slower response
memory cells:
- part of adaptive defense
- humoral (antibody-mediated) immunity
- cellular (cell-mediated) immunity
self-antigens: MHC proteins
- MHC = major histocompatibility complex
- these proteins are located on cell surface
- function to ID body cells as “self” so lymphocytes don’t attack them
- MHC proteins become altered when body cells are infected/cancerous
- T lymphocytes will attack any body cells with MHC on them
immunocompetence:
- lymphocytes develop unique receptors on their cell surface = enable them to recognize & bind specific Ag without ever having met the Ag first
clonal selection & differentiation of B cells:
- Ag triggers innate defenses (surface/internal)
- free Ags activate B cells
- clone & give rise to memory B cells
- plasma cells (effector B cells)
- antibodies produced
exudate:
- leaked fluid, rich in proteins & clotting factors & antibodies
- brings O2 & nutrients to damaged tissue
- exudate in interstitial fluid is picked up by lymphatic capillaries; cleansed by passing thru lymph nodes
hyperemia:
- excess amt of blood in vessels that supply specific organs
- ex: more blood in muscles after exercise, more blood in digestive system after a meal
humoral immunity:
- acquired in several ways, all involve circulating antibodies
- active: make own Abs & memory cells = natural (sickness then making antibodies & memory B cells) & artificial (vaccination)
- passive: receive Abs from outside source = natural (Abs pass from mother to fetus) & artificial (Abs in gamma globulin injection from donor)
HIV & AIDS:
- HIV = virus infects & depletes helper T cells (CD4)
- body may initiate immune responses, but without helper T cells = not enough activated B cells & cytotoxic T cells to give full response
- as T cell count drops (<200) = AIDS (acquired immune deficiency)
mechanism for cell killing by cytotoxic T cells (aka CD8) (NK cells)
- Ag recognition
- Ag binding
- perforin release
- cell perforation
- granzyme release
- apoptosis
humoral immunity primary & secondary responses:
- primary = initial encounter with antigen; Abs produced
- secondary = challenge by same antigen results in faster & stronger response; many more Ab molecules; boosters, vaccinations, next meet w Ag
MAC proteins:
- membrane attack complex
- mechanism of cell killing by cytotoxic T cells