Ma2 - Ma Of Lower Respiratory System

Front 1

The air carrying passages can be divided into two portions

Back 1

conducting and respiratory portions

Front 2

The conducting portions/airways - alveoli? lead where, located where, include what organs

Back 2

-Without Alveoli
-The conducting portions are those air passages that lead to the respiratory portions.
-These portions are located inside and outside the lung and also include nasal cavities, nasopharynx and oropharynx, larynx, trachea, bronchi, bronchioles

Front 3

Respiratory portions - Alveoli?, what takes place here, found where

Back 3

-Gas exchange takes place here
-With Alveoli
-Found in respiratory bronchioles, alveolar ducts, alveolar sacs, alveoli

Front 4

Tracheal Microscopic Anatomy - what type of epithelium, what type of BM, other cells/glands found here, cartilage (function), muscle, CT, mesothelium

Back 4

-Mucosal epithelium is pseudostratified, ciliated, columnar (PCC) WITH GOBLET CELLS
-Thick basement membrane
-Lamina propria
-Mixed glands
-C-SHAPED RINGS OF HYALINE CARTILAGE - prevent collapse of tracheal lumen during expiration
-Smooth trachealis muscles connect open tips of hyaline cartilages dorsally
-Adventitial CT
-No mesothelium

Front 5

Mucosal Epithelium of Trachea -

Back 5

-Numerous tall columnar CILIATED CELLS
-GOBLET CELLS (are nonciliated ; instead they have small blunt microvilli)
-Two types of BRUSH CELLS
-SMALL GRANULES CELLS (APUD)- nerve terminal present within epithelium next to cell
-BASAL CELLS

Front 6

Function of the ciliated cells in the trachea

Back 6

Ciliated cells are the most numerous. They provide a coordinated sweeping motion that moves mucous from distal air passages to the pharynx. This is an important protective mechanism for removing small inhaled particles.

Front 7

Function of the brush cells in the trachea and its distinctive feature

Back 7

-Brush cells have their basal surface in synaptic contact with afferent nerve ending. Transduction of general sensation.
-Distinctive feature is blunt microvilli involved in transduction of general sensory stimulation of mucosa.

Front 8

Function of the basal cells in the trachea

Back 8

Basal Cells are a reserve population of cells. These cells maintain replacement of individual cells in the epithelium.

Front 9

Tracheal Function - connects what, remains open or closed?, function of its cartilage and glands, function of the mucociliary layer

Back 9

-Connects inferior larynx to main-stem bronchi

-Must remain open for respiration

-Hyaline cartilages ensure patency during swallowing; hyaline cartilage may be replaced with bone tissue with age

-Glands produce mucus - -mucus secretions moisten air, and trap particles. Prevent dehydration due to moving air of underlying epithelium

-Mucociliary “escalator” beats toward larynx; mucociliary escalator is an important protective mechanism for removing small inhaled particles from the lungs.

Front 10

Bronchial Microscopic Anatomy - relation to trachea, cartilage

Back 10

-bronchi has same histological structure as trachea until it enters lungs; Mucosal and laminar propria similar to trachea.
-bronchi in lung (intrapulmonary) do not have cartilage rings instead have CARTILAGE PLATES of irregular shape, distributed in a linear array.
-plates eventually disappear as bronchi decrease in size (due to branching). Branch of small diameter with no plates is called bronchiole.

Front 11

Bronchiolar Microscopic Anatomy - two types of cells found here and their functions, muscle found here and where and its function

Back 11

-CILIATED CELLS in mucosa - move debris
-CLARA CELLS in mucosa - possibly secrete surface active material that prevents luminal adhesion in case airway collapses during expiration.
-SMOOTH MUSCLE ONLY IN WALL - contraction of smooth muscle in wall maintains diameter of airway

Front 12

Terminal Bronchioles - what two cell types found here, muscle?, alveoli?, terminal bronchioles lead to where, goblet cells?, are these bronchioles part of the conducting or respiratory?portion?

Back 12

-Have CILIATED CELLS and CLARA CELLS in mucosa
-Thin layer of smooth muscle
-No alveoli
-Lead to 2 respiratory bronchioles
-terminal bronchioles have no goblet cells present
-Terminal bronchiole is most distal part of conducting portion of respiratory system and is NOT involved in gas exchange.

Front 13

Clara Cell Function - restricted to what, mixed with what cells, increase in number when, secrete a complex of what

Back 13

-Clara cells (non-ciliated) are restricted to bronchioles
-Mixed with ciliated cells
-Ciliated cells decrease in number while Clara cells increase as you move distally down bronchioles
-Clara cells secrete complex of LIPOPROTEINS that are surface active, like surfactant

Front 14

Clara cells show characteristics of protein-secreting cells by having what organelles (3)?

Back 14

well developed basal rER, golgi apparatus, secretory granules that stain for protein

Front 15

Respiratory Bronchioles - what type of epithelium and what type of wall, contain what distinct unit, lead to where, proximal segments contain what 2 cell types (which one more distally)

Back 15

-Have low cuboidal epithelium and thin wall
-First conducting airway with ALVEOLI in walls
-Lead to alveolar ducts
-proximal segments contain ciliated cells and clara cells, distally there are a lot more clara cells.

Front 16

Alveolar Ducts - what connects to them, what are they, where do they terminate

Back 16

-Respiratory bronchioles connect to ALVEOLAR DUCTS
-These are basically airways lined everywhere by alveoli
-Alveolar ducts terminate in a cul de sac of alveoli called the ALVEOLAR SACS

Front 17

Alveolar Epithelium - what 2 types of cells found on it, their functions, and how are they joined to the epithelial sheet

Back 17

-Most cells are exceedingly thin cells with a flattened nucleus. These are called squamous alveolar epithelial cells or TYPE I CELLS for short. Most cells are type I– classic fried-egg, thin, squamous epithelium cells --> specialized for gas exchange
10:1 ratio of type I to II
-The other cells in the alveolar epithelium are great alveolar epithelial cells, aka TYPE II CELLS. These are dedicated to SURFACTANT synthesis and secretion. Type II cells are rounder, thicker
-Type I and type II cells are firmly joined into a continuous epithelial sheet by robust junctional complexes

Front 18

Alveoli - responsible for what, present as what, where does gas exchange occur and where does it not occur, how are bacteria inihibited from entering blood stream

Back 18

-Responsible for gas exchange
-Are present proximally as scattered evaginations of the wall of the respiratory bronchiole
-**Significant, efficient respiratory gas exchange occurs only across the walls of alveoli (alveoli epithelium), no gas exchange across epithelium of terminal bronchioles
-Bacteria prohibited from entering blood stream due to tight junctions in alveoli

Front 19

Alveolar Macrophages - part of what system, derivatives of what, dedicated to what organ, destroy what type of matter, ingest what type of matter, go where to deposit debris

Back 19

-These cells are part of the MONONUCLEAR PHAGOCYTE SYSTEM, along with monocytes, other macrophages, osteoclasts, etc. -They are bone marrow derivatives.
-They are DEDICATED PHAGOCYTES OF THE LUNGS.
-They can exit the pulmonary capillaries, cruise about on the carpet of surfactant.
-They phagocytose and often destroy organic matter inspired with the air, e.g. bacteria.
-They also ingest (but don’t destroy) inorganic matter in inspired air.
-Once loaded or worn out, macrophages can cross the alveolar epithelium and enter the CT domains of the lung, where they deposit debris.

Front 20

The Blood-Air Interface - what function, what types of cells found here (2), what type of cytoplasm found here, how thick is the barrier

Back 20

-Is exquisitely thin for maximal gas exchange
-Consists of thin layer of TYPE I CELL CYTOPLASM
-BASEMENT MEMBRANE of type I cells
-BASEMENT MEMBRANE of capillary endothelial cells
-Thin layer of ENDOTHELIAL CELL CYTOPLASM
-Entire barrier is routinely as THIN AS 0.1 µm, below the limit of resolution of a light microscope

Front 21

Pulmonary Capillaries - diameter, what happens to RBCs and gas exchange as they go through these (2)

Back 21

-Have SMALL DIAMETER, often less than diameter of RBC
-As RBCs are pushed through capillaries, they are elongated, increasing the SURFACE TO VOLUME RATIO, increasing efficiency of gas exchange.
-Narrowing of pulmonary capillaries also INCREASES RBC TRANSIT TIME, increasing efficiency of gas exchange

Front 22

Type II Pneumocytes Synthesize Surfactant - appearance of these pneumocytes, surfactant initially synthesized where, transported where

Back 22

-Have typical appearance of cell secreting proteins, e.g. large nucleolus, prominent basal RER, apical Golgi.
-Surfactant initially synthesized in RER, from choline, amino acids, and sugars transported into cells from blood.
-Surfactant is then passed to Golgi apparatus where it is glycosylated and put into multivesicular bodies.
-Multivesicular bodies are then converted into multilamellar bodies, containing numerous lamellae of surfactant.
-Upon exocytosis, surfactant coats air-water interface on apical surface of alveolar epithelium

Front 23

Role of Surfactant - its role, what happens if there is a deficiency of it

Back 23

-Surfactant REDUCES SURFACE TENSION of thin film of water at apical surface of alveolar epithelium
-If unopposed by surfactant, these forces would collapse alveoli, preventing gas exchange
-Surfactant ensures that alveoli remain expanded for maximal gas exchange efficiency
-Deficiencies in surfactant production can result in RESPIRATORY DISTRESS SYNDROME

Front 24

Biochemistry of Surfactant - Most abundant phospholipid component is, and what is it made of

Back 24

-Is a complex mixture of phospholipid and protein in micelles
-Most abundant phospholipid component is phosphatidyl choline, 2/3 of which is Dipalmitoyl Phosphatidyl Choline (DPC)(LECITHING)
-DPC is basically glycerol esterified to phosphocholine (a polar base) and palmitic acid (a fatty acid)
-Surfactant is a detergent that interacts with water molecules, reducing the mutual cohesion of water molecules and thus surface tension

Front 25

Function of Surfactant

Back 25

-Coats entire air - epithelial interface
-Acts as a detergent to REDUCE SURFACE TENSION
-Without surfactant, surface tension forces of a thin film of water on huge surface area is enough to collapse entire body
-Surfactant film reduces work of keeping lungs inflated**

Front 26

Cigarettes and The Lungs

Back 26

-All of your smoking patients should be encouraged to quit
-Smoking increases chances of getting LUNG CANCER, and also exacerbates HYPERTENSION
-The typical 220 lb male would need to gain over 25 pounds of fat to offset the health benefits of smoking cessation

Front 27

Tobacco Products and Lungs - tobacco products rich in what, cause what 3 things

Back 27

-Rich in CARCINOGENS (both initiators and promoters, and radioactive compounds), leading to lung cancers. Evidence for association between smoking and lung cancer is incontrovertible.
-Several components of tobacco smoke INCREASE BLOOD PRESSURE which can lead to hypertension
-Components of tobacco smoke also IMMOBILIZE CILIA, leading to accumulation of toxins in distal lungs
-Particulate matter induces macrophage accumulation. Macrophages then destroy lung parenchyma, leading the EMPHYSEMA

-Macrophages cannot digest inorganic compounds of smoker on right and thus accumulateà ends in loss of alveoli
-After 10 years after quitting smoking, the chances of lung cancer are the same as if you had never smoked at all

Front 28

The Trifecta of Poor Health

Back 28

-CIGARETTES - Lung cancer and hypertension-
ALCOHOL - GI cancer and hypertension
HYPERLIPIDEMIA - Three fired eggs and 6 strips of bacon in a butter-browned sandwich-GI cancer and hypertension
Watching rather than playing-no exercise- obesity and more hypertension