Test Three Histology

Front 1

Respiratory System: two main regions

Back 1

* Conduction: (brings air in and out)
- nasal cavity, nasopharynx, larynx, trachea, bronchi, bronchioles, terminal bronchioles

* Respiratory: (gas exchange)
- respiratory bronchioles, alveolar ducts, alveoli

Front 2

Respiratory Epithelium Cell Types

Back 2

- pseudostratified epithelium

*Ciliated Columnar- moves stuff through
*Mucous Goblet Cells- synthesize and secrete mucous
* Brush Cells- nerve endings (bear short microvilli)
*Basal Cells- stem cells from which other cells arise
*Sm Granule Cells- neuro endocrine. They resemble basal cells but contain secretory granules

- there are not as many brush cells or basal cells

Front 3

Nasal Cavity

Back 3

- protects and filters

Two Regions:
1. Vestibule
2. Nasal Fosse

- there is a transition from stratified squamous to respirational epithelium. Smoking pushes back the transition area.

Front 4

Vestibule

Back 4

- stratified squamous (external environment)
- sebacous glands (make mucous)
- sweat glands
- vibrissae (nose hair

Front 5

Nasal Fosse

Back 5

- Nasal Septum- the medial wall of the respiratory segment; left and right (divides)
- Conchae- lateral folds that create turbulence (makes sure more particles hit nose surface receptors and filters)
- Swell bodies- increased blood vessels and shuts off flow through one nostril.

*Laminar Turbulence- parallel flow of air around an object

Front 6

Olfaction

Back 6

*Superior Conchae
*Pseudostratified:
- Supporting Cells (columnar cells that provide mechanical and metabolic support to the olfactory cells)
- Basal Cells (stem cells from which new olfactory cells and supporting cells differentiate)
- Olfactory Cells (neural, they're bipolar neurons)

*Olfactory glands (Bowman's)- have a mucous that traps particles for recognition by olfactory.

Front 7

Larynx

Back 7

- covered by epiglottis (in the epiglottis, the top is stratified and the bottom is respiratory)

*Laryngeal cartilage:
- Hyaline
- Elastic

* Epiglottis- elastic cartilage

*Laryngeal folds:
- Vestibular fold (false vocal cords; have sebaceous glands; function not known)
- True Vocal Cords

*vibrissae- filters large particles
*fosse- mucous captures small particles and moistens the air

Front 8

Trachea

Back 8

- purely conductive

Four layers:
1. Mucosa (composed of respiratory epithelia)- thick basement membrane
2. Submucosa (dense CT)
3. Cartilagenous (composed of C-shaped hyaline cartilages)
4. Adventitia (composed of CT that binds the trachea to adjacent structures)

Front 9

Bronchial Tree

Back 9

- all respiratroy epithelia

*Trachea
* Two Primary Bronchi (split from trachea)
* Secondary (Lobar) bronchi (three lobes in right lung, two in left lung)
*Small Bronchi
*Bronchioles (when the airway reaches a diameter of about 1 mm, it is designated as a bronchiole)
- terminal bronchioles

Front 10

Order of respiration

Back 10

primary bronchioles --> lobular bronchioles --> small bronchi --> bronchioles

Front 11

Bronchi

Back 11

- larger ones are rings
- smaller ones are platelike

*Mucosa (pseudostratified epithelium)
*Cartilage (consists of discontinuous cartilage plates that become smaller as the bronchial diameter diminishes)
- irregular and encircles
*Smooth Muscle
- spiral and crisscrossing

Front 12

Bronchioles

Back 12

- get smaller and smaller down to cuboidal
- < 5mm diameter
- no cartilage, glands
* scattered goblet cells

* ciliated epithelium:
- Large = pseudostratified
- Small = cuboidal

*Clara cells- secretory cells for protection and get rid of oxidative pollutants. They are nonciliated cells that have a characteristic rounded or dome-shaped apical surface projection. They secrete a surface-active agent that prevents luminal adhesion should the wall of the airway collapse.

*Neuroepithelial bodies- nerve endings for chemoreception.

Front 13

Respiratory Bronchioles

Back 13

- first level/site of respiratory exchange

*Transition
- conducting to respiratory
*First gas exchange
*Ciliated cuboidal cells
*Gas exchange starts in alveolar sacs

Front 14

Alveolar Duct

Back 14

- multiple sacs open up into this; it has multiple sacs coming off a common area
- elastic and reticular fibers in walls
- transition from cuboidal cells to squamous cells to allow better gas exchange

*Alveolar ducts are elongate airways that have almost no walls, only alveoli, as their peripheral boundary.

Front 15

Alveoli- three regions of gas exchange

Back 15

1. Respiratory Bronchioles
2. Alveolar Ducts
3. Alveolar Sacs- most occurs here

* Interalveolar Septa- elastic and reticular fibers allow expansion and contraction

Front 16

Three main cell types in Alveoli

Back 16

1. type I alveolar cells (squamous, make up most of wall; gas exchange occurs through here)

2. type II alveolar cells (larger, responsible for producing surfactant; they are secretory cells)

3. Brush cells (not very many of these)

Front 17

Blood-Air Barrier

Back 17

*Alveolar cells
*Fused basal lamina
*Endothelial cells (of capillary)

-there is a fused basal lamina present

goes from: alveolar cells --> epithelium (with surfactant) --> fused basal lamina --> endothelium

Front 18

Surfactant

Back 18

- lipids with glycoproteins and other proteins
- made by type II cells
- creates surface tension
- help sacs inflate and deflate by separating them
- surfactant is critically important in babies. The respiratory system is one of the last things to develop (it develops within the last few weeks prior to birth). So pre-maturely born babies don't have sacs or surfactant.

Front 19

Cell Types

Back 19

*Capillary endothelium
*Type I alveolar cells
*Type II alveolar cells (produce surfactant)
*Macrophages
*Alveolar pores (regulate pressure)

Front 20

Neonatal Sufactants- Respiratory Distress Syndrome

Back 20

Immature Lung:
- thick blood gas barrier; low compliance; immature epithelial cells; low surfactant levels; small area for gas exchange; poorly vascularized; high resistance to blood flow

Mature Lung:
- thin blood gas barrier; highly compliant; mature epithelial cells; adequate surfactant; large area for gas exchange; highly vascular; low resistence to blood flow

Front 21

Circulatory and Lymphatic Vessels

Back 21

- two types: respiratory circulation and nutritave circulation
- lots of lymphatic nodules, BALT (Bronchial Associated Lymphatic Tissue)

Front 22

"Cleaning Air" and BALT

Back 22

- BALT= Bronchiole Associated Lymphatic Tissue
- > 10 um- nasal picks up these particles
- 2-10 um- mucus picks up these particles
- < 2 um- macrophages

Front 23

Emphysema

Back 23

- septa separating alveoli begin to deteriorate
- Neutrophils release elastase (breaks down elastin). Normally your body prevents too much elastase from being released.
- if you are continually exposed to antigens, more neutrophils are present and more elastase is made (this happens if you smoke). Leads to breakdown of septa and an increase in mucus.

- About 10% of people don't have the defense system that regulates elastase production, so these smokers are even worse off.

Front 24

Chronic Obstructive Pulmonary Disease (COPD)

Back 24

- emphysema and asthma
- obstructive and irreversible
- can occur in alveolar sacs or further up in respiratory bronchioles

- Centriacinar emphysema- the wall of respiratory bronchioles is destroyed by elastases and other proteases

- Panacinar emphysema (hits everywhere)- the wall of the respiratory bronchioles, alveolar ducts, and alveoli are destroyed by elastases and other proteases.

Front 25

Cystic Fibrosis

Back 25

- an increase in mucus that can't be cleared by cilia
- a gene is disrupted in the chloride ion channel (can't pump CL out and draws in Na and H2O), so outside becomes dehydrated and thicker; coats lining of respiratory system.

Front 26

Asthma

Back 26

- mucus hypersecretion; increase in H2O; constriction of smooth muscle
- Antigen comes into respiratory system and gets taken up by mast cells