1-Respiratory

Question 1

Two functional divisions of the lungs

Answer 1

1) Conducting portion

2) Respiratory portion

Question 2

Conducting portion(function, location, function)

Answer 2

• Structure: varying levels of wall thickness
• Location: parts inside and outside lungs
• Function: conduct and condition(filter,heat,humidify)

Question 3

Conducting portions parts

Answer 3

Outside lungs: nasal cavity to extrapulmonary bronchi

Inside lungs: Bronchi, bronchioles, terminal bronchioles.

Question 4

Respiratory portion(function, location, function)

Answer 4

Structure-Thin walled gas exchange
Location: Only in lungs
Function: gas exchange

Question 5

Respiratory portion parts

Answer 5

Respiratory bronchioles, Alveolar ducts and sacs

Question 6

Types of circulation in the lungs

Answer 6

• Pulmonary

- Bronchial

Question 7

Bronchial circulation

Answer 7

• Branches off the aorta
• provides nourishmnt ot the CT, walls of the bronchi and bronchioles, and pluera
• Vein-deoxy
• artery-oxy

Question 8

Pulmonary circulation

Answer 8

• Blood from right ventricle(RV)
• 100% of blood
• Arteries- DEOXY blood from RV. Arteries follows the branches of the bronchi and bronchioles down to capillaries.
• Veins- Carry OXY blood from capillaries to the left atrium. does not run with the arteries. Located in CT of the lung. 2 veins per lung

Question 9

Main histological components of respiratory system

Answer 9

• Cartilage
• Smooth muscle
• Collagen fibers
• Elastic fibers

Question 10

Emphysema

Answer 10

• Enlargement of the airspaces after the terminal bronchioles and dstruction of the walls without fibrosis
• COPD
• Enzymatic degradation of elastin
• most common cause is cigarette smoking

Question 11

Pleura

Answer 11

• Serous memebrane
• Parietal- associated withe the walls of the body cavity
• Viseral- adheres to and cover lung surface

Question 12

Turbinates or Conchae(structure, function and location)

Answer 12

Structure: Bony shelf like projections lined with pseudostratified epithelium. Well vascularized
Function: Increase Surface area
Location:lateral walls of the nasal cavities

Question 13

Trachea layers

Answer 13

• Mucosa(elastic rich lamina propria, no muscularis mucosae)
• Submucosa
• Adventitia/ C-shaped Cartilage become progressively smaller

Question 14

Tracheal epithelium and other associated cells

Answer 14

• Pseudostratified epithelium
• Ciliated cells
• Mucous cells
• Brush cells
• small granule cells( enteroendocrine cells)
• Basal cells

Question 15

Ciliated cells

Answer 15

• Maintain level of periciliary fluid (water and electrolytes)
• Each cell has 250 cilia that provide coordinated sweeping movement
• forms “mucociliary escalator”
• Clears mucous coat

Question 16

Mucous cells

Answer 16

Mucinognn granues in cytoplasm

Mucous floats on the periciliary fluid

Question 17

Brush cells

Answer 17

• Columnar cells with blunt microcilli
• Basal surface in synaptic contact with afferent nerve ending
• receptor cell

Question 18

Small granule cells(enteroendocrine cells)

Answer 18

• Contain secretory granules

- many function in reflexes

Question 19

Basal cell

Answer 19

Stem cell of individual cell replacement in the epithelium

Question 20

Metaplasia in respiratory system

Answer 20

Pseudostratified epithelium changes to stratified squamous non-keratinized epithelium
-Harder to remove mucous
-mucous build up in the lumen of respiratory tree
mucus secreting glads get bigger
- must cough to clear secretions
-Inhaled irritants such as smoking cause it.
- reversible if irritant eliminated

Question 21

Bronchi wall layers

Answer 21

• Mucosa- same epithelium as trachea
• Muscularis-reguates diameter of airway
• Submucosa- glands present
• Adventitia/cartilage-Plates smaller with decreasing diameter

Question 22

Intrapulmonary bronchus

Answer 22

• Plates of cartilage become plates and get smaller
• Muscularis is found
• More elastic fibers

Question 23

Bronchioles

Answer 23

• 1mm or less
• embedded in CT of the lungs so they diameter changed with lung volume
• Terminal-non respiratory or Respiratory-sites of gas exchange
• pseudostratified to simple columnar to simple cuboidal epithelium
• gradual changes

Question 24

Bronchiole special feature

Answer 24

• No cartilage
• Lack submucosal glands
• thick layer of smooth muscle
• ciliated cells decrease and club cells increase

Question 25

Club cells(or Clara)(structure, function and location)

Answer 25

- Simple columnar dome shaped, apical aspect poke into lumen - Detox harmful compounds in the air - secrete a lipoprotein that prevents luminal adhesion - Mitotically active stem cell - In bronchioles

Question 26

Repiratory bronchioles

Answer 26

- First region of gas exchange - Wall is interupted by alveoli - mostly club cells

Question 27

Aleoli(function and cells)

Answer 27

Site of gas exchange | -Lined with type I & II pneumocytes occasional brush cells

Question 28

Alveoar ducts

Answer 28

Smooth muscle disappears at the end of the duct | elastic and collagen are the only support for alveoli

Question 29

Alevolar sacs

Answer 29

Spaces surrounded by clusters of alveoli

Question 30

Type I pneumocyte(structure function,location)

Answer 30

-Structure: squamous, attenuated cells, many organelles clusted by nucleus while cytoplasm is spread for gas exchange Function: provide a barrier of minimal thickness for gas exchange Location- 95% of surface area of the alveolus

Question 31

Type II pneumocytes(septal cell)(structure function,location)

Answer 31

Structure: rounded cells apical cytoplasm contains lamellar bodies Location:Typically found in corners occupy 5% f surface area Function: Undergo mitosis to regenerate themselves and type I pneumocytes. Also continuously produce surfactant to prevent alveolar collapse

Question 32

Interalveolar septum-thin region

Answer 32

- site of air-blood barrier | - house capillaries that function in gas exchnage

Question 33

Interalveolar septum-thick region

Answer 33

Composed of collagen, elastic fibers, capillaries, lymphatic vessels, fibroblasts, mast cells, alveolar macrophages

Question 34

Blood-air barrier

Answer 34

-Layer of surfactant -alveolar epithelium(Type I pneumocytes) -Fused basement membrane of he alveolar and epithelial cells -endothelial cells All type I and type II pneumocytes have desmosomes and occluding junctions

Question 35

Alveolar Pores(Pores of Kohn

Answer 35

- Equilizing pressure in alveoli - enable collateral ventilation - allow macrophage migration

Question 36

Defense mechanisms

Answer 36

1. Nose and trachea 2. Mucocilliary escalator (traps and moves debris towards the nasopahrynx 3. Alveolar macropages(dust cells)