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IRS- Histology notes 2/18/2013 8:13:00 PM

1.) Describe the difference between cellular and mechanical

respiration

cellular respiration- the set of metabolic reactions that take place toconvert biochemical energy from nutrients into ATP at a cellular

level. Mechanical respiration- Breathing; exchanging air between the

lungs and the environment.

2.) Identify the organs of the respiratory system and their functions

Nasal cavityo Mucuso Pseudostratified columnar ciliated epithelium with goblet cellso Basement membraneo Lamina propria- Submucosa

Capillary bed Mucous gland

Nasal conchao Respiratory epitheliumo Lamina propria

Loose connective tissue with venous sinuseso Bony trabeculae

Olfactory mucosa

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Pharynxo Nasopharynxo Oropharynxo Laryngopharynx

Larynxo Epiglottis

Core of elastic cartilage Perichondrium- covers cartilage Bottom lingual surface and halfway down laryngeal

surface covered in nonkeritinized stratified squamous

epithelium

Other half of laryngeal surface = respiratory epithelium Basement membrane Lamina propria loose connective tissue

o Vocal fold- nonkeratinized stratified squamous epithelium

Vocal cord- elastic fibers Laryngeal ventricle False vocal fold- seromucous glands

- Conducting portion

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Tracheao Mucosa

Pseudostratified ciliated columnar epithelium Lamina propria (loose connective tissue)

o Hyaline cartilage arrangement- 16-20 C ringso Smooth muscle- trachealis muscleo Mucus secreting glands

Mixed seromucous glands- in submucosao The adventitia

Bronchio Primary

Respiratory epithelium with goblet cells Basement membrane Lamina propria

Elastic fibers Blood vessels Lymphatics

Smooth muscle Submucosal glands Perichondrium Hyaline cartilage plate

o Secondary 2 on the left and 3 on the righto Tertiary

Bronchopulminary segments Bronchioles- 1 mm or less

o Terminal bronchioles (creates lobular structure of lungs) No more goblet cells No more CARTILAGE No more glands Epithelium (columnar and cuboidal) YES

Simple columnar epithelium With dome-shaped clara cells

Apical regions contain smooth ER andelectron-dense secretory vesicles

Antiinflamatroy

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Detoxification Proteolytic Leukocyte protease inhibitor Lysozyme Water and electrolyte transport Chloride ion release Stem cells

Ciliated cells - YES Smooth muscle - YES Elastic fibers YES Adventiatia

Gas exchange

- Respiratory portion

Respiratory bronchioleso Cuboidal epitheliumo Transitional zone- gas exchange

Alveolar ductso Elongate airwayso Simple squamous epitheliumo Smooth muscle

Alveolar sacs Alveoli

o Elastic fiberso NO SMOOTH MUSCLE

Interalveolar septao Elastic fiberso Macrophageso fibroblastso Reticular fiberso Fused basal laminao Endothelialo epithelial cells- surfactant lines epithelium

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connected by occluding junctions- prevent leakage offluid into alveolar lumen

type 2 septal cells Secretion of surfactant! Synthesized in RER and golgi Stored in lamellar bodies

type 1 squamous cellso pores of Kohn- alveolar pores

Lungs3.)What layers/tissues make up the walls of the respiratory tract?

Trachea

Respiratory epithelium- pseudostratified ciliated columnarepithelium with goblet cells

Basement membrane Lamina propria- with diffuse lymphatic tissue Deep lamina propria with elastic fibers Submucosa?- with mucous gland

o Mucous and serous (fluid) acini Perichondrium- covering cartilage Tracheal cartilage Posterior- trachialis muscle Annular ligament- between cartilages

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4.)Identify the conducting and respiratory airways. What are the overall functions of the conducting airways? What histology is responsible for these functions?

5.) What is the histology of the outer surface of the lungs?

What is the function of this layer?6.) There are trends in respiratory system histology as the airways

branch to smaller airways.

What are the cell types making up the epithelium in theupper conducting organs?

Lower conducting airways? Respiratory airways?

7.) Identify the location and function of:

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goblet cells ciliated cells basal cells serous cells clara cells- dust cells- alveolar macrophage type I pneumocytes type II pneumocytes

8.) What is the trend relating to the presence of seromucous glands

in the submucosa?

9.) What is the trend relating to the presence of goblet cells, cilia,

cartilage, smooth muscle?

10.) How do these trends relate to the changing function of these

organs going from conducting to respiratory airways?

11.) What is the function of surfactant?

What cells secrete it?12.)What is the significance of the vast network of elastic andreticular fibers in lung tissue?

How do these tissues contribute to inhalation andexhalation?

13.)How is the air of a given lung lobule equilibrated between

adjacent alveoli served by that airway?

14.)What tissues make up the thinnest blood-air barrier?

15.)Trace the path of a molecule of oxygen from the alveolar lumen

to the hemoglobin of a red blood cell.

16.)Trace the path of a molecule of carbon dioxide from the cells of

the body to the alveolus to be expired.

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17.)Identify the organs of the pulmonary vasculature.

How would you distinguish between a vascular tubular organand an airway tubular organ when examining the histology

of the lung?

18.) What defense mechanisms are found along the airways?

A. Nasal hairs (old guys keep these neat!)

B. Secretory IgA

C. The famous mucociliary escalator

1. pseudostratified epithelium2. goblet cells

3. tracheobronchial glands

4. ciliated cells

D. Alveolar macrophages

1. how do these cells work? 2. Mycobacterium tuberculosis

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IRS- Embryology 2/18/2013 8:13:00 PM

Embryology learning objectives respiratory system and pharyngeal

apparatus

1.) What is the pharyngeal arch apparatus and what are the three main

components?- Paired swellings, lateral to cranial gut tube

contribute to formation of face and neck1. Pharyngeal arch

i. Pharyngeal arch arteryii. Cartilaginous rod-

1. skeletoniii. Muscular component-

1. head and neck musclesiv. nerves

2. Pharyngeal groovesi. Between archesii. External

o Pharyngeal grooves (ectoderm) 1st pair

ear canals others

cervical or branchial sinus sinuses may persist and cause problems

o3. Pharyngeal pouch

i. Between archesii. Internal

o Pharyngeal pouch (endoderm) 1st pouch

Tympanic membrane and other ear structures 2nd pouch

tonsillar sinus lymphatic nodules

3rd pouch thymus inferior parathyroid glands

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4th pouch superior parathyroid glands parafollicular cells

release calcitonin (calcium regulation)

What is the clinical significance of the overall structure of thesecomponents?

What does the pharyngeal arch apparatus contribute to (generalstructures, not every bone, muscle, etc.)?

o 1st arch- mandibular arch maxilla, zygomyatic bone, vomer mandible, temporal bone Cartilage

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Malleus, incus Muscles

Jaw muscles Tympanic membrane

o 2nd arch- hyoid arch hyoid bone cartilage

stapes, styloid process of temporal bone

Muscles Facial expression muscles

o 3rd arch hyoid bone (greater horn) epiglottis

o 4th arch epiglottis muscles

cricothyroid laryngeal cartilage

o 6th arch larynx intrinsic muscles of larynx

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2.)How do the thymus, parathyroid and thyroid glands form? What process

do those all have in common and what clinical significance does that have?

o Thyroid primordium invaginateso Thyroglossal duct- joins thyroid as it migrateso Thyroid gland- from endoderm

Pushed Ventrally Divides into lobes

3rd poucho thymus

initially bilateral fuse after caudal migration neural crest cells important

o inferior parathyroid glands move with the thymes to settleinferior to superior parathyroid gland

4th poucho superior parathyroid gland

parafollicular cells

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neural crest cells differentiate and migrate fusingwith thyroid

chief cells make parathyroid hormone regulate calcium balance in blood

Clinical significance

Migrations could result in remnant tissueo Cysts

Especially thyroglossal duct3.)How do the face, tongue and palate form (in general) and what is the

clinical significance, especially for the palate?

4.)What germ layers contribute to the respiratory system?

5.)Discuss the formation of the laryngotracheal diverticulum (or respiratory

bud) and the relationship between esophageal atresia and

tracheoesophageal fistula. (slide 11)

-

What are the signs/symptoms of TEF with and without esophagealatresia?

6.)Describe the four periods of lung development. Which is/are clinically

most significant and why? When is surfactant produced and why is that

important?

Pseudoglandular stage Canalicular stage Terminal sac stage

o Developing alveolio Surfactant productiono Critical fetal stage because surfactant is needed to for

survival

Alveolar stageo Functional alveoli

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7.)What abnormality is most common in the lower respiratory system?

Respiratory distress syndrome

What are the signs/symptoms?o Rapid, labored breathingo Lungs underinflatedo Fluid retention in lungs

How can this be prevented and treated?o Corticosteroids administered to mother before birtho Surfactant administered in babys trachea after birth

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2/18/2013 8:13:00 PM