Session 10 - Respiratory system

Question 1

Main functions of the respiratory system?

Answer 1

• Provides for gas exchange—intake of O2 and elimination of CO2 • Helps adjust the pH of body fluids • Contains receptors for sense of smell • Filters inspired air • Produces vocal sounds (phonation) • Excretes small amounts of water and heat

Question 2

The three basic steps of respiration

Answer 2

• Ventilation (breathing) • External (pulmonary) respiration = exchanges of gases of the lungs with the blood • Internal (tissue) respiration = exchanges of gases from the blood to the cells

Question 3

What does The upper respiratory system: consist of

Answer 3

• Nose • Nasal cavity • Pharynx (throat), and associated structures

Question 4

What does The lower respiratory system consist of?

Answer 4

• Larynx (voice box) • Trachea (windpipe) • Bronchi (airways) • Lungs

Question 5

What is the conducting zone consist of?

Function?

Answer 5

consists of a series of interconnecting cavities and tubes both outside and within the lungs.

•the nose, nasal cavity, pharynx, larynx, trachea, bronchi, bronchioles, and terminal bronchioles

oFunction: to filter, warm, and moisten air and conduct it into the lungs.

Question 6

What does the respiratory zone consist of?

Function?

Answer 6

consists of tubes and tissues within the lungs

•the respiratory bronchioles, alveolar ducts, alveolar sacs, and alveoli

oFunction: the main sites of gas exchange between air and blood.

Question 7

Nasal cavity duct openings?

Answer 7

Duct from the paranasal sinuses (which drain mucus) open in the nasal cavity and the nasolacrimal ducts (which drain tears - that’s why your nose runs when you cry) open in nasal cavity.

Question 8

What type of Epithelium lines the nasal cavity?

Answer 8

Also known as Airway epithelium

Ciliated pseudostratified columnar epithelium with goblet cells which produce a moving mass of mucus.

Question 9

Functions of the nasal structure

Answer 9

o Ciliated pseudostratified columnar with goblet cells:

Lines the nasal cavity

Warms air due to high vascularity

Mucous moistens air and traps dust

Cilia move mucous towards pharynx

o Olfactory epithelium: Detecting olfactory stimuli ( sense of smell)

o Paranasal sinuses: Modifying speech vibrations as they pass through the large, hollow resonating chambers. - gives us the ability to chnge pitch and tone. That’s why when you are sick your voice changes as the paranasal sinuses are full/blocked etc

• Resonance refers to prolonging, amplifying, or modifying a sound by vibration.

Question 10

Functions and regions of rhe pharynx

Answer 10

o Functions:

Passageway for food and air

Resonating chamber for speech production

Tonsils (lymphatic tissue) in the walls protects entryway into body

o Distinct regions: nasopharynx, oropharynx and laryngopharynx

Question 11

The larynx connects the…

and it’s function

Answer 11

laryngopharynx with the trachea

Function: voice production

Question 12

What is the trachea ?

and what are the layers of thr tracheal wall?

Answer 12

The windpipe

Anterior to the oesophagus

Question 13

Explain the bronichial tree? and the structural changes as the branching becomes more extensive

Answer 13

Consists of bronchi - they start large and end up small

The bronchial tree begins at the trachea and ends at the terminal bronchioles

* refer to picture for order

Structural changes:

as the branching becomes more extensive -

oThe mucous membrane: (epithelial layer)

•Gradually changes from pseudostratified ciliated to cuboidal non-ciliated

oRings of cartilage:

•Gradually replaced by rings of smooth muscle and then connective tissue

Question 14

What divides the Primary Bronchi into left and right

Answer 14

the trachea divides into a right primary bronchus and a left primary bronchus - supply each lung

oCarina: An internal ridge formed by a posterior and inferior projection of the last tracheal cartilage, at the point where the trachea divides into right and left primary bronchi

Question 15

What does the Secondary bronchi supply?

What does the tertiary bronchi supply?

Answer 15

o Secondary bronchi: Supply each lobe of the lungs (3 right + 2 left)

o Tertiary bronchi: Supply each bronchopulmonary segment (10 in each lung)

• The teritary divide into bronchioles which in turn branch repeatedly and divide into smaller tubes called terminal bronchioles

Question 16

What role does the sympathetic nervous system and parasympathetic nervous system

Answer 16

oSympathetic nervous system: stimulates adrenal glands to release epinephrine that relaxes bronchiolar smooth muscle.

• dilates airways and improves lung ventilation

o Parasympathetic nervous system: cause contraction of bronchiolar smooth muscle

• constricts of distal bronchiole

Question 17

what is the Pleural membrane and pleural cavity ?

Answer 17

oPleural membrane: A double-layered serous membrane that enclose and protect each lung

• Visceral pleura covers lungs
• Parietal pleura lines thoracic cavity

oPleural cavity: A potential space between the visceral and parietal pleurae

• Contains a pleural fluid secreted by the membranes.
• Reduces friction between the membranes, allowing them to slide easily over one another during breathing (inflation and deflation)

Question 18

Location of the lungs and what are they enclosed and protected by?

Answer 18

Location: in the thoracic cavity; extend from the diaphragm to just slightly superior to the clavicles and lie against the ribs anteriorly and posteriorly.

oEnclosed and protected by the pleural membrane.

Question 19

How many lobes does the right and left lung have?

Answer 19

The right lung: three lobes separated by two fissures-Oblique and horizontal fissure

•The left lung: two lobes separated by one fissure-Oblique fissure

Question 20

medial (mediastinal) surface of the lungs

Answer 20

oBlood vessels and airways enter lungs at hilus

oForms root of lungs

oCovered with pleura (parietal becomes visceral)

Question 21

What’s the order of the Microscopic airways following on down the bronchial tree?

What are the lobules?

Answer 21

Terminal bronchioles

respiratory bronchioles

alveolar ducts

alveolar sacs

alveoli

oLobules: Small compartments of bronchopulmonary segment

• Wrapped in elastic connective tissue (function: stretch and recoil when breathing)
• Each contains an arteriole, a venule, and a branch from a terminal bronchiole

Question 22

How many cell types are there of the alveoli sacs

Answer 22

3 - 4 types

Type 1 alveolar cells

Type 2 alveolar cells (septal cells)

Alveolar dust cells

Fibroblasts

Question 23

Type I alveolar cells:

Answer 23

• Form a continuous lining of the alveolar wall. (form the sac)
• Site for gas exchange.
• Are the most prevalent alveolar cells

** Single layer of cells where gas passes through them into the pulmonary capillaries or from the capillaries into the alveoli

Question 24

Type II alveolar cells (septal cells):

Answer 24

• Found between type I alveolar cells
• Secrete alveolar fluid containing surfactant (detergent)

–Surfactant lowers the surface tension of alveolar fluid, preventing the collapse of alveoli with each expiration - very important

Question 25

Alveolar dust cells

Answer 25

Wandering macrophages that remove debris

Question 26

Fibroblasts:

Answer 26

•Produce reticular and elastic fibers

Question 27

Blood supply to the lungs

Pulmonary arteries:

Answer 27

Carry deoxygenated blood from the right heart to the lungs for oxygenation

Question 28

Blood supply to the lungs

Bronchial arteries:

Answer 28

branch from the aorta and deliver oxygenated blood to the lungs primarily perfusing the muscular walls of the bronchi and bronchioles

perfuse: supply (an organ or tissue) with a fluid by circulating it through blood vessels or other natural channels.

Question 29

Answer 29

Answers on tutorial print out

Question 30

Label microscopic anatomy of a lobule of the lung

Answer 30

Answers on tutorial print out