Introduction and Anatomy of Lungs, Airways and Blood Supply Flashcards Preview

Systems I - respiratory > Introduction and Anatomy of Lungs, Airways and Blood Supply > Flashcards

Flashcards in Introduction and Anatomy of Lungs, Airways and Blood Supply Deck (42)
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1
Q

What is pulmonary blood flow/circulation?

A

Pulmonary artery carries deoxygenated blood away from the heart to lungs and pulmonary vein returns oxygenated blood back to heart. Delivers CO2 to lungs and picks up O2.

2
Q

What is systemic blood flow/circulation?

A

Carries oxygenated blood away from heart to peripheral tissues and returns deoxygenated blood back to heart.

3
Q

Main anatomical features of the airways

A

Nose, mouth, pharynx, epiglottis, larynx, trachea

4
Q

What happens to air at the nose?

A

Air enters, cilia and mucous trap particles, warmth of nose moistens air. Bigger surface area to breathe in through nose than mouth.

5
Q

What happens to air at the mouth?

A

Enters but doesn’t get moistened/saturated as much as in the nose.

6
Q

What happens at pharynx?

A

Air moves down here, also called throat

7
Q

What is the epiglottis?

A

Small flap of tissue that folds over trachea when swallowing to prevent food entering the lungs

8
Q

What is the larynx?

A

Voice box, contains vocal cords which vibrate to produce sound on expiration

9
Q

Features of trachea

A

Made of stiff rings of C-shaped cartilage rings that support it. They maintain patency of the upper airway. Patent = open.

10
Q

Gross anatomical features of the lungs

A

Right/left.
Right has 3 lobes (superior, middle, inferior). Horizontal fissure separates superior and middle; oblique fissure separates middle and inferior. Left has 2 lobes (superior, inferior). Oblique fissure separates them.

11
Q

What happens to trachea at T4?

A

It bifurcates to right and left bronchus. Right bronchus branches to 3 secondary bronchi; left bronchus branches to 2. Secondary bronchi then branch again to tertiary bronchi (bronchioles) and these lead to alveoli.

12
Q

How many times does each bronchus branch before terminating into a cluster of alveoli?

A

Around 23 times (24 divisions of trachea until alveoli)

13
Q

What’s different about the right and left bronchus?

A

Right bronchus splits at a greater angle than the left, it’s almost vertically underneath the trachea so aspirated foreign bodies commonly get stuck here.

14
Q

What does upper respiratory tract consist of?

A

Nose, mouth, pharynx, epiglottis, larynx.

15
Q

What does lower respiratory tract consist of?

A

Trachea, bronchus, lungs.

16
Q

What do bronchioles not have?

A

No cartilage

17
Q

Functions of respiratory system

A

Gas exchange
Acid base balance
Protection from infection
Communication via speech

18
Q

What gas exchange occurs in respiratory system?

A

Oxygen added to blood from air, carbon dioxide removed from blood into air. CO2 build up is toxic.

19
Q

What’s the most important function of the respiratory system?

A

Gas exchange because it allows oxygen to be taken in and used in cellular respiration to make energy and CO2 as a waste product.

20
Q

What is acid base balance?

A

Regulation of body pH. Maintains a pH of 7.4 of extracellular fluid.

21
Q

How does the respiratory system protect from infection?

A

Lymphoid tissue around respiratory tract to protect from infection, scans the air we’re breathing and activates immune response.

22
Q

How does the respiratory system allow us to talk?

A

Air vibrates vocal chords for speech, speaking occurs on expiration.

23
Q

Points of gas exchange between respiratory and cardiovascular system

A

In alveoli of lungs - O2 moves from inspired air to blood, CO2 moves from blood to air through expiration.
In systemic capillaries - O2 moves from blood to cells, CO2 moves from cells to blood.

24
Q

What are the different classes of airways?

A

Trachea, primary/secondary bronchus, bronchioles (tertiary), alveoli

25
Q

As each class of airways divide…

A

Diameter and cross-sectional area decreases. However, the number of each class increases.

26
Q

What can be altered by activity of bronchial smooth muscle?

A

Airway diameter and therefore resistance to air flow.
Contraction decreases diameter = increases resistance
Relaxation increases diameter = decreases resistance

27
Q

Where is resistance to air flow greatest/least?

A

Greatest in trachea, least in small deep airways because lots of small bronchioles but only one trachea.

28
Q

What’s the upper airway also known as?

A

Conducting zone because no gas exchange takes place, just conduction of air to and from alveoli.

29
Q

What is the respiratory zone?

A

The alveoli where gas exchange is because of thin walls

30
Q

What’s the air in the conducting zone called?

A

Anatomical dead space

31
Q

What are alveoli surrounded by?

A

Clusters are surrounded by elastic fibres (allow lung to stretch/recoil) and a network of capillaries.

32
Q

Type 1 pneumocyte

A

Bulk of alveolar wall (97%, involved in gas exchange, simple squamous epithelium.

33
Q

Type II pneumocyte

A

Produce surfactant, dispersed randomly, not involved in gas exchange, act as lubrication to reduce surface tension at alveolar surface

34
Q

Macrophage function in alveoli

A

Ingest foreign material that reach the alveoli, escape to pharynx/lymph nodes, immune defence

35
Q

3 types of cells in alveoli

A

Type I/II pneumocytes, macrophages

36
Q

What is respiratory tract lined with?

A

Pseudostratified ciliated columnar epithelia, glands, lymph nodes, blood vessels, mucous.

37
Q

How does epithelium change from nose to alveoli?

A

Becomes more squamous (flat). Mucous cells lost before cilia as mucous would drain into lungs if cilia lost first.

38
Q

Function of mucous

A

Moistens air, traps particles, provides large surface area for cilia to act on. Goblet cells secrete mucous.

39
Q

Basic function of cardiovascular system

A

Transport oxygen to tissues; carbon dioxide away from tissues

40
Q

What is external respiration?

A

Integration of respiratory and cardiovascular systems allowing movement of gases between the air and the body’s cells (air from environment into body)

41
Q

In the steady state, what is the net volume of oxygen exchanged in the lungs equal to?

A

The net volume of oxygen exchanged in the tissues. Same applies for CO2. Prevents gas build up in the circulation which would hamper gas exchange. Helps to ensure supply = demand.

42
Q

Average volumes of gas exchanged per minute

A

250ml O2 exchanged (consumed); 200ml CO2 exchanged (produced)