Respiratory System - Lung L18

Question 1

Overview of the respiratory system

Answer 1

Question 2

Core function of the respiratory system

Answer 2

Gas exchange - O2 in, CO2 out

Question 3

What are two main aspects important for efficient gas exchange?

Answer 3

1. Diffusion distance between air and blood must be small
2. Surface area over which exchange takes place must be large

Question 4

Types of respiration

Answer 4

External respiration, internal respiration, cellular respiration

Question 5

External respiration

Answer 5

The process in the lungs by which oxygen is absorbed from the atmosphere into blood within the pulmonary capillaries, and carbon dioxide is excreted. (physical)

Question 6

Internal respiration

Answer 6

The exchange of gases between blood in systemic capillaries and the tissue fluid and cells which surround them.

Question 7

Cellular respiration

Answer 7

The process within individual cells through which they gain energy by breaking down molecules such as glucose. Occurs in the mitochondria, consumes oxygen, and generates carbon dioxide.

Question 8

Pulmonary ventilation (breathing)

Answer 8

The physical/bulk movement of air into and out of the lungs.

Question 9

What does the ventilatory pump comprise of?

Answer 9

The rib cage with its associated muscles, and the diaphragm

Question 10

What is the conducting part of the respiratory system?

Answer 10

Series of cavities and thick-walled tubes which conduct air between the nose and the deepest recesses of the lungs, and in doing so warm, humidify and clean it. The conducting airways are the nasal cavities, pharnyx, larnyx, trachea, bronchi and bronchioles.

Question 11

Respiration

Answer 11

Transport of gases at various stages in the system

Question 12

Ventilation

Answer 12

The moving of air in and out of the lung tissue - nothing about gas exchange (need muscles + pressure for that to happen)

Question 13

What does the respiratory part of the system comprise of?

Answer 13

Tiny, thin-walled airways which gases are exchanged between air and blood. The airways are respiratory bronchioles, alveolar ducts and sacs, and the alveoli themselves.

Question 14

Is the conducting part of the respiratory system part of gas exchange?

Answer 14

No, it is preparing air for gas exchange

Question 15

How the lung, heart and tissue works together in the pulmonary cardio circuit.

Answer 15

Question 16

What is required for efficient gas exchange in terms of the nasal cavity?

Answer 16

1. Clean - needs to be free of bacteria, dust, pollen, viruses and all sorts of particulates.
2. Warm - room temperature of 37 degrees
3. Saturated - 100% of H2O. Must be wet as the lining of our airways is exposed to very dry environment, thus the more moisture we can put in the air protects the cellular lining of the airways and helps with a solid utilisation of those gases to be absorbed across the membrane.

Question 17

Different types of cross-section

Answer 17

Lateral, medial, coronal, transverse, cadaver

Question 18

Lateral cross section

Answer 18

slice that captures structures on the side, further from the body’s center.

Question 19

Medial cross section

Answer 19

structures closer to the midline or center of the body.

Question 20

Coronal Cross Section

Answer 20

A cut made along the coronal (or frontal) plane, dividing the body into anterior (front) and posterior (back) parts.

Question 21

Cadaver section

Answer 21

cutting or slicing a human cadaver (deceased body) to study its internal structures.

Question 22

Transverse (Axial) Cross Section

Answer 22

A cut made along the transverse plane, dividing the body into superior (upper) and inferior (lower) parts.

Question 23

What cells are in the nasal cavity?

Answer 23

Pseudostratified ciliated columnar epithelium with globet cells, basal cells and lined with a mucous membrane

Question 24

Mucociliary clearance

Answer 24

Responsible for trapping and removing inhaled particles, pathogens, and debris from the airways.

It relies on the coordinated action of two key components:
Mucus Layer: Goblet cells and submucosal glands in the respiratory tract produce mucus, which traps particles such as dust, bacteria, and viruses. The mucus is a sticky substance that captures these unwanted substances to prevent them from reaching the lower airways and lungs.

Cilia: The respiratory epithelial cells are lined with cilia, which are small, hair-like structures. These cilia beat in a coordinated, wave-like motion to propel the mucus (and trapped particles) upward toward the throat, where it can be swallowed or coughed out. This process is known as the mucociliary escalator.

Question 25

When is the mucociliary clearance most impaired?

Answer 25

• Allergies -> mucus runny (cannot cope with volume)
• Smoking (excess mucus) -> cough

Question 26

What happens with long-term smoking?

Answer 26

Cilia is paralysed - disappears
Mucus is then lost and risk of infection goes up
-> higher risks of pneumonia, cough and bronchitis

Question 27

What is the conchae?

Answer 27

Curved, bony structures located inside the nasal cavity. They serve several important functions related to airflow, filtration, and humidification in the respiratory system.

There are three pairs of conchae in each nasal cavity:
Superior nasal conchae: These are the smallest and are located near the top of the nasal cavity.
Middle nasal conchae: Slightly larger, these are found in the middle part of the nasal cavity.
Inferior nasal conchae: The largest of the three, these are located in the lower part of the nasal cavity.

Question 28

Functions of the Conchae

Answer 28

Airflow regulation: The curved shape of the conchae creates turbulence in the airflow, slowing it down and allowing more time for the air to be filtered, humidified, and warmed before it reaches the lungs.
Filtration: As air passes over the mucosa covering the conchae, particles like dust, pollen, and pathogens get trapped in the mucus, preventing them from entering the lower respiratory tract.
Humidification and warming: The large surface area of the conchae, covered by a mucous membrane, helps humidify and warm the air, which protects the delicate tissues of the lungs from cold, dry air.

Question 29

Which glands secrete water?

Answer 29

Serous glands and bowman’s glands

Question 30

What is under the epithelium?

Answer 30

Very rich blood supply - large blood vessels

Question 31

Properties of the nasal cavity - preparing air for gas exchange

Answer 31

• the nasal cavity is a tall, narrow chamber lined with mucous membrane. The wet membrane
  humidifies and warms inspired air.
• the medial surface is flat, the lateral surface carries three sloping shelves (conchae) which
  increase the surface area of the mucous membrane.
• air-filled (paranasal) sinuses open into the cavity. They lighten the face and add resonance to
  the voice.
• the roof of the cavity carries the olfactory epithelium. Turbulence caused by sniffing carries
  air up to the epithelium. Axons of olfactory receptor cells lead towards the brain through
  perforations in the overlying bone, the cribriform plate.

Question 32

Three parts of the pharnyx

Answer 32

Question 33

Nasopharynx (Upper part)

Answer 33

Location: Behind the nasal cavity, extending from the base of the skull to the soft palate.
Function:
Serves as a passage for air from the nasal cavity to the oropharynx.
Contains the pharyngeal tonsils (adenoids), which play a role in immune defense.
The Eustachian tubes open into the nasopharynx, allowing air pressure to equalize between the middle ear and the atmosphere.

Question 34

Oropharynx (Middle part)

Answer 34

Location: Behind the oral cavity, extending from the soft palate to the level of the hyoid bone.
Function:
Acts as a common passageway for both air (from the nasal cavity) and food (from the oral cavity).
Contains the palatine tonsils and lingual tonsils, which are involved in the immune response.
Plays a crucial role in swallowing, guiding food and liquids from the mouth to the esophagus.

Question 35

Laryngopharynx (Lower part)

Answer 35

Location: Extends from the hyoid bone to the esophagus and larynx.
Function:
Serves as a passageway for food and air.
It is where the pathways for food (to the esophagus) and air (to the trachea) separate. During swallowing, the epiglottis covers the trachea to prevent food from entering the airway.

Question 36

Esophagus

Answer 36

A muscular tube that carries food and liquids from the laryngopharynx to the stomach. It is part of the digestive system.

Question 37

Trachea

Answer 37

The windpipe that carries air from the larynx to the lungs. It is part of the respiratory system.

Question 38

`Epiglottis

Answer 38

A flap-like structure that acts as a switch between the trachea and esophagus. During swallowing, it closes over the trachea to prevent food and liquid from entering the airway.

Question 39

Pharynx

Answer 39

The pharynx is a muscular tube that extends from the base of the skull to the esophagus. It starts behind the nasal cavity and ends at the top of the esophagus and larynx. It is divided into three sections: the nasopharynx, oropharynx, and laryngopharynx.

Question 40

Larnyx

Answer 40

The larynx, also known as the voice box, is located just below the pharynx and above the trachea. It sits at the top of the windpipe (trachea), just behind the thyroid cartilage (commonly called the Adam’s apple).
Function:
Voice production: The larynx houses the vocal cords, which vibrate to produce sound when air passes through them. This makes the larynx the primary organ responsible for speech and voice modulation.
Airway protection: During swallowing, the epiglottis, a flap in the larynx, closes off the airway (trachea) to prevent food or liquids from entering the lungs, directing them into the esophagus instead.
Breathing: The larynx is part of the respiratory system, providing a passageway for air to flow between the pharynx and the trachea. It helps regulate the airflow to the lungs.

Question 41

Structure of the nasal cavity

Answer 41

Tall, narrow chamber lined with mucous membrane

Question 42

What does wet membrane do?

Answer 42

Humidifies and warms inspired air