S2 A&P Respiratory

Question 1

How does the body obtain oxygen

Answer 1

Oxygen from the air is diffused across the delicate exchange surfaces of the lungs.
It exchanges it for CO2 in the lungs

Question 2

What is the respiratory system responsible for? (3)

Answer 2

Production of sound
Gas exchange surface area between the air and blood
Participates in olfactory senses

Question 3

What is the respiratory tract and what does it consist of?

Answer 3

Is the pathway that carries air to surfaces in the lungs for gas exchange,
It consists of a conducting zone that transports the air, and the respiratory zone where gas exchange occurs.

Question 4

Describe the general structure of the bronchial tree in the lungs

Answer 4

They are a network of branched passageways, that branch a total of 23 times.
They are in an irregular dichotomous pattern – meaning each airway gives rise to two daughter airways

Question 5

What is the purpose of the irregular dichotomous pattern of the lungs

Answer 5

It allows for a larger number of alveoli, and hence a larger surface area for gas exchange

Question 6

Where do alveoli appear in the bronchioles?

Answer 6

From Branch 17-20 they are buds in the walls
From 20 onward the whole airway is alveoli

Question 7

What surrounds alveoli

Answer 7

A dense network of capillaries

Question 8

Describe the structure of the lungs

Answer 8

Both the two lungs are made of multiple lobes.
Right has 3, whereas the left has 2 and a cardiac notch to allow the heart to sit.
Each lobe is has many individual lobules which are the compartmentalized regions

Question 9

What lines the conducting portion of the respiratory system

Answer 9

Respiratory mucosa, a mucus membrane

Question 10

Describe the structure and function of the respiratory Mucosa

Answer 10

Has an epithelial and areolar layer
The epithelia are ciliated, meaning it has hair like structures that beat together moving mucus containing unwanted particles to the top of the tract

Question 11

What underlines the respiratory mucosa

Answer 11

The lamina propria:
Which in the upper respiratory system contains mucous glands, and in the lower contains more smooth muscle to allow for bronchodilation and bronchoconstriction.

Question 12

What does air pass through in the nasal cavity

Answer 12

External nares (nostrils)
Nasal vestibule
Three nasal membranes

Question 13

What happens in the nasal vestibule

Answer 13

Nasal hairs acts as the first particle filtration system

Question 14

What happens to air in the nasal membranes

Answer 14

The temperature and moistness of the air is controlled before it enters the lungs.

Question 15

What does the hard and soft palate do?

Answer 15

Hard - forms the roof of the oral cavity and the base of the nasal cavity
Soft - extends posterior to the hard palate and divides the nasopharynx from the lower pharynx

Question 16

What is the pharynx and its three subdivisions

Answer 16

Is a shared chamber between the respiratory and digestive system. It extends from the internal nares to the entrance of the larynx and the esophogus
nasopharynx
Oropharynx
Laryngopharynx

Question 17

What does the epiglottis do

Answer 17

Is a smooth lid that protects the top of the pharynx and larynx, preventing unwanted things (like food) getting in.

Question 18

What is the glottis

Answer 18

Whats known as the voice box, which is the opening between the folds in the larynx. Is involved in sound production and the change in pitch

Question 19

How is sound produced

Answer 19

From air passing through the glottis, which vibrates the vocal folds and produces sound waves. Tension on the cords allows for sound variation via voluntary muscles.

Question 20

Describe the structure of the Trachea

Answer 20

Is the trunk of the Bronchial Tree
About 2.5cm in diameter
Extends from the larynx to the top of the bronchi
Is surrounded by C shaped cartilaginous rings.

Question 21

Why are the Cartilage rings around the Trachea C shaped (3)

Answer 21

To provide rigidity to keep the airway open, whilst providing an element of flexibility.
Gap in C shape can be expanded for easier passage.
Trachealis muscle sits in the gap, which contracts to give large inhalations.

Question 22

Describe the structure of the bronchi

Answer 22

Is the large air passage that leads from t he trachea to the lungs. The right and left sides are separated by the carina

Question 23

What is the difference between the right and left bronchi

Answer 23

The right is larger and descends at a steeper angle (as supports more weight as more lobes) than the right

Question 24

What is the organisation of the bronchial tree

Answer 24

The primary bronchi branch to secondary bronchi to tertiary bronchi which branch into multiple bronchioles with branch to terminal bronchioles that contain bundles of alveoli.

Question 25

What is the wall of the bronchial tree made from

Answer 25

The walls of the primary, secondary and tertiary contain progressively less cartilage and more smooth muscle. This is to increase the muscular effect on airway constriction and resistance

Question 26

Describe the structure of bronchioles

Answer 26

They have no cartilage, and are dominated by smooth muscle They are regulated by autonomic control, which controls the diameter of the bronchioles and airflow resistance.

Question 27

What is bronchodilation and bronchoconstriction?

Answer 27

Bronchodilation - Is the widening of the bronchial airways by the parasympathetic ANS to reduce resistance Bronchoconstriction - Is the narrowing of the bronchi, caused by the parasympathetic ANS or the release of histamine

Question 28

What are alveoli

Answer 28

Air filled pockets within the lungs where gas exchange takes place

Question 29

What is pulmonary ventilation and what does it cause

Answer 29

The movement of air in and out of the respiratory tract, which provides alveolar ventilation, which is the movement of air in and out of the alveoli

Question 30

What is inspiration

Answer 30

How the body allows air into the lungs It is initiated by the respiratory control center in the medulla oblongata which causes contraction of the diaphragm and intercostal muscles.

Question 31

How does the diaphragm and intercostals allow for breathing

Answer 31

The diaphragm moves downwards and rotates the lower ribs towards the horizontal plane (1cm in normal, up to 10cm in forced) The external intercostals move the ribs up and out to increase the size of the thoracic cavity.

Question 32

What is expiration, and what powers is?

Answer 32

The process of breathing out. It is a passive event done by elastic recoil, powered by the elastic fibres in the connective tissue of the lungs. As well as surface tension of a film of fluid on the alveoli

Question 33

Where are alveoli located

Answer 33

In the terminal bronchioles

Question 34

Describe the surrounding structure of the singular alveolus

Answer 34

Has a close association (almost entanglement) with capillaries for gas exchange . They are also surrounded by elastic fibres, that recoil during exhalation,

Question 35

How does the structure of alveoli allow for efficient gas exchange

Answer 35

Walls are very thin and surface area is large

Question 36

What does the alveolar epithelium consist of

Answer 36

simple squamous epithelium (thin and flat allowing for a short diffusion distance) And two types of pneumoscytes: Type I cells Type II cells

Question 37

Describe type I and type II pneumocyte cells in the alveolar epithelium

Answer 37

Type I cells – which are thin and delicate. These are controlled by ALVEOLAR MACROPHAGES, and exist in the alveoli as a filtration system Type II cells – Are in the Alveolar Macrophages and produce a surfactant.

Question 38

What is boyles law

Answer 38

describes the relationship between volume and pressure during breathing in a contained gas: - External pressure forces molecules to move closer together, - Movement of gas molecules exerts pressure on the container. Decreased volume = more collisions and more gas pressure Increased volume = fewer collisions and less pressure (as it takes longer for a molecule to travel wall to wall).

Question 39

What is henrys Law

Answer 39

Describes what happens when gas under pressure meets a liquid: - It dissolves in a liquid until an equilibrium is reached. -At a given temperature, the amount of gas in a solution =the partial pressure of the gas.

Question 40

What are the 5 reasons alveoli have such efficency in gas exchange

Answer 40

1- substantial difference in partial pressure across the respiratory membranes 2- The short distances involved in gas exchange 3- O2 and CO2 are lipid soluble 4- The total surface area is LARGE 5- Blood flow and airflow are coordinated.

Question 41

What is the pulmonary circuit

Answer 41

blood flow from the heart to the lungs and back, where blood is oxygenated

Question 42

What is the systematic circuit

Answer 42

blood flow from the heart to the rest of the body and back, delivery to tissues is oxygenated, return is not

Question 43

What condition is the blood when it arrives at pulmonary arteries

Answer 43

It has LOW partial pressure of oxygen and high of CO2. The concentration gradient causes oxygen to enter and CO2 to leave the blood.

Question 44

What happens to the pulmonary circuit at altitude

Answer 44

There is not less oxygen, just lower pressure, meaning the diffusion gradient is not as large, and equilibrium is reached at a lower partial pressure.

Question 45

What happens to blood when it enters the systematic circuit

Answer 45

oxygenated blood mixes with the deoxygenated blood from the conducting passageways. This lowers the Pressure of O2, in the blood entering the systematic circuit.

Question 46

How is Oxygen and CO2 transported in the blood.

Answer 46

Red blood cells in the plasma, as the blood plasma itself cant transport enough to meet the bodies demands

Question 47

What happens to the oxygen in our blood to get to the rest of the body.

Answer 47

Haemoglobin absorbs the oxygen in the blood and carries it to anywhere in our bodies.

Question 48

How does carbon monoxide in the environment effect oxygen delivery

Answer 48

Haemoglobin has a higher affinity to carbon monoxide than oxygen, hence when monoxide is in the atmosphere it occupies the binding sites reducing the oxygen uptake, severely damaging the body.

Question 49

Describe Haemoglobins affinity to oxygen

Answer 49

When one subunit site is bound to, it changes the conformation of the others and increases their affinity to oxygen. Hence why when O2 levels are low, even a little bit of oxygen is beneficial to increase saturation.

Question 50

How does temp and pH effect the affinity of oxygen and hameoglobin

Answer 50

Increase temp = Less afinnitive (releases oxygen readily) Decreased temp = more affinitive (holds tightly) A lower pH decreases hemoglobin's affinity A higher pH increases its affinity. This is the bohr effect

Question 51

Describe how temperature of haemoglobins affinity facilitates delivery to tissues

Answer 51

Temperature from active (muscle) tissues reduce the affinity of haemoglobin in the blood, so oxygen is released when it passes the sites that are working, to allow the oxygen to go into the tissue and be used

Question 52

What are the 3 pathways for carbon dioxide

Answer 52

Produced by aerobic metabolism 1- Dissolve in the plasma 2- Bind to haemoglobin 3- Converted to H2 CO3 (carbonic acid).

Question 53

How is the rate of respiration controlled

Answer 53

In normal conditions, the cellular rate of oxygen absorption and CO2 production is equal to the oxygen absorption and CO2 secretion at the lungs

Question 54

What does increased activity in peripheral tissues do to the rate of respiration

Answer 54

Decreased partial pressure of oxygen Increased P of CO2 Change in gas exchange Increased blood flow

Question 55

What are the voluntary and involuntary components of the neural control of respiration

Answer 55

Involuntary = regulates respiratory muscle activity, frequency and depth by responding to info from the lungs and respiratory tract Voluntary = reflects activity in the cerebral cortex an affects output of respiratory centres in brain (medulla and pons) and motor neurons.

Question 56

What are the two parts of the pons, and their role in respiration

Answer 56

Apneustic and Pneumotaxic They control the rate and depth of respiration p = Rate and pattern of breaths A= promotes deep and prolonged inhalation

Question 57

What are the chemo, baro and stretch receptors in the lungs

Answer 57

Chemo = are sensory cells that detect changes in blood oxygen and carbon dioxide levels Baro = sensitive to changes in blood pressure. Examples are the aortic and carotid sinuses. Stretch = Respond to changes in lung volume

Question 58

What is the hering breuer reflex

Answer 58

Two reflexes that allow for forced breathing Inflation reflex = prevents lung overexpansion DRG (Dorsal respiratory group) is inhibited and VRG is stimulated Deflation reflex = Inhibits the expiratory centres and stimulates inspiratory centres during lung deflation

Question 59

What ingluences the respiratory centres

Answer 59

Cranial nerve IX (glossopharyngeal) Cranial nerve X (vagus) Central chemoreceptors that monitor cerebrospinal fluid

Question 60

What happens to the respiratory system at birth

Answer 60

Before birth, pulmonary vessels are collapsed as the lung contains no air. At birth, the newborn overcomes the force of surface tension to inflate the bronchial tree and alveoli, and takes its first breath.

Question 61

What happens to the respiratory system at old age

Answer 61

Deterioration in elastic tissue affects compliance and VC (vital capacity). There can be arthritic changes and decreased flexibility. As well as emphysema a lung disease from smoking.