week 2 quiz mechanics of respiration

Question 1

primary goals of the respiratory system?

Answer 1

Primary Goals Of The Respiration System Distribute air & blood flow for gas exchange Provide oxygen to cells in body tissues Remove carbon dioxide from the body Maintain constant homeostasis for metabolic needs

Question 2

4 functional events of respiration.

Answer 2

1. Mechanics of pulmonary ventilation 2. Diffusion of O2 & CO2 between alveoli and blood 3. Transport of O2 & CO2 to and from tissues 4. Regulation of ventilation & respiration

Question 3

External Respiration is?

Answer 3

1. Mechanics of breathing 2. The movement of gases into & out of body 3. Gas transfer from lungs to tissues of the body 4. Maintain body & cellular homeostasis

Question 4

Internal Respiration is?

Answer 4

1. Intracellular oxygen metabolism 2. Cellular transformation 3. Krebs cycle – aerobic ATP generation 4. Mitochondria & O2 utilization

Question 5

The main purpose of ventilation is to?

Answer 5

maintain an optimal composition of alveolar gas

Question 6

Alveolar gas acts like?

Answer 6

A stabilizing buffer compartment between the environment & pulmonary capillary blood 1. Oxygen constantly removed from alveolar gas by blood 2. Carbon dioxide continuously added to alveoli from blood 3. O2 replenished & CO2 removed by process of ventilation, by simple diffusion.

Question 7

the lungs have a Short diffusion pathway for gases. total lung blood volume is?

Answer 7

500ml (10% of total blood volume)

Question 8

what are the Multiple factors required to alter lung volumes

Answer 8

1. Respiratory muscles generate force to inflate & deflate the lungs 2. Tissue elastance & resistance impedes ventilation 3. Distribution of air movement within the lung, resistance within the airway 4. Overcoming surface tension within alveoli

Question 9

The Breathing Cycle. ( this is important)

Answer 9

1. Airflow requires a pressure gradient 2. Airflow from higher to lower pressures 3. During inspiration, alveolar pressure is sub-atmospheric allowing airflow into lungs 4. Higher pressure in alveoli during expiration than the atmosphere allows airflow out of the lungs. 5. Changes in alveolar pressure are generated by changes in pleural pressure.

Question 10

Inspiration ( Active Phase Of Breathing Cycle) nerve impulses initially come from where?

Answer 10

The brainstem and activate muscle contraction

Question 11

which nerves transmit stimulation to the diaphragm?

Answer 11

Phrenic nerves C 3,4,5

Question 12

Which nerves send signals to the external intercostal muscles?

Answer 12

Intercostal nerves (T 1-11).

Question 13

The act of inhaling is negative or positive pressure?

Answer 13

negative-pressure ventilation. Thoracic cavity expands to lower pressure in pleural space surrounding the lungs Pressure in alveolar ducts & alveoli decreases Fresh air flows through conducting airways into terminal air spaces until pressures are equalized Lungs expand passively as pleural pressure falls

Question 14

Most Important Muscle Of Inspiration is?

Answer 14

The Diaphragm. -Responsible for 75% of inspiratory effort -Thin dome-shaped muscle attached to the lower ribs, xiphoid process, lumbar vertebra

Question 15

what nerves innervate the diaphragm?

Answer 15

Innervated by Phrenic nerve (Cervical segments 3,4,5)

Question 16

During the contraction of the diaphragm, abdominal contents are moved which way?

Answer 16

downward & forward causing an increase in the vertical dimension of the chest cavity

Question 17

what happens to the rib margins during the contraction of the diaphragm?

Answer 17

Rib margins are lifted & moved outward causing an increase in the transverse diameter of the thorax

Question 18

the diaphragm moves how far during normal inspiration and how far during forced inspiration?

Answer 18

down 1 cm normally can move down 10cm during forced inspiration.

Question 19

Paradoxical movement of the diaphragm occurs when?

Answer 19

it is paralyzed. -Upward movement with an inspiratory drop of intrathoracic pressure -Occurs when the diaphragm muscle is denervated

Question 20

Movement of Thorax During Breathing Cycle

Answer 20

slide 13 photo.

Question 21

Effect of abdominal pressure

Answer 21

Abdominal pressure equal atmospheric pressure in a supine position when respiratory muscles are relaxed

Question 22

Increasing abdominal pressure does what?

Answer 22

pushes diaphragm cephalad into the thoracic cavity, decreasing FRC.

Question 23

FRC reduced by increased intra-abdominal pressure situations

Answer 23

Examples: Pregnancy, Obesity, Bowel obstruction, Laparoscopic surgery, Ascites, Abdominal mass, Hepatomegaly, Trendelenburg position, Valsalva maneuver

Question 24

what decreases abdominal pressure and allow easier lung ventilation

Answer 24

Upright, reverse Trendelenburg & prone positions

Question 25

External Intercostal Muscles are responsible for what percent of inspiratory effort.

Answer 25

25 %

Question 26

motor neuron pathway.

Answer 26

Motor neurons to the intercostal muscles originate in the respiratory centers of the brainstem and travel down the spinal cord. The motor nerves leave the spinal cord via the intercostal nerves. These originate from the ventral rami of T1 to T11, they then pass to the chest wall under each rib along with the intercostal veins and arteries

Question 27

Does an epidural affect inspiration?

Answer 27

Paralysis of EIM does not seriously alter inspiration because diaphragm is so effective but sensation of inhalation is decreased

Question 28

what muscles that assist with FORCED inspiration during stress or exercise?

Answer 28

1. Scalene Muscle - Attach cervical spine to apical rib - Elevate the first two ribs during forced inspiration 2. Sternocleidomastoid Muscle - Attach the base of the skull (mastoid process) to top of sternum and clavicle medially - Raise the sternum during forced inspiration

Question 29

what occurs during Expiration?

Answer 29

1. Chest muscles & diaphragm relax contraction 2. Elastic recoil of thorax & lungs return to equilibrium 3. Pleural & alveolar pressures rise 4. Gas flows passively out of the lung 5. Expiration - active during hyperventilation & exercise

Question 30

Muscles of Active Expiration

Answer 30

1. Rectus abdominus/abdominal oblique muscles - Contraction raises intra-abdominal pressure to move diaphragm upward - Intra-thoracic pressure raises and forces air out from lung 2. Internal intercostals muscles - Assist expiration by pulling ribs downward & inward - Decrease the thoracic volume - Stiffen intercostals spaces to prevent outward bulging during straining These muscles also contract forcefully during coughing, vomiting, & defecation

Question 31

Thorax Structures During Respiration

Answer 31

slide 21

Question 32

Transpulmonary pressure is?

Answer 32

The pressure difference between the alveolar pressure & pleural pressure on the outside of the lungs

Question 33

recoil pressure is?

Answer 33

The elastic forces which tend to collapse the lung during respiration are Recoil Pressure.

Question 34

Two parts of the pleural membrane are?

Answer 34

1. Visceral pleura- is a thin serosal membrane that envelopes the lobes of the lungs 2. Parietal pleura- lines the inner surface of the chest wall, lateral mediastinum, and most of the diaphragm

Question 35

Pleura space enclosed by a continuous membrane

Answer 35

1. The two pleural membranes slide against each other 2. The pleural membranes are difficult to separate apart 3. Separated by a thin layer of serous fluid ( a large amount would be a pleural effusion as seen in CHF, CA, infection)

Question 36

Pleura sac

Answer 36

1. The continuous membranes fold to create a sac inferiorly 2. Both pleura line this potential space inclosing a small amount of fluid

Question 37

Pleural fluid

Answer 37

1. Functions as a lubricant between the membranes, prevents frictional irritation 2. Causes the visceral & parietal pleura to adhere together, maintains surface tension 3. Lymphatic drainage maintains constant suction on pleura (-5cmH2O)

Question 38

is Pleural Pressure negative or positive

Answer 38

The pressure of the fluid in the space between the lung pleura (visceria) & chest wall pleura (parietal), always negative

Question 39

Normally at rest suction creates a negative pressure at beginning of inspiration of how much

Answer 39

(-5cmH20) This suction holds the lungs open at rest

Question 40

Pressure becomes more _____ during inspiration. also much

Answer 40

Pressure becomes more negative during inspiration moving to -7.5cmH20 allowing for negative pressure respiration

Question 41

If pleural pressure becomes positive the lung will ?

Answer 41

collapse: Pneumothorax, Hemothorax, Chylothorax

Question 42

FRC functional reserve capacity = ?

Answer 42

FRC = ERV + RV FRC = 2.5 L

Question 43

spirometry values IC= VC= TCL=

Answer 43

IC= 3 L VC= 4.5L TCL= 5.5L

Question 44

most tidal volumes are based on what kg adult and how many ml

Answer 44

70kg and 500 ml tidal volume based on ideal not actual weight

Question 45

Spirometry cannot measure what value?

Answer 45

Residual Volume (RV) thus Functional Residual Capacity (FRC) and Total Lung Capacity (TLC) cannot be determined using spirometry alone.

Question 46

FRC and TLC can be determined by

Answer 46

1) Helium dilution, 2) Nitrogen washout, or 3) body plethysmography