BIO - Respiratory System

Question 1

Respiratory System (fxn & Divisions)

Answer 1

All parts serve as air distributors (except Alveoli)
Air - warms, filters, humidifies
Speech, olfaction, homeostasis of blood pH
Upper Division: nose, nasopharynx, oropharynx, laryngopharynx, larynx
Lower Division: trachea, bronchial trees, lungs

Question 2

Nose

Answer 2

Two nasal bones surrounded by frontal bone
Nose is surrounded by the maxilla bone
Olfactory Epithelium - contains olfactory n
Paranasal sinuses: 4 pairs (sphenoid, frontal, ethmoid, maxillary) of air-containing spaces
Fxn: air passage to/from lungs, filters air, sense of smell

Question 3

Pharynx (throat)

Answer 3

Tubelike structure from base of skull to esophagus
Pathway for the respiratory/digestive tracts
- Nasopharynx: non collapsible - not
involved in digestion (pharyngeal tonsils-
when enlarged = adenoids)
- Oropharynx: above hyoid, palatine/lingual
tonsils
- Laryngopharynx: hyoid to esophagus

Question 4

Trachea (windpipe)

Answer 4

1st portion of lower respiratory division

Furnishes part of the opening airway to lungs

Question 5

Bronchi

Answer 5

Distribute air to alveoli, cleanse, warm/humidify air
Primary bronchi (L/R) enter lung > secondary bronchi > bronchioles > terminal bronchioles > respiratory bronchioles (last branch that solely conduct air)

Question 6

Alveoli

Answer 6

Primary gas (O2/CO2) exchange structure
Respiratory membrane: barrier btwn which gases are exchanged by alveolar air/blood
- consist of alveolar/capillary epithelium,
interstitial fluid
Surfactant: fluid coating in respiratory membrane, reduces surface tension, keeps alveoli from sticking

Question 7

Lungs

Answer 7

Hilum: medial surface of lung
Base: rest against the diaphragm
Costal surface: lies against the ribs
R- Lung: (3) lobes
L- Lung: (2) lobes

Question 8

Thorax

Answer 8

(3) divisions divided by pleura (lubricate)
- 2 pleural divisions occupied by lungs
- mediastinum: occupied by esophagus,
trachea, large blood vessels, heart
- Parietal pleura: lines thoracic cavity
- Visceral pleura: covers lungs
Fxn: brings about inspiration/expiration

Question 9

Inspiration

Answer 9

Diaphragm contracts > thoracic cavity volume incr (pushing down) > decr lung pressure > air rushes (high >low) into lungs

Question 10

Expiration

Answer 10

Diaphragm relaxes (moves upward) > thoracic cavity volume decr > incr lung pressure > air rushes (high>low) out of the lungs

Question 11

Quiet & Forced Inspiration

Answer 11

Quiet inspiration: contraction of diaphragm & sometimes external intercostals (ant rib/sternum elevation) to make thoracic cavity larger
Forced inspiration: accessory mm (SCM, pect minor, serratus ant) = thorax expansion
- decr intrapleural/alveolar pressure

Question 12

Quiet & Forced Expiration

Answer 12

Quiet Expiration: inspiratory mm relax = decr thorax
Forced expiration: abdominal & internal intercostals mm decr thorax pressure
- incr intrapleural pressure > incr alveolar
pressure above atmospheric
Elastic recoil: pulmonary tissue return to smaller size after being stretched = decreases lung size

Question 13

Transpulmonary Pressure

Answer 13

The difference btwn intrapleural/alveolar pressure
- intrapleural pressure is always less then
alveolar/atmospheric pressure = keep lung
from collapsing

Question 14

Pulmonary Volumes

Answer 14

Tidal Volume: air exhaled after normal inhale
Expiratory reserve volume: additional volume of air forcefully exhaled
Inspiratory reserve volume: additional volume of air forcefully inhaled
Residual volume: air in alveoli that can’t be forcefully exhaled

Question 15

Pulmonary Capacities

Answer 15

Sum of 2> volumes
Vital Capacity: max amount of air a person can in/out lungs
- Forced expiratory volume: 1st sec- 83%,
2nd sec- 94%, 3rd- 97% of vital capacity
Inspiratory Capacity: max amount of air a person can inspire
Functional Residual Capacity: amount of air at the end of normal respiration
Total Lung Capacity: total amount of air a lung can hold
Pulmonary Ventilation: volume of air that actually reaches the alveoli (gas exchange)

Question 16

Pulmonary Gas Exchange (pressure & factors)

Answer 16

Arterial blood O2/CO2 & Alveolar O2/CO2 pressure are very closely equal
Factors for O2 diffusion into blood:
- O2 pressure gradient
- total functional surface area (greater area =
greater exchange)
- respiratory minute volume
- alveolar ventilation

Question 17

Gas transport

Answer 17

Hemoglobin: O2 main way of transport
Bicarbonate ion: CO2 main way of transport
- high CO2 in blood = high H = low pH

Question 18

Respiratory Control Centers

Answer 18

Medulla (of the brainstem) contains a rhythmicity center: rhythm of respiratory cycle
- ventral respiratory group (VRG): stim/inhib
diaphragm
- dorsal respiratory group: PCO2
chemoreceptors signals to VRG to change
rhythm (incr if pH is low = high PCO2)
Pons (of brainstem) have apneustic centers: regulate length/depth of inspiration

Question 19

Negative Feedback Control of Respiration

Answer 19

Incr PCO2 plasma > integrators in brainstem (pons/medulla) signal to respiratory mm (effectors) > respiratory rate incr > PCO2 loss incr = lower volume = normal levels (homeostasis)

Question 19

Larynx (voice box)

Answer 19

Btwn root of tongue to upper trachea
Framework is cartilage (9)
- single & paired
Fxn: forms upper airway to lungs, produces voice, remove particles & warms & humidify air
- mm help vocalization, respiration, swallowing