BIOS 1310 lab final (slides)

Respiratory system functions

gas exchange

communication

olfaction

acid/base balance

BP regulation

• Ang II (ACE from lungs)

blood/lymph flow

blood filtration

expulsion of abdominal contents

Organs of the respiratory system

nose

pharynx

larynx

trachea

bronchi

lungs

Functions of the nose

warm

clean

humidify

detect oders

resonating chamber (voice)

structures:

• Nostrils/nares

• Nasal apertures

• facial part

  • shaped by hyaline cartilage and bone

• internal part

  • nasal cavity

  • R and L halves divided by septum

  • ethmoid, vomer, nasal cartilages

structures of the nose

Nostrils/nares

Nasal apertures

facial part

• shaped by hyaline cartilage and bone

internal part

• nasal cavity

• R and L halves divided by septum

• ethmoid, vomer, nasal cartilages

Borders of nasal cavity

roof

• ethmoid

• sphenoid

floor

• hard palate

Turbinates/conchae

• superior

• middle

• inferior

Olefactory epithelium (oders) of the nose

pseudostratified columnar epithelium

• cilia are immoblie

sensory cells in superior conchae, septum, roof or nasal fossa

Respiratory epithelium

pseudostratified columnar epithelia

goblet cells:

• secrete mucus—→pharynx

Pharynx

nasopharynx

• above soft palate

oropharynx

• below soft palate/ above epiglottis

laryngopharynx

• under epiglottis/above cricoid cartilage

Larynx

epiglottis

9 cartilages:

• epiglottis

• thyroid

• cricoid

• arytenoid

• corniclate

• cuneiform

functions:

• keep food/beverage out of trachea

• producing sound/phonation

Vocal cords

=glottis

intrinsic and extrinsic ligaments

Vestibular folds

Superior:

• play no role in speech

• close larynx during swallowing

Inferior:

• produce sounds when air passes between them

  • More taught: higher pitch

  • More slack: lower pitch

Loudness/volume of voice

determined by the force of air passing through (duck call)

Intelligible speech

produced as a combination effect of pharynx, oral cavity, tongue, and lips

Trachea

windpipe/airway

lies anterior to the esophagus

c shaped rings of cartilage

• trachealis mm

• keep it from collapsing as you inhale

pseudostratified columnar w/ goblet cells

• mucociliary escalator

Lungs

peak: apex

base: concave

• sits on diaphragm

root:

• hilum, BV, main bronchus, lymphatics, nerves

R lung is short than L

• liver

• 3 lobes

  • sup/mid/in

L lung narrower than R

• heart

• 2 lobes

  • sup/inf

neither fill thoracic cage

not symmetrical

Branching system of lungs

main bronchus—→bronchioles

R main bronchus

• wider/more vertical

• gives off 3 more branches

  • superior, middle, and inferior lobar/secondary bronchi

L main bronchus

• narrower/more horizontal

  • sup and inferior lobar/secondary bronchi

both then divide into:

• segmental bronchi

• bronchioles

• terminal bronchioles

then beings the respiratory zone:

• respiratory bronchioles

• alveolar ducts

• alveolar sacs

Air flow

Nasal cavity —→pharynx—→trachea—→main/primary bronchus—→lobar/secondary broncus—→segmental/tertiary broncus—→bronchiole—→terminal bronchiole—→(respiratory zone)respiratory bronchioles—→alveolar duct—→atrium—→alveolus

alveoli

~150 million tiny sacs

type 1

type 2

alveolar macrophages

Squamous (type 1) alveolar cells

thin, for rapid diffusion

Great (type 2) alveolar cells

cuboidal, for repair and surfactant secretion

Alveolar macrophages (dust cells)

wandering cells used for phagocytosis

• capture the “escapee” debris

most numerous of all lung cells

Visceral pleura

surface of lung, goes in b/t lobes

@ hilum, it turns on itself and forms parietal

Parietal pleura

adheres to mediastinum, inner rib cage, and superior diaphragm

Pleural cavity

lungs are NOT here

the space b/t layers

“potential” space

Pleural fluid

Functions:

• reduces friction

  • infection = pleurisy

• pressure gradient

• compartmentalization

Inspiration

breathing in

Expiration

breathing out

Quiet respiration

relaxed, unconscious, automatic

not thinking about breathing

Forced respiration

deep, rapid

exercise, singing, etc.

Muscles of respiration

Inspiration:

• diaphragm

  • contracts;flattens

    • decreases pressure/increases air flow in

• external intercostals

• SCM

• scalenes

• pec minor

Expiration

• diaphragm

  • relaxed; bulges upward

    • increases pressure and forces air out

• internal intercostals

• rectus abdomnius

• external oblique

• quadratus lumborum

stimuli from the brain that controls breathing

cerebral —→conscious

medulla—→unconscious

Ventral Resp group (VRG)

primary rhythm generator

Dorsal Resp group: DRG

issues output to VRG (modulates)

Pontine Resp group: PRG

• adapts breathing to special circumstances like sleep, exercise, speech, crying, or laughing

Central chemoreceptors

brainstem neurons

detect pH

Peripheral chemoreceptors

in carotid and aortic bodies

detect O₂ and CO₂

Detect pH

Strech receptors

in sm m of bronchi and bronchioles in visceral pleura

respond to inflation of lungs

signal by using CN X

Hering breuer reflex

• prominent in infancy and premies

Irritant receptors

nerve ending along airway

Pressure and airflow

governed largely by the same principles as blood flow

inspiration is driven by atmospheric pressure

• the weight of the air above us

Boyle’s Law

gas pressure is inversely proportional to volume

Dalton’s Law

total pressure of a gas mixture is equal to the sum of all individual gas partial pressures

Anatomical dead space

the air that never makes it to the alveoli for gas exchange

Physiological dead space

the sum of anatomical and pathological dead space

Spirometry

measurement of pulmonary ventilation

• helps to ID restrictive vs obstructive disorders

Tidal volume (TV)

amount of inhaled and exhaled air in one cycle

Inspiratory reserve volume (IRV)

amount of air that can be forcefully inhaled after a normal tidal volume inspiration

Expiratory reserve volume (ERV)

amount of air that can be forcefully exhaled after a normal tidal volume expiration

Residual volume

amount of air remaining in the lungs after a forced expiration

Total lung capacity (TLC)

maximum amount of air contained in lungs after maximum inspiratory effort

TLC = TV + IRV + ERV + RV

Vital capacity (VC)

maximum amount of air that can be expired after a maximum inspiratory effort

VC= TV+IRV+ERV

Inspiratory capactiy (IC)

maximum amount of air that can be inspired after a normal tidal colume expiration

IC=TV+IRV

Functional residual capacity

volume of air remaining in the lungs after a normal tidal colume expiration

FRC = ERV + RV

Apnea

skipped breaths

short tem absence of breathing

Dyspnea

gasping, labored, SOB (shortness of breath)

Hyperpnea

increase rate/depth, w exercise, pain

Hyperventilation

assoc w anxiety

expelling CO2 faster than produced

Hypoventilation

increase in blood CO2

respiratory acidosis

Orthopnea

positional dyspnea

emphysema, asthma, heart failure

Respiratory arrest

stopped breathing

Tachypnea

accelerated breathing

Kussmaul respiration

deep, rapid

assoc w acidosis

• diabetes

Oxygen transport

found bound to

• HbA in RBCs (98%)

• in blood plasma

CO₂ transport

3 forms

• carbonic acid/bicarbonate

  • in RBC

• Carbamino compounds

  • as in hemoglobin

• dissolved gas

Exercise

signals are sent in anticipation of need

excitory signals are sent from skeletal muscle and receptors to regulate gas exchange and respiratory rate

the main stimulus to pulmonary ventilation is H+ conc in CSF/brain

Hypoxia

deficiency of O₂ in tissues

Hypoxemic

m/c due to degenerative lung conditions

Ischemic

CHF, inadequate circulation

Anemic

d/t anemia leading to inability of O₂ carrying

Histotoxic

metabolic poisoning

• cyanide

Emphysema

COPD

alveolar walls break down and converge into fewer and larger spaces

barrel chested from trapped air

3-4x normal expanding just to breath

Chronic bronchitis

COPD

severe, persistent inflammation

• goblet cells secrete too much mucus that cilia can’t remove

  • bacterial lair

mucus and cellular debris = sputum

Acute rhinitis

the common cold

Pneumonia

lower respiratory infection

sleep apnea

10 second break in breathing

TB

pulmonary infection w mycobacterium

squamous cell carcinoma

lung cancer where basal cells multiply and metaplasia occurs w bleeding lesions

small cell carcinoma

lung cancer that is the least common, but most dangerous

atelectasis

collapse of the lung lobes