EXAM 3 (LECTURE)

Functional divisions of the respiratory system

Conducting zone: Conducts air to lungs

Respiratory zone: Main site of gas exchange

What is nasal conchae?

it subdivides nasal cavity

increase surface area and prevent dehydration

What are the functions of the pharynx?

Passageway for air and food

Resonating chamber

Houses tonsils

What are the 3 anatomical regions of the pharynx?

Nasopharynx

Oropharynx

Laryngopharynx

What structures are found in the oropharynx?

Fauces (opening from mouth)

Lingual tonsils

Palatine tonsils

What is another name for larynx?

voice box

What is true about larynx?

composed of 9 pieces of cartilage

Epiglottis

Vocal cords

Phonation

enunciate

androgens make folds thicker and longer

Example of laryngeal cartilage?

Thyroid cartilage (Adam's apple)

What is the function of the epiglottis?

Flap of tissue that closes during swallowing to prevent food from entering air passages

What is the function of vocal cords?

Vibrate and produce sound when air passes through

What is phonation?

produces sounds

What is enunciation?

produces words

How do androgens affect vocal cords?

it slows vibration and lower pitch

What is another name for the trachea?

Windpipe

What is another name for the trachea?

Windpipe.

Where is the trachea located compared to the esophagus?

anterior to the esophagus.

What does the trachea divide into?

divides into the right and left primary bronchi.

How many cartilage rings make up the trachea?

16-20 C-shaped rings of hyaline cartilage.

Why are the tracheal rings C-shaped?

The open part faces the esophagus

Trachea divides bronchi into?

right and left

Bronchi is located in…

Right and left primary bronchus

Bronchi is divided to

form bronchial tree

What is the order of the bronchi?

Primary, secondary, tertiary bronchi, bronchioles, terminal bronchioles, respiratory bronchioles, alveolar ducts, alveolar sac, alveoli

Alveolar ducts end at

alveolar sacs

Alveolar sacs contain

alveoli

Alveoli is where

gas exchange takes place

Sympathetic ANS

relaxation/dilation

epi pen

Parasympathetic ANS

constriction

Each lung enclosed by

double-layered pleural membrane

What is parietal pleura?

lines wall of thoracic cavity

What is visceral pleura?

covers lungs themselves

What is Pleura cavity?

space btw layers

What is pleural fluid?

it reduces friction

What is cardiac notch?

concavity on the left lung on medial area

heart makes left lung 10% smaller than right

How many lobes is it divided into?

1 or 2 fissures

Each lung has

oblique fissure

Each right lung have…

horizontal fissure

How many lobes does tht right lung have?

3

How many lobes does the left lung have?

2

Alveoli is main site of..

gas exchange

What is the function of surfactant?

reduces tendency of alveoli to collapse

Respiratory distress syndrome

not enough surfactant– often in newborn – blue/grunting

What are the steps for respiration (gas exchange)?

1. Pulmonary ventilation/breathing

2. External (pulmonary) respiration

3. Internal (tissue) respiration

pulmonary ventilation/breathing

inhalation and exhalation

exchange of air btw atmosphere and alveoli

external (pulmonary) respiration

exchange of gases btw alveoli and blood

Internal (tissue) respiration

Exchange of gases between systemic capillaries and tissue cells

High lung compliance

expands easily

Low lung compliance

resist expansion

Lung compliance decreased from

•    Scar tissue (TB)

• Decrease in surfactant

• Emphysema

• Pulmonary edema

• Paralysis of muscles that aid in breathing

What affects airway resistance?

Airway diameter affects resistance. Large diameter airways have less resistance, while narrow airways have more resistance.

How do large diameter airways affect resistance?

Large diameter airways have less resistance and allow easier airflow.

How do narrow airways affect resistance?

Narrow airways have more resistance and make airflow more difficult.

How does the sympathetic nervous system affect the airways?

The sympathetic nervous system causes airway relaxation and dilation, which decreases resistance.

Spirometer (respirometer)

used to measure volume of air exchanged during breathing.

Spirogram

is the record

Tidal volume

volume of one breath

What is another name for expiratory reserve volume?

ERV

Expiratory reserve volume

additional air that can be forcibly exhaled after the expiration of a normal tidal volume

inspiratory reserve volume

The additional air that can be forcibly inhaled after the inspiration of a normal tidal volume

Residual volume

air remaining after expiratory reserve volume exhaled

What is the percentage of nitrogen?

78.6%

What is the % of oxygen?

20.9%

What is the percentage of carbon dioxide?

.04%

What is the percentage of water vapor?

.04%

Rate of Pulmonary and Systemic Gas Exchange depends on

1) Partial pressures of gases

  2) Surface area available for gas exchange

  3) Diffusion distance

What factors affect hemoglobin's affinity for oxygen?

Acidity (pH), carbon dioxide (PCO2), and temperature changes.

How does increased acidity affect hemoglobin's affinity for oxygen?

As acidity increases (pH decreases), hemoglobin's affinity for oxygen decreases, causing more oxygen unloading.

Why does increased acidity enhance oxygen unloading?

Metabolically active tissues become acidic and require more oxygen, so hemoglobin releases oxygen more easily.

How does carbon dioxide affect hemoglobin's affinity for oxygen?

As PCO2 rises, hemoglobin unloads oxygen more easily.

How does increased temperature affect hemoglobin's affinity for oxygen?

As temperature increases, more oxygen is released from hemoglobin.

How does hypothermia affect oxygen binding?

During hypothermia, more oxygen remains bound to hemoglobin.

What is fetal hemoglobin (Hb-F)?

Fetal hemoglobin is a type of hemoglobin that has a higher affinity for oxygen than adult hemoglobin.

How does fetal hemoglobin compare to adult hemoglobin?

Hb-F has a higher affinity for oxygen and can carry up to 30% more oxygen than adult hemoglobin.

What is hypoxia?

Hypoxia is a deficiency of oxygen at the tissue level.

What is the most important factor influencing respiration?

PCO2 is the most important factor influencing respiration.

Why does PCO2 strongly influence respiration?

Small changes in PCO2 levels cause large changes in respiratory rate.

What is hypercapnia?

increase in arterial PCO2.

What is the most common cause of hypercapnia?

most commonly caused by hypoventilation.

What is hypocapnia?

decrease in arterial PCO2.

What is the most common cause of hypocapnia?

most commonly caused by hyperventilation.

Characteristics of aging

All aspects of respiratory function decrease with age:

Airways – less elastic, more rigid

Chest wall – more rigid

Decreased level of blood oxygen

Decreased action of cilia

Compliance is reduced with rib arthritis

More susceptible to pulmonary disorders

principal muscles are

diaphragm, external and internal intercostal muscles

Inhalation

active

Contraction of Diaphragm – most important muscle of inhalation

Flattens, lowering dome when contracted

Responsible for 75% of air entering lungs during normal quiet breathing

External intercostals

Contraction elevates ribs

25% of air entering lungs during normal quiet breathing

Exhalation/expiration

Pressure in lungs greater than atmospheric pressure

Normally passive – muscles relax instead of contract

Based on elastic recoil of chest wall and lungs from elastic fibers

Diaphragm relaxes and become dome shaped

Another name for Gastrointestinal tract

GI tract

What does GI tract contain?

mouth, pharynx, esophagus, stomach, small intestine, and large intestine

What does accessory digestive organs contain?

liver, gallbladder and pancreas

Mechanical digestion

churns foodC

Chemical digestion

enzymes

Layers of GI tract

1. Mucosa – inner lining

2. Submucosa

3. Muscularis

       Arranged in inner circular fibers and outer longitudinal fibers

4. Serosa

What is mucosa?

iner lining

What is muscularis?

arranged in inner circular fibers and outer longitudinal fibersW

What is serosa also called?

visceral peritoneum

What happens when food enters the mouth?

Secretion increases to lubricate and dissolve food and begin chemical digestion by salivary amylase.

3 pairs of major salivary glands secrete most of the saliva

Parotid, submandibular, and sublingual

Minor salivary glands

hundreds, soft and hard palates, tongue

What is another word lingual frenulum?

frenum

What is lingual frenulum?

tongue-tied

saliva

 Mostly water 99.5%

 Antibacterial

“Dry mouth” – radiation/medications

helps with taste

lubricates food