ANAPHY: RESPIRATORY AND ENDOCRINE

CO2 

a by-product of ATP production and must be removed from the blood.

**External nose**

encloses the chamber for air inspiration.

**Nasal cavity**

a cleaning, warming, and humidifying chamber for inspired air.

**Pharynx**

commonly called the throat, it serves as a shared passageway for food and air.

**Larynx**

the voice box

**Trachea**

commonly known as the windpipe. An air-cleaning tube to funnel inspired air to each lung.

**Bronchi**

tubes that direct air into the lungs.

**Lungs**

labyrinths of air tubes and a complex network of air sacs, called alveoli, and capillaries. Each air sac is the site of gas exchange between the air and the blood.

**Upper respiratory tract**

structures from the nose to the larynx

**Lower respiratory tract**

structures from the trachea through the alveoli in the lungs

**Conducting zone**

structures from the nose to the air tubes within the lungs used strictly for ventilation

**Respiratory zone**

small air tubes in the lungs and the alveoli where gas exchange occurs

**Ventilation**

breathing, the movement of air into and out of the lungs

**External Respiration**

the exchange of O2 and CO2 between the air in the lungs and the blood

**Gas Transport**

O2 and CO2 travel in the blood to and from cells

**Internal Respiration**

the exchange of O2 and CO2 between the blood and the tissues

**Regulation of blood pH**

The respiratory system can alter blood pH by changing blood CO2 levels.

**Production of chemical mediators**

The lungs produce an enzyme called angiotensin-converting enzyme (ACE)

angiotensin-converting enzyme (ACE),

it regulates blood pressure.

**Voice production**

* Air moving past the vocal folds makes sound and speech possible.

**Olfaction**

The sensation of smell occurs when airborne molecules are drawn into the nasal cavity.

**Protection**

The respiratory system provides protection against some microorganisms by preventing them from entering the body and removing them from respiratory surfaces.

**External nose:**

* composed of mainly of hyaline cartilage

**Nasal cavity:**

* extends from **nares** (nostrils) to the **choana** which are the openings to pharynx

**hard palate**

its the roof of the nasal cavity

**nasal septum**

Divides the nasal cavity in half

Nares

it means nostrils

choana

Opening of the pharynx

**Paranasal sinuses:**

* air filled spaces within bone
* open into nasal cavity
* lined with mucous

**Conchae:**

* bony projections on each side of nasal cavity
* increase surface area of nasal cavity
* help in cleaning, humidifying, warming of air

**Nasolacrimal ducts:**

* carry tears from eyes
* open into nasal cavity

* **Serves as a passageway for air -** remains open even when the mouth is full of food.
* **Cleans the air -** The nasal cavity is lined with hairs, which trap some of the large particles of dust in the air.
* **Humidifies and warms the air -** Moisture is added to the air as it passes through the nasal cavity.
* **Contains the olfactory epithelium -** the sensory organ for smell, is located in the most superior part of the nasal cavity.
* **Helps determine voice sound** *-* The nasal cavity and paranasal sinuses are resonating chambers for speech.

**Functions of the Nasal Cavity**

Olfactory epithelium

the sensory organ for smell

**Pharynx**

a common passageway for the respiratory and digestive systems

\`**Nasopharynx:**

* takes in air

**Oropharynx:**

* extends from uvula to epiglottis
* takes in food, drink, and air

**Laryngopharynx:**

* extends from epiglottis to esophagus
* food and drink pass through

**Uvula:**

* “little grape”
* extension of soft palate

\
**Pharyngeal tonsil:**

* aids in defending against infections

**Larynx**

Located in the anterior throat and extends from the base of the tongue to the trachea

**Thyroid cartilage:**

* largest piece of cartilage
* called Adam’s apple

**Epiglottis:**

* piece of cartilage
* flap that prevents swallowed materials from entering larynx

**Vestibular folds:**

* false vocal cords

**Vocal Folds:**

* source of voice production
* air moves past them, they vibrate, and sound is produced
* force of air determine loudness
* tension determines pitch

* Trachea
* Bronchi
* Tracheobronchial Tree in Lungs
* Alveoli

**Lower Respiratory Tract**

**Trachea**

* Windpipe
* Consists of 16 to 20 C-shaped pieces of cartilage called **tracheal rings**
* Lined with ciliated pseudostratified columnar epithelium
* Smoking kills cilia
* Coughing dislodges materials from trachea

**Bronchi**

* Divides into right and left main (primary) bronchi  in the lungs at the carina
* Lined with cilia
* Contain C-shaped pieces of cartilage

1. Primary bronchi
2. Lobar (secondary) bronchi
3. Segmental (tertiary) bronchi
4. Bronchioles
5. Terminal bronchioles
6. Respiratory bronchioles
7. Alveolar ducts
8. Alveoli

**Tracheobronchial Tree**

**Bronchodilation**

the smooth muscle relaxes, making the bronchiole diameter larger.

**Bronchoconstriction**

the smooth muscle contracts, making the bronchiole diameter smaller.

**Asthma attack**

contraction of terminal bronchioles leads to reduced air flow

**Alveoli**

* The sites of external respiration
* small air-filled sacs where air and blood come into close contact  
* where gas exchange occurs
* surrounded by capillaries
* 300 million in lungs
* From the terminal bronchioles to the alveoli, there are multiple levels of branching.

**Respiratory bronchioles**

have a few attached alveoli.

**Alveolar ducts**

arise from the respiratory bronchioles and open into alveoli.

**Alveolar sacs**

* are chambers connected to two or more alveoli at the end.

**Respiratory Membrane**

* In lungs where gas exchange between air and blood occurs
* Formed by walls of alveoli and capillaries
* Alveolar ducts and respiratory bronchioles also contribute
* Very thin for diffusion of gases

* Thin layer of fluid from alveolus
* Alveolar epithelium (simple squamous)
* Basement membrane of alveolar epithelium
* Thin interstitial space
* Basement membrane of capillary endothelium
* Capillary endothelium (simple squamous)

**Layers of Respiratory Membrane**

* thoracic vertebrae
* ribs
* costal cartilages
* sternum
* associated muscles

The **thoracic wall** consists of:

**Thoracic cavity**

the space enclosed by the thoracic wall and the **diaphragm**

Diaphragm

* a sheet of skeletal muscle separating the thoracic cavity from the abdominal cavity
* The diaphragm and skeletal muscles of the thoracic wall change thoracic volume during ventilation

**Lungs**

* Primary organ of respiration
* Cone shaped
* Contains many air passageways (divisions)

**base**

part of the lung which rests on the diaphragm

Apex

part of the lung extends above the clavicle

Right Lung

part of the lung which has 3 lobes

Left Lung

part of the lung which has 2 lobes

**Oxygenated blood**

has passed through the lungs and picked up O2 

**Deoxygenated blood**

has passed through the tissues and released some of its O2.

**Pulmonary arteries**

carry deoxygenated blood to **pulmonary capillaries**.

**pulmonary veins**

Blood becomes oxygenated and returns to the heart through this

**Superficial lymphatic vessels:**

* deep to the connective tissue that surrounds each lung
* drain lymph from the superficial lung tissue and the visceral pleura.

**Deep lymphatic vessels:**

* follow the bronchi
* drain lymph from the bronchi and associated connective tissues

**Pleural cavity:**  

space around each lung

**Pleura:**  

double-layered membrane around lungs

**Parietal pleura:**  

membrane that lines thoracic cavity

**Visceral pleura:**  

membrane that covers lung’s surface

Ventilation (breathing)

the process of moving air in and out of the lungs

* actions of the muscles of respiration  
* air pressure gradients

Two aspects to ventilation:

1. **Muscles of Inspiration**


2. **Muscles of Expiration**

**Muscles of Respiration**

**Muscles of Inspiration**

increase the volume of the thoracic cavity.

* diaphragm
* external intercostals
* pectoralis minor
* scalene muscles

**Muscles of expiration**

decrease thoracic volume by depressing the ribs and sternum.

* internal intercostals
* transverse thoracis
* abdominal muscles

**Quiet breathing**

expiration is a passive process due to elastic tissue in the thorax wall and the lungs.

**Labored inspiration**

more air moves into the lungs because all of the inspiratory muscles are active.

**Labored expiration**

more air moves out of the lungs due to the forceful contraction of the internal intercostals and the abdominal muscles.

**Inspiration**

* Diaphragm descends and rib cage expands
* Thoracic cavity volume increases, pressure decreases
* **Atmospheric pressure** is greater than **alveolar pressure**
* Air moves into alveoli (lungs)

**Expiration**

* **Diaphragm relaxes and rib cage recoils**
* **Thoracic cavity volume decreases, pressure increases**
* **Alveolar pressure** is greater than **atmospheric pressure**
* **Air moves out of lungs**

Spirometer

device that measures pulmonary volumes

Tidal volume (TV):

volume of air inspired and expired during quiet breathing

Expiratory reserve volume (ERV):

volume of air that can be expired forcefully after a normal expiration

Residual volume (RV):

volume of air remaining in lungs after a maximal expiration (can’t be measured with spirometer)

Inspiratory capacity (IC)

\
IC = TV + IRV

the amount of air a person can inspire maximally after a normal expiration

Vital capacity (VC)

\
VC = IRV + ERV + TV

maximum amount of air a person can expire after a maximal inspiration

Alveolar Ventilation

the measure of the volume of air available for gas exchange per minute.

dead space

no gas exchange occurs

Anatomical dead space

areas include all the structures of the upper respiratory tract, and structures of the lower respiratory tract to the terminal bronchioles.

Physiological dead space

the combination of the anatomical dead space and the volume of any alveoli with lower than normal gas exchange.

* Gender
* Age
* Body Size
* Physical Fitness

Factors Affecting Ventilation

Partial Pressure

the pressure exerted by a specific gas in a mixture of gases

760 mm Hg

the total atmospheric pressure of all gases at sea level

21% O2

What is the percentage of the Atmosphere

160 mm Hg

the partial pressure for O2 is?