Respiratory System, Glands, Peritoneums.

Biology II

Functions

Provides an area for gas exchange between the blood and air.

Protects the surfaces of the lungs and trachea from dehydration, temperature changes, and pathogens.

Produces sounds needed for speech. Aids the sense of smell.

Membranes and Cavities

There are two large cavities in the trunk: the thoracic and abdominal. Separated by the diaphragm.

Each of these body cavities and many of the organs within are lined with a thin covering similar in width to Saran Wrap. The peritoneum lines the abdominal cavity. The pericardium lines the heart.

Pericardium

Pleura Thoracic Cavity

Visceral pleura covers the surface of organs, such as the lungs.

The walls of the cavity are covered by parietal pleura.

The two pleural layers are separated a layer of pleural fluid that allows for low-friction gliding.

Nasal Cavity The superior surface is covered with olfactory

receptors, nerves that detect smell. The rest of the cavity is lined with pseudostratified

ciliated columnar epithelium. Moistens incoming air. Filters foreign particles (dust, bacteria)

Nasal Cavity The nasal cavity

contains sinuses; empty spaces that: Lighten the skull Act as resonance

chambers for speech Produce mucus

Nasal Concha

Nasal concha are curled bone shelves in the nasal cavity that force air flow over the largest surface area of cilia possible.

Larynx The entrance to the

larynx is the epiglottis, a flap of elastic cartilage that routes food to the esophagus and air to the trachea.

The larynx also contains the vocal cords, which vibrate to produce sound.

Epiglottis

Hyoid Bone

Thyroid Cartilage

Circoid Cartilage

Tracheal Cartilage

Trachea Connects the larynx with the

bronchi. The walls of the trachea are lined

with C-shaped rings of hyaline cartilage for support.

Lined with pseudostratified ciliated columnar epithelium. Cilia continuously beats in the

opposite direction of incoming air. Moves mucus away from the lungs

and out of the respiratory tract.

Frontal Sinus

Sphenoid Sinus

Nasal CavityConchae

Hard Palate

Oral CavitySoft Palate

Lingual Tonsil

EpiglottisHyoid Bone

Thyroid Cartilage

Cricoid Cartilage

Trachea

Auditory Tube

Pharyngeal TonsilNasopharynxOropharynxPalatine Tonsil

Laryngopharynx

Vocal Folds (Larynx)

Esophagus

Bronchi

Bronchi are formed by the division of the trachea. The bronchi continue to subdivide, becoming

more and more narrow. Primary bronchi → secondary bronchi →

tertiary bronchi → bronchioles

The Lungs

Along with the heart, the lungs occupy most of the thoracic cavity.

The apex of the lungs is near the clavicle, while the base rests on the diaphragm.

Each lung is divided into lobes. Right lung: Three lobes Left lung: Two lobes

The Lungs

The left lung has two lobes to allow space for the heart.

The lobes of the right lung are named: Superior Middle Inferior

The lobes of the left lung are: Superior Inferior

Larynx

Clavicle

Superior Lobe

Trachea

Mediastinum

Middle Lobe

Inferior Lobe

Pleural Space

Diaphragm

Primary BronchiSecondary

Bronchi

Tertiary Bronchi

Bronchiole

Visceral Pleura

Parietal Pleura

Alveoli

The bronchioles end at small air-filled sacs called alveoli. Each alveolus is lined with a layer of simple

squamous epithelium, followed by capillaries.

Alveoli Surfactant-

secreting cells produce a lipid that reduces the natural suface tension of water – preventing the wet surfaces of alveoli from sticking together.

Alveoli Macrophages are

white blood cells that will ingest (endocytosis) bacteria, viruses, or foreign objects that are inhaled and make it past the cilia.

Alveoli Simple squamous

cells provide a barrier thin enough for O2 and CO2 to diffuse through.

Capillaries allow red blood cells into the lungs, carrying O2 and CO2.

Alveolus

Bronchiole

Capillaries

Red Blood Cells (Inside capillary)

Simple Squamous

Red Blood Cell

Alveolus

Simple Squamous lining

Simple Squamous lining Basement

Membrane

CO2

O2

The path air takes…(External respiration)

1. Air is inhaled through the nose or mouth.2. Air flows into pharynx, passes the

epiglottis, and moves through the larynx.o The epiglottis closes when swallowing,

preventing food from entering the trachea.

3. Air travels down the trachea into two primary bronchi which lead into the lungs.

4. The primary bronchi divide into secondary, then tertiary bronchi.

External Respiration continued…

5. Air passes through the bronchioles into the alveoli.

a. Inhaled air has a higher concentration of O2 and a lower concentration of CO2 than the blood at this stage.

b. Diffusion (passive transport of substances from high to low concentration) causes the gas exchange.

6. Oxygen is carried by the capillaries back to the heart, where it is pumped to the rest of the body.

Blood transport of gases

1. Once the oxygen reaches the body cells, it is taken up by the mitochondria.

2. The mitochondria use oxygen to break down glucose into ATP. This is cellular respiration.

3. The remaining carbon dioxide is returned to the blood to be exhaled.

Mechanics of Breathing

1. INHALE – muscles between ribs contract and rib cage rises.

2. Diaphragm muscle contracts, becomes flattened, and moves lower in chest cavity.

3. The volume of the chest cavity increases, lowering the air pressure.

4. Air rushes into lungs (diffusion again) to equalize the pressure difference.

Mechanics of breathing

5. EXHALE – muscles relax and ribs drop down in chest cavity.

6. Diaphragm relaxes and returns to resting position.

7. Space in chest cavity decreases, causing the internal air pressure to rise. Diffusion causes air to exit to body.

Respiratory Capacity

Respiratory capacity is the amount of air the lungs are able to hold. This can be influenced by: A person’s size Gender Age Physical condition

Nonrespiratory Air Movements

Cough – Sudden rush of air outward; clears the lower bronchi.

Sneeze – Similar to a cough, but air is directed out the nose. Meant to clear the upper pharynx and nasal passages.

Hiccups – Sudden short inspirations caused by spasms of the diaphragm.

Yawn – Very deep inspiration; ventilates all of the alveoli.

Vocal Cords and Sound

The glottis is the space in between the vocal cords. False Vocal Cords are relatively inelastic ligaments that prevent

foreign objects from entering the glottis. True Vocal Cords contain elastic ligaments that stretch from the

thyroid cartilage to the arytenoid cartilage. They are responsible for sound. Food or liquids that touch the vocal cords trigger the coughing reflex.

Anatomy of the Larynx

Sound

The pitch depends on the diameter, length, and tension of the vibrating vocal cords.

The diameter and length of the vocal cords are directly related to the size of the larynx.

Children tend to have higher pitched voices than adults because of the smaller larynx.

Tension is controlled by small skeletal muscles that change the position of the cartilages.

Increased tension raises pitch while decreased lowers pitch. Your voice is not just created by the larynx.

Amplification and resonance in the pharynx, oral cavity, nasal cavity, and paranasal sinuses.

The production of distinct words depends on voluntary movements of the tongue, lips, and cheeks.

Smoking

Smoking damages the respiratory system in multiple ways.

Smoking and Cilia

This is a normal slide of tissue from the trachea. H - Cilia I – Pseudostratified

columnar cells J – Mucus L – Basal cells

Smoking and Cilia

This is a slide of tissue from a smoker of a few years. The columnar cells (I)

are beginning to die out. They are replaced by basal cells (L)

Many cilia (H) are also damaged or destroyed.

Smoking and Cilia This is a slide from a

heavy smoker after several years. The ciliated columnar

cells are gone, completely replaced with basal cells; some of which are cancerous.

Without cilia, smokers are unable to easily expel phlegm, causing “Smoker’s Cough”.

Smoking and the Lungs

Tissues that support the shape and function of alveoli in the lungs are destroyed. Alveoli are unable to maintain their

shape after exhaling. The bronchioles and lung tissue

can also become filled with tar and other compounds from the smoke.

Black Lung Disease

Coal workers' pneumoconiosis

Caused by prolonged exposure to coal dust.

Inhaled coal dust progressively builds up in the lungs and is unable to be removed by the body; that leads to inflammation, fibrosis, and in worse cases, necrosis.

Similar in damage to cigarette smoking.

Asthma

Asthma is an inflammatory disease that can obstruct the airway and cause spasms of the bronchi. The airways narrow, causing symptoms like

wheezing and shortness of breath. Asthma is caused by a complex

combination of factors, such as exposure to pollution and genetics.

Inhalers

Long Term Inhalers are used to treat chronic symptoms and to prevent asthma attacks.

Short Term (Rescue Inhalers) are used to treat flare ups and asthma attacks.

Inhaled corticosteroids are anti-inflammatory drugs that reduce swelling and tightening in your airways. You may need to use these medications for several

days to weeks before they reach their maximum benefit.

Pneumonia

Inflammation of the lungs resulting from an infection. Swelling of the bronchioles

constricts airways and fluid leaks into the alveoli reducing respiratory function.

Caused by bacteria, viruses, or fungi that spread to your lungs. More likely when respiratory

defenses have been compromised (by smoking, AIDS, etc).

Cystic Fibrosis (CF)

Inherited disease resulting from a defective gene on chromosome 7. Causes mucous cells to produce

dense viscous mucus that cannot be transported by the cilia.

Inability to remove the mucus causes breathing problems and opens the lungs to bacterial infections.

Individuals rarely survive past 30.

Tuberculosis

Caused by the bacterium Mycobacterium tuberculosis invading the lungs.

Highly contagious, and a leading cause of death by infectious disease.

Treated with antibiotics, although some strains are resistant.

Pneumothorax

A pneumothorax is a collapsed lung.

Occurs when air escapes from the lung and fills up the pleural space outside of the lung.

This buildup of air puts pressure on the lung, so it cannot expand like normal.

It may be caused by a puncture wound, gunshot, or broken rib.