the respiratory system - lecture powerpoint
DESCRIPTION
A set of lecture slides covering the anatomy and physiology of the respiratory system.TRANSCRIPT
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.