Human Respiratory System: Anatomy, Physiology, and Immune Response | Study notes Anatomy

Respiratory System

Functions of the Respiratory System

1.Oxygen supplier

2.Elimination

3. Gas exchange

4.Passageway

5. Humidifier

•Nostrils:

- allow air to enter the nasal cavities so it can be purified and

sent to the other parts of the respiratory tract.

•Nasal cavity :

- Forms the interior of the nose. It is the entry point for inhaled

air and the first of a series of structures which form the

respiratory system. The cavity is entirely lined by the nasal

mucosa, which form the physical barriers of the body’s immune

system. These barriers provide mechanical protection from the

invasion of infectious and allergenic pathogens.

•Olfactory receptors:

- located in the mucosa of the nasal cavity. They detect air-borne

odour molecules that enter the nasal cavity

•Respiratory mucosa:

- consists of various types of epithelial cells ranging from ciliated

columnar to simple squamous.

•Mucus:

- produced by the mucosa’s glands that moistens the air and

traps incoming bacteria and other foreign debris

•Nasal concha:

- also called Turbinate, or Turbinal, bony elements forming the

upper chambers of the nasal cavities. They increase the surface

area of these cavities, thus providing for rapid warming and

humidification of air as it passes to the lungs.

•Palate, in vertebrate anatomy, it is the roof of

the mouth separating the oral and nasal cavities

*The hard palate is a bony subsection of the skull that makes up

almost two-thirds of the entire palate. It forms a division

between the mouth and the nasal passages.

The hard palate creates a vacuum inside the mouth to enable

liquid ingestion. Together with the tongue, the hard palate

produces distinctive phonetic sounds, including palatal

consonants such as /ɟ/ and /j/.

*The soft palate is a muscular structure located in the posterior

part of the palate. It is mainly responsible for creating an

incomplete partition between the oropharynx and the mouth.

The soft palate prevents nasal reflux by closing the nasopharynx

during swallowing. Without the soft palate, liquid and solid food

can enter the nasal cavity. Additionally, the soft palate works

with the tongue to produce velar consonants such as [ŋ], [k] and

[g].

•The paranasal sinuses are air-filled extensions of the

respiratory part of the nasal cavity. There

are four paired sinuses, named according to the bone in

which they are located; maxillary, frontal, sphenoid and

ethmoid.

•The function of the sinuses is thought of humidifying

the inspired air. They also reduce the weight of the

skull.

Pharynx

Size. The pharynx is a muscular passageway about 13

cm (5 inches) long

Function. Commonly called the throat, the pharynx

serves as a common passageway for food and air.

Portions of the pharynx. Air enters the superior

portion, the nasopharynx, from the nasal cavity and

then descends through

the oropharynx and laryngopharynx to enter the larynx

below.

Eustachian tube (pharyngotympanic tube) connects the

middle ear cavity with the nasopharynx..

Palatine tonsils. The palatine tonsils are in the

oropharynx at the end of the soft palate.

Lingual tonsils. lie at the base of the tongue.

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Respiratory System Functions of the Respiratory System 1.Oxygen supplier 2.Elimination

Gas exchange 4.Passageway
Humidifier
- Nostrils:

allow air to enter the nasal cavities so it can be purified and sent to the other parts of the respiratory tract.
- Nasal cavity : - Forms the interior of the nose. It is the entry point for inhaled air and the first of a series of structures which form the respiratory system. The cavity is entirely lined by the nasal mucosa, which form the physical barriers of the body’s immune system. These barriers provide mechanical protection from the invasion of infectious and allergenic pathogens.
- Olfactory receptors: - located in the mucosa of the nasal cavity. They detect air-borne odour molecules that enter the nasal cavity
Respiratory mucosa: - consists of various types of epithelial cells ranging from ciliated columnar to simple squamous.
Mucus: - produced by the mucosa’s glands that moistens the air and traps incoming bacteria and other foreign debris
Nasal concha :
also called Turbinate , or Turbinal , bony elements forming the upper chambers of the nasal cavities. They increase the surface area of these cavities, thus providing for rapid warming and humidification of air as it passes to the lungs.
Palate , in vertebrate anatomy, it is the roof of the mouth separating the oral and nasal cavities *The hard palate is a bony subsection of the skull that makes up almost two-thirds of the entire palate. It forms a division between the mouth and the nasal passages. The hard palate creates a vacuum inside the mouth to enable liquid ingestion. Together with the tongue, the hard palate produces distinctive phonetic sounds, including palatal consonants such as /ɟ/ and /j/. *The soft palate is a muscular structure located in the posterior part of the palate. It is mainly responsible for creating an incomplete partition between the oropharynx and the mouth. The soft palate prevents nasal reflux by closing the nasopharynx during swallowing. Without the soft palate, liquid and solid food can enter the nasal cavity. Additionally, the soft palate works with the tongue to produce velar consonants such as [ŋ], [k] and [g].
The paranasal sinuses are air-filled extensions of the respiratory part of the nasal cavity. There are four paired sinuses, named according to the bone in which they are located; maxillary, frontal, sphenoid and ethmoid.
The function of the sinuses is thought of humidifying the inspired air. They also reduce the weight of the skull. Pharynx  Size. The pharynx is a muscular passageway about 13 cm (5 inches) long  Function. Commonly called the throat , the pharynx serves as a common passageway for food and air.  Portions of the pharynx. Air enters the superior portion, the nasopharynx , from the nasal cavity and then descends through the oropharynx and laryngopharynx to enter the larynx below.  Eustachian tube (pharyngotympanic tube) connects the middle ear cavity with the nasopharynx..

 Palatine tonsils. The palatine tonsils are in the

oropharynx at the end of the soft palate.

 Lingual tonsils. lie at the base of the tongue.

 Adenoids , also called Pharyngeal Tonsils , a mass

of lymphatic tissue, attached to the back wall of the nasal pharynx.

 Adenoids are tonsils, but not all tonsils are adenoids.

There are three types of tonsils in the lymphatic system. They provide protection against infections and flush away unwanted particles.

 Palatine tonsils. Located in the oropharynx at the end

of the soft palate. Prevents infection in the respiratory and digestive tracts by producing antibodies that help kill infective agents

 Lingual tonsils. lie at the base of the tongue.

The trachea is commonly known as the windpipe. It begins under the larynx (voice box) and runs down behind the breastbone (sternum). The trachea then divides into two smaller tubes called bronchi: one bronchus for each lung.
The trachea is composed of about 20 rings of tough cartilage. The back part of each ring is made of muscle and connective tissue. Moist, smooth tissue called mucosa lines the inside of the trachea. The trachea widens and lengthens slightly with each breath in, returning to its resting size with each breath out.
The vital function of the trachea is to provide air flow to and from the lungs for respiration. Bronchi
Bronchi are the main passageway into the lungs.
The bronchi become smaller the closer they get to the lung tissue and are then considered bronchioles. These passageways then evolve into tiny air sacs called alveoli , which is the site of oxygen and carbon dioxide exchange in the respiratory system.
Primary bronchi are located in the upper portion of the lungs, with secondary bronchi near the center of the lungs. Tertiary bronchi are located near the bottom of these organs, just above the bronchioles. NO GAS EXCHANGES OCCUR IN ANY OF THE BRONCHI.
When the bronchi become swollen due to irritants or infection, bronchitis results and makes breathing more difficult. Bronchitis sufferers also tend to have much more mucus and phlegm than someone without inflamed bronchi Lungs
The lungs are the center of the respiratory (breathing) system.
The right lung is made up of three lobes. The left lung has only two lobes to make room for your heart.
They are covered by a thin tissue layer called the pleura. The same kind of thin tissue lines the inside of the chest cavity -- also called pleura. A thin layer of fluid acts as a lubricant allowing the lungs to slip smoothly as they expand and contract with each breath.
Pleura. The surface of each lung is covered with a visceral serosa called the pulmonary , or visceral pleura
Pleural fluid. The pleural membranes produce pleural fluid, a slippery serous secretion which allows the lungs to glide easily over the thorax wall during breathing movements and causes the two pleural layers to cling together.
Bronchioles. The smallest of the conducting passageways are the bronchioles.
Alveoli. The terminal bronchioles lead to the respiratory zone structures, even smaller conduits that eventually terminate in alveoli, or air sacs.
Respiratory zone. The respiratory zone, which includes the respiratory bronchioles, alveolar ducts, alveolar sacs, and alveoli, is the only site of gas exchange.
Conducting zone structures. All other respiratory passages are conducting zone structures that serve as conduits to and from the respiratory zone.
Stroma. The balance of the lung tissue, its stroma, is mainly elastic connective tissue that allows the lungs to recoil passively as we exhale. Physiology of the Respiratory System
Pulmonary ventilation. Air must move into and out of the lungs so that gasses in the air sacs are continuously refreshed, and this process is commonly called breathing.
External respiration. Gas exchange between the pulmonary blood and alveoli must take place.
Respiratory gas transport. Oxygen and carbon dioxide must be transported to and from the lungs and tissue cells of the body via the bloodstream.
Internal respiration. At systemic capillaries, gas exchanges must be made between the blood and tissue cells.
Inspiration. Air is flowing into the lungs; chest is expanded laterally, the rib cage is elevated, and the diaphragm is depressed and flattened; lungs are stretched to the larger thoracic volume, causing the intrapulmonary pressure to fall and air to flow into the lungs.
Expiration. Air is leaving the lungs; the chest is depressed and the lateral dimension is reduced, the rib cage is descended, and the diaphragm is elevated and dome-shaped; lungs recoil to a smaller volume,

‘tonsillectomy’.

intrapulmonary pressure rises, and air flows out of the lung.

Intrapulmonary volume. Intrapulmonary volume is the volume within the lungs.
Intrapleural pressure. The normal pressure within the pleural space, the intrapleural pressure, is always negative, and this is the major factor preventing the collapse of the lungs.
Tidal volume. Normal quiet breathing moves approximately 500 ml of air into and out of the lungs with each breath.
Inspiratory reserve volume. The amount of air that can be taken in forcibly over the tidal volume is the inspiratory reserve volume, which is normally between 2100 ml to 3200 ml.
Expiratory reserve volume. The amount of air that can be forcibly exhaled after a tidal expiration, the expiratory reserve volume, is approximately 1200 ml.
Bronchial sounds. Bronchial sounds are produced by air rushing through the large respiratory passageways (trachea and bronchi).
Vesicular breathing sounds. Vesicular breathing sounds occur as air fills the alveoli, and they are soft and resemble a muffled breeze.
External respiration. External respiration or pulmonary gas exchange involves the oxygen being loaded and carbon dioxide being unloaded from the blood.
Internal respiration. In internal respiration or systemic capillary gas exchange, oxygen is unloaded and carbon dioxide is loaded into the blood. - Gas transport. Oxygen is transported in the blood in two ways: most attaches to hemoglobin molecules inside the RBCs to form oxyhemoglobin, or a very small amount of oxygen is carried dissolved in the plasma; while carbon dioxide is transported in plasma as bicarbonate ion, or a smaller amount (between 20 to 30 percent of the transported carbon dioxide) is carried inside the RBCs bound to hemoglobin. - Phrenic and intercostal nerves. These two nerves regulate the activity of the respiratory muscles, the diaphragm, and external intercostals. - Medulla and pons. Neural centers that control respiratory rhythm and depth are located mainly in the medulla and pons; the medulla, which sets the basic rhythm of breathing, contains a pacemaker, or self- exciting inspiratory center, and an expiratory center that inhibits the pacemaker in a rhythmic way; pons centers appear to smooth out the basic rhythm of inspiration and expiration set by the medulla. - Eupnea. The normal respiratory rate is referred to as eupnea, and it is maintained at a rate of 12 to 15 respirations/minute. - Hyperpnea. During exercise, we breathe more vigorously and deeply because the brain centers send more impulses to the respiratory muscles, and this respiratory pattern is called hyperpnea. - Volition (conscious control). Voluntary control of breathing is limited, and the respiratory centers will simply ignore messages from the cortex (our wishes) when the oxygen supply in the blood is getting low or blood pH is falling. - Emotional factors. Emotional factors also modify the rate and depth of breathing through reflexes initiated by emotional stimuli acting through centers in the hypothalamus.
Chemical factors. The most important factors that modify respiratory rate and depth are chemical- the levels of carbon dioxide and oxygen in the blood; increased levels of carbon dioxide and decreased blood pH are the most important stimuli leading to an increase in the rate and depth of breathing, while a decrease in oxygen levels become important stimuli when the levels are dangerously low.
Hyperventilation. Hyperventilation blows off more carbon dioxide and decreases the amount of carbonic acid, which returns blood pH to normal range when carbon dioxide or other sources of acids begin to accumulate in the blood.
Hypoventilation. Hypoventilation or extremely slow or shallow breathing allows carbon dioxide to accumulate in the blood and brings blood pH back into normal range when blood starts to become slightly alkaline. Immune system
network of cells, tissues, and organs that work together to defend the body against attacks by “foreign” invaders
defense system against foreign invaders of the body (pathogens)

ADAPTIVE IMMUNITY

Adaptive immunity refers to antigen-specific immune response.
The adaptive immune response is more complex than the innate. The antigen first must be processed and recognized. Once an antigen has been recognized, the adaptive immune system creates immune cells specifically designed to attack that antigen. Adaptive immunity also includes a " memory " that makes future responses against a specific antigen more efficient.
The adaptive defense consists of antibodies and lymphocytes, often called the humoral response and the cell mediated response.
The humoral response involves B cells that recognize antigens or pathogens that are circulating in the lymph or blood Humoral response process
Antigens bind to B cells.
Interleukins or helper T cells costimulate B cells.
B cells proliferate and produce plasma cells. The plasma cells bear antibodies. The antibodies are released and circulate through the body, binding to antigens.
B cells produce memory cells. Memory cells provide future immunity.
B cell: A type of white blood cell specifically a lymphocyte. Many B cells mature into plasma cells that produce antibodies necessary to fight off infections while other B cells mature into memory B cells. Cell mediated response
Type of immune response that is produced by the direct action of immune cells, such as T lymphocytes (T cells), rather than by antibodies.
A type of white blood cell. T lymphocytes are part of the immune system and develop from stem cells in the bone marrow. They help protect the body from infection and may help fight cancer. Also called T cell and thymocyte. ANTIBODIES
Antibodies are proteins produced and secreted by B cells. They bind to foreign substances that invade the body, such as pathogens. The term "antibody" refers to its function, which is to bind to an antigen. Another name for this protein molecule is immunoglobulin (abbreviated Ig).
IgG is the most abundant antibody accounting for 70- 75% of human immunoglobulins (antibodies). IgG detoxifies harmful substances. It is transferred to the fetus through the placenta and protects the infant until its own immune system is functional.
IgM circulates in the blood accounting for about 10% of human immunoglobulins.
It has a pentameric structure in which five basic Y- shaped molecules are linked together. B cells produce IgM first in response to microbial infection/antigen invasion.
IgA is abundant in serum, nasal mucus, saliva, breast milk, and intestinal fluid, accounting for 10-15% of human immunoglobulins.
IgA in breast milk protects the gastrointestinal tract of neonates from pathogens.
IgE is present in minute amounts, accounting for no more than 0.001% of human immunoglobulins. Its original role is to protect against parasites. In regions where parasitic infection is rare, IgE is primarily involved in allergy.
IgD accounts for less than 1% of human immunoglobulins. IgD may be involved in the induction of antibody production in B cells, but its exact function remains unknown. Blood and blood types
Blood types are determined by the presence or absence of certain antigens. Since some antigens can trigger a patient's immune system to attack the transfused blood, safe blood transfusions depend on careful blood typing and cross-matching.
Type A: has only the A antigen on red cells (and B antibody in the plasma)
Type B: has only the B antigen on red cells (and A antibody in the plasma)

Type AB: has both A and B antigens on red cells (but neither A nor B antibody in the plasma)
Type O: has neither A nor B antigens on red cells (but both A and B antibody are in the plasma)
Blood transfusion: The universal red cell donor has Type O negative blood. The universal plasma donor has Type AB blood.
Each person has a blood type (O, A, B, or AB). Everyone also has an Rh factor (positive or negative).
Rhesus (Rh) factor is an inherited protein found on the surface of red blood cells. If your blood has the protein, you're Rh positive. If your blood lacks the protein, you're Rh negative.
Rh positive is the most common blood type. Having an Rh negative blood type is not an illness and usually does not affect your health. However, it can affect your pregnancy. Your pregnancy needs special care if you're Rh negative and your baby is Rh positive (Rh incompatibility). A baby can inherit the Rh factor from either parent.

Human Respiratory System: Anatomy, Physiology, and Immune Response, Study notes of Anatomy

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Download Human Respiratory System: Anatomy, Physiology, and Immune Response and more Study notes Anatomy in PDF only on Docsity!

 Palatine tonsils. The palatine tonsils are in the

 Lingual tonsils. lie at the base of the tongue.

 Adenoids , also called Pharyngeal Tonsils , a mass

 Adenoids are tonsils, but not all tonsils are adenoids.

 Palatine tonsils. Located in the oropharynx at the end

 Lingual tonsils. lie at the base of the tongue.

‘tonsillectomy’.

ADAPTIVE IMMUNITY