respiratory system

 

Anatomy of the Respiratory System

• Primary functions is to bring oxygen into the body, in exchange for carbon dioxide

• Organs of respiratory system:

• Nose

• Nasal cavity

• Mouth

• Larynx

• Pharynx

• Lungs

• Diaphragm

Upper respiratory tract: nasal cavity, pharynx, larynx

Lower respiratory tract: trachea, bronchus, and lungs

Nasal cavity: opens the nose

• Nose and nasal cavity warm moisten air as person breathes

• Nose hairs + mucus produced by epithelial mucosa cells in nose to prevent particles in air from entering lungs

Pharynx: located behind nasal cavity, both food and air pass through this long tube

Larynx: below the pharynx, or voice box, channels air to the trachea and pushes food past epiglottis

Epiglottis: covers the trachea during swallowing to prevent food from entering the lungs

Trachea: windpipe

Alveoli: tiny air sacs in lung

• Gas exchange occurs in the alveolar region

Diaphragm: muscle that plays a large role in breathing, found at base of the lungs and spreads across the rib cage, forming chest cavity 

• Right lung is larger and heavier has 3 lobes

• Left lung has two lobes

Pulmonary surfactant: consist of chemical compounds that line alveolar surfaces of the lungs 

• Lipopolysaccharides with both hydrophobic and hydrophilic layer to help keep lungs inflated or prevent them from collapsing

Pleura: outside of lungs are serous membranes that cover each lung

• Two- layered membrane that cushions the lungs while reducing friction between the lungs and chest cavity or rib cage

Respiratory Functions and Breathing Mechanics

• Primary of respiratory system is to provide oxygen to and remove co2 from boud

• Helps person breathe, providing body with oxygen, important for cells to perform functions to keep body alive

• Primary muscle of inspiration is a diaphragm, flattens when it contracts

• Rib cage moves outwards for outside air to be drawn into the lungs

• During relaxation diaphragm move back into natural position to cause chest cavity to push air out of lungs 

• Respiratory system has two parts:

• Air conducting portion: Air is delivered to the lungs. Region is made up of upper and lower respiratory tract- specifically, the larynx, trachea, bronchi, and bronchioles

• Gas exchange portion: Takes place between the air and blood. Portion includes lungs, alveoli, and capillaries

•  Oxygen from the air enters our body through the respiratory system, cardiovascular system circulates oxygen throughout body via blood

• Blood can absorb oxygen + transport it through network of blood vessels in cell in various tissues throughout the body

• In gas exchange, blood system will absorb CO2 from cell to carry to respiratory system to be exhaled by the body

• Respiratory system work with cardiovascular system and nervous system to maintain blood gas and pH homeostasis

• Too much CO2 in blood = acidic (low pH) 

• Not enough CO2 in blood = too alkaline (high pH)

Mechanics of respiration

Respiration occurs on two levels:

• External respiration: 

• Occurs between lungs and blood

• Person inhales -> alveoli fills with oxygen through diffusion

• O2 content much higher than CO2 levels

• Alveoli, blood becomes oxygen rich

• Once oxygenated, blood leaves the lungs -> travels to left side of heart for it to be pumped into circulation

• Internal respiration:

• Occurs between blood and tissue

• Once blood enter circulation -> capillaries

• O2 diffuses through capillaries into cells

• CO2 diffuses from cell -> into capillaries

• CO2 content higher than O2 content blood is oxygen-poor

• Oxygen poor blood traveled to the right side of the heart and moves through pulmonary circuit where external respiration begins

Function of the Respiratory System 

• Transporting oxygen from the atmosphere into the body blood 

• Removing carbon dioxide from the body cells 

• Exchange oxygen and carbon dioxide.

The surface of the alveoli in the human lung is equivalent to half the size of a basketball court.

****Various part of the respiratory system 

*****How they contribute to the respiratory system

Structure of the respiratory system 

• The respiratory system mediates the uptake of the oxygen needed for metabolism 

• Release the carbon dioxide which is waste product of the human body back into the atmosphere 

Ventilation	The process of bringing oxygen into the lungs is known as breathing ( inhaling and exhaling) and exchanging the gas oxygen with the gas carbon dioxide in the lungs is  ventilation. Ventilation occur as a combination of muscle action and negative pressure
Trachea	Air enters through nasal openings, moves into the nasal cavity, and travels past the pharynx (throat) and into the trachea
Cells	The basic structural unit of an organism from which living things are created
alveoli	Tiny air sacs in the lungs where exchange of oxygen and carbon dioxide take place. Alveoli are site of gas exchange.
Organ systems	Functional groups of organs that work together within the body circulatory, integumentary, skeletal , reproductive, digestive, urinary ,respiratory, endocrine , lymphatic ,muscular ,nervous
Bronchi	Air continue to the first division of trachea : the right and left bronchi
Bronchioles	The right and left bronchi subdivide into smaller and smaller tubes called bronchioles .
Bronchioles terminate	Bronchioles terminate in alveoli which are thin walled ( one cell thick ) structures that organized to look like clusters of grapes .
Type I alveolar cells	Type I alveolar that make up the alveolar wall, alveoli have type II alveolar cell that release lipoprotein called surfactant, a substance that reduces the surface tension.
Type II alveolar	alveoli have type II alveolar cells that release lipoprotein called surfactant, a substance that reduces the surface tension.
surfactant	alveoli have type II alveolar cell that release lipoprotein called surfactant,
lipoprotein	alveoli have type II alveolar cell that release lipoprotein called surfactant,
Pleura	A membrane around the lungs and inside the chest cavity.
Passive transport	Movement across a cell membrane that does not require energy input
Inhalation	Inhalations bring in oxygen, while exhalation release carbon dioxide
Right lungs	The right lung  has 3 lobes , the superior , middle and inferior.
Left lungs	The left lung has 2 lobes THe superior and inferior lobes . Each lobe is divided into bronchopulmonary segments .
Tidal volume	The amount of air breath in and out of the lungs during a normal breath is called the tidal volume.
Residual volume	A small amount of air rich in carbon dioxide , called the “residual volume”, remains trapped in alveoli after expiration and mixes with the air rich in oxygen brought in through inspiration.
Increase respiration	If the blood PH start to decrease then respiration rate will increase to balance carbon dioxide and oxygen

Interaction of the cardiovascular and respiratory system 

Heart	Heart is located in the mediastinum ( the area between the two lungs ), marginally on the left side.
Bronchopulmonary segment	Each bronchopulmonary segment receives air from its own bronchus and receives blood from its own artery.
Pleura	Each lungs is contained within a tough, protective double membrane called the pleura and contain pleural fluid.
Gas exchanges in alveoli	The heart pulmonary systems send blood low in oxygen and high in carbon dioxide to the lungs where oxygen is picked up and carbon dioxide is dropped off. This happens where capillaries of the circulatory system interact with alveoli of the lungs .
Breathing	Breathing control centers of the brain’s medulla oblongata control respiration through monitoring carbon dioxide levels and blood PH.

Function of the respiratory system 

If Rate of diffusion increase 

The distance between the blood cell and alveoli is decreased 

Diffusion	Gas exchange in the lungs occurs by diffusion, which is a passive transport mechanism .
diffusion is directly proportional to the surface area	The rate of diffusion is directly proportional to the surface area involved and the concentration gradient and its inversely proportional to the distance between two solutions.

Factor affecting the respiratory system 

Asthma	Asthma is a condition in which the airways of the respiratory system narrow, resulting from the swelling of their ways from mucus build up .
Difficulty in breathing	Asthma can make it difficult to inhale and exhale normal amounts of air breathing, this can lead to shortness of breath, difficulty in  breathing and wheezing.
Causes of asthma	Effect of Environmental Pollutants  such as chemical , pollen, and smoke which can impede lung function by damaging cilia or causing emphysema , allergies and inflammation.
Genetic condition	Lungs surfactant insufficiency , asthma , cystic fibrosis , can seriously impede lung function,  Several pathogens that affect lung functions cause disease such as influenza, tuberculosis, pneumonia
Muscle	Fibrous tissue that produce force and motion to move the body or produce movement in parts of the body.
Inflammation	The resulting redness, swelling , heat and pain in an area of defense by innate immunity.
Allergies	An immune response to a foreign agent that is not a pathogen