Biology 20- The Respiratory System

cells breaking down

Respiratory System Notes Glucose to form

Signs of life: Why do we need breathe? #Adensine triphosphat

-The ABC's -Our cells need O2 to preform Cellular Respiration (ATP)

· Airway

· Breathing

· Circulation

Functions of the respiratory system:

1. Oxygenate Blood -> Ensures Blood gets to every Cell

2)Remove (O2 from our blood (waste product of CR)

3)Provides us w/ our voices +Air moving through the "Voice"box-pharynx

-

4)Control Acidity of bodily fluids by Fort (O2

Requirements for the respiratory system:

1)LARGE SURFACE AREA -for Dal (O2 Exchange

2)MOIST Enviroment-O2 + (O2 must be disolved in water)

Inspiration: Inhale

Expiration: Exhale

External Respiration: Exchange of O2 + CO2 between the air+blood

Internal Respiration: Exchange of O2 + CO2 between body cells and blood

Cellular Respiration: Energy releasing rx’s (glucose oxidation in body cells)(ATP)

Anatomy:

1. )Nasel Passages: Hollow area located behind the nose, rich in micas (to trap foreign

Particales, eg. Just and bacterial, Warms air as it travels to the lungs

-Turbinate Bones = 1S. A. of Nasal passages -* Helps to warm air to protect

structures in the lower respiratory track

2. )Pharynx (Throat): The passage way of air to the larynx and the trachea

3)Epiglottis -A flap of cartilage that closes over the opening to the trachea

when a person swallows -prevents food from enteries the trachea (choking

4)Larynx = Voice Box

upper cartilaginous portion of the trachea

-contains the vocal cords Elastic ligaments)that vibrate when air is forced out

of the less -> Note: & puberty of hormones causes vocal words to grow = lower pitch

-Protected by the Adams Apple (a think hand of cartilage

laryngitis = inflation of the larnyx

-caused by viral infection, allergies, voice strain (causes bore throat, horse, lose voice

5)Trachea (windpipe)

-Passage way from larynx to lungs

-Divides into Left and Right Bronchi cartilage rings

-

-Held open by C-shaped cartilaginous rings D

-Hair-like cilia line the trachea (catch and more particals up into

the nose and throat

6)Bronchus (plural = Bronchi)

-the trachen splits into 2 bronchi that pass air into the dregs& lined with

-each bronches further divides into smaller tubes -> Bronchiales Lilia and

-Bronchitis = Bronchi becomes inflamed + filled /fluid Muds

· due to an infection (e. g. bacterial -> acute

~ or irritants (e. g. Smoking)-7 Chronic

7)Bronchioles

-are not surrounded by cartilage (-rings

-walls are made of smooth muscle and connective tissue

-smooth muscles are relaxed so that the bronchioles remain open

· Asthma

-Bronchi and Bronchioles Swell, Bronchiele muscles contract (spasm

↓ in Airflow into/out of the lungs

8)Alveolus(Alveol: )

-dir-sacs with extremly this walls -> I cell thick surrounded by capillaries

-Alveal: Gas Exchange (De from alveolus -> blood)((Dr from blood -> Alveolus)

* Are covered in ridges rather than one large air sae to increase surface area

9)Diaphragm:

-A dome shaped sheet of muscle located below the longs

- it separates the thornic licity from the Abdominal Cavity

· Contract = inhale Relaxes = Exhale

↓ ↓

flattens dome shaped

10. )Pleural Membranes (Actually One Membrane

-L outer membranes surrounding the right and left lungs like "says"

· octer: Parietal Plevia -> Attached to the chest wall

· Inner: Visceral Pleura -> Attached to the lung

-Both secete fluid to provide lubrication so the Pleura

can stick together and ↓ friction when the lungs expand

-suction between the longs And the thoracic Cavity pull the longs against the

thoracic cavity wall and help keep the lungs expanded

The Mechanics of Breathing

· Note: when the volume of a gas increases pressure decreases

1)Inhalation: to breath in

· Diaphragm contracts and flattens out (moves down

· Intercostal Muscles (between the ribs)Contract -> ribs more up t out

· This causes volume of the thoracic (chest)Cavity

· Alveoli enlarge -> ↓ Dir pressure in the alveoli

· Air rushes into the lungs to equalize pressure

b)Exhalation: to breath out

· Diaphragm relaxes and becomes more dome shaped (pushes upwards)

· Intercostal Muscles relay -7 ribs more in+ down

· this causes volume of the thoracic (chest)cavity Do not require thought

· Alveoli shrink -> Pair pressure in the aleoli *

* Both inhalation and Exhalation are PASSIVE processes

Respiratory Volumes:

· measured with a spirometer (spirograph)

· A spirograph is a graph showing breathing volumes

1. )Tidal Volume:

-Volume of air that is inhaled and exhaled in normal breathing movement when the body is at rest

-Around 500mL (D. SL)

2. )Inspiratory Reserve Volume:

-The additional volume of air beyond the regular (tidal)inhalation

-About 2001-3000m (2-3)

3. )Expiratory Reserve Volume:

-The additional volume of air that can be forced out of the lungs beyond regular tidal)exhalation

-Around BOD-120RmL (d. B +. 2)

4)Vital Capacity:

-total long volume capacity

total volume of gas that can be moved intolert of the lungs

-VC = TV + IRV + ERV

-varies with sex, physical conditioning, occupation, body position ing, etc.

-Aprex. 3300-1700 ML (3. 3 - 1. 71)

5)Residual Volume

the gas that remains in the respiratory passageways (ie. Bronchi, Bronchioles, Alveoli

after a full exhalation

-this gas never leaves the respiratory system, if it did the lungs would collapse

-this gas is not exchanged with the environment

- Approx. (DPO-1300 mc Ll-1. 31)

6)Total Lung Capacity:

the total volume that the lungs can hold

-TLC = UC + RU

· Approx. 1000-6000ML (4-6L)

· Pheumothorax: Air entering the Plural Space

* A doctor may also reclease additional

Air around the lung by suching it out with it

Needle, which allows the lungs to fully

expand.

Oxygen And Carbon dioxide transport in Blood:

· the diffusion of gas occurs from an area of high pressure to an area of low pressure

Dalton's law of partial pressure:

· Each gas in a mixture excerts its own pressue which is proportinal to the total value

· In other words it is T the total air pressure that causes the diffusion of gases, but the

pressure of each individual gas

· The partial pressue of oxygen is lovest in the veins and tissues but highest in the

atmospheric zir

· The highest partial pressure of Carbon dioxide (CO2)is highest in the tissues and veins

And lowest in the Atmosphere

Hemoglobin: Oxygen carrying molecules that greatly increase the oxygen carrying capacity of blood

-consists of four polypetides that are composed of here, the iron containing pigment, and globin, it protein

component

· Each home group forms a wetl bond with oxygen farming oxyhemoglobin

· Hemoglobin gives up very little oxygen until the partial pressure of oxygen reaches

a much lower value in the surrounding tissues then in the lung

100 -Oxysen-Hemoglobin Association -Dissociation

Partial Pressure of Oxygen (KPa)

Oxygen Transport:

· Oxysen(Dal moves from the atmosphere, the area of highest partial pressure, to the alveoli

· It then diffuses from the alveoli into the blood to go to the cells, the area of lowest partial pressure

· Oxygen is transported in two different ways:

-99% of the time by hemoglobin

-1% of the time it is dissolved in blood plasma

Carbon Dioxide Transport

· Carbon Dioxide ((da)moves from the cells, the area of highest partial pressure, to the blood

· It then diffuses from the blood into the alveedi to go into the atmosphere, the area of lowest partial

pressure

· Carbon dioxide is transported in the blood in three ways:

-27% combines with hemoglobin to produce Carbminohemoglobin

-9% of CO2 produces in tissues is dissolved in blood plasma

-the remaining 64% combines with water to form carbonic Acid (Hells)

Maintaining Gas levels

· To help maintain equilibriumm, chemical receptors detect a change in gas levels and send a message to increase/decrease

breathing rate

Regulation of breathing movements

· Nerves from the medulla oblongate (brain, control breathing movements

· Information about the levels of carbon dioxide, mids(Id2 dissolves in the blood and forms carbonic

Acid)And the need for oxygen is detected by chemoreceptors

· A chemoreceptor is a specialized nerve receptor that is sensitive to specific chemicals.

· There are two different types of chemoreceptors:

1. )Carbon dioxide the moreceptors

-these are the bodies primam detectors

-located in the Medulla oblongata (braid

-Detect high levels of carbon dioxide

2)Oxygen Chemoreceptors

located in the carotic And Portic Arteries

-Detect low levels of oxygen

-Backup system

Diseases of the respiratory system

-

-Upper VS. lower Respiratory /ract

· The upper respiratory tract consists of the nose, mouth, phayny and lary > intections in the upper respiratory

tract are usually caused by viruses And bacteria

· Tonsillitis:

-an intection of the tonsils, which are located in the pharux

-A viral infection is the most common cause of tonsillitis

-The tonsils help prevent bacterial and other foreign pathogens from entering the body

· laryngitis:

-the inflammation of thLaryne

-The larynx contains the vocal cords

-The most common cause of laryngitis is a viral infection, allergies, and

overstraining of the voice

-reduced Ability to speak or no voice at all.

symptoms include sorethout, and hoarsenes

· The lower respiratory trict consists of the trachet, bronchial Tubes, And lungs -

the primary causes of lover tract respiratory disorders are primarily caused by

infections, obstructive respiratory disorders, and lung cancer

· Bronchitis: -

· a disorder that causes the bronchi to become inflamed and filled with mucas,

-

which is expelled by coughing

1. )Acute Bronchitis-> short term disorder caused by bacterial infections /treated with

antibiotics)

2)Chronic Bronchitis -long term disorder caused by regular exposed to irritants and

foreign bodes

-cilia are destroyed (no cleasing action)

-The most common cause is cisirette smoking.

· Tuberculosis (TB)

-TB is an infectious bacterial disease transmitted through the air from a person

with TB through coughing laughing, singing, and talking.

· Pneumonia

-Is a disease that occurs when the alveoli in the lungs is inflamed and

filled with liquids.

1)Lobular Pneumonia -> Affects a lobe of the luns

2. )Bronchial Pneumonia -> affects patches throughout both lungs

-lases: Bacterial and Viral infection are the main causes

-streptococcus Pneumoniae: A human pathogen bacterium