RESPIRATORY SYSTEM.

DR.MARIAM FATIMA

2^ND SEMESTER BSN.

RESPIRATORY SYSTEM.

• The respiratory system is the network of organs and tissues that
• help to breathe.
• It includes your airways, lungs, and blood vessels.
• The muscles that power lungs are also part of the respiratory

system.

• These parts work together to move oxygen throughout the body

and clean out waste gases like carbon dioxide.

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• The respiratory system has many functions. Besides helping inhale (breathe in) and exhale (breathe out).
• Allows to talk and to smell.
• Brings air to body temperature and moisturizes it to the humidity level body needs.
• Delivers oxygen to the cells in body.
• Removes waste gases, including carbon dioxide, from the body when exhale.
• Protects your airways from harmful substances and irritants.

Respiratory Organs.

• Nose
• Pharynx
• Larynx
• Trachea
• Bronchi
• Bronchiole & Alveoli
• Pleura
• Muscles of breathing

( Intercosting Muscles & Diaphram)

Organs of Respiratory System.

UPPER RESOIRATORY TRACT

1. Nasal Cavity

It is divided into right a left portions by

septum and lined by mucus membrane.

• The entrance to nasal cavity is formed by

anterior nares(nostrils).

• They contain small hairs which act as filter

for dust.

• The back of nasal cavities contains

posterior nares.

• They form the entrance to nasopharynx.

2. Pharynx

• Pharynx is divided into three parts

a. Nasopharynx

• Lies behind nasal cavities.
• Contains opening for Eustachian tube on

lateral wall.

b. Oropharynx

• Continuous infront with mouth and below
• laryngeal part of pharynx
• Its lateral wall contain tonsils.

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c. Laryo pharynx

Lowest part. lies behind the larynx

3. Larynx

• Larynx (voice box)-Hollow organ that allows you to talk and make sounds when air moves in and out.
• It lies between pharynx above and trachia below.
• It formed by following cartilages.
• a. Thyroid cartilage
• b. Cricoid cartilage
• c. Two aretenoid cartilage
• d. Epigloittis cartilage

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LOWER RESPIRATORY TRACT�1. Trachea (Wind pipe)

• Cylindrical tube
• Length - 11 cm
• Begins with the lower end of the pharynx.
• Made up of 16-20 c-shaped
• Incomplete cartilages.

2. Bronchi

• The trachea ends by dividing into two bronchi namely right and left bronchi.
• They pass to the the corresponding lungs.

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• The right bronchitus is shorter and wider than the left.
• Bronchi are made of complete rings of cartilage.

3. Bronchioles

• They are formed by the division of bronchi.
• Bronchioles are the fines branches
• of bronchi.
• Bronchioles do not have cartilage.
• They are lined by cuboidal

epithelium

4. Alveoli (Air Sac)

• They are final termination of each bronchi.
• They contain a thin layer of epithelial cells surrounded by neumerous

capillaries.

• Exchange og gases takes place through the walls of these capi

5.LUNGS.

• Lungs are the principle organs of the respiration.
• They are two in number lying one on each side of the chest cavity.
• Two lungs are separated in the middle line by heart and other structures of mediastinum.

Shape-

• Conical Shape.

Lobes-

• Each lungs is divided into lobes by means of fissures.
• The right and left lungs' structural organization is similar, though asymmetrical. The right lung is comprised of the right upper (RUL), middle (RML), and lower (RLL) lobes.
• The left lung consists of the left upper (LUL) and lower (LLL) lobes. Oblique and horizontal fissures separate the right lung's 3 lobes

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Pleura

Serous membrane which cover the lungs.

Root of the lungs

• • The medial surface of each lungs has a vertical slit called hylum. •Structure like blood vessels, nerves and lymphatic pass through the hylum.
• These structures together constitute the root of lungs

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Root of the lungs.

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• The medial surface of each lungs has a vertical slit called hylum.
• Structure like blood vessels, nerves and lymphatic pass through the hylum.
• These structures togather constitute the root of lungs.

The root of lung is formed by:

• 1. Pulmonary Arteries
• 2. Pulmonary Veins
• 3. Bronchial Arteries
• 4. Bronchial Veins
• 5. Bronchi
• 6. Lymphatic Vessel
• 7. Nerve

RESPIRATION

• Respiratory Rate 12-16 breath/ min

Respiration is of three types

• Internal Respiration
• External Respiration.
• Pulmonary Respiration.

External Respiration & Internal Respiration

• Exchange of respiratory gases i.e O2 and CO2 between lungs and blood is known

as E x t e r n a l Respiration.

• Exchange of gases between blood and tissue is known as

I n t e r n a l Respiration.

• The process of air flowing into the lungs during inspiration (inhalation) and out of the lungs during expiration (exhalation) is known as

P U L M O N A R Y Respiration.

PHYSIOLOGY OF :�

1 PULMONARY BREATHING.

• Two muscle groups are used during normal inspiration: the diaphragm and. the external intercostal muscles

Additional muscles can be used if a bigger breath is required.

• When the diaphragm contracts, it moves inferiorly toward the abdominal cavity, creating a larger thoracic cavity and more space for the lungs.

Contraction of the external intercostal muscles moves the ribs upward and outward, causing the rib cage to expand, which increases the volume of the thoracic cavity.

• Due to the adhesive force of the pleural fluid, the expansion of the thoracic cavity forces the lungs to stretch and expand as well. This increase in volume leads to a decrease in intra-alveolar pressure, creating a pressure lower than atmospheric pressure. As a result, a pressure gradient is created that drives air into the lungs..

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• Quiet breathing, also known as eupnea, is a mode of breathing that occurs at rest and does not require the cognitive thought of the individual. During quiet breathing, the diaphragm and external intercostals must contract
• Forced breathing, also known as hyperpnea, is a mode of breathing that can occur during exercise or actions that require the active manipulation of breathing, such as singing. During forced breathing, inspiration and expiration both occur due to muscle contractions.

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2 EXTERNAL RESPIRATION.

• Diffusion is the main mechanism of gaseous exchange, which involves movement of a substance from high- to low-concentrated areas.
• The basic 3 components of external respiration are surface area of alveolar membrane, partial pressure gradient of gases, and ventilation and perfusion matching.

3 INTERNAL RESPIRATION. (CELLULAR RESPIRATION)

Cellular respiration takes place in the cytoplasm and mitochondria of each cell of the body. Glycolysis occurs inside the cytoplasm, while the TCA cycle (THE CITRIC ACID) occurs inside the matrix of the mitochondria. Meanwhile, oxidative phosphorylation occurs on the inner mitochondrial membrane, with protons diffusing across into the membrane and later pumped back into the matrix.

REGULATION OF RESPIRATION.

Respiration is regulated by two controls

• 1. Nervous Control
• 2. Chemical Control

Nervous Control�

• It is exerted by respiratory center present in the medulla

oblangata of brain.

• From this center afferent impulses pass to-

1. Diphragm through phrenic nerve.

2. Intercostal muscle through inter costal nerves.

• These impulses causes rythmic contraction of diphragm and

intercostal muscle.

Chemical Control

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• This is effected through carbon dioxide content of blood.
• An increase in level of carbon dioxide produces stimulation of respiratory center.

Respiratory Volumes & Capacities.�

Respiratory Volumes

• Respiratory volume also known as lungs voume .
• Volume of gas in lungs at given time during respiratory cycle is

known as lungs volume.

• 1. Vital Capacity-
• Volume of air expelled by a forced expiration after a forced

inspiration (Normal Value- 4 litre)

• 2. Tidal Air-

Volume of air passing in and out of the lungs with ordinary quiet

breathing (Normal Value- 0.5 litre)

3. Inspiratory reserve-

• It is additional volume of air that can be taken in by forced inspiration.

(Normal Value- 2.5 litre)

4. Expiratory Reserve-

• Volume of air that can be expelled by forced expiration after

normal inspiration. (Normal Value- 1 litre)

5. Residual Volume-

• Volume of air which remains in the lungs on forced expiration after

normal inspiration. (Normal Value- 1 litre)

6. Total lungs capacity-

• Some of vital capacity ad residual volume. (Normal Value- 5litre)

Abnormal type of Respiration

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1. Cheyne- stroke breathing Form of periodic breathing in which group of breaths are separated by periods of apnea.

2. Apnea Stopping of respiration for short interval.

3. Hyperpnea Increase in depth of respiration.

4. Dyspnea Difficulty in breathing.

5. Polypnea Respiration characterise by rapid rate.

6. Tachypnea Exceedingly high or rapid respiration./ breathing.