RESPIRATORY_SYSTEM

RESPIRATORY SYSTEM

  • Instructor: Miss Fatima Sundus

  • Institution: GBSN, Liaquat College of Nursing

  • Semester: 2

OBJECTIVES

  • Define the respiratory system

  • Understand terminologies related to the respiratory system

  • Identify organs of the upper and lower respiratory system

  • Describe functions of each organ involved in respiration

  • Explain the physiology of respiration

  • Differentiate between internal and external respiration

  • Identify factors influencing the respiration process

  • Recognize patterns of respiration

DEFINITION

  • The respiratory system comprises organs responsible for breathing and facilitating oxygen and carbon dioxide exchange throughout the body.

TYPES OF RESPIRATION

  • Internal Respiration:

    • Gas exchange between the blood and body cells.

  • External Respiration:

    • Breathing process involving inhalation and exhalation of gases between blood and lungs.

ORGANS OF THE RESPIRATORY SYSTEM

  1. Nasal passages

  2. Pharynx (shared with the alimentary canal)

  3. Larynx

  4. Trachea

  5. Bronchi

  6. Lungs

DIVISION OF ORGANS

  • Upper Respiratory Tract:

    • Nose

    • Nasal passages

    • Paranasal sinuses

    • Pharynx

    • Part of the larynx above vocal folds

  • Lower Respiratory Tract:

    • Part of the larynx below vocal folds

    • Trachea

    • Bronchi and bronchioles

    • Alveoli

    • Lungs

NASAL CAVITY

  • Structure:

    • Floor: Hard palate

    • Roof: Olfactory region

    • Lateral Wall:

      • Above: Orbit and ethmoid sinus

      • Below: Maxillary sinus

PHARYNX

  • Length: Approximately 13 cm

  • Location: Extends from the base of the skull to the sixth cervical vertebra

  • Divisions:

    • Nasopharynx: Behind the nasal cavity, above the soft palate

    • Oropharynx: Behind the mouth cavity, from soft palate to epiglottis

    • Laryngeopharynx: Behind the larynx, from epiglottis to cricoid cartilage

LARYNX

  • Function: Organ of phonation

  • Length: 4 cm

  • Structure: Formed of thyroid cartilages, with the Adam’s apple formed by their midline meeting

  • Attached inferiorly to cricoid cartilage

TRACHEA

  • Description: Tube of fibro-elastic membrane supported by C-shaped cartilages

  • Length: About 6 inches

  • Location: Extends from the 6th cervical vertebra to bifurcation into bronchi at the angle of Louis

BRONCHI

  • Division: Right and left bronchi

    • Right bronchus: Wider (2.5 cm), shorter, and makes a 25-degree angle with vertical

    • Left bronchus: Narrower (4.5cm), longer, makes a 45-degree angle with vertical

  • More likely for foreign bodies to enter the right bronchus

PLEURA

  • Structure: Closed sac with two layers

    • Visceral Pleura: Covers the lungs

    • Parietal Pleura: Lines the chest wall

LUNGS

  • Shape: Each lung resembles half a cone

  • Structure: Each lung has an apex and base, with borders: anterior, posterior, and inferior

  • Surfaces:

    • Costal surface

    • Mediastinal surface

    • Diaphragmatic surface

  • Fissures:

    • Oblique fissure: Extends from the 3rd thoracic vertebra to the 6th rib

    • Horizontal fissure (only in the right lung): From the 4th costal cartilage meeting the oblique fissure

BRONCHO-PULMONARY SEGMENTS

  • Functional units of the lung, supplied by:

    • Segmental bronchus

    • Pulmonary artery

    • Pulmonary vein

DIFFERENCES BETWEEN RIGHT AND LEFT LUNGS

  • Left Lung:

    • Long, narrow, contains cardiac notch, has 2 lobes, 8 bronchopulmonary segments

  • Right Lung:

    • Short, wide, with no cardiac notch, has 3 lobes, 10 bronchopulmonary segments

FUNCTIONS OF THE RESPIRATORY SYSTEM

  • Gas Exchange:

    • Directionality: Atmosphere to blood, blood to tissues

  • Regulation of pH:

    • Related to the rate of CO2 release

  • Protection:

    • From pathogens and particulates

  • Vocalization:

    • Speech production

RESPIRATION

  • Definition: Series of exchanges leading to the uptake of oxygen by cells and release of carbon dioxide to the lungs

  • Steps in Respiration:

    1. Ventilation: Inhalation (inspiration) and exhalation (expiration)

    2. Exchange between alveoli and pulmonary capillaries (external respiration)

    3. Transport of gases in blood

    4. Exchange between blood and cells (internal respiration)

  • Cellular Respiration: Use of oxygen for ATP synthesis

STRUCTURAL ASPECTS IN RESPIRATION

  • Conduction and Exchange Portions:

  • Ventilation Structures:

    • Skeletal & musculature

    • Pleural membranes

    • Neural pathways

  • Divided into:

    • Upper respiratory tract (entrance to larynx)

    • Lower respiratory tract (larynx to alveoli)

BONES, MUSCLES & MEMBRANES

  • Pleural Membranes: Aid in creating and transmitting pressure gradient

  • Muscles of Respiration:

    • Inspirations: Sternocleidomastoid, Scalenes, External intercostals, Diaphragm

    • Expiration: Internal intercostals, Abdominals

LUNG VOLUMES

  1. Tidal Volume (TV): 500 ml

  2. Inspiratory Reserve Volume (IRV): 3 liters

  3. Inspiratory Capacity (IC): 3.5 liters

  4. Expiratory Reserve Volume (ERV): 1 liter

  5. Residual Volume (RV): 1.2 liters

  6. Functional Residual Capacity (FRC): 2.2 L

  7. Vital Capacity (VC): 4.5 liters

  8. Total Lung Capacity (TLC): 5.7 liters

RESPIRATION PATTERNS

  • Eupnea: Normal breathing (12-22 breaths/min)

  • Apnea: Cessation of breathing

  • Bradypnea: Breathing rate < 12 breaths/min

  • Tachypnea: Breathing rate > 22 breaths/min

BREATHING CYCLE

  • Inspiration:

    • Diaphragm contracts, pulling downward, thoracic cavity size increases, pressure decreases, air flows in.

  • Expiration:

    • Diaphragm relaxes, thoracic cavity volume decreases, pressure increases, air is forced out.

PRESSURE CHANGES IN BREATHING

  • Inhalation:

    • Pressure in lungs decreases, volume increases, diaphragm contracts, air is drawn in.

  • Exhalation:

    • Pressure in lungs increases, volume decreases, diaphragm relaxes, air is forced out.