Lecture Review - Respiratory and Renal Anatomy and Physiology

Discussion begins with a handout regarding the unit on Anatomy and Physiology (A&P) related to the respiratory system.

Primary Function: The main function of the respiratory system is gas exchange, specifically the exchange of carbon dioxide (CO2) and oxygen (O2).
  - Gas Exchange Details:
    - Oxygen enters the bloodstream via simple diffusion due to concentration gradients.
    - There is a higher concentration of oxygen in inhaled air compared to venous blood.
    - Conversely, there's more CO2 in venous blood compared to inhaled air, so CO2 diffuses into the lungs.
  - Apollo 13 Reference:
    - The narration refers to the Apollo 13 mission where astronauts faced dangers from building concentrations of CO2 rather than lack of O2, emphasizing the importance of CO2 removal from the body.
Shared Function with Kidneys: The respiratory system and kidneys share the function of acid-base balance (or pH balance) which regulates blood pH.

High levels of CO2 can affect blood pH negatively.
A scenario is presented where a person may hyperventilate and could be calmed by having them breathe CO2-rich air from a paper bag, which helps restore gas balance in the bloodstream.

Detailed anatomical features discussed in the context of physiology.
  - The lungs are wrapped in pleura similar to how the heart is wrapped in pericardium
    - Visceral Pleura: The inner layer of pleura attached to the lungs.
    - Parietal Pleura: The outer layer of pleura attached to the chest wall.

Facial Features in the Midline: An image of a face includes key features:
  - Apex: Tip of the nose.
  - Nasal Septum: The wall separating nostrils,
  - Philtrum: The indentation between the lip and nose.
  - Frenulum: The tissue connecting the tongue to the bottom of the mouth.
  - Note: Students should be familiar with identifying features located on the midline versus those that are not.

Turbinates (Conchae):
- There are three turbinate bones on each side of the nasal cavity (total of 6) that help warm incoming air.
Pharynx Sections: The pharynx has three sections:
  - Nasopharynx (top),
  - Oropharynx (middle),
  - Laryngopharynx (bottom).

Discussion on the larynx and several important components:
  - Epiglottis: A flap that covers the airway during swallowing.
  - Vocal Cords: Important for sound production. Their position varies during phonation:
    - Open (Abducted) Position: Vocal cords are apart for breathing.
    - Closed (Adducted) Position: Vocal cords come together for sound production.

Laryngoscopy: Examination technique through the mouth to visualize vocal cords.
- Bronchoscopy: Looking into the bronchi using a similar scope to check for issues that may relate to smoking, with histological assessment available through bronchial brushing.
Common Causes of Lung Cancer: Smoking is highlighted, indicating that lung cancer typically originates in the epithelium of the lungs due to exposure to carcinogens in smoke.

Nature of Lungs: The anatomy includes a right lung (three lobes, two fissures) and a left lung (two lobes, one fissure) with a cardiac impression on the left lung due to heart orientation.
Aspiration Risks: The right main bronchus is wider and steeper, where aspirated objects are likely to lodge.
Trachealis Muscle: Found in cross-section of trachea; relevance mentioned in exams.

Respiratory Epithelium: Composed of:
- Goblet Cells: Produce mucus to capture particles.
- Ciliated Cells: Move mucus up and out of the respiratory tract.

Alveoli: Functional units of the respiratory system designed for gas exchange with a diagram of layers:
  - Surfactant: Reduces surface tension within alveoli, preventing collapse (important in premature births).
  - Type I Pneumocytes: Squamous cells forming the alveolar walls.
  - Shared Basement Membrane: Holds alveoli and capillaries together, facilitating rapid gas exchange.
  - Capillary Endothelial Cells: One-cell thick walls of capillaries further ensuring rapid gas diffusion.
  - Alveolar Macrophages: Immune response cells to clear inhaled debris and pathogens.

Definitions:
  - Total Lung Capacity (TLC): Maximum air volume lungs can hold.
  - Vital Capacity (VC): Maximum volume of air that can be actively exhaled.
  - Residual Volume (RV): Volume of air remaining after maximal exhalation.
  - Tidal Volume (TV): Air volume inhaled or exhaled during normal breathing.
Equation:
- TLC = VC + RV

Upcoming discussion on the kidney, using similar foundational principles as those used in the respiratory tract.
Primary Function: Filtering plasma (correcting a common misconception that kidneys filter blood). Moreover, the shared function with respiratory is pH balance.

Structure includes:
  - Cortex: Outer part of the kidney.
  - Medulla: Inner section organized into renal pyramids.
  - Steel birder table flow of urine:
    - Renal papillae → Minor calyces → Major calyces → Renal pelvis → Ureters → Bladder → Urethra

Pathway of blood from the aorta to afferent arterioles:
- Branches: Aorta → Renal Artery → Segmental Artery → Interlobar Arteries → Arcuate Arteries → Cortical Radiate Arteries.
- Emphasis on correct anatomical orientation and naming discrepancies in textbooks.

Trigone: A feature in both male and female bladders.
- Detrusor Muscle: Smooth muscle telling when to void.
Differences:
- Male urethra vs. female urethra lengths and implications for urinary tract infections (UTIs).

Important discussion surrounding common urinary issues, misconceptions regarding treatments, and significance of hydration to alleviate kidney stones.
Notable emphasis on shared educational responsibility in understanding these anatomy and physiology components adequately in preparation for examinations and practical assessments.