Human Body Systems and Functions

Overview of the Human Body

  • Emphasis on the importance of understanding body systems and their medical relevance for trauma and medical calls.
  • Necessity of knowledge about anatomy and physiology for medical practitioners, particularly in emergency settings.

Terminology

  • Anatomy
    • Definition: The structure of the body.
    • Example: Identifying bones in the leg.
  • Physiology
    • Definition: The function of the body systems.
    • Example: The leg's function in supporting weight and facilitating movement.
  • Pathophysiology
    • Definition: The study of how diseases affect bodily functions.
    • Example: Effects of a broken leg, such as pain and swelling due to neuroreceptor signaling.

Anatomical Positioning

  • Standard Anatomical Position:
    • Patient stands upright, facing forward, with palms facing outward.
  • Directional Terminology:
    • Anterior: Front of the body. Example: Anterior head refers to the front part of the head.
    • Posterior: Back of the body. Example: Posterior head refers to the back part of the head.
    • Superior: Higher or above; Inferior: Lower or below.
    • Proximal: Closer to the center of the body; Distal: Further away from the center.

Body Structure

  • Cells: Basic building blocks of life.
  • Tissues: Groups of cells that perform a specific function.
  • Organs: Structures composed of different tissues working together.
  • Body Systems: Organ systems that work together to perform complex functions. Examples include the respiratory system and cardiovascular system.

Skeletal System Overview

  • Total number of bones: 206 (with variations in the wrist).
  • Axial Skeleton:
    • Comprised of the skull, spine (vertebral column), thoracic cage (ribs).
    • Function: Supports and protects vital organs.
  • Appendicular Skeleton:
    • Comprised of limbs and pelvic bones.
    • Not crucial for survival (appendages can be lost).

Joints

  • Types of Joints
    • Ball and Socket Joints: Allow for rotational motion; Examples: Shoulder and hip joints.
    • Hinge Joints: Allow for bending motion; Examples: Elbow and knee joints.

Skeleton and Bones

  • Facial Bones:
    • Nasal: Nose bone.
    • Zygomatic: Cheekbone.
    • Maxilla: Upper jaw.
    • Mandible: Lower jaw.
  • Skull Bones:
    • Temporal: Side of the skull.
    • Frontal: Front of the skull.
    • Parietal: Top of the skull.
    • Occipital: Back of the skull.
    • Foramen Magnum: Opening at the base of the skull for the spine to connect.

Vertebral Column

  • Sections:
    • Cervical: 7 vertebrae (neck).
    • Thoracic: 12 vertebrae (mid-back).
    • Lumbar: 5 vertebrae (lower back).
    • Sacrum: 5 fused vertebrae
    • Coccyx: Tailbone, 4 fused vertebrae.

Types of Muscles

  • Skeletal Muscle:
    • Voluntary muscles attached to the skeleton; enable movement.
  • Smooth Muscle:
    • Involuntary muscles in organs such as the digestive tract.
  • Cardiac Muscle:
    • Involuntary muscle specific to the heart.

Respiratory System

  • Divided into upper and lower airway:
    • Upper Airway: Primarily the nasal passage and throat.
    • Lower Airway: Trachea, bronchi, bronchioles, and alveoli.
  • Gas Exchange Mechanism: Oxygen enters the lungs, diffuses into blood capillaries at the alveoli, and carbon dioxide is expelled.
  • Diaphragm:
    • Major muscle involved in breathing; contracts to facilitate inhalation, relaxes during exhalation.

Circulatory System

  • Heart: Pumps blood throughout the body; consists of 4 chambers (two atria and two ventricles).
  • Blood Flow Path:
    1. Deoxygenated blood enters right atrium via superior vena cava.
    2. Flows through tricuspid valve into right ventricle.
    3. Sent to lungs via pulmonary artery for oxygenation.
    4. Oxygenated blood returns to left atrium via pulmonary veins.
    5. Flows through mitral valve into left ventricle.
    6. Pumped out to the body through the aorta.
  • Blood Pressure: Measure of pressure in arteries during heartbeats (systolic and diastolic readings).
    • Example: 120/80 mmHg is normal BP.

Conclusion

  • Importance of continued learning and examination of the skeletal, respiratory, and circulatory systems for effective medical practice and patient care.
  • Review of foundational anatomy and physiology concepts critical for understanding patient health and emergency response.