AIT's Version 7 Science Exam: Human Anatomy and Physiology

Respiratory System

• Nasal Cavity: Air enters here, where it's warmed, humidified, and filtered.
  • Structures: Nasal hairs and microscopic cilia.
• Pharynx: Crossroads for food (esophagus) and air (larynx).
• Larynx: Air travels through here (also known as the voice box).
• Trachea: Cylindrical tube supported by cartilage rings.
  • Splits into primary bronchi leading to lungs.
• Lungs:
  • Right lung: 3 lobes.
  • Left lung: 2 lobes, includes cardiac notch.
• Bronchi and Bronchioles: Pathway narrows as air moves down.
  • Leads to alveolar ducts and sacs where gas exchange occurs.

Zones in the Lungs

• Conducting Zone: Includes trachea, bronchi, and terminal bronchioles.
  • Function: Facilitation of air passage (no gas exchange).
• Respiratory Zone: Includes respiratory bronchioles, alveolar ducts, alveoli.
  • Function: Gas exchange occurs.

Circulatory System

• Oxygen Transport: Oxygen picked up by red blood cells, distributed throughout the body.
• Interconnected Systems:
  • Skeletal: Ribs protect lungs.
  • Muscular: Intercostal muscles aid in breathing.
  • Nervous: Autonomic control over breathing using blood pH levels.
• Breathing Mechanics:
  • Inspiration: Active process, diaphragm and intercostal muscles expand thoracic cavity.
  • Expiration: Usually passive, diaphragm relaxes.

Perfusion and Ventilation

• Ventilation: Movement of air in and out of lungs.
• Perfusion: Blood flow to alveolar capillaries.
• Imbalances: Hyperventilation (excessive CO2 expulsion) and hypoventilation (inadequate ventilation).

Cardiovascular System

• Blood: Always red, varies in shade by oxygen concentration.
  • Composed of plasma, red and white blood cells, platelets.
• Heart Chambers:
  • Right atrium and ventricle (deoxygenated blood).
  • Left atrium and ventricle (oxygenated blood).
• Valves: Prevent backflow, manage flow through heart.

Electrical Conduction System

• SA Node: Heart’s primary pacemaker (60-100 beats/min).
• AV Node: Secondary pacemaker (40-60 beats/min).
• Bundle of His: Transmits signals down the ventricles.
• Purkinje Fibers: Initiate ventricular contraction.

Digestive System

• Functions: Ingestion, digestion, absorption, elimination.
• Digestion:
  • Mechanical and chemical breakdown starts in the mouth.
  • Stomach: Highly acidic, uses enzymes for protein breakdown.
• Intestines:
  • Small Intestine: Duodenum, jejunum, ileum.
    • Duodenum: Digestion of chyme.
    • Jejunum: Nutrient absorption.
    • Ileum: Absorbs remaining nutrients, vitamins.
  • Large Intestine: Water absorption, forms stool.

Endocrine System

• Hormones: Regulate functions like growth, metabolism, reproduction.
  • Thyroid regulates metabolism.
  • Pancreas controls blood sugar (insulin, glucagon).
• Adrenal Glands: Manage stress responses (cortisol).

Muscular System

• Muscle Types: Cardiac, smooth, skeletal.
• Mechanics of Contraction:
  • Sliding filament model (actin and myosin interaction).

Reproductive System

• Male System:
  • Testes produce sperm and testosterone.
  • Seminal vesicles and prostate aid in semen production.
• Female System:
  • Ovaries produce eggs, estrogen, progesterone.
  • Fallopian tubes facilitate fertilization.

Nervous System

• Central (CNS) and Peripheral (PNS).
  • CNS: Brain and spinal cord.
  • PNS: Nerve pathways.
• Brain Regions: Hindbrain, midbrain, forebrain.
  • Functions: Motor control, sensory processing, cognitive functions.

Skeletal System

• Bone Types: Long, short, flat, irregular.
• Functions: Support, movement, mineral storage.
• Bone Marrow: Red (blood cell production), yellow (fat storage).

Immune System

• Barriers: Skin, mucus membranes.
• Adaptive Immunity: Involves B and T cells.
  • B cells produce antibodies.
  • T cells target infected cells.
• Active vs Passive Immunity: Active (body produces antibodies), Passive (received antibodies).

This comprehensive overview covers the key components and functioning of the body's systems as relevant to the AIT's Version 7 Science exam on human anatomy and physiology.