Lab Safety

General Laboratory Safety Rules

Laboratory safety is essential to prevent accidents and ensure a safe working environment. Students must be familiar with standard safety protocols before beginning any lab work.

• Personal Protective Equipment (PPE): Always wear lab coats, gloves, and safety goggles as required.

• No Eating or Drinking: Food and beverages are prohibited in the laboratory to avoid contamination.

• Proper Handling of Chemicals and Equipment: Follow instructions for handling all substances and instruments.

• Emergency Procedures: Know the location of safety showers, eyewash stations, fire extinguishers, and first aid kits.

General Laboratory Clean-Up Procedures

• Dispose of biological and chemical waste in designated containers.

• Clean and return all equipment to its proper place.

• Wipe down work surfaces after completing experiments.

Special Senses

General Senses vs. Special Senses

The human body detects stimuli through general and special senses, each with distinct characteristics.

• General Senses: Include touch, pain, temperature, pressure, and proprioception. These are distributed throughout the body.

• Special Senses: Include vision, hearing, equilibrium, taste, and smell. These are localized to specific organs.

Cranial Nerves Associated with Special Senses

• Olfactory (I): Smell

• Optic (II): Vision

• Facial (VII), Glossopharyngeal (IX), Vagus (X): Taste

• Vestibulocochlear (VIII): Hearing and equilibrium

Layers of the Eye

The eye consists of three main layers, each with specific functions.

Parts of the Eye and Their Functions

• Cornea: Transparent front part; refracts light.

• Iris: Colored part; controls pupil size.

• Lens: Focuses light onto the retina.

• Retina: Contains photoreceptors (rods and cones) for vision.

• Optic Nerve: Transmits visual information to the brain.

Structures of the External, Middle, and Internal Ear

Parts of the Ear and Their Functions

• Cochlea: Converts sound vibrations into nerve impulses.

• Semicircular Canals: Detect rotational movement (balance).

• Vestibule: Detects linear acceleration and head position.

Endocrine System

Hormones Produced by Endocrine Glands and Their Functions

The endocrine system regulates body functions through hormones secreted by glands.

Heart Anatomy and Physiology

Parts of the Heart

• Atria: Upper chambers that receive blood.

• Ventricles: Lower chambers that pump blood out of the heart.

• Valves: Ensure one-way flow (tricuspid, bicuspid/mitral, pulmonary, aortic).

Blood Flow Through the Heart

1. Deoxygenated blood enters right atrium via superior/inferior vena cava.

2. Passes through tricuspid valve to right ventricle.

3. Pumped through pulmonary valve to pulmonary arteries and lungs.

4. Oxygenated blood returns via pulmonary veins to left atrium.

5. Passes through mitral valve to left ventricle.

6. Pumped through aortic valve to aorta and systemic circulation.

Systemic vs. Pulmonary Circuits

• Pulmonary Circuit: Carries blood between heart and lungs for gas exchange.

• Systemic Circuit: Delivers oxygenated blood to body tissues and returns deoxygenated blood to the heart.

Cardiac Conduction System

• Sinoatrial (SA) Node: Pacemaker; initiates heartbeat.

• Atrioventricular (AV) Node: Delays impulse, allowing atria to contract before ventricles.

• Bundle of His, Bundle Branches, Purkinje Fibers: Conduct impulses through ventricles.

ECG Waveforms

• P wave: Atrial depolarization

• QRS complex: Ventricular depolarization

• T wave: Ventricular repolarization

Heart Physiology and Blood Vessels

Types of Blood Vessels

• Arteries: Carry blood away from the heart; thick muscular walls.

• Veins: Carry blood toward the heart; have valves to prevent backflow.

• Capillaries: Microscopic vessels for exchange of gases, nutrients, and wastes.

Tunics of Blood Vessels

Blood

Types of Leukocytes and Their Functions

Blood Types and Blood Typing

• Blood Types: Determined by presence of antigens (A, B, AB, O) on red blood cells.

• Rh Factor: Presence (+) or absence (−) of Rh antigen.

• Blood Typing: Mixing blood with anti-A, anti-B, and anti-Rh antibodies to determine type.

Lymphatic System

Organs/Glands Associated with the Lymphatic System

• Lymph Nodes: Filter lymph and house lymphocytes.

• Spleen: Filters blood, recycles old red blood cells.

• Thymus: Site of T cell maturation.

• Tonsils: Protect against pathogens entering via mouth/throat.

Functions of the Lymphatic/Immune System

• Returns excess tissue fluid to the bloodstream.

• Absorbs dietary fats from the digestive tract.

• Defends against pathogens and foreign substances.

Lines of Defense

• First Line: Physical and chemical barriers (skin, mucous membranes).

• Second Line: Innate immune responses (phagocytes, inflammation, fever).

• Third Line: Adaptive immunity (B and T lymphocytes, antibodies).