Preksha Dhyana Human Body

Here's a comprehensive summary of "Preksha Dhyana: Human Body - Part I: Anatomy and Physiology" by Jethalal S. Zaveri:

This book, part of the "Science of Living" series by Jain Vishva Bharati, aims to provide a simple yet accurate understanding of the human body's anatomy and physiology. It is intended for the general public, especially those interested in Preksha Dhyana, to foster a deeper knowledge of the self and promote better health and well-being.

Core Philosophy and Purpose:

The book emphasizes that in today's high-stress world, psychosomatic diseases are on the rise. It proposes that Preksha Dhyana, a technique rooted in ancient Jain philosophy and adapted to modern scientific understanding, offers a path to integrated personality development, attitudinal change, and behavioral modification. This is achieved through mindful perception (Preksha) of various aspects of existence, including the human body.

A key message is that understanding and caring for the body are fundamental to living a healthy and blissful life. The book bridges ancient wisdom and modern science to empower individuals to manage their health effectively.

Key Concepts Covered in Part I (Anatomy and Physiology):

The book systematically breaks down the human body into its fundamental components and systems:

• Organization of the Body: It begins by explaining that the body is a marvel of organization, from trillions of specialized cells to tissues, organs, and complex systems working in harmony.
• Cells and Tissues:
  • Cells: Introduced as the basic unit of life, detailing their microscopic nature, diverse sizes and shapes, and the fundamental structure of a "typical cell" (cell membrane, protoplasm, nucleus, organelles). It highlights the crucial role of the nucleus, DNA, and chromosomes in heredity and cell function.
  • Tissues: Explains how similar cells group together to form tissues. It categorizes the main types: epithelial, connective (including blood and lymph), bone and cartilage, muscle, and nerve tissues, describing their structures and functions.
• Skeletal System, Muscles, and Skin:
  • Skeleton: Describes it as the body's framework, composed of over 200 bones, with special emphasis on the spine and rib cage for support and protection. It touches upon bone structure, joints, and the process of ossification.
  • Muscles: Details the three types (skeletal, smooth, cardiac) and their roles in movement and internal functions. It explains muscle contraction, the concept of antagonists, and voluntary vs. involuntary muscle action.
  • Skin (Integumentary System): Presented as the largest organ, serving as a protective barrier and involved in temperature regulation. It covers the structure of the skin (epidermis and dermis) and its accessory organs (hair, nails, glands).
• Nervous System:
  • General: Identified as the body's primary communication and control system, responsible for coordinating all bodily activities and enabling adaptive responses to the environment. It highlights its vital link with the endocrine system.
  • Structural Organization: Divided into the Central Nervous System (brain and spinal cord) and the Peripheral Nervous System (nerves extending throughout the body).
  • The Brain: A detailed exploration of its structure and functions, including the cerebrum (lobes, cerebral cortex, memory, intellect), cerebellum (movement control, balance), and brainstem (vital functions like breathing and heart rate). It also introduces the Reticular Activating System (RAS) as a filter for sensory information.
  • The Spinal Cord: Describes its role in transmitting messages and as a reflex center.
  • Peripheral Nervous System: Covers cranial and spinal nerves, and importantly, the Autonomic Nervous System (sympathetic and parasympathetic divisions) that controls involuntary functions.
  • Neurons: Explains the structure and function of the neuron as the basic unit of nerve tissue, including axons, dendrites, and synapses.
• Sense Organs: Discusses the remarkable array of sensory receptors in the body. It details the structure and physiology of:
  • Sight and the Eye: Explaining refraction, accommodation, and the roles of rods and cones in vision.
  • Hearing and the Ear: Covering the three compartments of the ear and the process of converting sound waves into nerve impulses.
  • Taste and Smell: Describing taste buds and olfactory receptors and how they function.
  • Touch, Pain, and Temperature: Explaining the distribution and function of receptors for these sensations.
  • Visceral and Kinesthetic Senses: Mentioning internal body awareness and body position sense.
• Circulatory System:
  • Basic Functions: Emphasizes its role in transporting nutrients, oxygen, hormones, and waste products throughout the body.
  • Organs: Details the heart as the pump, and the network of arteries, veins, and capillaries.
  • The Heart: Explains its structure (four chambers) and the cardiac cycle, highlighting its continuous work and the concept of diastole and systole.
  • Blood Vessels: Differentiates arteries, veins, and capillaries in terms of structure, function, and blood pressure.
  • The Bloodstream: Describes its composition (plasma and formed elements like red blood cells, white blood cells, and platelets), their functions, and the importance of hemoglobin.
  • Blood Pressure: Explains systolic and diastolic pressure and factors influencing it, noting the impact of stress and the benefits of relaxation.
  • Lymphatic System and Spleen: Briefly covers their roles in fluid balance and immune defense.
• Respiratory System:
  • Respiration: Defines it as the process of energy release requiring oxygen and eliminating carbon dioxide.
  • Organs: Details the passageways (nose, pharynx, larynx, trachea, bronchi, bronchioles, alveoli) and the lungs, emphasizing the filtering, warming, and moistening functions of the nasal passages.
  • Breathing (Mechanics): Explains the roles of the diaphragm and intercostal muscles in expanding the chest cavity to facilitate inspiration and expiration.
  • Gas Exchange: Describes how oxygen enters the blood and carbon dioxide leaves in the alveoli, highlighting the large surface area and thin walls facilitating this process. It also touches upon the transport of gases in the blood.
  • Control of Respiration: Explains how breathing is primarily an unconscious, automatic process controlled by the brainstem.
• Digestive System:
  • Processes: Differentiates between mechanical and chemical actions in digestion.
  • Organs: Covers the alimentary canal (mouth, esophagus, stomach, small intestine, large intestine) and accessory organs (salivary glands, liver, gallbladder, pancreas).
  • Detailed functions: Explains how food is broken down, nutrients are absorbed, and waste is eliminated, detailing the roles of enzymes, acids, and hormones in these processes. It highlights the liver's numerous functions and the pancreas's dual role in digestion and endocrine secretion.
• Endocrine System:
  • Glands: Distinguishes between exocrine and endocrine glands.
  • Hormones: Explains their role as chemical messengers from ductless glands that regulate growth, metabolism, sexual activity, and other body functions.
  • Key Glands: Provides an overview of the major endocrine glands (pineal, pituitary, thyroid, parathyroids, thymus, adrenals, islets of Langerhans, gonads), their locations, and their primary hormonal secretions and functions. It emphasizes the interconnectedness of the endocrine system and its regulation by the hypothalamus and pituitary.
• Urinary System:
  • Functions: Explains the crucial role of kidneys in eliminating metabolic waste products and maintaining fluid and electrolyte balance.
  • Organs: Describes the kidneys, ureters, bladder, and urethra, and their respective functions in urine formation, storage, and excretion.
  • Urine Formation: Details the processes of filtration, reabsorption, and selection within the nephrons of the kidney.
  • Regulation: Highlights the role of ADH from the hypothalamus in water balance.
  • Urination (Micturition): Explains the control mechanisms involved.
• Reproductive System:
  • Gametes: Explains the role of sperm and ova in sexual reproduction and the process of fertilization.
  • Male System: Covers the testes and their functions (spermatogenesis, testosterone secretion) and the role of the system in reproduction.
  • Female System: Details the ovaries and their functions (oogenesis, ovulation, hormone secretion) and the role of the uterus and mammary glands.
  • Life Cycle: Briefly touches upon hormonal influences throughout different life stages, including puberty and menopause.

Benefits of Preksha Dhyana in Relation to the Body:

The book connects the knowledge of the human body to Preksha Dhyana practice, suggesting that understanding these biological processes enhances the effectiveness of meditation. Specifically:

• Physical Level: Preksha Dhyana revitalizes cells, improves digestion, respiration, and blood circulation.
• Mental Level: It trains concentration, helps manage psychosomatic illnesses, aids in overcoming bad habits, and deepens self-awareness.
• Emotional Level: It strengthens reasoning, harmonizes nervous and endocrine systems, and controls emotional responses.
• Spiritual Level: It leads to control over the mind and equanimity.

Accessibility and Approach:

The book is written in a non-technical, easy-to-read style, making complex biological concepts accessible to the layperson. It aims to equip readers with the knowledge to actively participate in their own health and well-being, aligning with the Preksha Dhyana philosophy of "Science of Living." The inclusion of illustrations and tables is mentioned as enhancing understanding.

In essence, "Preksha Dhyana: Human Body - Part I" serves as a foundational text that demystifies human anatomy and physiology, framing this scientific knowledge within the context of spiritual and psychological well-being as promoted by Preksha Dhyana.