Anatomy and Physiology

• The study of anatomy is the study of the structure of the human body.
• Physiology is the study of body function

Branches of Anatomy

• Microscopic Anatomy studies tissues and cells, including histology (the study of tissues) and cytology (the study of cells)
• Gross Anatomy involves the study of structures that are visible to the naked eye
• Regional anatomy focuses on all structures within a single body region
• Systemic anatomy studies all organs with related functions together in a system
• Surface anatomy studies the shapes and markings on the surface of the body
• Developmental anatomy traces structural changes throughout the lifetime -Embryology is the study of developmental changes of the body before birth
• Pathological anatomy studies structural changes caused by disease and diagnoses
• Radiographic anatomy studies internal structures visualized by X-ray studies
• Functional morphology explores functional properties of body structures and assesses efficiency of design

The Hierarchy of Structural Organization

• The human body is structurally complex, with multiple levels of organization
• Chemical Level:
• At the chemical level, atoms are the building blocks of matter
• Atoms combine to form molecules, both small and large called macromolecules
• Cellular Level:
• Cells and their functional subunits, organelles, are the smallest living things in the body
• Tissue Level:
• Tissues are groups of cells working together to perform a common function
• The four basic tissue types are epithelial, connective, muscle, and nervous tissue
  • Epithelial tissue covers body surfaces and lines cavities
  • Connective tissue supports the body protects organs
  • Muscle tissue provides movement
  • Nervous tissue is for communication
• Organ Level:
• Organs are discrete structures made up of more than one tissue type with most organs containing all four
• They are "functional centers" responsible for specific activities
• The brain controls the central nervous system and influences behavior
• The heart pumps blood
• Organ System Level:
• Organ systems consist of organs working together for a common purpose
• The integumentary system forms the external body covering, protects tissues, synthesizes vitamin D, and contains cutaneous receptors and glands
• The skeletal system protects and supports organs, provides a framework for muscles, forms blood cells, and stores minerals
• The muscular system enables manipulation, locomotion, facial expression, maintains posture, and produces heat
• The lymphatic system picks up leaked fluid, disposes of debris, houses lymphocytes and mounts immune responses
• The respiratory system supplies oxygen and removes carbon dioxide through the air sacs of the lungs
• The digestive system breaks down food into absorbable units for distribution to cells, undigestible foodstuffs are eliminated
• The urinary system eliminates nitrogenous wastes and regulates water, electrolyte, and acid-base balance
• The male reproductive system produces sperm and hormones aid in sperm delivery
• The female reproductive system produces eggs and hormones, supports fetal development, and provides milk
• The nervous system is the body's fast-acting control system activating muscles
• The endocrine system secretes hormones regulating growth, reproduction, and metabolism
• The cardiovascular system transports blood carrying oxygen, carbon dioxide, nutrients, and wastes, with the heart pumping blood
• Organismal Level:
• The organismal level is the culmination of all simpler levels working together and in unison

Metric System

• French scientists established a system of quantifying basic laboratory measurements in 1799
• Metric system is now universal in the scientific community
• The meter (m) is the basic unit of length
• The gram (g) is the basic unit of weight
• The liter (L) is the basic unit of volume
• Prefixes: -Mega (M) is equal to X 1,000,000 -Kilo (K) is equal to X 1,000 -Hecto (H) is equal to X 100 -Deka (D) is equal to X10 -Deci (d) is equal to X 1/10 -Centi (c) X 1/100 -Milli (m) is equal to X 1/1000 -Micro (μ) is equal to X 1/1,000,000

Anatomical Terminology

• Based on ancient Greek or Latin providing standard nomenclature worldwide
• Anatomists use a set of reference terms that are universally understood for clarity
• The lecture presents anatomical terminology and introduces basic concepts of gross anatomy
• Anatomical Position:
• The human body is erect, feet slightly apart
• Head and toes are pointed forward
• Arms hang at the sides with palms facing forward
• Directional Terminology, refers to the body in anatomical position:

Regional terms include:

• Axial region relates to the head, neck, and trunk
• Appendicular region relates to limbs and attachments to the axis.
• Abdominal divided in four quadrants; abdominal quadrants divides abdomen into four quadrants
• Right upper quadrant
• Left upper quadrant
• Right lower quadrant
• Left lower quadrant
• Abdominopelvic regions; has 9 regions
• Umbilical Region = centermost region
• Epigastric Region = superior to umbilical region
• Hypogastric (pubic) Region = inferior to umbilical region
• Right and left iliac or inguinal regions = lateral to hypogastric region
• Right and left lumbar regions = lateral to umbilical region
• Right and left hypochondriac regions = flank epigastric region laterally

Body Cavities and Membranes

• The axial portion of the body features two large cavities protecting organs

1. The dorsal (posterior) body cavity
2. The ventral (anterior) body cavity

• Dorsal Body Cavities; protects nervous system
  • Cranial cavity encloses the brain
  • Vertebral cavity runs within the vertebral column and encases the spinal cord
• Ventral Body Cavities are subdivided into the following:
  • Thoracic cavity; Houses the heart and lungs and is separated from rest by the diaphragm
  • Abdominopelvic cavity; Contains a superior abdominal cavity (stomach, intestines, liver, etc.) and an inferior pelvic cavity (reproductive organs, bladder, and rectum)
  • Visceral organs (Viscera) are an internal organ of an animal
  • Thoracic Cavity: Mediastinum divides into pleural cavities containing lungs
  • Mediastinum contains thoracic organs except lungs -Organs in the mediastinum include the heart (in the pericardial cavity), aorta, thymus gland, chest portion of the trachea, esophagus, lymph nodes, and important nerves
• Serous Membranes of the Ventral Body Cavity:
  • The walls of the ventral body cavity and the outer surfaces of the organs
  • Serosa (serous membrane) is a double-layered membrane -Parietal serosa lines cavity walls -Viceral serosa covers the external surface of organs -Thin lubricating fluid produced by the serous membrane that allows visceral organs to slide over one another

Serous Membranes Include:

• Peritoneum, the serosa lining the abdominal cavity.
• Pleura, the serosa lining the lungs.
• Pericardium, the serosa lining the heart.
• Other Body Cavities
  • Oral cavity is the mouth
  • Nasal cavity inside and posterior to the nose
  • Orbital cavity (orbits) housing the eyes in an anterior position
  • Middle ear cavity contains bones (ossicles) that transmit sound vibrations
  • Synovial cavity is joint cavities

Anatomical Terminology Body Sections Planes

• Objects can look odd when viewed in section
• Human organs need to be recognised in section, one must anticipate how organs will look
• Coronal (frontal) plane: lies vertically and divides body into anterior and posterior parts
• Transverse plane (Cross section): runs horizontally and divides body into superior and inferior parts
• Sagittal plane: runs longitudinally and divides body into right and left parts
• Median (midsagittal) plane: divides the body into equal parts
• Parasagittal plane: all other sagittal planes
• Oblique section: made diagonally

Microscopic Anatomy

• Examining small structures through a microscope Preparing human tissue for microscopy, includes specimens that are fixed (preserved) and sectioned
• Specimens stained to distinguish anatomical structures
• Artifacts = minor distortions of preserved tissues
• Light microscopy (LM): Illuminates tissue with a beam of light (lower magnification); 2D
• Transmission Electron microscopy(TEM): Uses beams of electrons (higher magnification); 2D
• Scanning electron microscopy(SEM): Heavy metal salt stain that deflects electrons in the beam to different extents; 3D

Explore the relationship between anatomy and physiology through practical examples. Understand different approaches to anatomical study, and organizational complexity in the human body.