Introduction to the Human Body - BDS104

Learning Outcomes

• Define anatomy and physiology; list their branches.
• Describe the levels of structural organization in the human body.
• Identify vital life processes that characterize living organisms.
• Explain homeostasis and its significance.
• List the twelve systems of the human body.
• Relate anatomical names to common names for body regions.
• Outline major body cavities and associated organs with their linings.
• Describe the anatomical position and terms of movement.
• Define anatomical planes, sections, and directional terms.

Anatomy

• Study of body structures and their interrelationships.
• Branches include:
  • Embryology: Development in the first eight weeks post-fertilization.
  • Developmental Biology: Complete development from fertilization onwards.
  • Cell Biology: Cellular structures and their functions.
  • Histology: Microscopic tissue structure.
  • Gross Anatomy: Structures visible without a microscope.
  • Systemic Anatomy: Structures within specific body systems.
  • Regional Anatomy: Structure within specific body regions.
  • Surface Anatomy: Surface markings to infer internal structures.
  • Radiographic Anatomy: Structures visualized through imaging techniques (X-ray, MRI, CT).
  • Pathological Anatomy: Structural changes due to diseases.

Physiology

• Study of body functions.
• Branches include:
  • Neurophysiology: Functions of nerve cells.
  • Endocrinology: Hormonal control and functions.
  • Cardiovascular Physiology: Heart and blood vessel functions.
  • Immunology: Body's defense mechanisms.
  • Respiratory Physiology: Functions of air passages and lungs.
  • Renal Physiology: Kidney functions.
  • Exercise Physiology: Bodily changes during physical activity.
  • Pathophysiology: Functional changes due to disease and aging.

Levels of Structural Organization

• Chemical Level: Atoms and molecules.
• Cellular Level: Cells as functional units formed from molecules.
• Tissue Level: Tissues are groups of cells performing specific functions.
• Organ Level: Organs formed from multiple tissue types with specific shapes/functions.
• System Level: Groups of organs working together.
• Organismal Level: Individual living entities.

Basic Life Processes

• Define human life processes:
  • Metabolism: Chemical reactions sustaining life.
  • Responsiveness: Reaction to stimuli.
  • Movement: Change in position.
  • Growth: Increase in size/number of cells.
  • Differentiation: Cells developing specialized functions.
  • Reproduction: Production of new organisms.

Homeostasis

• Equilibrium in the body's internal environment maintained by regulatory mechanisms.

Body Systems

• Integumentary System: Skin, hair, nails; protects and regulates temperature.
• Skeletal System: Bones and joints; supports, protects, and stores minerals.
• Muscular System: Skeletal, smooth, and cardiac muscles; movement and heat production.
• Nervous System: Brain, spinal cord, nerves; regulates body activities through impulses.
• Endocrine System: Hormone-producing glands; regulates activities through hormones.
• Lymphatic System: Lymphatic fluid/vessels; immune responses and fluid balance.
• Cardiovascular System: Heart, blood, blood vessels; transports nutrients and oxygen, waste elimination.
• Respiratory System: Lungs and air passageways; oxygen and carbon dioxide exchange.
• Digestive System: Gastrointestinal organs; processes food and absorbs nutrients.
• Urinary System: Kidneys and urinary tract; waste elimination and fluid balance.
• Reproductive System: Gonads and associated organs; reproduction and hormone regulation.

Body Positions

• Anatomical Position: Standard reference with subject standing upright, facing observer, arms at sides, palms forward.
• Supine Position: Lying face-up.
• Prone Position: Lying face-down.

Regional Names

• Head: Skull and face.
• Neck: Connects head to trunk.
• Trunk: Chest, abdomen, pelvis.
• Upper Limb: Shoulder to hand.
• Lower Limb: Buttock to foot.
• Groin: Area where trunk meets thighs.

Terms of Direction

• Superior: Toward the head.
• Inferior: Away from the head.
• Anterior: Front of the body.
• Posterior: Back of the body.
• Medial: Closer to midline.
• Lateral: Farther from midline.
• Intermediate: Between structures.
• Ipsilateral: Same side of the body.
• Contralateral: Opposite side of the body.
• Proximal: Closer to point of origin.
• Distal: Farther from point of origin.
• Superficial: On or near the body surface.### Directional Terms
• Deep (Internal): Refers to a position away from the surface of the body.
• Directional Terms: Provide a way to describe the position of one body part in relation to another.

Body Planes and Sections

• Planes: Flat surfaces that divide the body and organs.
• Sagittal Plane: Divides the body into right and left parts, can be midsagittal (equal sides) or parasagittal (unequal sides).
• Frontal (Coronal) Plane: Divides body into anterior (front) and posterior (back) sections.
• Transverse Plane: Divides the body into superior (upper) and inferior (lower) portions.
• Oblique Plane: Cuts through the body at an angle.
• Section: A cut through the body or organs made along a specific plane.

Body Cavities

• Body Cavities: Spaces that enclose internal organs, lined with membranes.
• Dorsal Body Cavity: Protects the nervous system, composed of cranial (brain) and vertebral (spinal cord) cavities.
• Ventral Body Cavity: Larger and more anterior, housing internal organs known as viscera. Contains:
  • Thoracic Cavity: Surrounded by ribs, further divided into pleural (around lungs) and pericardial (around heart) cavities.
  • Abdominopelvic Cavity: Extends from the diaphragm to the groin, encircled by abdominal and pelvic structures. Contains:
    • Abdominal cavity: Holds digestive organs.
    • Pelvic cavity: Contains bladder and reproductive organs.

Membranes in the Ventral Body Cavity

• Serous Membrane: A double-layered membrane that covers organs and cavities, consisting of parietal (lining cavity walls) and visceral (covering viscera) layers.
• Serous Fluid: Lubricating fluid between layers, allowing frictionless organ movement.

Other Body Cavities

• Oral Cavity: Contains tongue and teeth.
• Nasal Cavity: Located in the nose.
• Orbital Cavities: House the eyeballs.
• Middle Ear Cavities: Contain small bones facilitating sound transmission.
• Synovial Cavities: Found in joints, filled with synovial fluid for reduced friction.

Abdominopelvic Quadrants

• Quadrants: Help locate abdominal and pelvic organs by dividing the cavity with midsagittal and transverse lines through the umbilicus.

Abdominopelvic Regions

• Nine Regions: Defined by horizontal and vertical lines like a tic-tac-toe grid. Key regions include:
  • Umbilical Region: Surrounding the navel.
  • Epigastric Region: Superior to umbilical.
  • Hypogastric Region: Inferior to umbilical.
  • Iliac/Inguinal Regions: Lateral to the hypogastric.
  • Lumbar Regions: Lateral to the umbilical.
  • Hypochondriac Regions: Lateral to the epigastric.

Anatomical Terms of Movement

• Flexion: Bending a joint that decreases angle.
• Extension: Straightening a joint that increases angle.
• Abduction: Movement away from the midline.
• Adduction: Movement toward the midline.
• Circumduction: Circular movement combining flexion, extension, abduction, and adduction.
• Medial Rotation: Turning toward the midline.
• Lateral Rotation: Turning away from the midline.
• Elevation: Moving a structure upwards.
• Depression: Moving a structure downwards.
• Protraction: Moving a structure forward.
• Retraction: Moving a structure backward.

Additional Anatomical Terms

• Pronation: Forearm rotates palm backward.
• Supination: Forearm rotates palm forward.
• Plantar Flexion: Movement standing on toes.
• Dorsiflexion: Movement standing on heels.
• Inversion: Foot movement with the sole facing inward.
• Eversion: Foot movement with the sole facing outward.
• Intorsion/Extorsion: Eye movement around the pupil's axis.
• Opposition: Thumb movement toward other fingers' tips.

Learning Outcomes

• Define anatomy and physiology alongside their branches.
• Describe levels of structural organization in the body: chemical, cellular, tissue, organ, system, and organismal.
• Identify vital life processes: metabolism, responsiveness, movement, growth, differentiation, reproduction.
• Understand homeostasis as equilibrium of internal body conditions.
• List the body's 11 systems: integumentary, skeletal, muscular, nervous, endocrine, cardiovascular, lymphatic, respiratory, digestive, urinary, reproductive.
• Relate anatomical and common names for body regions.
• Outline core body cavities, organs contained, and their linings.
• Describe anatomical position and terms of movement.
• Define anatomical planes, sections, and directional terms used in anatomy.

Anatomy

• Study of body structures and interrelations.
• Major branches:
  • Embryology: Development in the first eight weeks after fertilization.
  • Developmental Biology: Comprehensive development from fertilization to maturity.
  • Cell Biology: Structures and functions of cells.
  • Histology: Microscopic tissue structures.
  • Gross Anatomy: Visible structures without microscopy.
  • Systemic Anatomy: Specific systems (e.g., nervous, respiratory).
  • Regional Anatomy: Specific body regions like head or chest.
  • Surface Anatomy: Surface markings for internal anatomy understanding.
  • Radiographic Anatomy: Visualization of body structures using imaging techniques.
  • Pathological Anatomy: Study of structural changes due to disease.

Physiology

• Science of body functions.
• Specialized fields:
  • Neurophysiology: Nerve cell functionalities.
  • Endocrinology: Hormonal regulation.
  • Cardiovascular Physiology: Heart and blood vessel functions.
  • Immunology: Body disease defenses.
  • Respiratory Physiology: Air passageway functions.
  • Renal Physiology: Kidney functions.
  • Exercise Physiology: Physiological changes from muscular activities.
  • Pathophysiology: Functional changes related to disease and aging.

Levels of Structural Organization

• Chemical Level: Consists of atoms and molecules (smallest units).
• Cellular Level: Molecules combine to form cells, which are basic functional units.
• Tissue Level: Groups of cells working together for specific functions.
• Organ Level: Two or more tissue types forming organs with unique functions.
• System Level: Related organs collaborating for a common function.
• Organismal Level: Any living individual characterized by the integration of systems.

Basic Life Processes

• Differentiates living organisms from non-living things.
• Life processes in humans:
  • Metabolism
  • Responsiveness
  • Movement
  • Growth
  • Differentiation
  • Reproduction

Homeostasis

• Condition of balance in the body's internal environment maintained through regulatory processes.

Body Systems

• Integumentary System: Skin, hair, nails, sweat and oil glands; protects and regulates temperature.
• Skeletal System: Bones, joints, cartilages; supports the body and provides mineral storage.
• Muscular System: Skeletal, smooth, cardiac muscles; enables movement and maintains posture.
• Nervous System: Brain, spinal cord, nerves; regulates activity via action potentials.
• Endocrine System: Hormone-producing glands; regulates body functions through hormones.
• Lymphatic System: Lymphatic fluid, vessels, and immune cells; returns fluids and aids immune response.
• Cardiovascular System: Blood, heart, blood vessels; distributes oxygen/nutrients and removes waste.
• Respiratory System: Lungs and airways; facilitates gas exchange and voice production.
• Digestive System: Gastrointestinal tract and accessory organs; breaks down food and absorbs nutrients.
• Urinary System: Kidneys and urinary tract; eliminates waste and regulates blood composition.
• Reproductive System: Gonads and reproductive organs; involved in gamete production and hormone regulation.

Body Positions

• Anatomical Position: Standing erect, facing forward, arms at sides with palms facing forward.
• Supine Position: Lying face-up.
• Prone Position: Lying face-down.

Regional Names

• Head: Skull and facial features.
• Neck: Supports the head.
• Trunk: Comprises chest, abdomen, and pelvis.
• Upper Limbs: Shoulder to hand.
• Lower Limbs: Buttock to foot.
• Groin: Area connecting trunk and thighs.

Terms of Direction

• Superior: Toward the head.
• Inferior: Away from the head.
• Anterior (ventral): Front of the body.
• Posterior (dorsal): Back of the body.
• Medial: Nearer to midline.
• Lateral: Farther from midline.
• Intermediate: Between structures.
• Ipsilateral: Same side of the body.
• Contralateral: Opposite side.
• Proximal: Nearer to origination.
• Distal: Farther from origination.
• Superficial (external): On or toward the surface.### Directional Terms
• Internal (deep) refers to the position away from the body's surface.
• Directional terms define the location of one body part in relation to another.

Body Planes and Sections

• Body planes are flat surfaces dividing the body into sections.
• Sagittal plane: Vertical plane splitting the body into right and left sides.
• Midsagittal plane (median): Lies at the midline, creating equal right and left sides.
• Parasagittal plane: Offset from the midline, resulting in unequal sides.
• Frontal (coronal) plane: Divides body into anterior (front) and posterior (back).
• Transverse plane: Horizontal division into superior (upper) and inferior (lower) sections.
• Oblique plane: Cuts through the body at an angle.
• Sections are cuts made along these planes.

Body Cavities

• Body cavities are enclosed spaces housing internal organs, lined with membranes.
• Dorsal body cavity protects the nervous system, subdivided into:
  • Cranial cavity: Encases the brain.
  • Vertebral (spinal) cavity: Encloses the spinal cord, continuous with cranial cavity.
• Ventral body cavity is anterior and larger, containing visceral organs.
• Ventral cavity subdivisions:
  • Thoracic cavity: Surrounded by ribs and chest muscles.
    • Further divided into pleural cavities (around lungs) and pericardial cavity (surrounding the heart).
  • Abdominopelvic cavity: Extends from diaphragm to groin, encircled by abdominal wall and pelvis.
    • Subdivisions: abdominal cavity (houses stomach, liver, intestines) and pelvic cavity (contains bladder and reproductive organs).

Membranes in the Ventral Body Cavity

• Serous membranes cover and protect organs, consisting of parietal (lining cavity walls) and visceral layers (covering organs).
• Serous fluid lubricates the space between these layers, reducing friction.

Other Body Cavities

• Oral cavity contains the tongue and teeth.
• Nasal cavity is located in the nose.
• Orbital cavities hold the eyeballs.
• Middle ear cavities contain bones for sound transmission.
• Synovial cavities, found in joints, contain synovial fluid to minimize friction.

Abdominopelvic Quadrants

• Quadrants simplify the location description of abdominal and pelvic organs.
• Defined by a midsagittal line and a transverse line through the umbilicus.

Abdominopelvic Regions

• Divides the abdominopelvic cavity into nine regions using two horizontal and two vertical lines.
• Key regions include:
  • Umbilical region: Center region surrounding the umbilicus.
  • Epigastric region: Above the umbilical region.
  • Hypogastric (pubic) region: Below the umbilical region.
  • Right and left iliac (inguinal) regions: Lateral to the hypogastric region.
  • Right and left lumbar regions: Lateral to the umbilical region.
  • Right and left hypochondriac regions: Lateral to the epigastric region.

Anatomical Terms of Movement

• Flexion: Bending that reduces the angle between body parts.
• Extension: Movement that increases the angle between body parts.
• Abduction: Movement away from the midline.
• Adduction: Movement towards the midline.
• Circumduction: Combined movement, including rotation and angular motions.
• Medial rotation: Turning toward the midline.
• Lateral rotation: Turning away from the midline.
• Elevation: Moving a structure upwards.
• Depression: Moving a structure downwards.
• Protraction: Movement in the anterior direction.
• Retraction: Movement in the posterior direction.
• Pronation: Medial forearm rotation; palm faces backwards.
• Supination: Lateral forearm rotation; palm faces forwards.
• Plantar flexion: Standing on toes.
• Dorsiflexion: Standing on heels.
• Inversion: Sole of foot faces inwards.
• Eversion: Sole of foot faces outwards.
• Intorsion/Extorsion: Eye movement around the antero-posterior axis.
• Opposition: Thumb touches tips of other fingers.