Introduction to Anatomy & Physiology

Anatomical Terms and Directional Terminology

Anatomical terms are essential for accurately describing locations and relationships of structures in the human body. These terms are based on the standard anatomical position.

• Directional Terms:

  • Superior: Toward the head or upper part of a structure.

  • Inferior: Away from the head or toward the lower part.

  • Anterior: Toward the front of the body.

  • Posterior: Toward the back of the body.

  • Medial: Toward the midline of the body.

  • Lateral: Away from the midline.

  • Proximal: Closer to the point of attachment or origin.

  • Distal: Farther from the point of attachment or origin.

  • Superficial: Toward or at the body surface.

  • Deep: Away from the body surface, more internal.

  • Parietal: Pertaining to the wall of a body cavity.

  • Visceral: Pertaining to the internal organs.

• Body Regions: Commonly referenced regions include abdominal, lumbar, antebrachial, nasal, axillary, occipital, brachial, pelvic, calcaneal, scapular, cephalic, sternal, cervical, tarsal, cranial, thoracic, femoral, umbilical, frontal, vertebral.

Body Cavities and Membranes

The body is divided into major cavities that house organs and provide protection.

• Dorsal Cavity:

  • Cranial cavity: Contains the brain.

  • Vertebral (spinal) cavity: Contains the spinal cord.

• Ventral Cavity:

  • Thoracic cavity: Contains heart and lungs.

  • Pleural cavity: Surrounds each lung.

  • Mediastinum: Central region containing heart, trachea, esophagus.

  • Pericardial cavity: Contains the heart.

  • Abdominopelvic cavity: Subdivided into abdominal and pelvic cavities.

  • Abdominal cavity: Contains digestive organs.

  • Pelvic cavity: Contains urinary bladder, reproductive organs.

• Serous Membranes: Double-layered membranes lining cavities and covering organs.

  • Pleural: Visceral (covers lung) & Parietal (lines cavity)

  • Pericardial: Visceral (covers heart) & Parietal (lines cavity)

  • Peritoneal: Visceral (covers abdominal organs) & Parietal (lines cavity)

• Abdominopelvic Quadrants: Four quadrants used for clinical reference.

• Abdominopelvic Regions: Nine regions for more precise localization.

Sectional Anatomy

Sectional anatomy refers to the planes used to divide the body for study.

• Sagittal Plane: Divides body into left and right parts.

• Mid-sagittal: Divides body into equal left and right halves.

• Parasagittal: Divides body into unequal left and right portions.

• Coronal (Frontal) Plane: Divides body into anterior and posterior parts.

• Transverse Plane: Divides body into superior and inferior parts.

• Oblique Plane: Cuts at an angle between horizontal and vertical planes.

Organs and Organ Systems

The human body is organized into organ systems, each with specific functions.

• Integumentary

• Skeletal

• Muscular

• Nervous

• Endocrine

• Cardiovascular

• Lymphatic

• Respiratory

• Digestive

• Urinary

• Reproductive

Introduction to Cells and the Microscope

Microscope Parts and Functions

Microscopes are essential tools for studying cells and tissues. Understanding their parts and functions is crucial for laboratory work.

• Arm: Supports the microscope.

• Base: Provides stability.

• Lamp (light source): Illuminates the specimen.

• Stage: Platform for holding slides.

• Mechanical stage: Allows precise movement of slides.

• Ocular lens: Eyepiece, usually 10x magnification.

• Objective lenses: Varying magnifications (e.g., 4x, 10x, 40x, 100x).

• Iris diaphragm: Adjusts light intensity.

• Nosepiece: Holds and rotates objective lenses.

• Coarse adjustment knob: Moves stage for focusing.

• Fine adjustment knob: Fine-tunes focus.

Microscope Terminology

• Resolution: Ability to distinguish two points as separate.

• Working distance: Distance between objective lens and specimen.

• Field of view: Area visible through the microscope.

• Parfocal: Ability to switch objectives with minimal refocusing.

• Depth of Field: Thickness of specimen in focus.

Magnification

Total magnification is calculated by multiplying the objective lens magnification by the ocular lens magnification.

• Formula:

• Example: 4x objective and 10x ocular: total magnification.

Common Slides

• Letter "e" slide

• Crossed threads

• Wet mount of hair

• Wet mount of cheek cells

• Live specimens: Paramecium, Euglena

Diffusion, Osmosis, and Tonicity

Definitions

• Diffusion: Movement of molecules from an area of higher concentration to lower concentration.

• Osmosis: Diffusion of water across a selectively permeable membrane.

• Tonicity: The effect of a solution on cell volume, based on solute concentration.

• Filtration: Movement of particles through a membrane by pressure.

Experiments and Observations

• Experiment 1: Diffusion in Liquid

  • Observation of methylene blue in water demonstrates diffusion.

• Experiment 2: Diffusion in Semi-Solid Medium

  • Use agar with wells containing KMnO4 (MW 158g) and methylene blue (MW 320g).

  • Observation: Lower molecular weight (KMnO4) diffuses faster than higher molecular weight (MeBlue).

• Experiment 3: Diffusion and Membrane Permeability

  • Dialysis bag in beaker; color changes indicate permeability.

  • IKI (iodine) test: Positive result indicates presence of starch.

• Experiment 4: Thistle Tube Osmometer

  • Molasses in thistle tube, water in beaker; water moves into tube by osmosis.

• Experiment 5: Osmosis and Living Cells (RBCs)

  • RBCs in 0.9% NaCl (isotonic), 100% dH2O (hypotonic), 10% NaCl (hypertonic).

  • Hypotonic: Water enters cells, causing hemolysis (cell bursting).

  • Isotonic: No net movement; cells retain normal shape.

  • Hypertonic: Water leaves cells, causing crenation (shriveling).

• Experiment 6: Filtration

  • Mixture of copper sulfate, charcoal, and starch filtered.

  • Copper sulfate: Passes through (dissolved ions).

  • Charcoal: Does not pass (large particles).

  • Starch: Does not pass (large molecules).

Cell Division and Tissue Types

Cell Cycle and Mitosis

The cell cycle consists of interphase and mitosis, essential for growth and repair.

• Interphase:

  • G0: Resting phase, non-dividing cells.

  • G1: Cell growth.

  • S: DNA synthesis.

  • G2: Preparation for mitosis.

• Mitosis (M phase):

  • Prophase: Chromosomes condense, spindle forms.

  • Metaphase: Chromosomes align at cell equator.

  • Anaphase: Sister chromatids separate.

  • Telophase: Nuclear envelope reforms, chromosomes decondense.

• Slides: Whitefish blastula for mitosis observation.

Gametogenesis

• Spermatogenesis: Formation of sperm in testis.

• Oogenesis: Formation of ova in ovary.

• Slides: Testis, sperm, ovary.

Tissue Types

The body contains four main tissue types, each with distinct functions and characteristics.

• Epithelial Tissue:

  • Simple squamous: Single layer, flat cells; found in lung (mesothelium).

  • Simple cuboidal: Single layer, cube-shaped; found in kidney tubules.

  • Simple columnar: Single layer, tall cells; found in small intestine villi, contains goblet cells.

  • Stratified squamous: Multiple layers, flat cells; found in esophagus, skin (epidermis).

  • Pseudostratified ciliated columnar (PSCCE): Appears layered, all cells touch basement membrane; found in trachea.

  • Transitional: Multiple layers, changes shape; found in urinary bladder.

• Connective Tissue:

  • Adipose (Fat): Stores energy, insulates; found in subcutaneous tissue.

  • Dense irregular connective tissue: Provides strength; found in skin (dermis).

• Muscle Tissue: Specialized for contraction (not detailed in these notes).

• Nervous Tissue: Specialized for communication (not detailed in these notes).

Integumentary System

Regions and Functions of the Cutaneous Membrane

The integumentary system protects the body and consists of three main regions.

• Epidermis: Outermost layer; provides barrier and protection.

• Dermis: Middle layer; provides strength and elasticity.

• Hypodermis: Deepest layer; stores fat, anchors skin (not considered part of the integument).

Epidermis: Structure and Cell Layers

The epidermis is composed of stratified squamous epithelium and contains five specific cell layers (strata).

• Stratum corneum: Outermost, dead keratinized cells.

• Stratum lucidum: Clear layer, only in thick skin (palms, soles).

• Stratum granulosum: Granular cells, keratin formation.

• Stratum spinosum: Spiny cells, strength and flexibility.

• Stratum basale: Deepest, mitotically active cells.

Dermis: Structure and Layers

The dermis is composed of connective tissue and has two specific layers.

• Papillary layer: Superficial, loose connective tissue, forms dermal papillae.

• Reticular layer: Deep, dense irregular connective tissue, provides strength.

Hypodermis

The hypodermis is composed mainly of adipose tissue and provides insulation and energy storage.

• No specific layers; not considered a region of the integument.

Histology of the Integument

• Thick skin (palmer): Contains all five epidermal layers.

• Thin skin (scalp): Lacks stratum lucidum, fewer layers.

• Structures to identify: Arrector pili muscle, hair follicle, sweat glands, sebaceous glands, hair shaft.

Summary Table: Layers and Tissue Types of Skin

Key Examples and Applications

• Clinical Application: Understanding tonicity is essential for intravenous fluid administration.

• Microscopy: Identifying tissue types is fundamental for histology and pathology.

• Sectional Anatomy: Used in medical imaging (CT, MRI) to view internal structures.

Additional info: Academic context was added to clarify tissue types, cell cycle phases, and clinical relevance of tonicity and sectional anatomy.