Homeostasis and Body Regions Quiz

Anatomical Terminology

• Anatomic Position: Feet flat and parallel on the ground, body standing upright, arms at sides, palms facing forward, head level, and eyes looking forward.
• Section: A cut or slice of the body for examination.
• Plane: Imaginary flat surface bisecting the body.
• Coronal/Frontal Plane: Divides the body into anterior (front) and posterior (back) parts.
• Transverse Plane: Divides the body into superior (upper) and inferior (lower) parts.
• Midsagittal Plane: Divides the body into equal left and right halves.
• Oblique Planes: Pass through structures at an angle.

Body Cavities

• Ventral Cavity: Contains organs not encased by bone, separated into thoracic and abdominopelvic cavities by the diaphragm.
• Posterior Aspect: Enclosed cavities consisting of the cranial cavity (housing the brain) and vertebral canal (housing the spinal cord).
• Serous Membranes: Combinations of parietal (lining body wall) and visceral (lining organ surfaces) layers with a serous cavity in between, secreting lubricant fluid.
• Thoracic Cavity: Contains the mediastinum (heart, thymus, esophagus, trachea, major blood vessels) and is enclosed by serous membranes (e.g., pericardium).
• Pleura: Two-layer membrane surrounding the lungs, consisting of parietal and visceral pleura.
• Abdominopelvic Cavity: Divided into abdominal cavity (above hip bone) and pelvic cavity, with the peritoneum acting as the serous membrane.

Homeostasis

• Homeostasis: Regulates internal conditions such as temperature, heart rate, blood pressure, blood sugar, and oxygen levels.
• Components:
  • Receptor: Detects changes in the environment.
  • Control Center: Integrates input and initiates response, typically the brain or a gland.
  • Effector: Implements change, such as muscles or glands.
• Feedback Loops: Concern the sequences of stimulus, receptor, control center, effectors, and restoration of homeostasis.
• Types of Feedback:
  • Negative Feedback: Most common; counteracts the stimulus to restore balance.
  • Positive Feedback: Less frequent; enhances the stimulus (e.g., childbirth, breastfeeding).
• Homeostatic Imbalance: Example is diabetes affecting blood sugar regulation.

Tissues Overview

• Tissues: Groups of similar cells and extracellular material performing common functions.
• Histology: Study of tissues through microscopy.
• Four Tissue Types: Muscle, connective, nervous, epithelial (CONMEN).

Epithelial Tissue

• Characteristics:
  • High cellularity with minimal extracellular matrix.
  • Polarity: Apical (exposed) and basal (attached) surfaces.
  • Avascular (lacks blood vessels), relies on diffusion for nutrients.
  • High regeneration ability due to exposure to the environment.
• Functions:
  • Protection: Shields against physical and biological agents.
  • Selective Permeability: Regulates passage of materials.
  • Secretion: Produces glands (e.g., goblet cells).
  • Sensation: Contains sensory receptors for touch, temperature, etc.
• Classification:
  • Simple (one layer) vs. Stratified (multiple layers).
  • Cell shapes: Squamous (flat), Cuboidal (cube-shaped), Columnar (tall).
  • Specialized types: Transitional (stretchable) and Pseudostratified (appears layered).

Connective Tissue

• Extracellular Matrix: Composed of protein fibers, ground substance, and varying from fluid to solid.
• Protein Fibers:
  • Collagen: Strong and flexible, major component of tendons/ligaments.
  • Reticular Fibers: Thin and flexible, found in organ stroma.
  • Elastic Fibers: Stretchable, prominent in skin and lungs.
• Functions: Protection, structural support, storage, transport, immune defense.
• Embryonic Connective Tissue:
  • Mesenchyme: Primary connective tissue in embryos, from which others develop.
  • Mucous Connective Tissue: Found in the umbilical cord.

Integumentary System

• Skin Functions: Selective permeability, temperature regulation, immune responses, and sensory perception.
• Nails and Hair: Derived from epidermal cells, growing primarily from dead keratinocytes.
• Nail Structure:
  • Composed of nail plate, body, and matrix (growing part).
  • Free edge lighter due to absence of capillaries; body appears darker due to underlying blood flow.
  • Lunula: Whitish area at proximal end, indicating growth.

Skin Properties

• Drug Absorption: Transdermal administration uses skin's selective permeability for slow drug release.
• Temperature Control: Vascular adjustments (vasodilation and vasoconstriction) regulate heat, with sweat glands providing cooling mechanisms.
• Immune Functions: Epidermal cells guard against pathogens and cancer cells.
• Sensory Detection: Diverse sensory receptors provide environmental feedback.

Test your knowledge on body regions and the concept of homeostasis. This quiz covers the anatomical quadrants and the key components that maintain bodily functions, including temperature regulation and blood pressure control. Perfect for students studying human anatomy or physiology.