Homeostasis and Directional Terms Quiz

Homeostasis

• The body's ability to maintain stable internal conditions despite external changes
• Two mechanisms: autoregulation (automatic) and extrinsic regulation (nervous and endocrine systems)
• Three steps: sensors (detect change), controllers (process information), effectors (take action)

Directional Terms and Planes

• Median Plane: Imaginary vertical plane dividing the body into equal right and left halves
• Sagittal Plane: Any plane parallel to the median plane
• Transverse Plane: Horizontal plane dividing the body into cranial and caudal segments
• Horizontal Plane: Perpendicular to the median and transverse planes, dividing the body into dorsal and ventral segments
• Cranial: Toward the head
• Caudal: Toward the tail
• Dorsal: Toward or beyond the backbone
• Ventral: Away from the backbone, toward the mid-abdominal wall
• Medial: Close to or toward the median plane
• Lateral: Away from the median plane

Bone Classification

• Long Bones: Limb bones, contain a medullary cavity filled with bone marrow (e.g., femur, humerus)
• Flat Bones: Outer compact bone, inner cancellous bone, no medullary cavity (e.g., skull bones, scapula, ribs)
• Short Bones: Outer compact bone, core of cancellous bone, no medullary cavity (e.g., carpal and tarsal bones)
• Irregular Bones: Similar to short bones in structure, but with a less uniform shape, lie in the midline and are unpaired (e.g., vertebrae)
• Sesamoid Bones: Develop within tendons or ligaments, help change tendon angle (e.g., patella)
• Pneumatic Bones: Contain air-filled spaces (sinuses) to reduce weight (e.g., maxillary and frontal bones)

Fibrous and Cartilaginous Joints

• Fibrous Joints: Connect bones with dense fibrous connective tissue, mostly immovable (e.g., sutures of the skull)
• Cartilaginous Joints: Unite bones using cartilage, limited mobility (e.g., joints between vertebrae)

Synovial Joints

• Structure: Joint cavity, articular cartilage, joint capsule (with synovial membrane and fibrous layer)
• Components:
  • Ligaments: Connective tissue bands connecting bone to bone
  • Meniscus: Fibrocartilage partially or fully dividing the joint cavity, improving stability
  • Synovial Fluid: Lubricates the joint
• Types:
  • Plane Joint: One flat bone surface glides over another
  • Hinge Joint: Allows flexion (decreasing angle) and extension (increasing angle)
  • Condylar Joint: Allows for finger movements
  • Ball and Socket Joint: Rotation, but more flexible and prone to instability (e.g., hip and shoulder)
  • Saddle Joint: Opposition movement (e.g., thumb)
  • Pivot Joint: Rotation (e.g., supination and pronation of the forearm)
  • Ellipsoid Joint: Allows for flexion-extension, adduction-abduction, and circumduction, but not axial rotation

Movement Types

• Flexion/Extension: Antagonistic movements, flexion decreases angle, extension increases angle
• Abduction/Adduction: Movement away from (abduction) or towards (adduction) the median plane
• Rotation: Twists on the own axis, inward or outward
• Circumduction: Circular movement of an extremity
• Gliding/Sliding: Articular surfaces slide over one another
• Protection:
  • Cranial: Limb moves forward
  • Retraction: Limb moves backward

Muscle Forms and Classification

• Attachments: Most muscles attach to two bones, the less mobile attachment is the origin, the more mobile attachment is the insertion
• Classification:
  • By Number of Joints: Uniaxial, biaxial, triaxial (referring to the number of planes of movement)
  • By Functional Effect: Flexors, extensors, adductors, abductors, rotators, etc.

Accessory Muscle Structures

• Fasciae: Connective tissue sheets surrounding and separating muscles, organs, and other structures, providing support and reducing friction
• Tendon Sheaths: Tubular coverings around certain tendons, containing synovial fluid for lubrication and protection
• Bursae: Fluid-filled sacs between bones and soft tissues, cushioning and reducing friction

Thoracic Cavity

• Walls: Rib cage, thoracic vertebrae, and muscles
• Mediastinum: Central compartment between the lungs, houses the heart, trachea, esophagus, thymus, and major blood vessels
• Pleura: Double-layered membrane covering the lungs (visceral pleura) and lining the cavity (parietal pleura)
• Organs: Lungs, heart, trachea, bronchi, esophagus, thymus

Abdominal Cavity

• Walls: Abdominal muscles, vertebral column, diaphragm, and pelvic bones
• Anatomical Regions: Divided into nine regions or four quadrants
• Peritoneum: Double-layered membrane lining the cavity, supports and reduces friction between organs
• Organs: Stomach, intestines, liver, gallbladder, pancreas, kidneys, spleen, adrenal glands

Pelvic Cavity

• Walls: Pelvic bones, sacrum, coccyx, and muscles
• Anatomical Regions: Greater (false) pelvis and lesser (true) pelvis
• Peritoneum: Covers organs in the pelvic cavity
• Organs: Bladder, rectum, reproductive organs (e.g., prostate, uterus, ovaries)

Biosafety

• Anatomy and Physiology Department Biosecurity Standard Operating Procedures (Chapter 3)
• Procedures in Dissection Classes

Test your knowledge on homeostasis and directional terms in anatomy. This quiz covers the mechanisms of autoregulation and extrinsic regulation, as well as various anatomical planes and directional terminology. Perfect for students of anatomy and physiology.