Anatomy and Physiology Study Notes

Bone Terminology and Anatomy

  • Spinal Canal: spī-nahl kuh-nahl
  • Spinal Column: spī-nahl kohl-uhm
  • Spinous Process: spī-nuhs proh-sehs
  • Splint Bone: splihnt bōn
  • Stapes: stā-pēs
  • Sternal Rib: stɘr-nahl rihb
  • Sternebrae: stɘr-neh-brā
  • Sternum: stɘr-nuhm
  • Stifle Joint: stī-fuhl joynt
  • Suture: soo-chɘr
  • Synarthrosis: sihn-ahrth-rō-sihs
  • Synovial Fluid: sihn-ō-vē-ahl floo-ihd
  • Synovial Joint: sihn-ō-vē-ahl joint
  • Synovial Membrane: sihn-ō-vē-ahl mehm-brān
  • Tarsal Bone: tahr-sahl bōn
  • Tarsus: tahr-suhs
  • Temporal Bone: tehm-pohr-ahl bōn
  • Temporomandibular Joint: tehm-pohr-ō-mahn-dihb-ū-lahr joynt
  • Thoracic Limb: thohr-ah-sihck lihm
  • Thoracic Vertebrae: thohr-ah-sihck vɘrt-eh-brā
  • Tibia: tih-bē-ah
  • Tibial Crest: tih-bē-ahl krehst
  • Transverse Process: trahnz-vɘrs proh-sehs
  • Trochoid Joint: trō-koyd joynt
  • Turbinate: tuhr-buh-nāt
  • Tympanic Membrane: tihm-pahn-ihck mehm-brān
  • Ulna: uhl-nah
  • Ungual Process: uhng-gwuhl proh-sehs
  • Vertebra: vɘrt-eh-brah
  • Vertebral Column: vɘr-tēh-brahl kohl-uhm
  • Visceral Skeleton: vih-sɘr-ahl skehl-ih-tuhn
  • Volkmann’s Canal: vawhlk-mahnz kuh-nahl
  • Vomer Bone: vō-mɘr bōn
  • Xiphoid: zī-foyd
  • Yellow Bone Marrow: yehl-lō bōn meɘr-ō
  • Zygomatic Arch: zī-gō-maht-ihck ahrch
  • Zygomatic Bone: zī-gō-maht-ihck bōn
  • Osteoclast: ohs-tē-ō-klahst
  • Osteocyte: ohs-tē-ō-sīt
  • Palatine Bone: pahl-ah-tīn bōn
  • Palpation: pahl-pā-shuhn
  • Paranasal Sinus: pahr-ah-nā-sahl sī-nehs
  • Parathyroid Hormone: pahr-ah-thī-royd hohr-mōn
  • Parietal Bone: pah-rī-eh-tahl bōn
  • Patella: pah-tehl-ah
  • Patellar Ligament: pah-tehl-ahr lihg-ah-mehnt
  • Pelvic Limb: pehl-vihck lihm
  • Pelvic Symphysis: pehl-vihck sihm-fih-sihs
  • Pelvis: pehl-vihs
  • Periosteum: peɘr-ē-ohst-ē-uhm
  • Phalanges: fah-lahn-jēz
  • Phalanx: fah-lahngks
  • Pituitary Fossa: pih-too-ih-teɘr-ē fohs-ah
  • Pivot Joint: pihv-eht joynt
  • Primary Growth Center: prī-mahr-ē grōth sehn-tər
  • Process: proh-sehs
  • Proximal Sesamoid Bone: prohck-sih-mahl sehs-ah-moyd bōn
  • Pterygoid Bone: teɘr-ih-goyd bōn
  • Pubis: pyoo-bihs
  • Radius: rād-ē-uhs
  • Ramus of the Mandible: rā-muhs of the mahn-dih-buhl
  • Red Bone Marrow: rehd bōn meɘr-ō
  • Rib: rihb
  • Rotation: rō-tā-shuhn
  • Sacral Vertebrae: sā-krahl vɘrt-eh-brā
  • Sacroiliac Joint: sā-krō-ihl-ē-ahck joynt
  • Sacrum: sā-kruhm
  • Scapula: skahp-ū-luh
  • Secondary Growth Center: sehk-uhn-dahr-ē grōth sehn-tər
  • Sesamoid Bone: sehs-ah-moyd bōn
  • Shaft of the Mandible: shahft of the mahn-dih-buhl
  • Short Bone: shohrt bōn
  • Skull: skuhl
  • Sphenoid Bone: sfē-noyd bōn
  • Sphenoidal Sinus: sfē-noyd-ahl sī-nuhs
  • Spheroidal Joint: sfeer-oyd-ahl joynt

Introduction to the Skeleton

  • Imagery of a Skeleton-less Animal: Imagine an animal’s body without a skeleton, resembling a furry sac of gelatinous material. Muscles contract, moving the body; however, the body lacks support and cannot function effectively.
  • Function of the Skeleton: The skeleton is the framework of bones that supports and protects soft tissues of the body. It also has various vital functions.

Functions of Bones

1. Leverage

  • Mechanism: Bones function as levers for skeletal muscles to facilitate body movement. Tendons attach muscles to bones, enabling motion at the joints.

2. Storage

  • Role: Bones serve as reservoirs for minerals, especially calcium, allowing the body to manage calcium levels in the bloodstream.
  • Importance of Calcium: Calcium is vital for muscle contraction, blood clotting, lactation, and maintaining the skeleton.
  • Hormonal Regulation: Two hormones regulate calcium levels:
    • Calcitonin: Prevents hypercalcemia (high calcium levels).
    • Parathyroid Hormone: Prevents hypocalcemia (low calcium levels).

Bone Terminology

1. Os and Osteo

  • Usage: Terms os and osteo refer to bone (e.g., os penis, osteocytes).

2. Characteristics of Bone

  • Vital Tissue: Bone is a living tissue capable of excellent self-repair.
  • Composition: Bone comprises a sparse array of cells in a hardened matrix. Osteoblasts produce this matrix, which consists of collagen fibers and polysaccharides, before ossifying through calcium phosphate infiltration into hydroxyapatite crystals, conferring hardness.

3. Types of Bone Cells

  • Osteoblasts: Cells that form bone, contributing to the creation of the matrix.
  • Osteocytes: Mature bone cells that reside in lacunae and have limited communication through canaliculi.
  • Osteoclasts: Cells that break down bone, essential for remodeling and calcium mobilization.

Functions of Bones

Support

  • Basis: Bones support softer body tissues, providing a rigid framework.

Protection

  • Function: Bones protect delicate organs (e.g., skull protecting the brain).

Calcium Homeostasis and Bone Health

Hormonal Regulation of Calcium

  • High Calcium Levels: Calcitonin encourages calcium deposition in bones via osteoblasts and inhibits reabsorption.
  • Low Calcium Levels: Parathyroid hormone prevents calcium deposition, promotes reabsorption by osteoclasts, and retains calcium via kidneys.

Blood Cell Formation

  • Hematopoiesis: Certain bones contain marrow that produces blood cells.

Bone Structure

1. Types of Bone

  • Compact Bone: Densely structured, forms the outer layer and shaft of long bones.
  • Cancellous Bone: Lightweight, spongy structure consisting of spicules with spaces filled with marrow.

2. Blood Supply and Formation Mechanisms

  • Formation Mechanisms: Two principal methods account for bone formation:
    • Endochondral Formation: Bone replaces a cartilage model.
    • Intramembranous Formation: Bone develops from fibrous tissue membranes, especially in the skull.

Types of Joints

1. Fibrous Joints

  • Characteristics: Synarthroses, immovable, e.g., sutures of the skull.

2. Cartilaginous Joints

  • Characteristics: Amphiarhroses, slightly movable, e.g., intervertebral discs.

3. Synovial Joints

  • Characteristics: Diarthroses, freely movable, e.g., shoulder, hip, stifle joints. Includes features like articular surfaces, cartilage, joint cavity with synovial fluid, and ligaments.

Joint Movements

  1. Flexion: Decreases the angle between bones.
  2. Extension: Increases the angle between bones.
  3. Adduction: Moves towards the median plane.
  4. Abduction: Moves away from the median plane.
  5. Rotation: Twisting movement.
  6. Circumduction: Moving in a circular motion.

Conclusion

  • Understanding bone anatomy and joint mechanics facilitates an appreciation for the complexities of skeletal structure and function, relevant in both veterinary and human medicine.