synovial fluid

Examples of synovial fluid in the following topics:

• Classification of Joints on the Basis of Structure and Function

  • This space, referred to as the synovial (or joint) cavity, is filled with synovial fluid.
  • Synovial fluid lubricates the joint, reducing friction between the bones and allowing for greater movement.
  • Knees, elbows, and shoulders are examples of synovial joints.
  • Since they allow for free movement, synovial joints are classified as diarthroses.
  • Synovial joints are the only joints that have a space or "synovial cavity" in the joint.

• Movement at Synovial Joints

  • Synovial joints allow for many types of movement including gliding, angular, rotational, and special movements.
  • The range of movement allowed by synovial joints is fairly wide.
  • Synovial joints give the body many ways in which to move.

• Types of Synovial Joints

  • Synovial joints include planar, hinge, pivot, condyloid, saddle, and ball-and-socket joints, which allow varying types of movement.
  • Synovial joints are further classified into six different categories on the basis of the shape and structure of the joint.
  • Rheumatoid arthritis (RA) is an inflammatory disorder that primarily affects the synovial joints of the hands, feet, and cervical spine.
  • The six types of synovial joints allow the body to move in a variety of ways.

• Bone and Joint Disorders

  • Synovial joints are the most common type of joint in the body.
  • A key structural characteristic for a synovial joint that is not seen at fibrous or cartilaginous joints is the presence of a joint cavity.
  • Arthritis is a common disorder of synovial joints that involves inflammation of the joint.
  • In rheumatoid arthritis, the joint capsule and synovial membrane become inflamed.

• Fluid Mosaic Model

  • The fluid mosaic model describes the plasma membrane structure as a mosaic of phospholipids, cholesterol, proteins, and carbohydrates.
  • The fluid mosaic model was first proposed by S.J.
  • The fluid mosaic model describes the structure of the plasma membrane as a mosaic of components —including phospholipids, cholesterol, proteins, and carbohydrates—that gives the membrane a fluid character .
  • Therefore, phospholipids form an excellent lipid bilayer cell membrane that separates fluid within the cell from the fluid outside of the cell.
  • The fluid mosaic model of the plasma membrane describes the plasma membrane as a fluid combination of phospholipids, cholesterol, and proteins.

• Introduction to Osmoregulation

  • The intake is balanced by more or less equal excretion of fluids by urination, defecation, sweating, and, to a lesser extent, respiration.
  • The solutes in body fluids are mainly mineral salts and sugars.
  • The body's fluids include blood plasma, the cytosol within cells, and interstitial fluid, the fluid that exists in the spaces between cells and tissues of the body.
  • Mammalian systems have evolved to regulate osmotic pressure by managing concentrations of electrolytes found in the three major fluids: blood plasma, extracellular fluid, and intracellular fluid.
  • Water movement due to osmotic pressure across membranes may change the volume of these fluid compartments.

• Tonicity

  • Three terms—hypotonic, isotonic, and hypertonic—are used to relate the osmolarity of a cell to the osmolarity of the extracellular fluid that contains the cells .
  • In a hypotonic situation, the extracellular fluid has lower osmolarity than the fluid inside the cell, and water enters the cell.
  • (In living systems, the point of reference is always the cytoplasm, so the prefix hypo- means that the extracellular fluid has a lower concentration of solutes, or a lower osmolarity, than the cell cytoplasm. ) It also means that the extracellular fluid has a higher concentration of water in the solution than does the cell.
  • As for a hypertonic solution, the prefix hyper- refers to the extracellular fluid having a higher osmolarity than the cell's cytoplasm; therefore, the fluid contains less water than the cell does.
  • In an isotonic solution, the extracellular fluid has the same osmolarity as the cell.

• Glia

  • They provide nutrients and other substances to neurons, regulate the concentrations of ions and chemicals in the extracellular fluid, and provide structural support for synapses.
  • Ependymal cells line fluid-filled ventricles of the brain and the central canal of the spinal cord.
  • They are involved in the production of cerebrospinal fluid, which serves as a cushion for the brain, moves the fluid between the spinal cord and the brain, and is a component for the choroid plexus.
  • Ependymal cells produce cerebrospinal fluid that cushions the neurons.

• Membrane Fluidity

  • First, the mosaic characteristic of the membrane helps the plasma membrane remain fluid.
  • A cold environment tends to compress membranes composed largely of saturated fatty acids, making them less fluid and more susceptible to rupturing.
  • In animals, the third factor that keeps the membrane fluid is cholesterol.
  • Cholesterol extends in both directions the range of temperature in which the membrane is appropriately fluid and, consequently, functional.
  • The plasma membrane is a fluid combination of phospholipids, cholesterol, and proteins.

• Endocytosis

  • This literally means "cell drinking" and was named at a time when the assumption was that the cell was purposefully taking in extracellular fluid.
  • In reality, this is a process that takes in molecules, including water, which the cell needs from the extracellular fluid.
  • If uptake of a compound is dependent on receptor-mediated endocytosis and the process is ineffective, the material will not be removed from the tissue fluids or blood.
  • Instead, it will stay in those fluids and increase in concentration.
  • In pinocytosis, the cell membrane invaginates, surrounds a small volume of fluid, and pinches off.