The plasma membrane, a flexible yet sturdy barrier that surrounds and contains the cytoplasm of a cell, is best described by using a structural model called the fluid mosaic model. According to this model, the molecular arrangement of the plasma […]
Normally, the osmotic pressure of the cytosol is the same as the osmotic pressure of the interstitial fluid outside cells. Because the osmotic pressure on both sides of the plasma membrane (which is selectively permeable) is the same, cell volume […]
In carrier mediated facilitated diffusion, a carrier (also called a trans porter) is used to move a solute down its concentration gradient across the plasma membrane. The solute binds to a specific carrier on one side of the membrane and […]
The cell contains various structural components to allow it to maintain life which are known as organelles. All the organelles are suspended within a gelatinous matrix, the cytoplasm, which is contained within the cell membrane. One of the few cells […]
Ball and Socket Joint The ball and socket joint (or spheroid joint) is a type of synovial joint in which the ball-shaped surface of one rounded bone fits into the cup-like depression of another bone. The distal bone is capable of motion around […]
In a condyloid joint or ellipsoidal joint (a type of synovial joint), the convex oval-shaped projection of one bone fits into the oval-shaped depression of another bone. A condyloid joint is biaxial because the movement it permits is around two […]
Thyroid Gland The butterfly-shaped thyroid gland is located just inferior to the larynx (voice box). It is composed of right and left lateral lobes, one on either side of the trachea, that are connected by an isthmus anterior to the […]
Oogenesis occurs in the outermost layers of the ovaries. As with sperm production, oogenesis starts with a germ cell, called an oogonium (plural: oogonia), but this cell undergoes mitosis to increase in number, eventually resulting in up to one to […]
Hemoglobin is a conjugated protein with prosthetic group heme. Hb is found in the RBCs and carries oxygen from lungs to the tissues and the reverse process occurs when Hb carries CO2 from tissues to the lungs. The red color […]