Cellular Basis of Animal Physiology

• Membrane Carbohydrates and Glycocalyx:
• Carbohydrates constitute approximately $2 - 10\%$ of the plasma membrane mass, occurring exclusively on the external outer leaflet covalently linked to lipids (glycolipids) or proteins (glycoproteins).
• Together, they form the carbohydrate-rich coating termed the glycocalyx.
• Primary Physiological Role:
• Cell Recognition and Specificity: Serves as molecular fingerprint tags for self vs non-self immune recognition, tissue histocompatibility, cell-to-cell adhesion, and docking sites for hormones and pathogens.
• nalysis:
• (Recognition): Correct primary function.

Correct option: (3) Recognition

• Starling's Equation of Microvascular Fluid Movement:

• Factors Promoting Edema:

• Increased capillary hydrostatic pressure ($P_c$) (congestive heart failure, venous obstruction).
• Increased capillary permeability ($K_f$) (inflammation, toxins).
• Obstruction of lymphatic drainage (lymphedema).
• Decreased plasma oncotic pressure ($\pi_c$) (hypoalbuminemia).
  • Effect of Increased Plasma Proteins:

• An increased concentration of plasma proteins elevates intravascular oncotic pressure ($\pi_c$), which reabsorbs fluid from the interstitial space into the vascular bed, thereby preventing edema.
• nalysis:
• (Increased concentration of plasma proteins): Correct (does not cause edema).

• Physiological Ophthalmology Pairings:
• Protanope: Red-green color blindness caused by the complete (IV) loss / absence of red-sensitive cones (photoreceptor L-opsin).
• Deuteranope: Dichromacy resulting from the (I) loss / absence of green-sensitive cones (photoreceptor M-opsin).
• Fovea (Fovea centralis): Specialized avascular depression in the center of the macula densely packed exclusively with cones, providing (II) acute and detailed vision (highest visual acuity).
• Emmetropia: The refractive state of an ideal eye where parallel light rays focus precisely onto the retina without accommodation, representing (III) normal vision.
• Matching Result:
• (IV), (B)-(I), (C)-(II), (D)-(III). Hence, Option 4 is correct.