In the absence of ATP, the myosin head is firmly attached to the actin filament. 

TLS Online TPP Program

#Id: 2573

#Unit 7. System Physiology – Animal

Paracellular Pathway

Water and solutes can be transported between the cells by moving across the tight junctions and intercellular spaces.

TLS Online TPP Program

#Id: 2574

#Unit 7. System Physiology – Animal

Water is transported through the cells and between the tubular cells by osmosis

TLS Online TPP Program

#Id: 2575

#Unit 7. System Physiology – Animal

Transport of water and solutes from the interstitial fluid into the peritubular capillaries occurs by ultrafiltration.

TLS Online TPP Program

#Id: 2576

#Unit 7. System Physiology – Animal

Glucose reabsorption is a two-step process: 

Na+-glucose cotransport across the luminal membrane 

Facilitated glucose transport across the peritubular membrane

TLS Online TPP Program

#Id: 2577

#Unit 7. System Physiology – Animal

Proximal tubular reabsorption

Reabsorbs 67% of the filtered Na+

Reabsorbs 67% of the filtered water

Reabsorbs 100% of the filtered glucose & amino acids 

Reabsorbs 85% of the filtered HCO3−

Reabsorbs most of the filtered phosphate, lactate, and citrate

TLS Online TPP Program

#Id: 2578

#Unit 7. System Physiology – Animal

Isosmotic reabsorption is a hallmark of proximal tubular function: Solute and water reabsorption are coupled and are proportional to each other.