Kidney: Lecuture 4

Osmosis

Passive movement of water, (facilitated diffusion)

From Low → HigH concentration

Osmolarity/ Serum Osmolarity

Measure of Solutes/Concentrations

Ex:Sodium, gluscose, and Urea in blood

Hypo, Hyper, Isotonic

Hyper

• High Concentration Solute outside

• Water flows out → Shrivels up

Hypo

• Low Concentration/Solute outside

• Water flows in → Swells up

Isotonic

• Equal Concentration on inside/outside of cell

Epithelium

layer of cells at interface of between inside/outside of the body

Apical and Basal side

Apical Side: World/Outside/Pee side

Basolateral Side: Blood/Boody/Inside

Kidney

Functions in our body to eliminate waster and retain materials for serum osmolarity

Urea

Waste collected in by nephrons, excreted by kidney

Nephron

Functional unit of the kidney

• In renal tubule

• continous with OUTSIDE of body

Bowmans Capsule

cup-shaped structure in the kidney's nephron that surrounds the glomerulus (a network of capillaries)

• Filters waste from blood

Glomerulus

Is a tuft of capillaries that filters blood

Promximal tubule

First Segment of the nephron

• Responible for 2/3rds of water and salt absorbtion, and vitamins and glucose

• Done Via active and passive transporters

Descending Loop of Henle

More Reabsorbtion

• Outside surrounding has high concentration so water flows out

• Via aquaporins

• left behind is remain Na and Cl

Ascending Loop of Henle

More Reabsorbtion

• remaining salt recovered

• via passive transport

• urine has high salt concentratio because lost water

• Na+/Cl- passive transporters present

Na/K+ - ATPase

a vital cell membrane protein that uses energy from ATP to pump 3 sodium ions (Na+) out of a cell and 2 potassium ions (K+) into the cell

Na+/Glucose Co-transporter

is a protein family that moves glucose into cells by using the energy from the sodium (Na+) gradient

Na+/Cl- Co-transporter

in the distal convoluted tubule that reabsorbs sodium(𝑁𝑎+) and chloride (𝐶𝑙−) ions, vital for balancing electrolytes and blood pressure

Na+/Vitamin Co-transporter

crucial membrane proteins that use the sodium ion gradient to import essential vitamins,into cells for various physiological functions

Passive transporter for: K+, Cl-, Glucose, Vitamins

you need specific protein channels/carriers:

• K+ and Cl- use ion channels, Glucose uses GLUT transporters

• water-soluble Vitamins can use facilitated diffusion via carriers or sometimes specific vitamin transporters

• though often secondary active), all moving down concentration gradients without direct ATP.