Homeostasis & the Kidney Flashcards
(27 cards)
Homeostasis
Maintenance of a … internal environment despite … changes
By negative feedback
Constant
External
Negative feedback
1) … detects a …
2) receptors sends instructions to a …
3) coordinator cummincated with 1 or more … which makes a … response
4) factors returns to … point (normal)
Receptor
Deviation
Coordinator
Effector
Corrective
Set
What monitors deviations from the set point of the internal environment?
Monitored by the …
Information fed back to the … which stop making the …
Receptors
Effectors
Correction
Excretion
Removal of … waste product from the body
Metabolic
Functions of the Kidney
- e…
- o…
Excretion
Osmoregulation
Urea
Excess amino acids are … in the …
Deaminated
Liver
Deamination of amino acids
… group is removed & converted into … (toxic) and then to … (less toxic)
Urea is removed by the …
Amino
Ammonia
Urea
Kidney
Kidney structure
Humans have 2 kidneys
Each enclosed in a … capsule
Blood enters he kidney via the renal … & leaves via the renal …
Renal
Artery
Vein
The nephron
B… C… and the … & … convulsed tubules are in the … of the kidney
The loop of henle is in the …
Bowman’s capsule
Proximal & distal
Cortex
Medulla
Modification of Nephron in desert animals
…
Longer
Ultrafiltration
Filtration under high …
Separates molecules from …
Pressure
Blood
Bowman’s Capsule & Glomerulus
Responsible for ultrafiltration
Blood enters the glomeruus via … arteriole and leaves via the …
Afferent - wider … than … - blood capillaries become more narrow causing high … pressure
Afferent
Efferent
Diameter
Efferent
Hydrostatic
Glomerulus & bowman’s capsule adapted for ultrafiltration
- p… (f…) between … cells
- p… in the basement …
- … slits in feet of … (pedicels)
Pores (fenestrations)
Endothelial
Pores
Membrane
Filtration
Podocytes
Glomerular Filtrate
Smaller molecules pass through filtration layers & enter the bowman’s capsule & tubule as filtrate
Glomerular filtrate contains:
W…
G…
S…
U…
… …
Water
Glucose
Salts
Urea
Amino acids
Journey of Glomerular Filtrate
High … pressure, from … of capillaries in the capillary …, forces smaller molecules through … (pores) of the endothelial cells, then pores in the … membrane, and then through … slits in the … into the Bowman’s …
Hydrostatic
Narrowing
Knot
Fenestrations
Basement
Filtration
Pedicels
Space
Selective reabsorption by the PCT
Useful substances (e.g. glucose, amino acids & salts) are … back into the … plasma - occurs in the PCT (cortex)
Re absorbed substances pass from PCT into blood plasma in the v… r…
Cells lining the PCT are specialised to maximise …
Reabsorbed
Blood
Vasa recta
Absorption
Specialise cells of the PCT
M… - protrude, increase … for absorption
Folded basal … - extends, increases … for absorption
Many … - produce ATP for … transport
Microvilli - s.a.
Membrane - s.a.
Mitochondria - active
Selective re absorption
Uptake of specific molecules from g… f… into the …
Glomerular filtrate
Bloodstream
Secondary active transport
Coupling a …, down an … gradient, providing … for … transport
Diffusion
Electrochemical
Energy
Active
Glucose threshold
Usually all reabsorbed by the … and the re-enters the blood via v… r…
If conc. of glucose in filtrate is too high, … transport proteins become … - not all glucose will be reabsorbed, it remains in filtrate and passes out of the body in …
PCT
Vasa recta
Intrinsic
Limiting
Urine
Loop of Henle - Counter current multiplier
… flows in … directions (counter current) and the conc. of … in the filtrate … towards the … (multiplied)
Longer the loop of henle, … the conc. of … at the …
Filtrate
Opposite
Solutes
Increases
Apex
Higher
Solutes
Apex
Variation in loop length
Longer loop = … ions can be pumped into the …
Which … the water … of the medulla, allowing more water to be … into … by …
More
Medulla
Lowers
Potential
Reabsorbed
Bloodstream
Osmosis
Insufficient water
If insufficient water can be … due to action of ADH trying to … water potential of the plasma, … triggered by the … will encourage an individual to drink more …
Reabsorbed
Restore
Thirst
Hypothalamus
Fluid
Antidiuretic Hormone (ADH)
Produced in the …, secreted by the … gland
ADH increase the … of cells of the collecting duct & DCT to …, allow more to be … by …
Urine more … and a lower …
Hypothalamus
Pituitary
Permeability
Water
Reabsorbed
Osmosis
Concentrated
Volume
