BMS2043 Renal Function 2023.pdf

Kidney Phsyiology Dr Sarah Bailey [email protected] Student feedback and consultation Thursday 30/03/23 14.00 – 15.00 Thursday 27/04/23 13.00-14.00 Or book an appointment if these hours do not work for you : https://calendly.com/sgbailey/15min Click here for other weeks 27AY04 Learning outcome...

Kidney Phsyiology Dr Sarah Bailey [email protected] Student feedback and consultation Thursday 30/03/23 14.00 – 15.00 Thursday 27/04/23 13.00-14.00 Or book an appointment if these hours do not work for you : https://calendly.com/sgbailey/15min Click here for other weeks 27AY04 Learning outcomes Describe the functional role of the kidney in: blood composition blood pressure maintenance hormone production Identify clinically relevant readouts regarding kidney function Explain why the readouts mentioned above are relevant and identify how these are measured. Structure of the kidney – a recap Key parts of the kidney: - Hilum: entry/exit of blood vessels, veins and ureter - Cortex (outer pale layer) and the medulla (pinky central area) contain nephrons. - Nephrons are a complex tubular structure that enables the refinement of the filtrate, which will eventually be excreted, based on what components the blood needs. Fig 19.1 Human Physiology; An Integrated Approach (2017) Silverthorn DU, 7th International Edition. (Ebook through the library website when you log in) Structure of the kidney – a recap Fig 19.1 Human Physiology; An Integrated Approach (2017) Silverthorn DU, 7th International Edition. The Nephron Renal tubule Renal corpuscle Human Physiology; An Integrated Approach (2017) Silverthorn DU, 7th International Edition. Collecting Duct The Nephron  The functional unit of the kidney.  Responsible for blood processing.  Change in the types of cells along the length of the nephron to enable it to perform its function.  3 main areas:   Renal Corpuscle  Renal Tubule  Collecting Duct Two different kinds – juxtamedullary and cortical Refining the filtrate Variable reabsorption of water and solutes Proximal tubule Isosmotic fluid leaving the proximal tubule becomes progressively more concentrated in the descending limb. Removal of solute in the thick ascending limb creates hyposmotic fluid. Permeability to water and solutes in the distal tubule and collecting duct is regulated by hormones. Final urine osmolarity depends on reabsorption in the collecting duct. 300 mOsM Only water reabsorbed 900 mOsM 1200 mOsM Distal tubule 300 mOsM R Cortex is isosmotic to plasma. CORTEX MEDULLA 100 300 Renal medulla becomes progressively more concentrated. R R Ions reabsorbed but no water R 300 mOsM 300 mOsM 600 mOsM Variable reabsorption of water and solutes 900 mOsM Loop of Henle Collecting duct 1200 1200 mOsM E 50−1200 mOsM urine excreted Fig 20.4 Human Physiology; An Integrated Approach (2017) Silverthorn DU, 7th International Edition. Glomerular filtration Efferent arteriole 80% Afferent arteriole Plasma volume entering afferent arteriole = 100%. Peritubular capillaries 20% of volume filters. Bowman’s capsule >99% of plasma entering kidney returns to systemic circulation. >19% of fluid is reabsorbed.