Resumen
Summary Notes on Osmoregulation - AQA A Level Biology
- Grado
- Institución
Summary Notes on Osmoregulation - AQA A Level Biology A* and A quality Tailored to mark schemes as with all of my notes AQA specific
[Mostrar más]Vista previa 2 fuera de 5 páginas
Vista previa 2 fuera de 5 páginas
Añadir al carrito
Añadir al carrito
Vendedor
Seguir
studytogether
Comentarios recibidos
Vista previa del contenido
3.6.4.3 Control of blood water potential – AQA A Level BiologyOsmoregulation – homeostatic control of the water potential of the blood
The structure of the nephron
The kidney has two primary roles: excretion of metabolic waste from the body and control
of blood water potential
Nephrons
- Functional units of the kidney
- Straddle across the cortex and medulla of kidney
, The nephron’s role in the formation of glomerular filtrate (GF)
First process is ULTRAFILTRATION when blood enters the nephron
- Leads to formation of liquid called GLOMERULAR FILTRATE in Bowman’s capsule (renal)
1) Blood arrives into glomerulus via renal artery, which divides into smaller vessels called
arterioles
2) AFFERENT arteriole enters Bowman’s capsule and divides further to form capillaries of
glomerulus
3) Capillaries rejoin to form EFFERENT arteriole which leaves Bowman’s capsule
AFFERENT arteriole has a larger diameter, which helps increase the blood pressure in the glomerulus
- High pressure forces liquid and small molecules in the blood out of the capillary and into the
Bowman’s capsule
Larger molecules and blood cells cannot pass through so stay in blood
- Some of these larger molecules are soluble so affect the osmotic properties of the blood
Liquid and small molecules pass through 3 layers to reach renal capsule (Bowman’s):
- Blood capillary endothelium (gaps between cells so blood can pass out)
- Basement membrane (from collagen fibres and glycoproteins which act as filter for larger
molecules)
- Epithelium of renal capsule made of PODOCYTES with specialised shape
Describe how ultrafiltration occurs in a glomerulus (marking points)
1) Small molecules arrive under high hydrostatic pressure
2) Glucose and water pass out
3) Through fenestrations in the capillary endothelium
4) And through the capillary basement membrane
5) Then fluid is collected in Bowman’s capsule called GF
Rate at which glomerular filtrate is generated is called Glomerular Filtration Rate (GFR)
- GFR is dependent on blood pressure, higher BP = increased GFR
- Impaired kidney function is associated with low GFR
The nephron’s role in the reabsorption of glucose and water by the proximal convoluted tubule
Once GF is formed “useful” substances eg glucose, water and amino acids must be reabsorbed into
the blood, whilst “waste” eg urea and excess water will stay in the filtrate (which will eventually
leave as urine)
= carried out by PCT and is called SELECTIVE REABSORPTION
Los beneficios de comprar resúmenes en Stuvia estan en línea:
Garantiza la calidad de los comentarios
Compradores de Stuvia evaluaron más de 700.000 resúmenes. Así estas seguro que compras los mejores documentos!
Compra fácil y rápido
Puedes pagar rápidamente y en una vez con iDeal, tarjeta de crédito o con tu crédito de Stuvia. Sin tener que hacerte miembro.
Enfócate en lo más importante
Tus compañeros escriben los resúmenes. Por eso tienes la seguridad que tienes un resumen actual y confiable. Así llegas a la conclusión rapidamente!
Preguntas frecuentes
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
100% de satisfacción garantizada: ¿Cómo funciona?
Nuestra garantía de satisfacción le asegura que siempre encontrará un documento de estudio a tu medida. Tu rellenas un formulario y nuestro equipo de atención al cliente se encarga del resto.
Who am I buying this summary from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller studytogether. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy this summary for $8.25. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
45,681 summaries were sold in the last 30 days
Founded in 2010, the go-to place to buy summaries for 14 years now