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By the end of this section, you will be able to:
  • Distinguish the histological differences between the renal cortex and medulla
  • Describe the structure of the filtration membrane
  • Identify the major structures and subdivisions of the renal corpuscles, renal tubules, and renal capillaries
  • Discuss the function of the peritubular capillaries and vasa recta
  • Identify the location of the juxtaglomerular apparatus and describe the cells that line it
  • Describe the histology of the proximal convoluted tubule, loop of Henle, distal convoluted tubule, and collecting ducts

The renal structures that conduct the essential work of the kidney cannot be seen by the naked eye. Only a light or electron microscope can reveal these structures. Even then, serial sections and computer reconstruction are necessary to give us a comprehensive view of the functional anatomy of the nephron and its associated blood vessels.

Nephrons: the functional unit

Nephrons take a simple filtrate of the blood and modify it into urine. Many changes take place in the different parts of the nephron before urine is created for disposal. The term forming urine    will be used hereafter to describe the filtrate as it is modified into true urine. The principle task of the nephron population is to balance the plasma to homeostatic set points and excrete potential toxins in the urine. They do this by accomplishing three principle functions—filtration, reabsorption, and secretion. They also have additional secondary functions that exert control in three areas: blood pressure (via production of renin    ), red blood cell production (via the hormone EPO), and calcium absorption (via conversion of calcidiol into calcitriol, the active form of vitamin D).

Renal corpuscle

As discussed earlier, the renal corpuscle consists of a tuft of capillaries called the glomerulus that is largely surrounded by Bowman’s (glomerular) capsule. The glomerulus is a high-pressure capillary bed between afferent and efferent arterioles. Bowman’s capsule surrounds the glomerulus to form a lumen, and captures and directs this filtrate to the PCT. The outermost part of Bowman’s capsule, the parietal layer, is a simple squamous epithelium. It transitions onto the glomerular capillaries in an intimate embrace to form the visceral layer of the capsule. Here, the cells are not squamous, but uniquely shaped cells ( podocytes    ) extending finger-like arms ( pedicels    ) to cover the glomerular capillaries ( [link] ). These projections interdigitate to form filtration slits    , leaving small gaps between the digits to form a sieve. As blood passes through the glomerulus, 10 to 20 percent of the plasma filters between these sieve-like fingers to be captured by Bowman’s capsule and funneled to the PCT. Where the fenestrae (windows) in the glomerular capillaries match the spaces between the podocyte “fingers,” the only thing separating the capillary lumen and the lumen of Bowman’s capsule is their shared basement membrane ( [link] ). These three features comprise what is known as the filtration membrane. This membrane permits very rapid movement of filtrate from capillary to capsule though pores that are only 70 nm in diameter.

Questions & Answers

master gland Kon si h
kajal Reply
Pituitary gland
pituitary gland because it give harmonies and control other gland
glands often secrete hormones which play an important role in maintaining homeostasis.
pituitary gland
pituitary gland is master gland because it present in biran and secrtehormones and play other gland of human body and function its gland so that also called master gland.
pituitary glandis the master gland of our body
how do you study for A&P? lab and lecture?
Aubrey Reply
When one is suffering from motion sickness what area of the brain may trigger emesis?
amy Reply
that is the sign of stroke. if the patient have a stroke. the left side of body is weakness, the affected right of cerebrum but if right side of the body is weakness surely in left side!
thank you sooo much bro
Fatima Reply
Fatima hw a u
any one elaborate fr me foramens of the skull and features which they transmit
icant undrestand plz
zahruuzh Reply
try to read I hop you will understand
state and explain 20 radiology uses
what are chemicals in anatomy and physiology?
Mike Reply
what can I do to find it easy for me in anatomy and physiology course
study up on the basics of the periodic chart, learn bones and muscles attachments, and learn muscles. Those take the longest to memorize. After that it should be a little easier.
what are the two types of body cells
Jennifer Reply
what is malnutrition
malnutrition refers to faulty nutrition resulting from malabsorption,poor diet or overeating. Sometimes too these food do not contain all the six food nutrients in their right proportion.
thank you
Will u be malnourished?
What's the difference between radiology and radiology
Nothing! Radiology it means the study or using of radiation in medical science it can be 1.diagnose or treatment diagnosed radiology! x- ray. ultrasound. ct-scan. mammogram. MRI. 2. treatmen- radiation oncology, like Cobalt 60. and nuclear medicine
what is X-ray?
X-ray is type of light that make it possible to see inside any object. as human body
How the nervous system develops
ayiesher Reply
From the cells at the back of an embryo
breifly explain anatomy of thorax
Hadiza Reply
How many region the rib is divided
how many bon of human being
how to study for the skeletal system
and anatomy
I really need sources immediately
I printed out all the different bones. Put them in the see through protective sheaths and got dry erase markers. I could right on them and erase to help me learn to spell the names of markings and bones.
Or go to a book store, Barnes and Noble(doesn't have to be this) and they have coloring books for anatomy. $16. Really helpful.
okay thanks and are what study tools you use to study the materials and get a better understanding
*what are
I prefer diagrams, pictures that lay out each step with the information in each step. For Example: how action potential creates muscles to move. A pictured diagram gives me a better understanding of how each piece plays a role in each step of the process.
Also for basics, such as memorizing vocab. Flash cards are great. Don't become discouraged if you don't get them all right the first times through. The more you go through them, your brain will remember pieces of information from each and help you to pull out the information 😉
okay thanks
what is the functions of the lips in human
Momboi Reply
could I say sensation?
for protection
Lips assist in speech and eating
Too many easy questions. Which bones are the axial and appendicular? What are the abbreviations for TEE, TTE, AED, A-Mode, B-Mode, and LTH? What is the difference between hypothalamus and thalamus? Where is the parathyroid located? How many True Ribs do we have?
Sovilace Reply
Transesophageal echocardiography Transthoracic Echocardiography automated external defibrillator brightnees mode Los Hermanos Taverna
what is anatomy
okello Reply
anatomy is scientific study of body structures and how they relate to each other
Are there other functions of the nucleolus apart from synthesis of RNA and formation of ribosomes
Peninah Reply
plays a role in cell response to stress
what is angle of auscultation
Bryan Reply

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