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Left kidney

The left panel of this figure shows the location of the kidneys in the abdomen. The right panel shows the cross section of the kidney.

Renal hilum

The renal hilum    is the entry and exit site for structures servicing the kidneys: vessels, nerves, lymphatics, and ureters. The medial-facing hila are tucked into the sweeping convex outline of the cortex. Emerging from the hilum is the renal pelvis, which is formed from the major and minor calyxes in the kidney. The smooth muscle in the renal pelvis funnels urine via peristalsis into the ureter. The renal arteries form directly from the descending aorta, whereas the renal veins return cleansed blood directly to the inferior vena cava. The artery, vein, and renal pelvis are arranged in an anterior-to-posterior order.

Nephrons and vessels

The renal artery first divides into segmental arteries, followed by further branching to form interlobar arteries that pass through the renal columns to reach the cortex ( [link] ). The interlobar arteries, in turn, branch into arcuate arteries, cortical radiate arteries, and then into afferent arterioles. The afferent arterioles service about 1.3 million nephrons in each kidney.

Blood flow in the kidney

This figure shows the network of blood vessels and the blood flow in the kidneys.

Nephrons are the “functional units” of the kidney; they cleanse the blood and balance the constituents of the circulation. The afferent arterioles form a tuft of high-pressure capillaries about 200 µm in diameter, the glomerulus    . The rest of the nephron consists of a continuous sophisticated tubule whose proximal end surrounds the glomerulus in an intimate embrace—this is Bowman’s capsule    . The glomerulus and Bowman’s capsule together form the renal corpuscle    . As mentioned earlier, these glomerular capillaries filter the blood based on particle size. After passing through the renal corpuscle, the capillaries form a second arteriole, the efferent arteriole    ( [link] ). These will next form a capillary network around the more distal portions of the nephron tubule, the peritubular capillaries    and vasa recta    , before returning to the venous system. As the glomerular filtrate progresses through the nephron, these capillary networks recover most of the solutes and water, and return them to the circulation. Since a capillary bed (the glomerulus) drains into a vessel that in turn forms a second capillary bed, the definition of a portal system is met. This is the only portal system in which an arteriole is found between the first and second capillary beds. (Portal systems also link the hypothalamus to the anterior pituitary, and the blood vessels of the digestive viscera to the liver.)

Blood flow in the nephron

This image shows the blood vessels and the direction of blood flow in the nephron.
The two capillary beds are clearly shown in this figure. The efferent arteriole is the connecting vessel between the glomerulus and the peritubular capillaries and vasa recta.

Visit this link to view an interactive tutorial of the flow of blood through the kidney.

Cortex

In a dissected kidney, it is easy to identify the cortex; it appears lighter in color compared to the rest of the kidney. All of the renal corpuscles as well as both the proximal convoluted tubules (PCTs)    and distal convoluted tubules    are found here. Some nephrons have a short loop of Henle    that does not dip beyond the cortex. These nephrons are called cortical nephrons    . About 15 percent of nephrons have long loops of Henle that extend deep into the medulla and are called juxtamedullary nephrons    .

Chapter review

As noted previously, the structure of the kidney is divided into two principle regions—the peripheral rim of cortex and the central medulla. The two kidneys receive about 25 percent of cardiac output. They are protected in the retroperitoneal space by the renal fat pad and overlying ribs and muscle. Ureters, blood vessels, lymph vessels, and nerves enter and leave at the renal hilum. The renal arteries arise directly from the aorta, and the renal veins drain directly into the inferior vena cava. Kidney function is derived from the actions of about 1.3 million nephrons per kidney; these are the “functional units.” A capillary bed, the glomerulus, filters blood and the filtrate is captured by Bowman’s capsule. A portal system is formed when the blood flows through a second capillary bed surrounding the proximal and distal convoluted tubules and the loop of Henle. Most water and solutes are recovered by this second capillary bed. This filtrate is processed and finally gathered by collecting ducts that drain into the minor calyces, which merge to form major calyces; the filtrate then proceeds to the renal pelvis and finally the ureters.

Questions & Answers

What is the differences between anabolism and catabolism?
Ikenze Reply
what are steroid hormones
Mwesige
it doesn't have nothing to do with are sex hormones
isaiah
it's something with food we eat,the air we breathe into the energy we need to function
isaiah
There are two parts to metabolism: Catabolism and Anabolism. An example of Anabolism is steroids. They build muscle. Where as Catabolism is the dagratative process or the breakdown process.
Eric
Yes, in a way. Insulin is catabolic when it comes to glucose. Where as glucacon is anabolic when it comes to sugar. The two words are like the prepositions up and down. They describe a position. In which can be used to describe anything. However, they are biologic terms to describe metabolism.
Eric
The food analogy has merrit. The conversation if food and oxygen into energy. Is a part of our metabolism called cellular respiration. In which is a METABOLIC PROCESS. Respiration has many steps and products. So, it is both anabolic and catabolic.
Eric
FOR ALL OF MY SCIENTIST, ALWAYS BREAK UP WORDS YOU DO NOT KNOW. BREAK THEM UP INTO THEIR BASE, PREFIX AND SUFIX. LET'S USE HYDROLYSIS. HYDRO MEANS WATER AND LYSIS MEANS TO BREAK DOWN. SO A HYDROLYTIC REACTION IS ONE WHERE WATER IS BROKEN DOWN.
Eric
I hope my explanation helped.
Eric
whats the difference between regional anatomy and systematic anatomy?
mitchxidyllic Reply
Regional anatomy is the scientific study of the structure of a particular region of the body, e.g the heart. systematic anatomy is the scientific study of the structure of a particular body system. e.g The reproductive system.
Ikenze
how many litres of blood does a human body have
George Reply
hi
Sweetlin
hliii
Mohd
there are around 10.5p.(5literes) adult body
Shubu
what is homeostasis
Antwi Reply
it is self regulating ability of the body to adjust to the surroundings
Angela
it is like maintaining an equilibrium type of environment between the inside and outside of the body, so that our body can adjust to the external environmental changes
Angela
this is the negative feedback loop of the body,.... that naturally helps to keep the body in a stable or constant internal environment.
Matthew
this is the activities in the body that keeps the internal environment of the body in equilibrium or to keep it constant.
Ikenze
list four long bones
Mary Reply
the four long bones are: tibia, fibula, femur, and humerus.
Isaac
from Zambia
Mary
femur, radius , ulnar, humerus
Om
humerus, femur, tibia and fibula
Sheryl
Humerus,redius,ulnar,in hand. Femur,tibia,fibula in leg. it is long bone.
Sneha
there is contradiction between radius ulna & tibia fibula because of the variation in the upper and lower limb of the according to growth and development of human body so humerus & femur are longer bones ( ex you can see Michael phaleps upper limb is longer than the lower limb)
Prashant
if anyone having dout so he she can please explain it to me
Prashant
which one want explain something
Dr
sir post which I have send look at it & tell is it correct or not
Prashant
about four long bones is the topic
Prashant
femur, humerus, tibia and fibula
Ikenze
how are you doing
Rekah Reply
hi everyone.
AR
Im new here, I came from the philippines. I study nursing. Im a first year student.
AR
really
Isaac
so what help do you want
Isaac
yeah I came from the philippines..and I have struggle about this subject the anatomy and physiology because I dont any books that I barrowed with. I cant afford buy books.
AR
hii
Meher
I'm from India
Jamy
I struggle with this subject
Jamy
can I ask here a question I hope you can help me because I dont have any references/books that I should see or read it.
AR
AR
Meher
you are from india nice to talk to you jamy.
AR
Alright Always drop your concerns here and they will be addressed. Thanks sister.
Isaac
nice meeting with you
Jamy
I am also from India
shiv
thank you Isaac.
AR
yes Meher?
AR
you are all india
AR
By the way I have question
AR
describe a person in anatomical position?
AR
i come from Ghana
Isaac
are you all nursing students?
AR
no I'm pharmacy student
Jamy
oh nice.
AR
yes
shiv
jamy me too
Meher
yes
shiv
yes
shiv
my name is sweety
Jamy
you have any chat group that we can talk there.
AR
Anatomical position is the description of any region or part of the body in a specific stance. In the anatomical position, the body is upright, directly facing the observer, feet flat and directed forward. The upper limbs are at the body's sides with the palms facing forward. The standard anatomic
Isaac
yes
shiv
jamy is my nick name
Jamy
I am a nursing student
Isaac
thank you Isaac
AR
Final year, level 400
Isaac
ohh what year are you now?
AR
Nice
AR
welcome madam
Isaac
do you have any chat group here
AR
describe the six levels of organization of the body and describe the major characteristics of each level?
AR
ahh its okay jammy
AR
jammy i am from kashmir nd u
Meher
It is convenient to consider the structures of the body in terms of fundamental levels of organization that increase in complexity, such as (from smallest to largest): chemicals, cells, tissues, organs, organ systems, and an organism.
Isaac
hi
Yaminah
am from somalia
Yaminah
5th year in medical student nice to meet ya all
Yaminah
thxs yaminah
Meher
y not.. jamy for what purpose...?
Meher
inbox me i will guide u ...?
Meher
i also dont know...?
Meher
open this app - click 'start learning' - click 'preface' - select the chat that you wanna join into I guess that is it !
Angela
Hello am from Sierra Leone
junisa
I am from Kerala
Angela
I am from india
Om
tell the easyst way to learn anatomy
Khaliif Reply
try to draw 👌
Rahil
what
shiv
learn subject with drawing anatomy diagrams some with flow chart i dont say it is easiest way bt yes u can rember for longer period
Shakerah
ooh
shiv
Can u say me parturation
Sweetlin
parturition is one of the 7 stages of human reproduction. parturition is actually that last or the 7th stage, that is giving birth to the baby or the delivery of the baby.
Angela
Mr. khaliff.. never ever use a short cut or easiest way to Acquire knowledge.. the knowledge what we got from an easiest way , cuz it will be become temporary, not permanent.. especially in the anatomy.. cuz it's a complex subject.. you can shortlist as per your syllabus, not yourself..
Sanjith
I think shakeerah's ideology of learning anatomy is one of a best method to easy learning.. and try to share with your friends or here, what you've acknowledged each day.. thankyu
Sanjith
I am agree with that point
shiv
if u get time aftr learning this 2_3 ppl join , make group make questions if urself even if its silly make it as flash card sometimes u fail , its okay. dont be less heart. u vl do it anyway if u concentrate. bt choosing ppl or the selection of ppl during studying it really matters.
Shakerah
if u get time aftr learning this 2_3 ppl join , make group make questions if urself even if its silly make it as flash card sometimes u fail , its okay. u vl do it anyway if u concentrate. bt choosing ppl or the selection of ppl during studying it really matters.
Shakerah
😊
Sanjith
what Tk
shiv
good night all... stay safe.. bye
Sanjith
hello im new here, im a nursing student
SHUGA Reply
ooh
shiv
welcome
shiv
wlcm
Rahil
dub
Ndowmi
maleria
Ndowmi
Anopheles
shiv
welcome shuga
Om
please am new here. Am a nurse awaiting to be posted .
Ntiamoah
hi I'm new here too
faleke
FAKE DrLUPO thank you
faleke
hello guys
Chuks
hello guys 🤗
Sneha
hello
Chuks
whose in Nigeria
Chuks
🙋🙋
faleke
what is inner breeding
Vijay Reply
you don't have any answer
Vijay
please don't waste my time
Vijay
wait
shiv
inbreeding is mating or breeding with organism that are genetically related
shiv
s
Pankaj
who this SRY
Pankaj
inner breeding is breeding among the same species of organisms
Anna
*inbreeding
Anna
yes same speciesor same genetic organism
shiv
description of the menstruation cycle
Namyalo Reply
explain the menstruation cycle
Namyalo
explain the menstrual cycle
Ugo
menstrual cycle is came due to FSH and LH
shiv
fsh
Ndowmi
This is the periodic release of waste(blood) from the reproductive organ of the females (human) for a period of some days, after which or during then, ovulation takes place, which is the release of eggs from the ovaries for fertilization by the spermatozoa.
Ikenze
Description of menestraul cycle
Amos Reply
i want to improve my study i like this app i interest physiology and anatomy
Su Reply
I also like this app am really interested in learning anatomy and physiology.
Johny
I have this book with my anatomy class it's awesome! also if look at crashcourse anatomy on you tube!
AMY
what the name
isaiah
umesh. rede
Rede
what is heart and long type answer
Lalita Reply
its a organ in the body
ay
describe about hear chambers.. valves.. arteries.. veins.. circulation.. inferior/superior venacava, aorta., tricuspid valve, mitral valve. pulmonary artery/vein, how oxigenation occur,systolic presure diastolic pressure.. stroke volume,cardiac output, ets.. heart located in which place, describe it
Sanjith
if you describe what I cited up, thogh you can write a long type answer about heart
Sanjith
hi
Riyaz
autonomic functions took over
Vanarith Reply
What did they take over?
Eric
what is the average volume of blood in men and why does it varrie from women?
Esther Reply
what is the average volume of blood in men
Esther
5to6liter
Sarita
5to6liter dt
Sarita
umesh. rede
Rede
estimated at 5.5litres
Ikenze

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Source:  OpenStax, Anatomy & Physiology. OpenStax CNX. Feb 04, 2016 Download for free at http://legacy.cnx.org/content/col11496/1.8
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