Anatomy Flashcards
What are the 3 major parts of the urinary system?
- kidneys
- ureters
- bladder
How do the kidneys relate to the diaphragm within the abdomen?
anterior and inferior
How do the ureters relate to the muscular wall of the abdomen?
anterior and posterior
How does the bladder relate to the pubic symphysis within the abdomen?
bladder is posterior to it
What is found at the superior boundary of the abdomen?
the inferior thoracic aperture and diaphragm
What is found at the inferior boundary of the abdomen?
the pelvic inlet/brim
What is found at the posterior boundary of the abdomen? (4)
- the posterior abdominal wall muscles highlighted in blue
- vertebrae L1-L5
- ribs 11 and 12
What muscle is found at the antero-lateral boundary of the abdomen?
the anterior abdominal wall muscles highlighted in red
- transverse abdominis
What plane is a major anterior anatomy landmark for the abdomen?
the transpyloric plane
What are 3 things that can be remembered from the transpyloric plane?
- it’s at vertebral level L1
- it’s the midpoint of the kidneys
- it’s the site of the pancreas’ and duodenum’s anatomical relations to the kidneys
where is the transpyloric plane? halfway between….
halfway between:
jugular notch and pubic symphysis
What can be seen when you take away the anterior wall of the abdomen?
the greater omentum
What can be seen when you take away the small intestine from the abdomen? (5)
- stomach
- start of duodenum
- Liver (retracted)
- peritoneum (centre of LI)
- bladder (subperitoneal)
What can be seen when you take away the large intestine and liver from the abdomen?
the kidneys being immediately anterior to the diaphragm and posterior to the peritoneum
What can be seen when you take away the peritoneum from the abdomen?
that the kidneys, ureters and major blood vessels are retroperitoneal
Are the kidneys, ureters, inferior vena cava and abdominal aorta:
retroperitoneal or intraperitoneal?
retroperitoneal (outside the red line - peritoneum)
Are the small intestine and stomach:
retroperitoneal or intraperitoneal?
intraperitoneal sit within peritoneum (red line)
Right kidney:
a) SUPERIORLY related structures and retro/intra peritoneal? (very top)
b) ANTERIORLY related (above)
a) the suprarenal gland, retroperitoneal
b) liver (separated by peritoneum)
Right kidney:
a) MEDIAL structure and is it retro or intraperitoneal? (in curve)
b) INFERIOR and are they retro or intraperitoneal?(back of curve)
a) duodenum (from stomach to SI), retroperitoneal
b) - right colic flexure (sharp bend between ascending + transverse colon of LI), retroperitoneal
- small intestine, intraperitoneal
Left kidney:
a) SUPERIORLY related structures and retro/intra peritoneal? (very top)
b) ANTERIORLY related (above)
a) - suprarenal gland, diaphragm: retroperitoneal
- stomach, spleen: intraperitoneal
b)tail of pancreas, retroperitoneal
Left kidney:
a) MEDIAL structure and is it retro or intraperitoneal? (in curve)
b) LATERAL and are they retro or intraperitoneal?(back of curve)
a) small intestine (specifically jejunum), intraperitoneal
b) left colic flexure (where transverse becomes descending colon), descending colon, retroperitoneal
What are the posterior anatomical relations to the kidneys? (2 - anterior view)
3 muscles (medial to lateral) and diaphragm are the posterior anatomical relations to the kidneys? name the muscles
1) psoas major
2) quadratus lumborum
3) transversus abdominis
What are the posterior anatomical relations to the kidneys? (3 - posterior view)
- LEFT: rib 11 and 12
- RIGHT: rib 12
- ureters in sagittal plane w/ transverse processes of lumbar vertebrae
Are the kidneys and ureters intraperitoneal or retroperitoneal?
retroperitoneal
What plane do the kidneys sit in?
the transpyloric plane (level L1 vertebrae)
What are the retroperitoneal relations to the urinary system? (4)
- suprarenal glands
- posterior abdominal wall muscles
- diaphragm
- ascending and descending colon
What are the intraperitoneal relations to the urinary system?
right:
- duodenum
left:
- jejunum
- spleen
- stomach
ureters are continuous superiorly with what?
renal pelvis- which narrows as it passes inferiorly through hileum of kidney + becomes continuous with ureter at URETEROPELVIC junction.
3 points along urinary course when ureters are constricted? (where kidney stones become lodged)
- URETEROPELVIC junction.
- where ureters cross common iliac vessels at pelvic brim
- where ureters enter wall of bladder
what does the liver do? when used for clean up
directs dead cells and chemicals to digestive and urinary systems
what does the liver convert?
AAs –> toxic ammonia, liver back to urea, less toxic to be disposed
4 medical problems regarding urine, the causes, and indictaors
- pyuria: UTI (from studying leukocytes)
- glycosuria: diabetes mellitus (gluc)
- hematuria: UT bleeding (erythrocytes)
- proteinuria: pregnancy/HF/high BP (proteins)
what 2 things inhibit ADH and how does this = dehydration?
caffeine and alcohol
= no moving aquaporins = little water reabsorption = urinate more = dehrdration
how much do aquaporins absorb that are located on:
a) apical side of LoH desc limb
b) basal side of collecting duct
a) lots of reabsorption
b) less reab
What are the 2 main gross external features of the kidney and what do they contain?
HILIUM: renal pelvis, artery, vein, nerves, lymphatics (where blood vessels and nerves enter, and ureters leave at transpyloric plane)
medial side of right kidney
SINUS: major/minor calyx, perinephric fat
renal vein in relation to renal artery?
RV is always anterior (below?) to RA
What is the hilum of the kidney?
concave medial border where vessels, nerves, and the ureter connect with the kidney
What is the sinus of the kidney?
a cavity within the kidney which is occupied by the renal pelvis, renal calyces, blood vessels, nerves and fat
(occurs from the expansion of the hilum)
What are the gross internal features of the kidney? (3)
lobes
outer: cortex, renal columns
inner: medulla
What composes the medulla?
the renal pyramids, which point towards the renal sinus
What is found at the ‘apex’ of each renal pyramid?
the renal papilla
What does the renal papilla drain urine into?
the minor calyx, merges into:
the major calyx, merges into:
renal pelvis
How is the renal artery anatomically related to the renal vein?
and how do their lengths compare?
it’s posterior to the renal vein in both kidneys
diff lengths
where does the renal artery emerge from?
the abdominal aorta at the transpyloric plane, vertebrae level L1 or L2
what is found on the transpyloric plane?
pancreas and duodenum
Which renal artery is longer and why?
the right renal artery
- abdominal aorta is to the left of the midline
- right artery needs to pass posteriorly to the inferior vena cava (which is also on the right) in order to reach abdominal aorta on left
Which renal vein is longer and why?
the left renal vein
- has to travel longer anteriorly to abdominal aorta to reach inferior vena cava which is towards right
What is superior mesenteric artery syndrome in the kidneys?
left renal vein is compressed by the superior mesenteric artery = blood back up to kidneys affecting filtration process and damaging it
What 2 arteries does the renal artery branch into?
- anterior
- posterior
What do the posterior and anterior branches of the renal artery branch into?
interlobar arteries (between lobes of kidney) then arcuate arteries then
interlobular arteries
…
become afferent arterioles entering glomerulus (nephron)
What plexus innervates the kidneys?
renal plexus
What is the origin (supply) of the renal plexus (para/sympathetic? what plexus? motor/sensory? what vertebrae?)
- sympathetic nerves in prevertebral plexus (vasoconstriction, renin secretion)
- motor and sensory information via least splanchnic nerve (T12 origin)
what blood supply in regions of the ureters:
a) superior
b) middle
c) inferior
a) renal arteries
b) - gonadal arteries
- aorta
- common iliac arteries
c) internal iliac arteries
What structure is anatomically related to the ureter in the pelvis in
a) females
b) males
a) uterine artery, wrapped around ureter
b) ductus deferens
What is an anatomical restriction of the ureter?
these are created by tight angles created by ureters of physical structures pressing on them
What are 3 anatomical restrictions of the ureters?
- Ureteropelvic junction
- Pelvic inlet/brim
- Bladder entrance
What 2 areas does the spinal cord receive sensory information from that results in referred pain?
- Viscera (visceral afferent nerves – unconscious monitor of internal systems)
- Skin and muscle (somatic afferent nerves – conscious sensation).
somatic and visceral nerves enter the spinal cord together
What are dermatomes?
area that represent areas of the skin innervated by a single spinal cord segment
In which dermatomes would pain in the ureters (e.g. from kidney stones) be felt and why?
- T11-L2
- this is where sensory innervation of the ureters reach
- a patient would describe groin, abdominal region (see image)
How is the bladder anatomically related to the 1) pubic symphysis 2) peritoneum?
- Posterior to pubic symphysis.
- Inferior to the peritoneum.
what is the bladder anterior to in:
a) females
b) males
vagina
rectum
what are kidneys innervated by?
sympathetic nerves that cause vasoconstriction and renin release
What is the bladder superior to and supported by?
pelvic floor muscles
Where does the bladder sit when empty?
in the pelvic cavity
Where does the bladder extend to when filling?
extends through pelvic brim and into abdominal cavity
What is the female bladder blood supply? (3)
- right internal iliac artery
- vaginal artery (specific to female)
- superior vesical artery
What is the male bladder blood supply? (3)
- right internal iliac artery
- superior vesical artery
- inferior vesical artery (specific to male)
All arteries to the bladder are branches of what artery?
the internal iliac arteries
Where does venous drainage for the bladder occur?
through the internal iliac veins
What are the internal features of the bladder? (4)
- trigone: internal surface (external is base)
- rugae (foldings of smooth muscle)
- ureter openings
- internal urethral orifice and sphincter (prominent in males but less in females)
In which pouches can fluid accumulate during infection or bleeding in the female pelvis?
- recto-uterine pouch (between uterus and rectum)
- vesico-uterine pouch (between bladder and uterus)
In what pouch can fluid accumulate during infection or bleeding in the male pelvis?
the recto-vesical pouch (between rectum and bladder)
What is the structure of the female urethra?
- short (4cm)
- passes through deep perineal pouch and perineal membrane
how is female urethra controlled?
voluntarily controlled by external urethral sphincter
you can squeeze the hold the sphincter in
why is the female urethra susceptible to…
UTIs (urinary tract infections)
it is short.
primary symptom of UTI: bladder inflammation (cystitis)
How can UTIs affected children under 1 year old?
can reach kidneys, leading to pyelonephritis and renal failure, making it deadly
How are UTIs treated?
oral antibiotics
How do the female and male urethra compare?
male is much longer at 20cm and divided in 4 parts
What are the 4 segments of the male urethra?
- Preprostatic urethra
- Prostatic urethra.
- Membranous urethra
- Spongy (penile) urethra.
Where is the internal urethral sphincter found in men and is it voluntary or involuntary? Why is it more prominent in men?
- within the preprostatic urethra segment; involuntary (smooth muscle)
- closes off during ejaculation to prevent acidic urine mixing with sperm
Where is the external urethral sphincter found in men and is it voluntary or involuntary?
within the membranous part of the urethra, being under voluntary control
where do the urinary and reproductive systems join in maile urethra?
at prostatic urethra
What is the pelvic floor?
funnel-shaped sling structure that attaches to the walls of the lesser pelvis
separates pelvic cavity from perineum inferiorly (region which includes the genitalia and anus).
What is the muscle found on the pelvic floor?
and what 3 muscles is it composed of?
the levator ani muscle:
- Puborectalis
- Pubococcygeus
- Iliococcygeus
What 2 apertures are found within the pelvic floor and which muscle slings around them?
- urogenital hiatus
- anal apeture
- puborectalis (innermost) slings around them and compresses anus
What nerve supplies the levator ani muscle?
pudendal nerve (somatic)
what 2 structures does the urogenital hiatus contain in females?
urethra
vagina
What is the
a) sympathetic nerve supply to the bladder?
b) parasympathetic nerve supply to the bladder?
a) sacral splanchnic nerves (T10-L2)
b) pelvic splanchnic nerves (S2-S4)
How does the micturition reflex work when the bladder is empty? (3)
- sympathetic nerves activate
- muscles are told to relax
- also tells internal urethral sphincter to contract
what receptors detect how full the bladder is?
stretch receptors
How does the micturition reflex work when the bladder is full? (3)
- mechano(stretch) receptors detect stretch
- visceral afferent fibres feed to the CNS- brainstem pontine micturition centre
- parasympathetic nerves contract the detrusor muscle and relax the internal urethral sphincter
What is stress incontinence (more common in females) caused by?
and how can it be improved?
a weakened pelvic floor (muscle trauma)- levator ani muscles, which can be improved by kegel exercises in mild cases
What triggers stress incontinence?
- increased intra-abdominal pressure e.g. during coughing, laughing, sneezing, exercise as the bladder pressure > urethral pressure
- urethral hypermobility (bladder neck/prox urethra descends out of pelvis) associated w/ impaired urethral sphincter function
what may cause damage of ligaments in females, resulting in stress incontinence?
childbirth: cant form sling
What is urge incontinence of an overactive bladder caused by?
- spontaneous detrusor muscle overactivity during bladder filling (bladder pressure > urethral pressure)
- neurogenic e.g. stroke/ multiple sclerosis
- exacerbated by caffeine, alcohol consumption
what is urge incontinence?
overactive bladder
involuntary leakage of urine w/ urgency to urinate.
more prevalent in elderly
how can urge incontinence be combat?
anti-cholinergic drugs- stop contraction of smooth muscle. decreases chance but still may be exacerbated by caffeine/alcohol
what is micturition controlled by? and how can it be overridden?
controlled by ANS
override: somatic nervous system
What are the 2 main types of epithelium found within the urinary system?
simple
stratified (muliple layers)
- transitional- ureter, bladder
What are the 3 shapes of simple epithelium found within the urinary system?
- a: squamous
- b: cuboidal
- c: columnar
3 types of simple epithelium in urinary system. where are each of them found?
a) squamous
b) cuboidal
c) columnar
a) LoH
b) PCT, DCT, collecting tubule
c) collecting duct
nephron located in lobes of kidney. what 2 parts comprise it?
cortex
medulla (pyramids and papillae)
whats in the cortex of nephron? (3)
renal corpusclce (Bowman’s capsule + glomerulus)
PCT
DCT
whats in the medulla of nephron? (2)
(renal pyramids and papillae)
LoH
collecting ducts drain into minor calyx
summary of nephron and CDs. what 6 things compose it?
- renal corpuscle (Bowman’s capsule + glomerulus)
- PCT
- loop of Henle
- DCT
- juxtaglomerular apparatus
- collecting tubule and collecting duct
what do the macula densa in DCT do?
regulate BP as part of juxtaglomerular apparatus
glomerulus is the site of?
ultrafiltration in blood- passes through podocyte layer and processes of viseral layer of BC –> enters space –> PCT –> inferiorly passed to medulla LoH..
which type of epithelium found in PCT and DCT?
simple- cuboidal
What composes the renal (Malpighian) corpuscle?
- glomerulus (capillary bed)
- Bowman’s capsule
What structure is the renal corpuscle continuous with?
PCT
visceral layer has podocytes. why?
podocytes have foot processes = form slits and filter large molecules (proteins)
location of renal corpuscle
in cortex, continuous with PCT
EA at renal corpuscle will continue as…?
vasa recta
what will parietal (outer) layer of bowmans capsule form?
simple- squamous epithelium
What specialised feature do the epithelium of the PCT have and why?
- the simple cuboidal epithelium have microvilli
- increases the surface area for the absorption of Na+
What is the PCT’s epithelium continuous with?
the parietal layer of the Bowman’s capsule
What is the difference in epithelium between the thick and thin ascending loop of Henle?
- thin = simple squamous (a)
- thick = simple cuboidal (b)
Histological section of loop of Henle and medulla- 4 components
- t = thin limb of loop of Henle
- V = vasa recta
- CD = collecting ducts
- CT = collecting tubules
What is the function of the vasa recta?
important for counter-current multiplication; as water is removed from the thin limb of the LoH, more Na will leave via passive diffusion
What’s the difference between the PCT and DCT’s epithelium and therefore lumen?
DCT has no microvilli whereas the PCT does
so DCT = larger, clear lumen
What composes the juxtaglomerular apparatus?
macula densa and juxtaglomerular cells
What is the role of the juxtaglomerular apparatus?
regulates blood pressure through the secretion of renin when BP low.
How does the juxtaglomerular apparatus respond to decreased blood pressure?
decreased BP-decreased GFR - decreased Na+ conc in DCT fluid - Macula densa (osmoreceptors) - renin release
OR
decreased BP - JG cells (mechanoreceptors) - renin release
What is the difference between the epithelium of the collecting tubules and collecting ducts?
- collecting tubules = simple cuboidal epithelium
- collecting ducts = simple columnar epithelium
What is the role of the collecting tubules and ducts?
reabsorb water and urea into the medulla (last opportunity to concentrate urine)
Are the collecting tubules part of the nephron?
no
Summary of the functions of the different parts of the nephron
- PCT: Water, Na+/Glucose (active)
- Thin LoH: passive reabsorption of water only; concentrates urine in the tubule
- Thick LoH: Na+ only (impermeable to water)
- DCT: Active reabsorption of Na+, secretion of H+
- Collecting tubules: Active reabsorption of urea, H+; water reabsorption controlled by ADH.
summary of characteristics of upper urinary system
- PCT: cortex
simple cuboidal epithelium with microvilli (brush border) - LoH: medulla
simple squamous epithelium - DCT: cortex
simple cuboidal epithelium no microvilli - Collecting tubules: medulla
not part of nephron. simple cuboidal (proximal), simple columnar (distal), large lumen
What is the specialised epithelium found in the ureter and bladder?
transitional, stratified epithelium = urothelium
- highly folded with ability to stretch, (creating rugae in bladder)
What do the umbrella cells within the ureter do?
create an impermeable barrier to the toxic urine
What are the 2 types of smooth muscle found in the ureter?
longitudinal (L) and circular (C) controlled by the autonomic NS, having peristaltic movements
What type of muscle layers found in the bladder wall?
smooth muscle
function of urothelium in ureter?
protection from urine, ability to stretch and relax during peristalsis in ureter.
what type of epithelium is found in bladder?
transitional/ urothelium
What are 3 drug classes of diuretics? (drugs acting on nephron)
- loop diuretics
- thiazides
- potassium sparing diuretics
Where and how do loop diuretics work?
Thick ascending limb (site of Na+ transporters), reduces Na+ reabsorption, diuresis - water follow the Na+ excreted. osmotic gradient
Where and how do thiazides (most common) work?
DCT, reduces Na+ reabsorption (less drastic than loop diuretics) still = diuresis
Where and how do potassium-sparing diuretics work?
Aldosterone receptor antagonist at the DCT - reduces water reabsorption (avoids hypokalaemia)
site of ultrafiltration in the blood?
renal corpuscle
role of diuretics?
affect reabsorption of Na+ and water along diff parts of the tubule
give an example of the three different classes of diuretic:
a) loop diuretics
b) thiazide diuretics
c) aldosterone antagonists
a)e.g. furosemide,
b)e.g. bendroflumethiazide
C) e.g. spirononlactone.
