anatomy Flashcards
where do the kidneys develop from embryologically
intermediate mesoderm
what is the first nephric structure to form in embryology
pronephric system
what does the metanephric system develop from
metanephric blastema and uteric bud
what does the metanephric blastema give rise to
nephron components: bowman’s capsule, PCT, loop of henle and DCT
what does the uteric bud give rise to
renal pelvis, ureters, collecting ducts
how do the kidneys move during embryonic period
ascend from pelvis to L1 level during weeks 6-9
name and describe to developmental abnormalities in the kidney
pelvic kidney - one fails to ascend
horseshoe kidney - inferior poles fuse before ascent and become trapped beneath the inferior mesenteric artery
where do ejaculatory ducts develop from
mesonephric ducts
what are the 4 main components of the urinary tract
kidney, ureter, bladder, urethra
what is the role of the ureter
drains urine from the kidneys to the bladder
role of the urethra
excretion of urine (and semen in males)
how would you describe kidneys in terms of association with the peritoneum
retroperitoneal
describe flow of urine through the kidneys
produced in the nephron and moves into collecting ducts
collecting ducts converge towards renal papilla
-> minor calyx -> major calyx -> renal pelvis -> ureter
what is the pelviureteric junction
where the renal pelvis transitions into the ureter
which kidney is slightly lower than the other and why
right kidney due to the size of the liver
vertebral level of the kidneys
L1-3 right kidney
T12-L2 left kidney
what region of the abdomen do you find the kidneys in
lumbar
describe the layers surrounding the kidney, from superficial to deep (4)
pararenal fat, renal fascia, perinephric fat, renal capsule
what are the 2 main areas in the kidney
outer cortex and inner medulla
what is the renal papilla
the apex of the renal pyramids
what collects urine from the pyramids
minor calyx
what are the structures of the renal hilum
renal artery, renal vein and ureter
what component of the nephron is responsible for creating the hyperosmotic environment in the renal medulla
loop of henle
what supplies the medulla with blood
vasa recta
what is the vasa recta
collection of capillaries that maintain countercurrent exchange in the kidney
where does lymph from the kidneys drain
lumbar nodes
sympathetic nerve supply to the kidney
from T10-L2 via sympathetic chains and abdominopelvic splanchnic nerves
parasympathetic nerve supply to the kidney
CN X
where do the ureters arise from
renal pelvis
what is the ureteropelvic junction
where the renal pelvis narrows to form the ureter
what type of epithelium lines the lumen of the ureter
transitional epithelium
blood supply to the ureters
branches of the internal iliac artery
venous drainage of the ureters
internal iliac vein
where does lymph from the ureters drain
lumbar and iliac nodes
what is hydronephrosis
water inside the kidney
what causes hydronephrosis
urine back pressure into the calyces compresses the nephrons causing renal failure
what is the name of the muscle that forms most of the bladder wall
detrusor
how does the detrusor muscle prevent the reflux of urine into the ureters
encircle the orifices to close them when the bladder contracts
what is the most anterior organ in the pelvis
bladder
histology of the female urethra
transitional epithelium which transitions into stratified squamous epithelium near its termination
what are the 3 main sections of the male urethra
prostatic, membranous and penile
where does the prostatic urethra run
from the bladder through the prostate gland
histology of the prostatic urethra
transitional epithelium
where does the membranous urethra run
prostate to the bulb of the penis
histology of the membranous urethra
transitional epithelium into stratified columnar
histology of the penile urethra
stratified columnar into stratified squamous near the tip
how do the testes move during foetal development
from the posterior abdomen, through the inguinal canal and to the scrotum
where do the testis sit in
sac called the tunica vaginalis
what is hydrocele
excess fluid between the visceral and parietal layers of the tunica vaginalis
where can the epididymis be palpated
at the posterior aspect of the testis
where can the vas deferens be palpated and what does it feel like
within the spermatic cord, in the scrotum superior to the testes
feels like a thick piece of string
what are the 3 main components found in the spermatic cord
vas deferens, testicular artery, pampiniform plexus
where do the right and left testicular veins drain into
right - IVC
left - left renal vein
what are the main types of erectile tissue
corpus cavernosum and corpus spongiosum
blood supply to the scrotum
internal pudendal and branches from the external iliac
where do most prostate cancers arise
in the peripheral zone
where is sperm produced
seminiferous tubules
what is the inferior aspect of the prostate in contact with
levator ani muscle
what is the role of sertoli cells
coordination of sperm production
what stimulates sertoli cells
FSH
what is the role of leydig cells
produce testosterone in response to LH
where are leydig and sertoli cells found
in the testes
what are the main 5 modalities of nerves
somatic motor, somatic sensory, visceral motor (autonomic), visceral sensory, special sensory
what is somatic referring to
structures of the body wall (soma) -> skin, muscles and joints
what is the role of somatic sensory nerves
carry information from sensations from the soma back to the CNS
what can somatic sensory nerves detect and transmit information about
touch, temperature, pain, proprioception and vibration
what is decussation
crossing over of nerve fibres from one side of the CNS to another
what is the consequence of decussation
information being transmitted from one side of the body is processed on the opposite side of the brain or spinal cord
what is the role of somatic motor nerves
carries signals from the CNS and controls voluntary movements by stimulating contraction of skeletal muscle
what do afferent and efferent mean
afferent = arriving at the CNS - sensory
efferent = exiting the CNS - motor
what is visceral referring to
internal organs, including blood vessels and glands
what is the role of visceral afferent nerves
SENSORY
carry information back from the organs to the CNS
what receptors are particularly sensitive to vibration
pacinian corpuscles
what are the 2 kind of mechanoreceptors responsible for detecting touch
merkel discs and meissners corpuscles
where are merkels discs found
in the epidermis
detect fine details of touch so mainly in areas like lips and fingertips
where are meissners corpuscles found
dermis
mostly found in fingertips, palms and soles of feet
what is the process of detecting pain called
nociception
what can visceral sensory nerves detect and transmit information about
stretch and pressure of internal organs, chemical changes e.g. pH and O2 levels, pain, temperature
how is visceral pain usually described
dull, achy, poorly localised
how is somatic pain usually described
sharp, stabbing, well-localised
which kind of pain can commonly be referred, somatic or visceral?
visceral pain
what usually causes somatic pain
tissue damage, injury or inflammation of structures
what usually causes visceral pain
stretching, distension, ischaemia or inflammation of internal organs
what is the role of visceral efferent nerves
carry information back from the CNS to control involuntary movements
what are the 2 main divisions of visceral efferent nerves
sympathetic and parasympathetic
how is sympathetic innervation usually described
fight or flight
where does sympathetic innervation originate from
thoracolumbar region of the spinal cord (T1-L2)
what is the primary neurotransmitter in sympathetic innervation
noradrenaline
effect of sympathetics on HR, vaso and bronchioles
increased HR
vasoconstriction to increase BP
dilate bronchioles
effect of parasympathetics on HR, vaso and bronchioles
decreased HR
vasodilatation so lowers BP
constricts bronchioles
how is parasympathetic innervation usually described
rest and digest
where does parasympathetic innervation originate from
craniosacral
cranial nerves involved in parasympathetic innervation
3, 7, 9 and 10
spinal nerves involved in parasympathetic innervation
S2-4 - pelvic splanchnic nerves
primary neurotransmitter in parasympathetic innervation
acetylcholine
what stimulates the internal urethral sphincter to contract
sympathetic fibres
what stimulates the internal urethral sphincter to relax
parasympathetic fibres inhibit (relax) the sphincter
what stimulates contraction of the external urethral sphincter
somatic motor fibres in the pudendal nerve
where is pain from the kidneys usually felt
loin
where is pain from the bladder usually felt
suprapubic
what nerves sense the stretch of the bladder when it fills up with urine
visceral afferent fibres S2-4
