Anatomy Exam 3 Flashcards
kidneys
- retroperitoneally on posterior abd wall at T12-L3 lvl
- regulate blood volume and osmolarity
- produce hormones (renin, erythropoietin, calcitriol)
suprarenal/adrenal glands
- superomedial on kidneys
- part of endocrine system = secrete corticosteroids & androgens; make epinephrine & norepinephrine
structure of outside of kidneys
- R lower than L due to liver placement
- lateral margins (convex)
- medial margins (concave) = renal sinus, renal pelvis and renal hilum
- — anterior - renal vein, renal artery, renal pelvis - posterior
flow of urine thru the body
renal papilla → minor calyx → major calyx → renal pelvis → ureter → bladder
ureters
- retroperitoneal muscular tubes with narrow lumina
- route = run inferiorly from kidneys → passes over pelvic brim at bifurcation of common iliac arteries → run postero-inferiorly on lateral walls of pelvis → curve anteromedially, superior to levator ani, to enter bladder
- urine transported down by peristaltic contractions
- in males, only structure that passes between ureter & peritoneum is ductus deferens
- in females, ureter passes medial to origin of uterine artery & continues to lvl of ischial spine
sites of ureters constriction (kidney stones)
- junction of ureters & renal pelvis
- where ureters cross brim of pelvic inlet
- passage thru wall of urinary bladder
bladder
- hollow sac with strong detrusor muscule walls on pelvic cavity floor
- parts of it = apex, body, fundus & neck
- when empty → in lesser pelvis & has tetrahedral shape
- as it fills → ascends superiorly into intraperitoneal fatty tissue of anteiror abd wall & into greater pelvis
- trigone = triangle area on bladder floor formed by opening of two ureters & urethra
- neck of male bladder = continuous w/ fibromuscular tissue of prostate; form involuntary internal urethral sphincter which contracts during ejaculation to prevent retrograde ejaculation of semen into bladder
- neck of female bladder = continuous with wall of urethra
ureteric orifices & internal urethral orifice are wrapped with detrustor muscle to tighten when bladder contracts to avoid urine reflux into ureters
urethra
- conveys urine from bladder to outside
- female urethra (3-4cm) «< male urethra (~18cm) so females are at greater risk of UTIs
male urethra regions
- prostatic urethra (closes off if prostate enlarged - difficulty voiding)
- membranous urethra
- penile urethra
diuretics
- increase urine volume
- treat hypertension & CHF b/c reduces overall fluid volume
- increase GF (caffeine) or decrease tubular absorption (alcohol - suppress release of ADH)
kidney blood supply
- renal artery (IVD L1 & L2) divides into 5 segmental arteries & distributes to kidney segments
- renal veins (anterior to renal arteries) drain into IVC
ureters blood supply
- abd part arteries = renal, testicular/ovarian & abd aorta arteries
- pelvic part arteries = branches of common & internal iliac arteries
- – females → uterine artery branches
- – males → inferior vesical arteries
- veins drain into renal & testicular/ovarian veins for abd part
suprarenal/adrenal blood supply
arteries
- superior suprarenal arteries (from inferior phrenic artery)
- middle suprarenal arteries (from abd aorta)
- inferior suprarenal arteries (from renal artery)
veins
- R suprarenal vein → IVC
- L suprarenal vein + inferior phrenic vein → L renal vein
renal lymph drainage
renal lymphatic vessels follow renal veins and drain into lumbar lymph nodes
- superior part → + vessels from kidneys or pass directly to lumbar nodes
- middle part → common iliac lymph nodes
- inferior part → common, external or internal iliac lymph nodes
kidney nerve innervation
- renal nerve plexus (fibers of abd splanchnic nerves)
- — sympathetic & visceral afferent (pain sensations) fibers
ureters nerve innervation
- renal nerve plexus + abd aortic & superior hypogastric plexuses (for abd part of ureters)
suprarenal/adrenal glands nerve innervation
- celiac plexus & abdominopelvic (greater, lesser & least) splanchnic nerves
pelvic cavity
continuation of abd cavity into pelvis through pelvic inlet
perineum
shallow compartment, deep to perineal region and inferior to pelvic diaphragm
peritoneum
lining of abd cavity that continues into pelvic cavity
perineal region
area of trunk between thighs and buttocks, from pubis to coccyx
pelvic inlet
- bounded by linea terminalis of pelvis
- formed by;
- – arcuate line of ilium
- – anterior border of ala of sacrum
- – sacral promontory
pelvic outlet
- bounded by:
- – anteriorly = inferior margin of pubic symphysis
- – anterolaterally = inferior rami of pubis & ischial tuberosities
- – posterolateral = sacrotuberous ligaments
- – posteriorly = tip of coccyx
pelvic girdle
- bones surrounding pelvic cavity that connect vertebral column to femurs
- – R & L hip bones (fusion of ilium, ischium & pubis)
- – sacrum (fusion of 5 sacral vertebrae)
- function = transfer weight from axial to lower appendicular skeleton; withstand compression and forces; hold & protect pelvic viscera
greater/false pelvis
- broader
- superior to pelvic inlet
- bounded by abd wall anteriorly, ala of ilum laterally and L5 & S1 vertebrae posteriorly
- location of some abd viscera (sigmoid colon & ileum)
lesser/true pelvis
- narrower
- b/w pelvic inlet & outlet
- location of pelvic viscera (bladder & repro organs)
- bounded by pelvic surfaces of hip bones, sacrum & coccyx
- limited inferiorly by musculomembranous pelvic diaphragm (levator ani)
sacro-iliac (SI) joints
- strong, weight-bearing synovial joint (but limited mobility) b/w sacrum & ilium
- anterior SI ligaments = fibrous capsule
- interosseous SI ligaments = transfer weight to ilia and then femur and ischial tuberosities
- posterior SI ligaments = posterior external continuation of interossesous ones
- sacrospinous & sacrotuberous ligaments = limited upward movement of inferior sacrum
pubic symphysis
- interpubic/fibrocartilaginous disc b/w 2 pubic bones
- superior pubic ligament & inferior pubic ligament = connect 2 pubic bones to each other
lumbosacral joints
- IV joints
- Z joints
- iliolumbar ligaments = connect transverse processes of L5 to ilia
sacrococcygeal joints
- anterior & posterior sacrococcygeal ligaments = reinforce joint
antero-inferior pelvic wall
- formed by bodies & rami of pubic bones & pubic symphysis
- helps bear weight of urinary bladder
2 lateral pelvic wall
- formed by hip bones, including obturator foramen
- covered & padded by obturator internus muscles
- contain obturator nerves & vessels & other branches of internal iliac vessels
posterior pelvic wall
- wall & roof in midline (sacrum & coccyx) and musculoligamentous posterolateral walls (SI joints & ligaments and piriformis muscles)
- – each piriformis muscle leaves lesser pelvis thru greater sciatic foramen (sacrospinous & sacrotuberous ligaments) to attach to femur
- site of nerves forming sacral plexus
pelvic diaphragm
- bowl- or funnel-shaped
- within lesser pelvis
- consists of coccygeus & levator ani muscles + fascias covering these muscles
- separates pelvic cavity from perineum for which it forms the roof
coccygeaus
- small part of pelvic diaphragm
- supports pelvic & flexes coccyx
levator ani
- forms most of pelvic diaphragm
- helps support pelvic viscera & resists increases in intra-abd pressure
- consists of iliococcygeus, pubococcygeus & puborectalis muscles
- tonically contracted most of time to support abdominopelvic viscera
- actively contracted during activities such as forced expiration, coughing, sneezing, vomiting, and when lifting heavy objects to increase support of the viscera during increased intra-abd pressure & to contribute to the increased pressure (to aid expulsion)
puborectalis
- assists in urinary & fecal continence
- penetrated centrally by anal canal of which puborectalis forms a sling for defecation control
- active contraction of the (voluntary) puborectalis portion is important in maintaining fecal continence immediately after rectal filling or during peristalsis when the rectum is full and the involuntary sphincter muscle is inhibited (relaxed)
pelvic fascia
connective tissue between membranous peritoneum and muscular pelvic walls & floor not occupied by pelvic organs
- parietal pelvic fascia = membranous layer that lines the internal part of muscles forming walls & floor of pelvis
- visceral pelvic fascia = membranous fascia directly covering pelvic organs
- both become continuous where organs penetrate the pelvic floor
- endopelvic fascia = connective tissue between & continuous with parietal and visceral membranous layers
pelvic floor injury during childbirth
- perineum, levator ani and pelvic fascia may be injured
- most commonly torn muscles = pubococcygeus (second is puborectalis)
- weakening or tearing of levator ani → incontinence issues or visceral prolapse
episiotomies
a surgical incision of perineum and inferoposterior vaginal wall to enlarge the vaginal orifice
- done to avoid damage to levator ani muscles
- mediolateral incisions»_space;> median incision
median incision
- scar produced would be similar to fibrous tissue surrounding it & tearing would be minimal
- if tearing occurred, it would extend toward anus → fistulas or sphincter damage would result
mediolateral incision
- circumvents perineal body & directs tearing away from anus
autonomic nerves enter pelvic cavity via:
1) sacral sympathetics = sympathetic innervation to lower limbs
2) periarterial plexuses (sympathetic) = postsynaptic, sympathetic, vasomotor fibers to superior rectal, ovarian & internal iliac arteries
3) hypogastric plexuses (mixed) = VI route that sympathetic fibers are conveyed to pelvic viscera
4) pelvic splanchnics (parasympathetic) = parasympathetic innervation of pelvic viscera, descending and sigmoid colon
sciatic nerve
- largest nerve in body
- origin = anterior rami of spinal nerves L4-S3
- passes thru greater sciatic foramen inferior to piriformis to enter gluteal region
- supplies = hip joint (via articular branches) and flexors of knee (hamstrings) and all muscles in leg & foot (via muscular branches)
- composed of tibial and common fibular nerves
pudendal nerve
- supplies = skin, organs and muscles of perineum
- micturition, defecation, erection, ejaculation and parurition
sacral plexus branches
- sciatic nerve (L4-S3) = tibial (L4-S3) & common fibular (L4-S2)
- superior gluteal (L4-S1) - gluteus medius and minimus and tensor fasciae latae
- inferior gluteal (L5-S2) - gluteus maximus
- posterior femoral cutanoues (S1-S3) - skin of butt, posterior thigh, calf and heel
- pudendal - skin and muscles of perineum