Exam V: Lymph and ANS

Question 1

Pelvic Lymphatics

Answer 1

Lymphatic drainage follows blood supply (arteries) in retrograde direction

Connections are formed during development, so if an organ migrates it takes its lymphatics along (testes)

Flows back up into lumbar nodes then cystera chylii; if superficial then superficial inguinal nodes

Question 2

Pelvic Lymph Nodes

Answer 2

Nodes located along all arteries and edges of organs, typically named according to vessels or location

Drainage follows arteries retrograde to lumbar nodes

Lumbar nodes form lumbar lymph trunks that lead into cisterna chili

Pelvic viscera nodes named simply by location:
Pre-Aortic – inferior mesenteric, lumbar, common Iliac, internal Iliac, external Iliac, sacral

Question 3

Lymph Drainage: Anal Canal, Ureter, Bladder, Urethra (M vs. F)

Answer 3

Anal canal:
above pectinate line – internal iliac nodes
below pectinate line – superficial inguinal nodes

Ureter - “iliac” nodes.

Bladder – nearly all end in external iliac nodes

Urethra: female, prostatic/membranous(M) - internal iliac nodes

Urethra: spongy (penile)(M) – inguinal nodes

Question 4

Lymph Drainage: Ductus Deferens, Prostate, Testes, and Scrotum

Answer 4

Ductus deferens/seminal vesical - iliac nodes

Prostate – internal iliac and sacral nodes

Testes – lumbar nodes

Scrotum & skin over penis/perineum – superficial inguinal nodes

Question 5

Uterus Lymph Drainage

Answer 5

Cervix – “iliac” nodes

Upper body/fundus/uterine tube – mainly to lumbar (some to external iliac)

Lower body – external iliac nodes
The region near the point where the uterine tubes join the uterus has lymph channels that follow the round ligament and drain to superficial inguinal nodes.

Question 6

Vagina Lymph Drainage

Answer 6

Lymph drainage is in thirds and poorly defined

Upper 3rd – internal & external iliac nodes

Middle 3rd – internal iliac nodes

Lower 3rd – superficial inguinal nodes

Clitoris and labia minora- drain into deep inguinal nodes and external iliac nodes

Question 7

General Concepts of Pelvic Autonomics

Answer 7

ANS utilizes two neuron pathway: one in CNS / one in periphery
Wherever there are GVE fibers there are GVA fibers
Sympathetics go all over: superficial and deep
Parasympathetics go deep only, EXCEPT for genitalia (which do receive parasympathetic innervation)

Greater, lesser, and least splanchnics – all synapse near target organ
Pelvic splanchnic: parasympathetic for hindgut, perineal,
GVE: sympathetic or parasympathetic
GVA: carrying sensation away

Question 8

Sympathetic Innervation

Answer 8

Base of skill to sacrum – sympathetic trunk
IML in spinal cord – preganglionic sympathetic fibers coming out to join mixed spinal nerve, then white rami (T1-L2 and preganglionic sympathetics only)
Synapse at level and exit sympathetic chain via gray rami carrying postganglionic that join ventral and dorsal rami

Ventral is to body wall
Cardiac – rise levels on sympathetic chain
Or nerves can just exit the chain without synapsing – splanchinics because synapse at pre vertebral chain

Question 9

Lumbar and Sacral Splanchnics

Answer 9

Sympathetic
Preganglionic cell bodies in lower portion of IML, level T10-L2
Enter chain via white ramus
Traverse chain WITHOUT synapse; pass as splanchnic nerve to hypogastric plexus
Accompanied by GVA fibers

Question 10

Inferior Hypogastric Plexus

Answer 10

The Inferior Hypogastric Plexus surrounds viscera and is named as such:
Middle Rectal Plexus
Vesical Plexus
Prostatic Plexus
Uterovaginal Plexus

Question 11

Spinal Cord Levels of Sympathetic Innervation: Ureters, Gonads, Epididymus, Uterine Tubes, Bladder, Prostate, and Uterus

Answer 11

Ureters and Epididymis: T11-L2
Gonads and Uterine Tubes: T10-L1
Bladder and Prostate: T11-L1
Uterus: T12-L1

Question 12

Pelvic Splanchnic Nerves

Answer 12

Parasympathetic from sacral spinal cord, S2,3,4
Preganglionic neurons in IML-like area

Axons traverse ventral root, spinal nerve, and then ventral ramus

Preganglionic axons leave ventral ramus as pelvic splanchnic nerve then synapse occurs at organ OR in hypogastric plexus

Question 13

Hypogastric Plexus: Sympathetic vs. Parasympathetic

Answer 13

Sympathetics:
contract smooth muscle to move fluid and blood through structures
Innervate blood vessels

Parasympathetics:
Vasodilatory
Stimulate bladder contraction
Stimulate erection
Digestion

Question 14

Hypogastric Plexus: Contents

Answer 14

1. Pre and Post ganglionic Sympathetic fibers (GVE)
2. Associated GVA pain (from T10 -L2)
3. Pre and Post Ganglionic Parasympathetic fibers (GVE)
4. Associated GVA interoceptive and pain from S2,3 + 4

Superior hypogastric plexus- anterior to L5

Hypogastrics nerves- connect the two plexi
Inferior hypogastic plexus- situated on either side of pelvis
Form multiple plexi associated with viscera

Cavernous nerves: innervate erectile tissue; are extensions from prostatic plexus, pass between arcuate ligament and fascia of UGD

Question 15

Mechanisms of Erection /Ejaculation

Answer 15

Point = Parasympathetic pelvic splanchnic nerves (S2,3,4)
Coiled arteries relax and fill with blood, allow cavernous spaces inside erectile tissue to fill with blood.
Bulbospongiosus and Ischiocavernosus compress venous plexus

Shoot = Sympathetic (mostly)
Emission:
Sacral Splanchnic Nerves (L1 and L2)
Peristaltic movement of semen through ejaculatory ducts

Ejaculation:
Closure of vesical sphincter (sympathetics)
Contraction of urethral muscles (parasympathetic)
Contraction of bulbospongiosus (pudendal)

Question 16

Defecation

Answer 16

partially under voluntary control
rectum generally empty
increased pressure in rectal ampulla stimulates stretch receptors

Voluntary: relaxation of puborectal sling allows feces to enter anal canal and increase in intra-abdominal pressure

Parasympathetic: relaxation of internal anal sphincter; contraction of circular muscle fibers

Voluntary: relaxation of external anal sphincter; contraction of levator ani

Question 17

Micturition

Answer 17

Parasympathetics (S2,3,4) – excitatory to detrusor muscle and inhibitory to internal sphincter, parasympathetic innervation to bladder is required for normal micturition

Sympathetics (T11 – L2) – inhibitory to detrusor and excitatory to internal sphincter; when you aren’t urinating, sympathetic takes over

Voluntary relaxation of external urethral sphincter.

Pain fibers run with both sympathetics and parasympathetics