Pelvic floor muscles

Question 1

How is the pelvic floor formed

Answer 1

Formed by the bowl/funnel shaped pelvic diaphragm

Question 2

What is the pelvic diaphragm made up of

Answer 2

Coccygeus
Levator ani muscles
Fascias covering the superior and inferior aspect of these muscles

Question 3

Where is the pelvic diaphragm

Answer 3

It lies within the lesser pelvis, separating the pelvic cavity from the perineum
Pelvic diaphragm stretches between the anterior, lateral and posterior walls of the lesser pelvis, giving it the appearance of the hammock suspended from these attachments, closing much of the ring of the pelvic girdle

Question 4

What are the muscles of levator ani

Answer 4

Pubococcygeus
Puborectalis
Iliococcygeus
Levator ani forms a dynamic floor for supporting the abdominal viscera

Question 5

What is the proximal and distal attachments, nerve innervation and function of pubococcygeus

Answer 5

Dorsal surface of pubis and fascia of obturator internus
Annococcygeal body between tip of coccyx and the anal canal and sacrum
Function: elevation of pelvic floor
Nerve Innervation: nerve to levator ani (branches of S4), inferior rectal nerve (from pudendal nerver S3,S4), coccygeal plexus

Question 6

What is the proximal and distal attachments, nerve innervation and function of puborectalis

Answer 6

Dorsal surface of pubis and fasica of obturator internus
Same as pubococcygeus–>unites with it to make a ‘U’ shaped sling around the rectum
Function: controls defecation by pulling anorectal junction forward, which aids in contraction of the anal sphincter
Nerve Innervation: nerve to levator ani (branches of S4), branch of pudendal nerve (S2-4)

Question 7

What is the proximal and distal attachments, nerve innervation and function of iliococcygeus

Answer 7

Posterior aspect of arcus tendinous levator ani and ischial spine
Anococcygeal body and coccyx
Function: Helps support pelvic viscera and lateral coccyx
Nerve Innervation: nerve to levator ani (branches S4), inferior rectal nerve (from pudendal nerve- S3,S4), coccygeal plexus

Question 8

What is the anococcygeal body

Answer 8

also called anococcygeal ligament

strong, fibrous body that joins coccyx to fibres of levator ani muscle and external anal sphincter

Question 9

What is the proximal and distal attachments, nerve innervation and function of pubovaginalis (female) & puboprostaticus/levator prostatae (male)

Answer 9

Posterior pelvic surface of the body of pubic bone
Central perineal tendon–> posterior to vagina (females) posterior to prostate (males)
Nerve innervation: anterior rami of S3 and S4
Function: act to separate the base of pelvic cavity from the ischiorectal fossa lying inferiorly
Act in coordination with the other levator ani to support pelvic viscera

Question 10

What is the proximal and distal attachments, nerve innervation and function of ishiococcygeus (coccygeus)

Answer 10

ischial spine
Lower 2 sacral and upper 2 coccygeal vertebras blends with sacrospinous ligament on its external surface
Nerve innervation: anterior rami of S4,S5–> nerve to levator ani
Function: supports pelvic viscera,flexion of coccyx, stabilises sacro-iiac joint
It is considered more as a ligament that muscle

Question 11

What is the proximal and distal attachments, nerve innervation and function of bulbospongiosus in males

Answer 11

Median Raphe, ventral surface of bulb pf penis abd central tendinous point
Corpora spongiosum and cavernosa, fascia of bulb of penis–> deep penile fascia
Nerve Innervation: Deep branch of perineal nerve (branch of pudendal nerve)
Function: Empties urethra, acts as a sphincter to compress bulb of penis, assists erection, propels semen down urethra

Question 12

What is the proximal and distal attachments, nerve innervation and function of bulbospongiosus in females

Answer 12

Perineal body, then divided to wrap around vagina
Fascia of corpus cavernosa
Nerve innervation: deep branch of perineal nerve (branch of pudendal nerve)
Function: Empties urethra, acts as a sphincter to reduce lumen of vagina and assists erection of clitoris, compresses deep veins and decreases vaginal orifice

Question 13

What is the proximal and distal attachments, nerve innervation and function of ischiocavernosus

Answer 13

Ischial ramus and medial surface of ischial tuberosity
Crus of penis or clitoris and corpus cavernosum
Nerve innervation: deep branch of perineal nerve (branch of pudendal nerve)
Function: Maintains erection of penis /clitoris by compression of outflow veins

Question 14

What is the tone of the pelvic floor muscles

Answer 14

they are tonically (continuous tone of muslce, hence continuous tension/contraction) contracted most of the time to support the abdominopelvic viscera and to assist in maintaining urinary and faecal continence

Question 15

When are the pelvic floor muscles actively contracted

Answer 15

During activities such as:
Forced expiration
Coughing
Sneezing
Vomiting
Fixation of trunk during movements of UL

Question 16

Why are the pelvic floor actively contracted during some activities

Answer 16

Occurs primarily to increase support of viscera during periods of increased intra-abdominal pressure and secondarily to contribute to increased pressure (to aid expulsion)

Question 17

How does puborectalis contraction to maintain faecal continence

Answer 17

Active contraction
Contracts immediately after rectal filling or during peristalsis when rectum is full and the involuntary sphincter muscle is inhibited (relaxed)

Question 18

What role do the levator ani muscles play in urination and defecation

Answer 18

Increased intra-abdominal pressure for defecation is provided by contraction of the thoracic diaphragm and muscles of the anterolateral abdominal wall
Acting together, the parts of the levator ani elevate the pelvic floor after their relaxation and the consequent descent of the pelvic diaphragm that occurs during urination and defecation

Question 19

What is the perineal body

Answer 19

The fibromuscular structure located between the vagina/testicles and anus

Question 20

What are the attachments of the perineal body

Answer 20

Attaching to the sides of the ishiopubis rami by the deep transverse perineal muscle

Question 21

Why is the perineal body known as the ‘central tendon’

Answer 21

because many pelvic floor structures intersect with the perineum at this structure

Question 22

What is the proximal and distal attachments, nerve innervation and function of deep transverse perineal

Answer 22

Inner aspect of ishiopubic ramus
Median raphe (male), perineal body and external anal sphincter
Nerve Innervation: deep branch of perineal nerve (branch of pudendal nerve)
Function: fixes perineal body, supports the function of the levator ani and urethra sphincter

Question 23

What is the perineal membrane

Answer 23

Fascial thickening not a muscle
Fascial attachments at pubis symphysis
Fascial attachments at ischial spine
Suspensory ligament that provides extra support to prevent descent of perineal body

Question 24

What is the urogenital diaphragm

Answer 24

Also called ‘triangular ligament’
Strong, muscular membrane that occupies the area between the symphysis pubis and ischial tuberosity
Stretches across the triangular anterior portion of the pelvic outlet
It is external and inferior to the pelvic diaphragm

Question 25

What is the proximal and distal attachments, nerve innervation and function of superficial transverse perineal

Answer 25

Ischial tuberosity Perineal Body Nerve innervation: Deep branch of perineal nerve (branch of pudendal nerve) Function: reinforces action of deep transverse perineal muscle to stabilise perineal body--> poorly/variable developed

Question 26

What is the proximal and distal attachments, nerve innervation and function of external anal sphincter

Answer 26

Perineal body encircles anal canal Coccyx Nerve innervation: Inferior rectal (anal) nerve Function: part of voluntary sphincter of anal canal--> tone keep anus closed, defecation muscles relaxed

Question 27

Describe the internal anal sphincter

Answer 27

Part of the inner surface of canal Composed of concentric layers of circular muscle tissue Not under voluntary control

Question 28

What makes up the urogenital triangle

Answer 28

Bulbocavernosus (bulbospongiosus in men) Ischiocavernosus Superficial transverse perineal External anal sphincter

Question 29

What makes up the urogenital diaphragm

Answer 29

``` Urethral sphincter Compressor urethrae Sphincter urethral vaginalis Deep transverse perineal Perineal mebrane ```

Question 30

What is the pelvic diaphragm

Answer 30

Wide but thin muscular layer of tissue forms the inferior border of the abdominopelvic cavity Composed of a broad, funnel-shaped sling of fascia and muscle Extends from the symphysis pubis to the coccyx, from one lateral wall to another

Question 31

What is the pelvic diaphragm made up of

Answer 31

``` Levator ani (pubococcygeus, pubovaginalis, puborectalis, iliococcygeus) Coccygues Piriformis Obturator internus Arcus of tendinous of levator ani Arcus tendinous fascia pelvic ```

Question 32

Male and female organs in pelvic cavity, function and nerve innervation

Answer 32

read notes

Question 33

Explain role of pelvic floor muscles in inspiration

Answer 33

For inspiration lung pressure must be lower than atmospheric pressure to allow air in Rib cage moves up and out, diaphragm contracts/flattens to increase lung volume=decrease lung pressure When diaphragm contract, pushes down on abdominal organs=increase in abdominal presssure Pelvic floor muscles relax, dropping down and increasing abdominal space= decrease abdominal pressure

Question 34

Explain role pf pelvic floor in expiration

Answer 34

Lung pressure must be higher than atmospheric pressure= air moves out Diaphragm relaxes to decrease lung volume=increase lung pressure Causes decreased pressure in abdominal cavity, hence pelvic floor contracts to decrease abdominal space and increase pressure

Question 35

What is continence

Answer 35

Self control | ability to retain urine/faeces

Question 36

Explain importance of pelvic floor in continence

Answer 36

Urethra, vagina(females) and rectum pass through the pelvic floor and are surrounded by pelvic floor muscles During increased intra-abdominal pressure, the pelvic floor muscles must contract to provide support Pelvic floor muscles contract= urethra, vagina, rectum closed Contraction is important in preventing involuntary loss of urine or rectal contents Pelvic floor muscles also relax in order to void A contraction of PFM also causes a reflex inhibition of the detrusor muscle= smooth muscle found in bladder wall (remains relaxed to allow storage of urine and contracts during urination to release Hence weakness/damage to PFM=incontinence

Question 37

What is the bladder wall muscle and describe its fibres

Answer 37

Detrusor muscle 3 different layers of fibres in different directions Allows for better 'squeeze'

Question 38

How many ureteric orifices are there and what are they

Answer 38

2 ureteric orifices | they are the openings of the ureter in the bladder

Question 39

What forms the trigone of the bladder

Answer 39

Internal urethral sphincter and ureteric orifices

Question 40

What is micturition

Answer 40

the act of emptying the bladder (urination) Involves autonomic reflexes (parasympathetic) and some voluntary control Micturition= autonomic + voluntary (pudendal nerve)

Question 41

What is the micturition reflex

Answer 41

when bladder is full, stretch receptors in the bladder wall trigger the micturition reflex Sensory nerves are stimulated: -To void -To ignore/hold on

Question 42

How does the body void micturition

Answer 42

Detrusor muscle that surrounds the bladder contracts Internal urethral sphincter relaxes Allowing urine to pass out of the bladder through the ureteric orifice and sphincter Both these reactions are involuntary

Question 43

How does the body hold on/ignore the micturition reflex

Answer 43

Voluntary inhibition of the detrusor contractions Voluntary contraction of internal and external uretheral sphincters Contraction of pelvic floor muscle (poor PFM=incontinence)

Question 44

How and where is micturition coordinated

Answer 44

Coordinated in Pons Autonomic reflexes are parasympathetic from S2-4 (via pelvic nerve) to create contraction to allow voiding and then relax to fill (hence parasympathetic=contract bladder) Bladder relaxed to fill via increased sympathetic input via thoracic 11&12 and lumbar 1,2 spinal levels through mesenteric ganglion Which becomes post ganglionic fibres and travel through hypogastric nerve to bladder to relax the wall and constrict the internal sphincter

Question 45

Explain the process of micturition

Answer 45

Full bladder Pelvic floor muscles relax--> except internal and external urethral sphincter Contraction of abdominal wall muscles= increase intra=abdominal pressure Contraction of detrusor muscle Internal urethral sphincter relaxes--> sympathetic External urethral sphincter relaxes--> pudendal n=urine flow Continued contraction of detrusor Complete emptying of bladder Bladder relaxation (detrusor relaxes) Contraction of internal sphincter Contraction of external uretheral sphincter--> actions from bulbospongiosus, pudendal nerve

Question 46

How does spinal injury affect micturition

Answer 46

Cervical and thoracic SC lesion= spinal reflex control of micturition (micturition reflex) still intact but connection to pons not in tact Hence no voluntary control of micturition Leave the reliance on the micturition reflex control, therefore overfilling stimulates the reflex to void the bladder Bladder is not completely emptied dur to loss of voluntary contribution Hence stasis/retention/infection= need for catherters Catheters= risk of infection=kidney infection=delirium

Question 47

What is defecation

Answer 47

Final act of digestion

Question 48

Explain the process of defecation

Answer 48

Faeces from sigmoid-rectum Distends rectum--> stimulates stretch receptors and sends sensory impulse to spinal cord (stimulates defecation reflex) Motor impulses from cord via parasympathetic fibres to descending colon, sigmoid, rectuma nd anus Contraction of longitudinal rectal muscle fibres= shortens rectum and increases internal pressure Shorter rectum+ increases internal pressure + voluntary contraction of abdominal wall and diaphragm+ parasympathetic relaxation of internal anal sphincter + voluntary relaxation of external anal sphincter = defecation Peristaltic waves propel the faeces out of the rectum As faeces exit, the anus is drawn up over the passing mass by pelvic diaphragm to prevent prolapse (pushing out of the body)

Question 49

How many muscular constrictors are there in the anus

Answer 49

2--> internal and external anal sphincter | They allow the faeces to be passes or retained

Question 50

How is the infant defecation reflex different

Answer 50

Autonomic-->Voluntary control of external anal sphincter not yet developed Distended rectum+ stretch receptor + sensory impulses to spinal cord = stimulates defecation reflex Motor impulses from the cord via parasympathetic fibres to descending colon, sigmoid, rectum, anus Contraction of longitudinal rectal muscle fibres therefore shorten rectum and increasing internal pressure

Question 51

Describe the basic physiological affects of pregnancy on female pelvis

Answer 51

lesser pelvis experiences the most effects Hormonal changes cause the tissues to soften and become more elastic to prepare for delivery and accommodate growing baby As uterus increases in weight, progressively more vulnerable to stretch and associated weakness During vaginal delivery, pelvic floor muscles and tissues stretch well beyond normal limits causing pelvic floor weakness immediately after delivery Trauma and damage to the PFM and nerves can occur during vaginal delivery contributing to post natal pelvic floor dysfunction

Question 52

How can you prevent/recover from pelvic floor damage

Answer 52

Pelvic floor exercise can help in recovery and prevention of long-term problems of the pelvic floor after pregnancy and delivery

Question 53

What effect does the hormone relaxin have on the pelvis during pregnancy

Answer 53

Produced and secreted by the corpus luteum of ovary and later by placenta 'Relaxes' ligaments in pelvis Increase stability of the pubic symphysis and ligaments of the SIJ and sacrococcygeal joint Helps dilate the uterine cervix during labor--> easing delivery Increased flexibility of ligaments around SIJ results in ligaments being lax and muscles which usually stabilise the joint aren't able to work as efficiently due to the change in joint structure Added load of foetus on pelvis results in an unstable pelvis which often causes pain

Question 54

What is the adult nulliparous uterus

Answer 54

Nulliparous= female who hasn't given birth/become pregnant Piriform (pear shaped) right angle with vagina

Question 55

Describe the post parturition uterus

Answer 55

Parturition=giving birth Almost returns to normal Slightly larger than nulliparous

Question 56

Explaint he uterus changes

Answer 56

Menstruation= slightly enlarged, rounder, more vascular Pregnancy= enlarged (hypertrophy of muscle fibres and new ones), walls thinner with progression Post parturition= Nearly normal, muscle layers thicker, larger cavity Old age= atrophy,paler and denser, constriction

Question 57

Lymph drainage of uterus

Answer 57

Upper body+uterine tube= aortic nodes Lower body= external iliac nodes Cervix= external and internal nodes, rectal & sacral nodes READ NOTES

Question 58

What is the perinuem

Answer 58

Area of soft tissue between thighs and butt Female--> from anterior aspect of vagina to ischial tuberosities to coccyx to distal end of sacrum Male--> posterior aspect of scrotum to ischial tuberosities to coccyx

Question 59

What 2 regions is the perinuem divided into

Answer 59

Urogenital region | Anal region

Question 60

What is the obsteric perineum

Answer 60

The region from the posterior aspect of vagina to anterior aspect of anus