Muscles of the pelvis and perineum region

Question 1

Levator ani muscles

Answer 1

These muscles keep the organs from falling out of the pelvis and are the muscles of the pelvic floor;
-Pubococcygeus
-Puborectalis
-Iliococcygeus
-(Ischio)coccygeus

Question 2

Pubococcygeus

Answer 2

-This is in the centre and connects the pubic bones in front with the coccyx bone in the back
-It is arched so it can connect with more surface area on the bone

Question 3

Puborectalis

Answer 3

-It originates on the pubic bone and forms this structure called the puborectal sling around the rectum

Question 4

Iliococcygeus

Answer 4

-Its origin is a broad sheet of connective tissue called the internal obturator fascia

Question 5

Ischiococcygeus

Answer 5

-It is a long sheet of muscle that spans from each ischium to the coccyx in the center

Question 6

Perineum muscles

Answer 6

-Superficial transverse perinei
-Deep transverse perinei
-Ischiocavernosus
-Bulbospongiosus

Question 7

Superficial transverse perinei

Answer 7

-It is superficial because it is closer to the surface
-It is transverse because it runs side to side
-The perinei points to its location between the urethra anteriorly and anus posteriorly

Question 8

Deep transverse perinei

Answer 8

-It is deep to the superficial transverse perinei

Question 9

Ischiocavernosus

Answer 9

-Originates at the ischium and connects with the genitals
-If its attached to a penis it inserts on the crust or crura of the penis, the part that attaches to the ischial rami. While the rest of the shaft (mostly the corpus cavernosum) dangles off
-If the person has a vagnia it inserts on the clitoris
-When the ischiocavernosus contracts it squishes blood towards the distal part of the genitals and compresses some of the veins that drain blood from the genitals which help maintain an erection/swelling of the clitoris

Question 10

Bulbospongiosus

Answer 10

-When it accompanies a vagina the pair of muscles runs from the pubic bone in front of the sides of the vagina
-Around the penis it circles the bulb which is close to the base

Question 11

Sphincter muscles

Answer 11

Ring-like tubes that prevent anything from leaking out of the anus or urethra by squeezing them shut;
-Internal anal sphinter
-External anal sphinter
-Internal urethral sphinter
-External urethral sphinter

Question 12

Internal anal sphinter

Answer 12

-Smooth muscle under involuntary control
-Smooth muscle is a lot richer in mitochondria so can contract for long amount of time without fatiguing

Question 13

External anal sphinter

Answer 13

-Skeletal muscle under voluntary control

Question 14

Internal urethral sphinter

Answer 14

-Smooth muscle under involuntary control
-Right below the bladder

Question 15

External urethral sphinter

Answer 15

-Skeletal muscle under voluntary control
-Surrounds the urethra
-For people with penis it is below the prostate at the base of the penis
-For people with vaginas it will be right below the bladder

Question 16

Cremaster muscle

Answer 16

-For people who have testicles
-A thin muscle layer that lines the scrotum and tucks the testicles into the body
-If it is too cold it contracts and brings them towards body heat