Lab X and XI

how is the rectum oriented

it is curved and conforms to the curvature of the sacrum (concave anteriorly) and joins the anal canal at a 90 degree angle

how the is angle of the rectum maintained

puborectalis muscle (important for controlling defecation)

what are the rectal valves

2 left and 1 right transverse folds in the rectal mucosa that protrude into the rectal lumen and support the weight of stool

describe the blood supply to the rectum

superior rectal artery (terminal branch of the inferior mesenteric artery) supplies the proximal portion of the rectum

middle rectal artery (branches of the internal iliac artery) supply the middle and inferior portions of the rectum

inferior rectal artery (branches of the internal pudendal arteries) supply the most inferior part of the anal canal

where do the superior, middle, and inferior rectal veins drain into?

superior rectal vein drains into the inferior mesenteric vein

middle rectal vein drains into the internal iliac vein

inferior rectal vein drains into the internal pudendal vein

what structures can be palpated in a digital rectal exam (male and female)?

male - prostate gland

female - uterus (cervix)

what are the boundaries of the anal triangle?

lateral borders are the ischial tuberosities and the posterior border is the tip of the coccyx

what is contained within the anal triangle?

anal canal and ischioanal fossae

how does the anal canal begin and end?

it begins at the angle formed by the puborectal sling and ends at the anus

describe the internal anal sphincter

it is continuous with the smooth muscle of the rectum and is involuntary

describe the external anal sphincter

it is comprised of skeletal muscle and is voluntary

what are anal columns?

a series of longitudinal folds in the wall of the anal canal that are highly vascular and contain the terminal branches of the superior rectal artery and part of the rectal plexus of veins

what are between anal columns and what do they end as?

anal sinuses are between anal columns and end as anal valves

what do the anal valves form and what does it signify

pectinate line that indicates the junction of the visceral and somatic portions of the anal canal

what is the blood supply and innervation of the anal canal above the pectinate line?

superior rectal artery

visceral (autonomic) motor and sensory nerves

what is the blood supply and innervation of the anal canal below the pectinate line?

middle and inferior rectal arteries

somatic motor and sensory form inferior rectal nerves (branches of the pudendal nerve)

what are internal hemorrhoids?

vein dilations in the anal columns superior to the pectinate line (painless, but dangerous), discovered through blood in stool

what are external hemorrhoids

vein dilations in the anal columns inferior to the pectinate line (extremely painful)

what are the ischioanal fossae?

spaces between the ischial tuberosities and the external anal sphincter containing fat and inferior rectal nerves and vessels (branches of the pudendal nerve and internal pudendal vessels)

what is the function of the ischioanal fossae?

they allow the anal canal to expand during defecation, cushion the inferior rectal vessels/nerves, and provide structural support to the pelvic floor

what is the urogenital triangle bound by?

ischial tuberosities laterally and the pubic symphysis anteriorly

what is part of the male urogenital triangle?

the scrotum, penis (root, body, glans), membranous urethra, and superficial perineal muscles (ischiocavernosus and bulbospongiosus)

what is part of the female urogenital triangle?

external female genitalia (mons pubis, labia majora, labia minora, vestibule of the vagina, bulbs of the vestibule, clitoris), superficial perineal muscles

what is included in the root of the penis?

the bulb of the penis (proximal expansion of corpus spongiosum) and crura (proximal aspect of corpus cavernosum located along the inferior pubic rami)

what is included in the body of the penis?

paired corpus cavernosum on the dorsal aspect and single corpus spongiosum on the ventral aspect

what tissue makes up the glans penis?

corpus spongiosum

how does the spongy urethra travel?

it travels the length of the corpus spongiosum: enters the bulb, continues through the body and glans penis, and exits at the external urethral meatus

describe the ischiocavernosus muscles

surround the crura of the corpus cavernosum along the inferior pubic rami and help maintain erection (male and female) by forcing blood from the crura into the body of the penis/clitoris

describe the bulbospongiosus muscles

they surround the bulb of the penis and aid in expelling urine and semen from the urethra in addition to erection (male)

they cover the bulbs of the vestibule on either side of the vagina, extending from the perineal body to the clitoris and can act as a vaginal sphincter

what is the neurocranium

it houses the brain and is a rigid box (cannot expand)

what is the viscerocranium?

they are related to the structures of the oral and nasal cavities, pharynx, sinuses, orbit, and ear

which skull bones are singular?

frontal bone, mandible, sphenoid bone, occipital bone, ethmoid bone, vomer

which skull bones are paired?

maxillae, zygomatic bones, temporal bones, parietal bones, nasal bones, lacrimal bones, palatine bones, inferior nasal conchae

which skull bones are not visible from a lateral view?

palatine bones, inferior nasal conchae, vomer

what does the sagittal suture separate?

the two parietal bones

what does the coronal suture separate?

the frontal bone and two parietal bones

what does the lambdoid suture separate?

the occipital bone and two parietal bones

what do the squamous sutures (2) separate?

the parietal and temporal bones

what is a suture?

the joint between skull bones that appears like a line and prevent movement of the bones as adults

what skull bones are on the lateral aspect?

frontal bone, parietal bone, occipital bone, temporal bone (zygomatic process, mastoid process, styloid process, external acoustic meatus), sphenoid bone (body, greater wing, lesser wing), zygomatic bone, pterion (where frontal, parietal, squamous part of temporal, and greater wing of sphenoid bones come together)

what artery runs deep to pterion and what clinical condition can injury to the area cause?

middle meningeal artery, epidural hematoma

what are the parts of the mandible?

body (alveolar part and mental foramen), ramus, angle, coronoid process, condylar process

what is on the anterior aspect of the skull?

frontal bone, nose (nasal bones, maxillae, piriform aperture, superior nasal conchae, middle nasal conchae, inferior nasal conchae), nasal septum (vomer, perpendicular plate of the ethmoid bone, septal cartilage)

what are the parts of the maxilla

body (containing maxillary sinus), zygomatic process, frontal process, palatine process, alveolar process

what do the zygomatic bones articulate with?

maxilla, frontal, temporal bones

what forms the zygomatic arch?

the articulation between the zygomatic bone and the zygomatic process of the temporal bone

what are the parts of the orbit?

supraorbital margin, supraorbital notch/foramen, infraorbital foramen, superior orbital fissure, inferior orbital fissure, optic canal

what is the superior border of the orbit?

frontal bone

what is the medial border of the orbit?

frontal bone, lacrimal bone, maxilla

what is the inferior border of the orbit?

maxilla and zygomatic bone

what is the lateral border of the orbit?

zygomatic bone and frontal bone

which bones are found in the orbit?

maxilla, frontal bone, zygomatic bone, ethmoid bone, lacrimal bone, sphenoid bone, palatine bone

what muscles are part of the pelvic diaphragm?

puborectalis, pubococcygeus, iliococcygeus, and coccygeus muscles

what are the levator ani muscles?

puborectalis, pubococcygeus, and iliococcygeus

what are the functions of the pelvic diaphragm?

support the abdominal and pelvic viscera

assist abdominal muscles to increase intraabdominal pressure

help support and anchor the prostate gland (male) and vagina (female)

what structures pierce the pelvic diaphragm?

urethra, rectum, and vagina (female)

what shape is the bladder?

inverted cone/pyramid

what does the inferior surface of the bladder rest on?

prostate gland (male) or pubic symphysis (female)

where do the ureters open into the bladder?

1-3 cm medial from the point where they entered the bladder wall

describe the path of the ureters and what this causes

they take an oblique course through the bladder wall, which results in them getting pinched off when pressure increases due to a filling bladder. this prevents reflux of urine

what is the trigone?

a region of the bladder that remains smooth even when the bladder is contracted and the rest of the bladder mucosa is thrown into folds

what do the openings of the ureters into the bladder form?

the lateral sides of the triangular area called the trigone

what does the inferior angle of the trigone form?

the beginning of the urethra (internal urethral meatus)

describe the length and position of the female urethra

short (2-4 cm) and the distal opening (external urethral meatus) is within the vestibule of the vagina, anterior to the vaginal opening and posterior to the clitoris

describe the length and position of the male urethra

long, it passes through the prostate gland, pelvic diaphragm, and penis before opening at the external urethral meatus in the glans penis

what are the different parts of the male urethra

prostatic urethra, membranous urethra, and spongy urethra

what/where is the external urethral sphincter

the muscle fibers inferior to the pelvic diaphragm, closest to the urethra, form a voluntary sphincter controlling urination (skeletal muscle)

where is the involuntary internal urethral sphincter?

the neck of the bladder where the urethra begins

what supplies blood to the pelvic viscera?

branches of the internal iliac vessels

what are the branches of the internal iliac artery

umbilical artery (—> superior vesical arteries), obturator artery, internal pudendal artery (—> inferior rectal arteries), middle rectal artery

describe the umbilical artery (including superior vesical arteries)

proximal part is patent, distal part becomes the medial umbilical ligament

goes to the bladder

superior vesical arteries (many) supply the fundus of the bladder

describe the obturator artery

goes through the obturator foramen

describe the internal pudendal artery

exits the pelvis through the greater sciatic foramen, winds around the sacrospinous ligament, and passes through the lesser sciatic foramen to enter the perineum

describe the middle rectal artery

supplies the rectum, may arise with the internal pudendal artery

where is the sacral plexus found and what is it composed of

the anterior surface of the piriformis muscle and is composed of the lumbosacral trunk (L4-L5) and the ventral primary rami of S1-S4

what are the nerve roots of the sciatic nerve

L4-S3

what are the nerve roots of the pudendal nerve

S2-S4

where is the pudendal nerve?

follows the same course of the internal pudendal artery and divides into several perineal nerves that innervate the external genitalia (ends as the dorsal nerve of the penis or clitoris) after exiting the pudendal canal

where do parasympathetic and sympathetic innervation of the pelvis come from?

parasympathetic: pelvic splanchnic nerves (S2-S4)

sympathetic: sacral sympathetic ganglia via the sacral splanchnic nerves

what are the parts of the male internal genitalia

ductus deferens, seminal vesicles, prostate gland

where do spermatozoa mature and where are they stored?

they mature in the seminiferous tubules of the testes and are stored in the epididymis

how do spermatozoa move from the epididymis to the ejaculatory duct

the tail of the epididymis accumulates a thick muscular wall to become the ductus deferens, which transports spermatozoa to the ejaculatory duct during sexual excitement

what is the path of the ductus deferens?

it is a component of the spermatic cord and travels through the inguinal canal to enter the lateral aspect of the pelvis. it circles the bladder laterally and passes to the posterior bladder surface, where it enlarges to form the ampulla of the ductus deferens

what are seminal vesicles and what do they do?

secretory glands that lie between the fundus of the bladder and the rectum. source of seminal fluid, they do not store semen

what forms the ejaculatory duct

the ampulla of the ductus deferens joins the duct of the seminal vesicle to form the ejaculatory duct

what is the prostate gland

a walnut-sized gland surrounding the prostatic urethra, between the bladder and the external urethral sphincter

what does the prostate gland do?

it secretes seminal fluid into the prostatic urethra

how does the ejaculatory duct reach the prostatic urethra?

it courses anteriorly through the prostate gland to empty into the prostatic urethra

what is benign hypertrophy of the prostate gland?

noncancerous enlargement of the prostate gland that commonly occurs in older men and causes urinary symptoms due to compression of the prostatic urethra (nocturia, dysuria, amenuria)

describe the path of sperm

seminiferous tubules, epididymis, vas deferens (ductus deferens), ejaculatory duct, (now semen), urethra, penis

what is the female reproductive system comprised of?

paired ovaries and oviducts, the uterus, and the vagina

what is the process of ovum life cycle

ova mature in the ovary and are released into the oviduct where they are fertilized and conducted to the uterus. the uterus is the site of implantation of the fertilized ovum

what structures are a part of the female internal genitalia

vagina, uterus, uterine tubes, ovaries, peritoneal folds

what is the vagina?

a muscular tube extending from the external surface to the uterine cervix

where is the vagina located?

posterior to the bladder, anterior to the rectum, and passes through the pelvic diaphragm

what are the vaginal fornices?

recesses around the lateral, anterior, and posterior surfaces of the cervix

where is the urethra in terms of the vagina

it is in the anterior wall of the vagina

what are the parts of the uterus

fundus, body (superior 2/3) and cervix (inferior 1/3 that protrudes into the vagina and has an external opening (os))

what is the vesicouterine pouch

region between the bladder and uterus

what is the rectouterine pouch

region between the rectum and uterus