Colon & Urinary Excretion (7)

Question 1

What is micturition?

Answer 1

process by which the urinary bladder empties

Question 2

What does micturition involve?

Answer 2

progressive filling until the tension in the walls rises above threshold triggering a reflex that empties the bladder

Question 3

What is the bladder made up of?

Answer 3

smooth muscle (aka: detrussor muscle)

Question 4

To empty the bladder does the detrussor muscle relax or contract?

Answer 4

it contracts

Question 5

What are the trigone and internal sphincter made of?

Answer 5

smooth muscle

Question 6

Do the trigone and internal sphincter relax or contract during emptying?

Answer 6

They relax

Question 7

What does the urethra pass through?

Answer 7

the urogenital diaphragm

Question 8

What plays a large role in triggering the bladder emptying reflex?

Answer 8

Stretch signals from the posterior urethra

Question 9

What controls the detrussor muscle and urinary sphincters?

Answer 9

Pontine micturition center

Question 10

What controls the pontine micturition center allowing for voluntary control?

Answer 10

suprapontine centers

Question 11

What do pelvic nerves contain?

Answer 11

Sensory (afferent stretch) and motor (efferent parasympathetic)

Question 12

Where do PNS fibers terminate (in regards to micturition)?

Answer 12

Ganglion cells in the bladder wall

Question 13

What does the pudendal nerve control (in regards to micturition)?

Answer 13

Skeletal motor fibers of the external sphicter

Question 14

What does voiding begin with?

Answer 14

Voluntary relaxation of the external urinary sphincter

Question 15

What causes an atonic bladder?

Answer 15

Destruction of sensory nerve fibers

Question 16

What causes an automatic bladder?

Answer 16

Spinal cord damage aboce the sacral region

Question 17

What causes an uninhibited neurogenic bladder?

Answer 17

Lack of inhibitory signals from the brain

Question 18

What are the three primary functions of the colon?

Answer 18

1- move material through the large intestine to the rectum

2- eliminate fecal material through anus

3- extract water, electrolytes and some nutrients

Question 19

What is the function of the mucus that the large intestine creates?

Answer 19

Bind feces and aid in its movement through the colon

Question 20

What is the gastroileal reflex?

Answer 20

food entering the stomach intensifies peristalsis in the ileum and empties ileal content into the cecum

Question 21

What is the main function of the ascending and transverse colon?

Answer 21

extraction of water and elextrolytes

Question 22

What is the main function of the descending colon?

Answer 22

store stool

Question 23

What is the function of the sigmoid colon?

Answer 23

Move stool between the descending colon and the rectum

Question 24

What causes constipation and what helps constipation?

Answer 24

Poor motility causes constipation….there is greater absorption of liquids and results in hard feces

Increasing fiber intake can help constipation

Question 25

What causes diarrhea?

Answer 25

Rapid movement of fecal matter through the large intestine

Question 26

What are the two types of diarrhea?

Answer 26

Osmotic form and secretory form

Question 27

What does distention/ pressure or irritation of the cecum inhibit and excite?

Answer 27

Inhibits ileal peristalsis and excites sphincter contraction and delaying emptying

Question 28

What nerve controls the ileoceal sphincter?

Answer 28

myenteric plexus (and SNS)

Question 29

What is characteristic of colonic epithelium?

Answer 29

Contains numerous crypts/ invaginations but lacks villi

Question 30

What are two notable cells of the surface epithelium of the colonic epithelium?

Answer 30

Mucus secreting goblet cells and columnar absorptive cells

Question 31

What are the major ions that the colon secretes?

Answer 31

K+ and HCO3-

Question 32

What are the major ions that the colon absorbs?

Answer 32

Na+, Cl-, and water

Question 33

How much fluid does the colon absorbe a day?

Answer 33

1.9 L

Question 34

Which ion can move passively through tight junctions?

Answer 34

K+

Question 35

True or False: The colon is a net secretor of Na+

Answer 35

False...it is a net secretor of K+

Question 36

What provides spontaneous electrical activity in the colon?

Answer 36

ICC's

Question 37

What is a "mass movement"?

Answer 37

One giant peristaltic wave that occurs 1-3 times a day and lasts 10-30 minutes

Question 38

What portions of the SNS innervate the colon?

Answer 38

Celiac plexus, superior mesenteric plexus and inferior mesenteric plexus

Question 39

What portions of the PNS innervate the colon?

Answer 39

Vagus and pelvic nerves

Question 40

What is hirschprung's disease?

Answer 40

congenital disease present at birth where an individual lacks the ENS in the distal part of the GI that leaves the distal GI tonically contracted. As a result the proximal segment becomes distended with fecal matter

Question 41

What composes flatus?

Answer 41

swallowed air, bacterial action and diffusion from blood

Question 42

What is IBS usually associated with?

Answer 42

females ages 20-40 and stress/ high anxiety

Question 43

What is fecal incontinence?

Answer 43

involuntary defication

Question 44

What triggers defecation?

Answer 44

Triggered by distension of the rectum by feces (sensed by mechanoreceptors) this is the rectosphinteric reflex

Question 45

What do the mechanoreceptors in the rectum activate?

Answer 45

the myenteric nerves...which send signals back to the rectum to relax the internal anal sphincter and then also send signals to the brain to stimulate the urge to defecate

Question 46

What does the rectosphincteric reflex do to the external anal sphincter?

Answer 46

It makes it contract until defecation, when it then relaxes