Transcript dark blue parotid – light green Large intestine

CHAPTER 14
DIGESTIVE SYSTEM
VOCABULARY WORDS
alimentary canal
lesser omentum
appendix
lingual frenulum
bile
liver
cecum
lumen
chyme
masticated
duodenum
pancreas
esophagus
phenylketonuria (PKU)
gallbladder
pyloric sphincter/valve
greater omentum
rugae
ileocecal valve
small intestine
ileum
stomach
jejunum
uvula
Large intestine
COLOR CODE – Plate 78
Oral cavity – peach
liver - red
Pharynx – dark green
gall bladder – light green
Esophagus – brown
pancreas - purple
Stomach – magenta (dk. pink)
spleen - tan
Duodenum – light blue
submandibular - yellow
Jejunum – blue
sublingual - orange
Ileum – dark blue
parotid – light green
Large intestine – orange
Appendix – pink
Rectum – gray
Tongue – red
Color Code – Plate 79
Frenulum – aqua
Gingiva (gum) – pink
Hard palate – dark blue
Soft palate – light blue
Uvula – purple
Oral pharynx – tan
Palatine tonsil – green
Tongue – red
Sublingual gland – orange
Submandibular gland – yellow
Parotid gland – light green
Epiglottis – brown
Lingual tonsils – dark green
Color Code – Plate 83
Fundus – dark blue
submucosa - pink
Body – blue
oblique muscle - brown
Pylorus – light blue
circular muscle – light brow
Pyloric sphincter – purple longitudinal muscle - tan
< curvature – aqua
serosa - magenta
> Curvature – turquoise
diaphragm - gray
Rugae – peach
esophagus - yellow
Surface/mucous cells – dark green duodenum - red
Parietal cells – green
Chief cells – light green
Muscular mucose - orange
Color Code – Plate 87
Liver – red
Gallbladder – light green
Pancreas – gray
Spleen – tan
Abdominal aorta – pink
Inferior vena cava - magenta
I. Anatomy of Digestive Sys.
A. 2 main groups of organs
1. those forming the alimentary canal
2. accessory digestive organs
B. Alimentary canal
1. performs all dig. Functions
2. functions: ingesting, digesting,
absorbing, defecation
C. Accessory digestive organs
assist in the process of digestion
II. ALIMENTARY CANAL
A. Also called the GI tract
(gastrointestinal)
B. Approx. 9m / 30 ft. long
C. Shorter in a living person  muscle
tone
D. Mouth / Oral Cavity
1. masticated  chewed
2. break down of food b/g b/f food leaves
mouth
3. tongue – continually mixes food w/
saliva & initiates swallowing
4. lingual frenulum
a. fold of mucous membrane that
secures tongue to floor of mouth
b. limits posterior mmt. of tongue
c. if extremely short  “tongue-tied”
E. Pharynx
1. common passageway for food, fluid, air
2. has 3 sub÷
a. nasopharynx – part of respiratory
passageway
b. oropharynx – posterior to oral cavity
c. laryngopharynx – continuous w/
esophagus
3. peristalsis
a. propelling mech. for food from
pharynx i/t esophagus
b. alternating contraction of 2 muscle
layers
Picture A shows peristalsis
F. Esophagus
1. passageway for food to stomach
2. food conducted by peristalsis
3. has 4 basic tissue layers  tunics
a. mucosa
*inner most layer
*lines cavity / lumen of esophagus
*epithelium is >ly simple columnar
b. submucosa
*just b/n mucosa
c. muscularis externa
*has 2 layers of smooth muscle:
inner circular layer
outer longitudnal layer
d. serosa
G. Stomach
1. C-shaped; left side of abdominal cavity
2. when full  approx. 4-L / 1-gal of food
3. covered by omentum
a. > omentum
* xtension of peritoneum
* drapes downward & covers
abdominal organs like a lacy
apron
b. < omentum
* double layer of peritoneum
* covers from liver to <er curve
4. has 3 muscle layers
a. longitudinal
b. circular
c. muscularis externa - obliquely arranged
layer
5. where chemical break down of proteins b/g
6. produces 2-3 L of gastric juice / day
a. intrinsic factor – sub. needed for
Vitamin B-12 absorption
b. chief cells – produce protein-digesting
enzymes
c. parietal cells – produce HCl (corrosive,
activates pepsinogen  pepsin)
7. chyme
a. sub. from food processed
b. resembles heavy cream
c. enters small intestine thru pyloric
sphincter (3-6 hr. journey thru sm. int.)
H. Small Intestine
1. mj. dig. organ
2. where chemical dig. really begins
3. where nearly all food absorption occurs
4. longest part of alimentary canal –
length: 2½ – 7m / 8 – 18 ft.
5. has 3 subdivisions:
a. duodenum
b. jejunum
c. ileum
6. extends from pyloric sphincter to
ileocecal valve
a. pyloric sphincter
*controls food mmt. i/t sm. int.
*prevents sm. int. from being
overwhelmed (“gatekeeper”)
b. ileocecal valve
I. Large Intestine
1. larger in diameter, shorter in length than
sm. int.
2. passage of feces (undigested food
particles) to end of dig. tract
3. has 5 sub÷
a. cecum
b. appendix – hangs from cecum &
collects bacteria
c. colon
d. rectum
e. anal canal
III. Accessory Digestive
Organs
A. Salivary Glands
1. 3 pr. that empty secretions i/t mouth
a. parotid glands
*larger
*inflammation  mumps
b. submandibular glands
just inferior to midmandible
c. sublingual glands
deep & inferior to floor of mouth
2. saliva
*prod. of salivary glands
*mixture of mucous & serous fluid
*contains enzyme amylase wh/ b/g
process of starch digestion
B. teeth
1. for mastication
2. have 2 sets:
*deciduous/baby teeth (20 teeth)
*permanent teeth (32 teeth)
C. Pancreas
1. extends across abdomen from spleen to
duodenum
2. produces enzymes to break down all categories
of digestible foods
3. enzymes are secreted i/t duodenum
4. enzymes neutralize acidic chyme from stomach
5. pancreatic juice contains enzymes:
a. amylase – starch dig.
b. trypsin – protein dig.
c. lipase – lipid dig.
d. nuclease – nucleic acid dig.
D. Liver
1. largest gland in body
2. has 4 lobes wh/ a/m completely cover stomach
3. digestive function  produce bile
4. other functions:
a. ATP production
b. degrades hormones
c. detoxify drugs/alcohol
d. make cholesterol
(has > 500 functions in body)
5. Bile
a. yellow-green, H2O-y solution
b. contains: bile salts, bile pigments,
cholesterol, phospholipids, electrolytes
c. emulsifies fats (breaks lg. globules i/t
sm.r ones
E. Gallbladder
1. sm. green sac snuggled i/t a fossa of
inferior surface of liver
2. stores bile when digestion is not
occurring
3. gallstones
a. occurs when bile is stored for too
long in the gallbladder or when
too much H2O is removed from
bile
b. cholesterol crystallizes forming
sharp stones  gallstones
IV. Digestive Diseases/conditions
A. Jaundice
1. occurs when blockage prevents bile from
entering sm. int./ actual liver prob.s
2. bile accumulates & backs up i/t the liver &
b/g to enter bloodstream
3. pigments circulate t/o the body  tissues
to b/c yellow  jaundiced
B. Hepatitis
1. inflammation of the liver
2. > often due to viral inf.  contaminated
H2O or needles
C. Cirrhosis
1. chronic inflammatory cond. of liver
2. liver is severely damaged & b/c hard &
fibrous
3. al/m guaranteed when drinking alcohol
for many years
4. a/s a consequence of hepatitis
D. Phenylketonuria (PKU)
1. inability to digest/use protein
(specifically the amino acid phenylalanine)
2. special diet is needed  brain damage &
MR occurs