Digestion I Study Guide Flashcards

1
Q

sequence for the movement of food through the gastrointestinal tract

A

Mouth, pharynx, esophagus, stomach, small intestine, large intestine, anus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

accessory organs

A

teeth, tongue, gallbladder, digestive glands

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

glands

A

salivary glands, liver, pancreas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Peristalsis

A

takes place during propulsion (moving food through GI tract), rhythmic waves of smooth muscle contraction – propels food through the GI tract

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Segmentation

A

takes place during mechanical breakdown (chewing, mixing food with saliva, churning food), local contractions of the SI to mix food with digestive juices

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

digestion

A

series of catabolic steps in which enzymes break complex food molecules into their chemical building blocks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Absorption

A

passage of digested fragments from the lumen of the GI tract into blood/lymph

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Peritoneum

A

robust serous membranes of the abdominopelvic cavity
- Visceral peritoneum: membrane on the external surface of most digestive organs
- Parietal peritoneum: membrane on the wall of the abdominal cavity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Peritoneal cavity

A
  • Fluid filled space between the two peritoneum
  • Fluid lubricates the mobile organs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Mesentery

A

a double layer of peritoneum – extends to the digestive organs from the abdominal walls
- Provides routes for blood vessels, lymphatics, and nerves
- Holds organs in place and stores fat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

retroperitoneal organ

A

Organs located outside – posterior to – the peritoneum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

layers/tunics of GI tract from most internal to external

A

Mucosa, submucosa, muscularis externa, serosa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Submucosa

A

consists of areolar connective tissue, contains blood and lymphatic vessels, lymphoid follicles and a nerve plexus. Has an abundant number of elastic fibers to help organs regain their shape after storing a large meal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Serosa

A
  • Outermost, superficial layer
  • Same as the visceral peritoneum
  • Formed from areolar connective tissue covered with mesothelium – a single layer of squamous epithelium
  • Replaced by fibrous adventitia in the esophagus
  • Retroperitoneal organs have BOTH an adventitia and a serosa
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Muscularis externa

A
  • Muscle layer responsible for segmentation and peristalsis
  • Contains an inner, circular muscle layer and an outer, longitudinal muscle layer
  • The circular layer occasionally thickens to form sphincters
  • Sphincters: act as valves to prevent backflow and control the passage of food
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Mucosa

A

tunic layer that lines the lumen, a moist epithelial membrane
Functions:
- Secretes mucus, digestive enzymes, hormones
- Absorbs the end products of digestion
- Protects against infectious disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

3 sublayers of mucosa

A

epithelium, lamina propria, muscularis mucosae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Epithelium

A

most often a simple, columnar epithelium rich in mucus secreting cells
- The mouth, esophagus, anus are stratified, squamous
- Protects digestive organs from enzymes, eases food passage
- May create and secrete its own enzymes and hormones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Lamina Propria

A

loose, areolar connective tissue
- Contains lymphoid follicles to defend against microbes
- Rich supply of capillaries for nourishment and absorption

20
Q

Muscularis Mucosae

A

very thin layer of smooth muscle

21
Q

simple epithelium of GI tract

A

Stomach and intestines have simple columnar epithelium

22
Q

stratified epithelium in the GI tract

A

The mouth, esophagus, anus are stratified, squamous

23
Q

How many layers of muscularis exist in the stomach? How is this different from the rest of the GI tract?

A

3 – Most of the body has 2

24
Q

Sphincter

A

act as valves to prevent backflow and control the passage of food (muscularis externa)

25
Q

Is blood entering hepatic circulation rich or poor in Oxygen? How about nutrients?

A
  • Collects nutrient-rich venous blood draining from the digestive viscera and brings it to the liver
  • Enters oxygenated, leaves deoxygenated?
26
Q

branch of the ANS that stimulates digestive activity

A

Parasympathetic nervous system

27
Q

The GI tract’s own nervous system is called the

A

enteric nervous system

28
Q

saliva

A

mostly water, and slightly acidic. It contains electrolytes, salivary amylase, mucin, lysozyme, urea, igA antibodies, and defensins

29
Q

Major extrinsic salivary glands

A

produce most of the saliva, located outside oral cavity
- parotid, submandibular, sublingual

30
Q

Parotid gland

A

anterior to the ear. External to the masseter; parotid duct to the oral vestibule

31
Q

Submandibular gland

A

medial to the body of the mandible, duct to the base of lingual frenulum

32
Q

Sublingual gland

A

anterior to the submandibular, opens to the floor of the mouth via 10-12 ducts

33
Q

How many permanent, mature teeth are there?

A

32

34
Q

Incisors

A

chisel shaped for cutting 8

35
Q

Canines

A

fang-like for tearing, piercing 4

36
Q

Premolars

A

broad crowns with rounded cusps, used to grind/crush 8

37
Q

molars

A

broad crowns with rounded cusps, best for grinding 12

38
Q

Wisdom teeth

A

3rd molars, emerge around 17-25 years of age
4

39
Q

Where esophagus pierces through the diaphragm

A

Esophageal hiatus

40
Q

sphincter on the proximal end of the stomach

A

gastroesophageal /cardiac sphincter (surrounds cardial orifice)
- Orifice is closed when food is not being swallowed
- Mucus cells on both sides of the sphincter help protect the esophagus from acid reflux

41
Q

Heartburn

A
  • Burning, radiating, substernal pain; mimics MI pain
  • Cause: regurgitation of stomach acid into the esophagus
  • First symptom of Gastroesophageal Reflux Disease (GERD)
  • Increased risk with excessive intake of food/drink, obesity, pregnancy, running
  • Frequent episodes -> esophagitis, esophageal ulcers
42
Q

Hiatal hernia

A
  • Structural abnormality caused by abnormal weakening of the gastroesophageal sphincter
  • Superior portion of the stomach protrudes above the diaphragm
43
Q

two phases of deglutination (swallowing)

A

buccal phase and pharyngeal-esophageal phase

44
Q

Buccal phase

A

voluntary contraction of the tongue

45
Q

pharyngeal-esophageal phase

A

involuntary phase driven by the vagus nerve; controlled in the swallowing centers of the medulla and lower pons, respiration is momentarily inhibited, and all undesired routes are blockers