Lecture 18

Question 1

Primary organs:
1.
2.
3.
4.
5.
6.

Accessory organs: they are not apart of the digestive tract, but they contribute to the process of digestion indirectly
1.
2.
3.
4.
5.
6.

Answer 1

1. oral cavity (mouth)
2. pharynx
3. esophagus
4. stomach
5. small intestine
6. ## large intestine
7. teeth
8. tongue
9. salivary glands
10. liver
11. gallbladder
12. pancreas

Question 2

• alimentary canal= __________ which refers to the whole passage (______ hollow) along which food passes through the body from the _____ to ____
• gastrointestinal (GI) tract= _________ + _________

Answer 2

• digestive tract; muscular; mouth; anus
• stomach; intestines

Question 3

Four layers of the organs of the digestive tract
1.
2.
3.
4.

• the _______ layer comes into contact with food particles

Answer 3

1. mucosa
2. submucosa
3. muscularis propria (aka muscularis extnera)
4. adventitia or serosa

• mucosa

Question 4

Organs of the digestive system that have adventitia instead of serosa…

Where within the digestive system can the serosa be found?

Answer 4

• oral cavity
• pharynx
• esophagus
• rectum

the outermost layer of the digestive tract, covering organs within the abdominal cavity, such as the stomach and intestines

Question 5

• The muscularis externa (or propia) is located in between the _________ and ________
• two layers of smooth muscle that constitute it
  1.
  2.

Answer 5

• submucosa; adventitia/serosa
  1. Circular
  2. longitudinal

Question 6

The GI tract has its own nervous system called the ___________
- this system coordinates _______, _______, and ______ to achieve adequate nutrient _________

Answer 6

• enteric NS
• digestion; secretion; motility; absorption

Question 7

• plexus= a _____ of ________ or vessels)
• in the enteric NS, the two main plexus are the _______ plexus (or ______ plexus) and the ________ plexus (or _______ plexus)

Answer 7

• network; nerves
• myenteric (Auerbach’s)
• submucosal (meissner)

Question 8

Alternative term for the submucosal plexus= ________ plexus
- the _________ layer houses the submucosal plexus and the primary function is to regulate _____ __________

Answer 8

Meissner
- submucosa; GI secretions

Question 9

Another name for the myenteric plexus= _________
- located between the ________ and _______ muscle layers of the ________ ______
- primary function is to control the _______ and ______ of the digestive tract (________)

Answer 9

Auerbach
- circular; longitudnal; muscularis externa
- motility; movement; peristalsis

Question 10

alternative terms for long and short reflexes in the GI tract
- long reflexes= ________ reflexes
-involve _____ integration centers & ____

• short reflexes= _______ reflexes
  -mediated entirely by _______ _______ in response to stimuli within the GI tract

Answer 10

• vagovagal
  -CNS; ANS
• myenteric
  -enteric NS plexuses

Question 11

Subdivision of the ANS
- ____________ inputs enhance digestive activity: motility & secretion
-stimulation occurs from the cranial nerve: _____
- _________ impulses inhibit it

Answer 11

• parasympathetic
  -Vagus
• sympathetic

Question 12

Long reflexes
- pathway:
- stimuli: originate _____ the GI tract
- response time: _________ due to ____ involvement

Answer 12

• CNS & ANS
• outside (sight, smell, emotion)
• slower; CNS

Question 13

Short reflexes
- pathway:
- stimuli: originate ______ GI tract
- response time: _______ due to local processing

Answer 13

• entirely within ENS
• within (pressure, chemical changes)
• faster

Question 14

The olfactory or visual perception of appetizing food triggers the secretion of salvia.. in this scenario the type of reflex likely involved is _______ reflex

Answer 14

long

Question 15

_________: alternating waves of smooth muscle contraction; results in the ________ (movement) of materials through the GI tract

• takes place in the following digestive system organs…

Answer 15

peristalsis; propulsion
- esophagus
- stomach
- intestines

Question 16

_____________: rhythmic contraction and relaxation of non-adjacent segments of the digestive tract; moving materials ______ and ______ to aid the _______ of undigested materials with intestinal secretions
- ensures _______ digestion and _______ are both completed
- takes place in the following digestive system organs…

Answer 16

segmentation; back and forth; mixing
- chemical; absorption
- intestines

Question 17

• for propulsion (movement) of food particles through the GI tract, which type of GI motility is more relevant: _________
• in terms of mixing food particles with GI secretions, which the of GI motility is more effective: ___________
• is it possible to utilize segmentation to move food particles through your esophagus towards your stomach? ______

Answer 17

• peristalsis
• segmentation
• no (there is no net movement in segmentation)

Question 18

• __________: the selective intake of food (occurs in the __________)
• digestion: the _______ (physical) and ______ (by digestive enzymes) breakdown food into a form usable by the body
• processes responsible for mechanical breakdown of food particles in the….
  -mouth=
  -stomach=
  -small intestine=

Answer 18

• ingestion (oral cavity)
• mechanical; chemical
  -chewing
  -churning
  -segmentation

Question 19

• propulsion= __________________
• ___________: the uptake of nutrient molecules into the epithelial cells of the digestive tract and then into the ______ or ______

Answer 19

• movement of food particles through the GI tract
• absorption; blood; lymph

Question 20

• compaction: absorbing ______ and consolidating the ________ residue into _____
• __________: the elimination of feces through the anus

Answer 20

• water; indigestible; feces
• defecation

Question 21

Digestive processes that occur in the oral cavity
- _______ digestion: through the activation of _______ (_________) reflex
- ________ digestion: _____ is partially digested by _______ in the mouth

Answer 21

• mechanical; chewing (mastication)
• chemical; starch; enzymes

Question 22

Four types of teeth and number of roots associated with each type
1.
2.
3.
4.

Answer 22

1. incisor (1 root)
2. canine (1 root)
3. premolar (1-2 roots)
4. molar (2-3 roots, 3rd molar all roots are fused into 1)

Question 23

• Canines are also called ______ due to their ______, cusp-like shape
• ______ are also recognized as _________
• the role of these “cusps” is to _______ and _______ food during the chewing process
• ________ are typically referred to as “the grinders” because of their broad, ______ surfaces designed for crushing, shredding, and grinding

Answer 23

• cuspids; pointed
• premolars; bicuspids
• tearing; grinding
• molars; flat

Question 24

Type of teeth that are blade-shape and located at the front of the mouth, and are particular useful for ________ or _______

Answer 24

incisors; clipping; cutting

Question 25

Adults normally have _____ teeth in the mandible (lower jaw) and _____ in the maxilla (upper jaw)= ____ teeth - ____ incisors - _____ canines - _____ premolars - _____ molars

Answer 25

16; 16; 32 - 8 - 4 - 8 - 12

Question 26

Three parts of a tooth 1. 2. 3. ______: the portion of the tooth that extends beneath the gum line

Answer 26

1. crown 2. neck 3. root

Question 27

- _______ covers the crown, the outer layer of the tooth - _________ covers the root

Answer 27

- enamel - cementum

Question 28

Composition of enamel - _____________ containing _______ and ________ - primary function: to provide a hard and durable ________ layer for the underling _____ and ______ of the tooth, facilitating effecting biting and chewing

Answer 28

- hydroxyapatite crystals; calcium; phosphate - protective; dentin; pulp

Question 29

- Dentin: ________ hard tissue that makes up the _____ of all teeth lying beneath _______ and ________ - it contains _____ _______ and is responsible for providing support to the enamel and transmitting sensory signals to the nerve - it consists of mainly _____________

Answer 29

- yellowish; bulk; enamel; cementum - dentin tubules - hydroxyapatite (apatite crystals)

Question 30

- Pulp of the tooth is the ________ layer of the tooth located in the ______ chamber of the tooth, within the pulp cavity - pulp contains: _______ tissue, ______ ______ (supplies nutrients), _______ ______, and ______ (tooth sensation) - name of the cells in pulp that contribute to define formation= ____________

Answer 30

- innermost; central - connective; blood vessels; lymphatic vessels; nerves - odontoblasts

Question 31

- Part of the tooth that is responsible for sensitivity to pain, pressure, and temperature= ________ (because it contains nerves, particularly nociceptive nerve fibers) - When _______ covering the dentin erodes, exposing the dentin ________, fluid within them moves - this moment activates ______ receptors at the dental pulp, believed to be the mechanisms behind tooth pain sensation

Answer 31

- pulp - enamel; tubules - pain

Question 32

______________: bone-like material covering the roots; _______ the tooth to the surrounding ________ bone - located over the ______ of the root - structure in the mouth that covers both the cementum and the root of the tooth= _____________

Answer 32

dental cementum; anchors; alveolar - dentin - periodontal ligament (attaches tooth securely to the jawbone)

Question 33

__________: passageway for blood vessels and nerves to the pulp cavity (within the root); it is also a colloquial term for a dental operation, where pulp is cleaned out, the space disinfected and then filled

Answer 33

root canal

Question 34

There main MAJOR salivary glands 1. 2. 3. - intrinsic (minor) small salivary glands are dispersed in _____ _______ and secrete saliva at a constant rate in relatively small amounts

Answer 34

1. Parotid gland 2. Submandibular gland 3. Sublingual gland - oral tissue (oral mucosa)

Question 35

The ________________ are responsible for producing the greatest amount of saliva when consuming food

Answer 35

extrinsic (major) salivary glands

Question 36

saliva is a ______ fluid produced by ______ pairs of major glands and numerous ______ salivary glands located in the oral cavity

Answer 36

watery; 3; minor

Question 37

Two elements of saliva that contribute to combating bacteria 1. _______: an enzyme that has antibacterial properties (break down cell walls of certain bacteria, leading to their destruction) 2. ______: an antibody that plays a role in the immune defense against bacteria and viruses

Answer 37

1. lysozyme 2. IgA

Question 38

Two enzymes in saliva that initiate the chemical breakdown of carbohydrates (starch) and lipids - ___________: begins starch digestion - ___________: begins fat digestion

Answer 38

- amylase - lipase

Question 39

Salvia makes swallowing easier by binding the food particles into a soft mass= ______ and lubricating it with mucus

Answer 39

bolus

Question 40

Two structures that the esophagus connects 1. 2. Two sphincters of the esophagus 1. 2.

Answer 40

1. pharynx 2. stomach - 1. Upper esophageal sphincter (UES) 2. Lower esophageal sphincter (cardiac sphincter)

Question 41

Upper Esophageal Sphincter - situated at the lower end of the ________ - it safeguards the entrance into the esophagus Main functions 1. prevent entry of ______ into the esophagus during _______ 2. Prevent ______ of esophageal contents into the pharynx to protect against airway aspiration

Answer 41

- pharynx 1. air; breathing 2. reflux

Question 42

Lower Esophageal Sphincter (cardiac sphincter) - situated at the junction of the esophagus and the ________ Main function 1. protects the esophagus from the _____ of ______ contents

Answer 42

- stomach 1. reflux; gastric

Question 43

Swallowing involves over 22 muscles coordinated by the swallowing center (in the _________)

Answer 43

medulla

Question 44

Three phases of the swallowing process 1. 2. 3. - phases are named based on the _______ and actions involved in the movement of the ______ during the process of swallowing)

Answer 44

1. Oral (or buccal) phase 2. Pharyngeal phase 3. Esophageal phase - location; bolus

Question 45

- What prevents food from being aspirated? ________ rises so that the _______ blocks the trachea which happens during the ________ phase - the bolus is pushed down through the esophagus toward the stomach through ________ which happens in the ________ phase

Answer 45

- larynx; epiglottis; pharyngeal - peristalsis; esophageal

Question 46

It is essential to close the cardiac sphincter once the bolus reaches the stomach in order to prevent _________ (the process of bringing swallowed food or liquids back up into the mouth)

Answer 46

regurgitation

Question 47

What phase of the swallowing process do you have "voluntary" control? ___________

Answer 47

Oral (or buccal) phase (because it involves the voluntary actions of chewing)