A&p 2 Lecture - Digestive System

Front 1

The breaking apart of food into smaller pieces for increased surfacee area, begins here. More, small particles get the food greater exposure to chemical enzymes that bring about chemical digestion.

Back 1

Mechanical digestion

Front 2

The enzymatic (chemical) breakdown of carbohydrates, fats, proteins and nucleic acids into their component parts begins here, too.

Back 2

Chemical digestion

Front 3

What is responsible for beginning mechanical digestion?

Back 3

Teeth

Front 4

The teeth break food down into smaller pieces, increasing surface area. Why?

Back 4

So that enzymes (chemical digestion) have a larger surface area on which to work.

Front 5

Contains the first digestive enzyme, salivary amylase, which breaks downwhich breaks down carbohydrates (starch)

Back 5

Saliva

Front 6

Saliva contains _________ which, when activated by the low pH in the stomach, breaks down lipids

Back 6

lingual lipase

Front 7

Lingual Lipase breaks down ________ when activated by the low pH in the stomach

Back 7

lipids

Front 8

Saliva also contains mucus, __________, electrolytes and _______.

Back 8

lysozyme, IgA

Front 9

Chewing (________) with the teeth, manipulation of the food with the time and moistening the food with the saliva prepare it for further digestion in the stomach

Back 9

mastication

Front 10

The long "tube" from mouth to anus.

Back 10

The alimentary canal

Front 11

Any organ through which food or drink passes is part of the alimentary canal - T/F?

Back 11

T

Front 12

All other organs through which food or drink does not pass (not part of the alimentary canal) are called what?

Back 12

Accessory organs

Front 13

No digestion occurs in the pharynx, T/F? Explain.

Back 13

T, no digestive enzymes present.

Front 14

No digestion occurs here; contractions of its muscle layers help and swallowing to propel food downward and when no swallowing is occurring, excluding air from the esophagus.

Back 14

Pharynx

Front 15

Another word for "swallowing reflex"

Back 15

Deglutition

Front 16

Note that the "swallowing (deglutition) reflex" is a complex voluntaryis a complex voluntary action mediated by several skeletal muscles. It is a complicated maneuver that causes the _______ to be blocked by the ________ when materials are being swallowed. This prevents ________.

Back 16

Glottis; Epiglottis; aspiration

Front 17

Foreign materials other than air entering the glottis is called?

Back 17

aspiration

Front 18

One should never give anything by mouth to an unconscious person or one with a disturbed swallowing reflex; choking and airway obstruction could occur, resulting in death. T/F?

Back 18

T

Front 19

Swallowing (deglutition) is mediated by several ______ muscles.

Back 19

Skeletal

Front 20

No digestion occurs in the esophagus. T/F? Explain.

Back 20

T, no enzymes present.

Front 21

Amuscular tube that propels food from the pharynx into the stomach.

Back 21

Esophagus

Front 22

Name the organ: stratified squamous epithelium (Non-keratinized); other layers of mucosa, submucosa, and ​external muscle layers present; our muscle layers transition from skeletal muscles to a mix of skeletal and smooth muscle to entirely smooth muscle before the cardiac sphincter; covered by connective tissue adventitia.

Back 22

Esophagus

Front 23

Smooth muscle contractions are voluntary/involuntary and under ________ control.

Back 23

Involuntary; autonomic

Front 24

Most of the esophagus is in the _________ and is not, therefore, covered by ________. It is instead covered by _______, adventitia

Back 24

mediastinum, serosa, connective tissue

Front 25

Prevents reflux of materials in the stomach (including the HCl) into the esophagus.

Back 25

Cardiac sphincter

Front 26

After vomiting, the burning sensation one feels is associated with the exposure of the HCl to the esophageal lining which has no protective mucus and can be injured by the acid. Persons who have frequent reflux due to an incompetent sphincter or other reasons can develop chronic damage that may enhance formation of esophageal cancers. This is one reason why it is unwise to lie down soon after a meal. The active stomach is secreting acid which may get past the sphincter and into the esophagus, Causing what?

Back 26

Gastroesophageal reflux

Front 27

Both mechanical digestion and chemical digestion occur in the stomach, T/F?

Back 27

T

Front 28

Innervation of the stomach: Parasympathetic (branches of the _________) and some _____________. The ___________ (part of the autonomic nervous system) is most directly in charge of the nervous system regulation of food movement through the alimentary canal as a whole (________.), and uses neurotransmitters including ______ and ______.

Back 28

vagus nerve, enteric nervous system, peristalsis; histamine, serotonin

Front 29

Branches of the vagus nerve account for the sympathetic/parasympathetic innervation of the stomach.

Back 29

Parasympathetic

Front 30

The enteric nervous system is part of the ________ nervous system.

Back 30

autonomic

Front 31

What is most directly in control of nervous system regulation of food movement through the alimentary canal as a whole (peristalsis)?

Back 31

Enteric Nervous System

Front 32

The enteric nervous system uses what two neurotransmitters?

Back 32

histamine; serotonin

Front 33

Blood supply/drainage of the stomach: _______ branching from the _________ supply the stomach (the _________ is the largest of these.) Veins from the stomach drain into the ___________. (Veins from the stomach either drain directly into the hepatic portal vein or into the splenic vein.)

Back 33

Gastric arteries; Celiac trunk; left gastric artery; hepatic portal system of veins