Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
BIO202-CH23-Stomach
BIO202 - Ch 23 - Digestive System - Stomach - Marieb/Hoehn - RioSalado - AZ
| Question | Answer |
|---|---|
| deciduous teeth | milk or baby teeth |
| The outer surface of the tooth root is covered by __. | cementum - calcified CT |
| What anchors tooth in bony alveolus of jaw? | Peridontal ligament |
| Bonelike material underlying enamel cap & makes up bulk of tooth. | Dentin |
| Dental caries | cavities |
| Calculus | tartar |
| Histology of pharyngeal wall | Stratified squamous w/mucus-producing glands |
| There are 2 __ layers in pharyngeal wall. | skeletal muscle |
| How long is esophagus? | 25 cm (10 inches) long |
| How does epithelium change abruptly at esophagus-stomach junction. | Esophageal mucosa change from nonkeratinized stratified squamous to simple columnar epithelum which is specialized for secretion. |
| Submucosa's esophageal glands secrete? | Mucus to grease the esophageal walls to aid food passage. |
| The outermost layer of esophagus. | Adventitia (Fibrous CT) |
| Name 2 digestive system structures whose only role is food propulsion. | Pharynx & esophagus |
| deglutition | Swallowing - involves 22 separate muscle groups - buccal phase & pharyngeal-esophageal phase. |
| Which phase of deglutition is voluntary? | buccal phase |
| The pharyngeal-esophageal phase of deflutition is controlled by __. | Swallowing center in brainstem - medulla & lower pons - transmitted through vagus nerves. |
| What structural modification of stomach tunic allows mechanical digestion? | Muscularis externa has 3rd layer of smooth muscle to churn food - runs obliquely. |
| Size of adult stomach | 15-25 cm (6-10 inches) 50 ml empty - 1 gallon full |
| What part of stomach is continuous with duodenum. | Pylerus |
| Lining of stomach | Simple columnar epithelium w/goblet cells that produce alkaline mucus - makes a bicarbonate-rich fluid layer. |
| Mucous neck cells of stomach | Produce thin mucus - acidic |
| Parietal cells of stomach | Secrete HCl & intrinsic factor - have microvilli |
| Intrinsic factor is? | Glycoprotein for B12 absorption in small intestine, but produced in stomach. |
| Ph of stomach | 1.5 - 3.5 |
| Chief cells of stomach | Produce pepsinogen (inactive) - activated by HCl & becomes pepsin - positive feedback process. |
| Enteroendocrine cells of stomach | Release chemical messengers - histamine, gastrin, serotonin, somatostatin |
| What barrier protects stomach from self-digestion? | Gel-like mucosal barrier - (1) bicarbonate-rich mucus, (2) tight junctions, (3) stem cells that divide & replace quickly. |
| gastritis | inflammation of stomach wall due to anything that breaches mucosal barrier |
| Name some H2-receptor blocker drugs | Tagmet & Zantac |
| Vagus nerve does what what with stomach. | Stimulates secretory activity of virtually all of its glands. |
| Which hormone controls gastric secretion? | Gastrin - enzymes, HCL |
| 3 phases of gastric secretion | Cephalic (reflex), gastric, & intestinal - all may be occuring at same time. |
| Cephalic reflex (Phase 1) | Conditioned reflex - occurs before food enters stomach - triggered by senses, prepares stomach - suppressed when emotinally depressed. |
| Gastric Phase (Phase 2) | In stomach - 3-4 hours long - distension & gastrin are stimulus. |
| G cells | Gastrin - secreting enteroendocrine cells. |
| Highly acidic gastric contents __ gastrin secretion. | Inhibit |
| Protein __ pH in stomach | raises - stimulates gastrin & HCl release |
| HCl secretion is stimulated by which 3 chemicals? | ACh, gastrin, & histamine (by enterochromaffin-like cells) - all 3 combined causes HCl to pour forth. |
| Blood draining from stomach is more __ than blood serving it. | alkaline - phenomenon called alkaline tide. |
| Intestinal Phase (3) | 2 components - excitatory & inhibitory - excitatory - gastric gland in duodendum produce intestinal gastrin: inhibitory - enterogastric reflex that puts on "breaks" to protect small intestine from acidity. |
| Enterogastric reflex | release is inhibited. |
| Plasticity | Smooth muscle's ability to stretch without greatly increasing tension & contracts expulsively. |
| What sets rate of stomach's peristalic waves? | Pacemaker cells in longitudinal small muscle layers called interstitial cells of Cajal - don't initiate beat, neural does. |
| Basic electrical rhythm (BER) | Cyclic slow waves of stomach due to pacemaker interstitial cells of Cajal. |
| Stomach usually empties completely within __ hours. | 4 |
| emesis | vomiting |
| Where is emetic center located? | Controls vomiting - in medulla |
Created by:
Ladystorm
Popular Laboratory Science sets