Anatomy II Final Exam

Mainly digestion

What are the two groups of the digestive organs called?

Alimentary Canal and the Accessory digestive organs

List all of the alimentary canal organs

• mouth

• pharynx

• esophagus

• stomach

• small intestine

• large intestine

• anus

What is the function of the alimentary canal?

Digests food and absorbs fragments

List all of the organs apart of the accessory organs

• teeth

• tongue

• gallbladder

• digestive glands

• liver

• pancreas

What are the three types of salivary glands?

parotid, sublingual, submandibular

What is the function of the mouth during digestion? How long does it take?

Taste, chewing, bolus formation, digestion. 0 seconds

What is the function of the pharynx during digestion? How long does it take?

Transport. 8 seconds?

What is the function of the esophagus? How long does it take?

Transport, 10 seconds

What is the function of the stomach and how long does it take?

Storage, processing, digestion, portioning, 1-3 hours

What is the function of the small intestine? How long does this take?

digestion and absorption. 7-9 hours

What is the function of the large intestine? how long does this take?

Storage and absorption (water), 25-30 hours

What is the function of the rectum and how long does this process take?

Storage and excretion 20-120 hours

What are the six processes in digestion?

1. Ingestion

2. Propulsion

3. Mechanical breakdown

4. Chemical breakdown

5. Absorption

6. Defecation

What type of epithelium is the mouth made of?

Non-keratinized stratified squamous epithelium

What is the area between the teeth and cheek called?

The vestibule

Where are the insertions of the tongue?

Hyoid bone, styloid processes of temporal bone, and lingual frenulum

If the lingual frenulum is too anterior what condition could that cause?

Ankyloglossia

list the 5 primary functions of the tongue

1. mechanical & chemical processing

2. Assistance in chewing and swallowing

3. Formation of bolus

4. Sensory analysis

5. Lubrication

What are the two tonsils of the mouth?

Palatine and lingual tonsils

What is the main function of the teeth?

To masticate food

What are the two sets of teeth called that humans have?

Deciduous and permanent teeth

How many teeth are in the deciduous teeth and the permanent teeth?

20 teeth and 32 teeth

What are incisors used for (teeth)?

Cutting

What are canines used for?

tearing or piercing

What are premolars used for?

grinding

What are molars used for?

grinding

What are the three pairs of salivary glands?

1. Parotid

2. Submandibular

3. Sublingual

What is saliva a mixture of?

Mucus and serous fluids

What are the functions of saliva?

helps to form a bolus, dissolves chemicals (gustation), and contains salivary amylase to break down starch

What enzyme helps break down complex sugars?

Salivary amylase

What are the four main digestive activities of the mouth?

1. Ingestion

2. Propulsion

3. Mechanical breakdown

4. Chemical digestion

In what ways does the mouth do mechanical breakdown?

Mastication, mixing with saliva, and initiation of swallowing by the tongue

What is starch broken down into?

Maltose

True or False: the pharynx is a passageway for only food

False

What type of tissue is the pharynx lined with?

Stratified squamous epithelium

What are the two layers of the pharynx that propels food to the esophagus?

longitudinal and circular layers

What are the two phases of deglutition?

Buccal phase and the pharyngeal-esophageal phase

What is the buccal phase associated with?

voluntary contractions of the tongue and lips that forms the bolus (occurs in the mouth)

What is the pharyngeal-esophageal phase?

Involuntary transport of the bolus to the stomach

What type of movement is happening in the pharynx and through the esophagus?

Peristalsis

What are three ways the body directs food into the esophagus?

The tongue presses on hard palate to block off the mouth, the soft palate (uvula) blocks the nasopharynx, epiglottis blocks the larynx

What are the names of the sphincters in the esophagus?

Upper esophageal sphincter and cardioesophageal sphincter

What type of tissue is the esophagus made of?

non-keratinized stratified squamous epithelium

What are the four main layers of the alimentary canal?

1. mucosa

2. submucosa+glands

3. muscularis

4. Serosa

What are the parts of the mucosa layer and what type of tissue are they?

Epithelium (non-keratinized stratified squamous epithelium), lamina propria (areolar CT, vessels, nerves, glands), muscularis mucosae (smooth muscle).

What does the muscularis mucosae do?

Promote the ejection of glands into esophagus to lubricate and keep bolus moving

What type of tissue does both the visceral and parietal serosa have?

areolar connective tissue with epithelium

What is peristalsis?

The movement of digestive material

What is the importance of circular muscle in peristalsis?

It keeps the food moving in one direction

What is the importance of the longitudinal muscle in peristalsis?

It moves bolus distally

What is the smooth muscle of peristalsis regulated by?

pacemaker (autorhythmic) cells

What does peristalsis cause?

Waves that move a bolus

Where are the major and minor placed peristalsis occurs?

Major: esophagus, large intestine Minor: stomach and small intestine

What is segmentation?

churns, mixes, and fragments a bolus

Where does segmentation usually occur?

In the stomach and small intestine

What are the major functions of the stomach?

1. Mechanical breakdown

2. Chemical breakdown

3. Production of intrinsic factor

4. Storage of food

5. Delivers chyme to small intestine

What chemicals does the stomach produce?

HCL to activate pepsinogen into pepsin

What type of enzyme is pepsin?

An endopeptidase

What are smaller structures of proteins called (not amino acids)?

Oligopeptides (peptones)

What is the importance of Vitamin B12?

DNA synthesis (RBC production)

What part of the stomach stores food?

Fundus

When does the bolus become chyme?

When the bolus is processed by the stomach with all of the juices

What drugs do get absorbed in the stomach?

alcohol and aspirin

Where is the stomach?

On the left side of the abdominal cavity

What are the internal folds of the mucosa called?

Rugae

Why does acid reflux or heartburn happen?

The LES is dysfunctional

How many muscularis externa layers are in the stomach? Name them and the tissue type

3 smooth muscle layers (circular, longitudinal, oblique)

What is the function of the muscularis externa in the stomach?

allows stomach to churn, mix, move, and physically break down food

What type of tissue is the mucosa in the stomach?

Simple columnar epithelium and secretory cells

What are secretory cells?

Cells that produce and secrete substances (tight junctions)

What do the mucous cells secrete?

Two-layer coat of neutralizing alkaline (HCO3-) mucus (protective gel-like layer)

What are the mucous cells dotted with?

gastric pits → gastric glands that produce gastric juice

What are the four secretory cells in the stomach mucosa?

1. surface mucous cells

2. chief cells

3. parietal cells

4. enteroendocrine cells

What do surface mucous cells secrete?

produce thick, alkaline neutralizing & protective bicarbonate-mucus

What do chief cells produce?

Lipases, Pepsinogen, Rennin

What is the function of lipases?

digest around 15% of lipids

What does pepsinogen do once in acid (pepsin)?

Digests proteins

What does Rennin do?

Works on digesting milk protein in infants (not adults)

What do parietal cells produce?

Intrinsic factor and hydrochloric acid

Where does vitamin B12 absorb if it binds to intrinsic factor?

In the small intestine at the ileum

What is the acidity of the stomach and what does it do?

Caused by HCL between 1.5-3.5. It activates pepsinogen into pepsin (protease)

What do enteroendocrine cells produce?

Hormones

• G cells

• ECL cells (H cells)

• D Cells

What are G cells and what do they secrete?

gastrin

What are ECL cells and what do they secrete?

Histamine

What are D cells and what do they secrete?

somatostatin (GHIH)

What does somatostatin do?

Stops the function of gastrin

What are the three reflex pathways that stimulate and regulate acid secretion of the stomach?

1. ParaSympathetic NS (PSNS) → ACh

2. Gastrin (by G-cells_

3. Histamine (by enteroChromaffin-Like cells)

What cells inhibit the reflex pathways for stomach acid (HCL)?

somatostatin (D cells)

What pump is responsible for HCL in the lumen?

H+/K+ ATPase

The PSNS regulates which nerve in stomach acid secretion?

Vagus N.

What does the vagus nerve release (stomach acid secretion)?

ACh

What receptors do the parietal cells have?

ACh, gastrin, and histamine receptors

Along with promoting HCL in the stomach what function does gastrin have?

promote HCL cells to produce histamine

What specific cell do the D cells inhibit and how does the stop most of the HCL?

The D cells inhibit G cells (Gastrin) which causes ECL cells to also stop producing histamine

What is the function of gastrin in the stomach?

Induce the movement/ peristalsis in the stomach, promote mucous neck cells, induce pepsinogen, and HCL

What is HCL important for besides converting pepsinogen?

Create a hostile environment to get rid of any pathogens that could have arrived from food

What are the two ways the stomach does propulsion?

1. Segmental movements by the three muscle layers

2. Extrinsic gastrointestinal reflexes as food enters stomach

What are the two responses of the stomach when it is filling?

1. receptive relaxation

2. gastric accommodation

What is receptive relaxation? Describe it.

The smooth muscle in the stomach will allow to bring in the food (coordinated by swallowing brain centers)

What is gastric accommodation?

Stretch muscles induce relaxation instead of contraction →temporary reservoir