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Lab Exercise 5: Respiratory & Digestive Organs of the Head and Neck, Human; Lab Exercise 6: Histology of the Respiratory System Lab Exercise 7: Digestive System Models, Human Lab Exercise 8: Histology of the Digestive System "Stuff to Know"

Dr. L. M. Bacha Fall 2011

Objectives: After completing this exercise, you should be able to: ◦ identify the structures of the head and neck. Materials: ◦ textbook

◦ model of the sagittal head, human

◦ model of thoracic organs, human

1. Sagittal section of head, human model: Identify the following structures:

skull brain spinal cord cervical vertebrae

frontal sinus sphenoidal sinus

hard palate soft palate uvula - the free tip of the soft palate oral cavity tongue nasal bone nostril (external naris)

nasal cavity - located above (superior to) the hard palate superior, middle, and inferior conchae superior, middle, and inferior meatus

nasopharynx – located superior to the soft palate and posterior to the nasal cavity pharyngeal tonsil (adenoid) - in posterior wall of nasopharyx) opening of the auditory tube (Eustachian tube)

oropharynx - lies posterior to the oral cavity; extends from the uvula to the epiglottis palatine tonsil - each is embedded in the lateral wall of the oropharynx lingual tonsil - located at the base of the tongue

larynx: epiglottis

vocal folds (true vocal cords)

vestibular folds (false vocal cords)

esophagus trachea

Lab #5 p.1

DON”T FORGET: To avoid making marks on the models, do NOT use open pens or pencils as pointers!

2. Thoracic organs, human model: Identify the following:

heart superior vena cava inferior vena cava diaphragm esophagus esophageal hiatus – opening in the diaphragm through which the esophagus passes

thyroid gland

larynx: epiglottis vocal folds (true vocal cords) vestibular folds (false vocal cords) thyroid cartilage cricoid cartilage

trachea right primary bronchus left primary bronchus

Lungs:

apex base hilus - opening on the mediastinal surface of each lung through which pass the pulmonary arteries

& veins, bronchial arteries, primary bronchi, lymphatic vessels, and nerves

Each lung is divided into lobes:

right lung 3 lobes: superior lobe

middle lobe inferior lobe

left lung 2 lobes: superior lobe inferior lobe

cardiac notch

Lab #5 p.2

3. Torso Model, Human: Viscera of the Thoracic Cavity

right lung superior lobe middle lobe inferior lobe

left lung

superior lobe inferior lobe

right primary bronchus left primary bronchus esophagus heart superior vena cava inferior vena cava pulmonary trunk right pulmonary artery left pulmonary artery pulmonary veins aorta diaphragm

Lab #5 p.3

CLEAN UP TIPS: Reassemble models that were taken apart and return all models to the cart or cabinet from which they were obtained.

Objectives: After completing this exercise, you should be able to: ◦ identify the main structures on a histologic section of the trachea and lungs. Materials: ◦ textbook

◦ microscope

◦ prepared microscope slides

1. slide: Trachea & Esophagus, x.s.

pseudostratified epithelium - can you see cilia? goblet cells? hyaline cartilage

Lab #6 p.1

.2 slide: Lung

bronchus bronchiole alveoli (singular is “alveolus”)

Lab 6 p.2

Objectives: After completing this exercise, you should be able to: ◦ identify the organs and associated structures of the abdominal cavity listed in bold print.

Materials: ◦ textbook

◦ human gastrointestinal tract model and human torso model

I. GASTROINTESTINAL TRACT MODEL

Sagittal section of the Head: Review these respiratory and digestive structures of the head:

frontal sinus sphenoidal sinus

hard palate soft palate uvula - the free tip of the soft palate oral cavity tongue nasal bone nostril (external naris)

nasal cavity - located above (superior to) the hard palate superior, middle, and inferior conchae superior, middle, and inferior meatus

nasopharynx – located superior to the soft palate and posterior to the nasal cavity pharyngeal tonsil (adenoid) - in posterior wall of nasopharyx) opening of the auditory tube (Eustachian tube)

oropharynx - lies posterior to the oral cavity; extends from the uvula to the epiglottis palatine tonsil - each is embedded in the lateral wall of the oropharynx lingual tonsil - located at the base of the tongue

larynx: epiglottis

vocal folds (true vocal cords)

vestibular folds (false vocal cords)

esophagus trachea

Lab 7 p.1

Digestive Organs esophagus

upper esophageal sphincter (estimate its location) lower esophageal sphincter(estimate its location) stomach:

cardia fundus body pylorus

pyloric sphincter pancreas pancreatic ducts liver gall bladder cystic duct spleen small intestine:

duodenum jejunum ileum

ileocecal valve large intestine:

cecum appendix ascending colon transverse colon descending colon sigmoid colon rectum anus

II. TORSO MODEL Body Wall and Peritoneal Cavity

The peritoneum is a serous membrane that lines the wall of the abdominal cavity and covers the viscera within it. The visceral peritoneum is that portion of the peritoneum which covers the viscera, and the parietal peritoneum is that portion of the peritoneum which lines the wall of the abdominal cavity. The peritoneal cavity is the potential space between the parietal and visceral layers. In life, it contains a serous fluid, called peritoneal fluid, which allows the viscera to glide upon each other and upon the body wall with minimal friction.

Lab 7 p.2

Abdominal Cavity and Organs

The abdominal cavity is a potential space that contains most of the gastrointestinal tract and the abdominal accessory digestive organs, as well as the peritoneal cavity.

The caudal, concave surface of the dome-shaped diaphragm forms the cranial wall of the abdominal cavity. The descending aorta, inferior vena cava, and esophagus pass from the thoracic cavity into the abdominal cavity through the diaphragm. Note the location of the esophageal hiatus of the diaphragm through which the esophagus passes.

The large liver lies just caudal to the diaphragm and is shaped to fit into it cranially.

Identify the hepatic portal vein and hepatic artery entering the underside of the liver. The gall bladder is partially concealed in a depression in the right lobe of the liver. The cystic duct carries bile from the gallbladder. It unites with the common hepatic duct from the liver, forming the common bile duct which joins with the pancreatic duct and empties into the duodenum.

Note the position of the stomach. Most of the stomach lies on the left side of the abdominal cavity and is more or less "J"-shaped. Observe the esophagus passing through the diaphragm to join the stomach. The portion of the stomach adjacent to the esophagus is the cardiac region; the dome shaped portion extending cranially to the left of the cardiac region is the fundic region (fundus); the main part of the stomach is the body; and the narrow caudal portion is the pyloric region.

ESTIMATE the location of the lower esophageal sphincter (gastroesophageal sphincter; cardiac sphincter) and the pyloric sphincter. (You can’t see these sphincters on the model; just estimate their location!) The spleen lies on the left side of the abdominal cavity, dorsal and superior to the stomach.

The small intestine is differentiated into three parts: the duodenum, jejunum, and ileum. The duodenum is the first, approximately "U"-shaped, loop of the small intestine. The other parts of the small intestine can not be distinguished in the model.

A portion of the pancreas can be seen in the loop of the duodenum, called the head of the pancreas. The remainder of the pancreas extends across to the left side of the body but is not visible on the model.

The large intestine consists of the cecum, colon, rectum, and anal canal. A blind diverticulum called the cecum, extends caudally from the beginning of the colon. The appendix of humans is located at the end of the cecum.

The colon comprises most of the large intestine. The ascending colon extends cranially on the right side of the body for a short distance. The transverse colon crosses to the left side of the body. The descending colon extends caudally into the pelvic canal. The "S"-shaped portion of the colon between the descending colon and the rectum is called the sigmoid colon.

Deep within the pelvic canal the colon passes into the terminal segment of the large intestine, the rectum. The terminal part of the rectum is called the anal canal, and its external opening to the outside is the anus.

Also locate the right kidney, left kidney, renal artery and renal vein, adrenal gland, ureters, and the urinary bladder.

Lab 7 p.3

Lab 7 p.4

Objectives: After completing this exercise, you should be able to: ◦ identify the histologic features of selected organs of the digestive system listed in bold print.

Materials: ◦ textbook

◦ microscope

◦ prepared microscope slides

Examine the following histologic preparations and identify the structures that are underlined. It may be helpful to make sketches of each

1. slide: Tongue, rabbit, taste buds

The tongue is covered by a thick stratified squamous epithelium. Note the foliate papillae (well developed in rabbits) with numerous, well developed taste buds along their lateral surfaces. The taste buds appear as pale oval bodies in the more darkly stained epithelium. Taste buds contain gustatory cells that are responsible for the sensation of taste.

Note the large amount of skeletal muscle in the tongue.

Lab 8 p.1

2. slide: Esophagus and Trachea, x.s.

Identify the esophagus on this slide. Identify the stratified squamous epithelium, which is part of the mucosa. The muscularis externa, which is evident as a pink layer, consists of two thick layers muscle tissue.

3. slide: Stomach, fundic region

The wall of the stomach consists of four main layers, as does most of the gastrointestinal tract (mucosa; submucosa; muscularis externa; serosa). The innermost main layer, the mucosa, is formed by the epithelium, lamina propria of loose CT, and muscularis mucosae of smooth muscle:

Identify the simple columnar epithelium, and note that the apical (lumenal) side of each columnar cell contains a cup-shaped vacuole. In living tissue, this vacuole is filled with mucus. This type of epithelium is unique to the stomach.

Invaginations of the surface epithelium form gastric pits.

The lumen of each gastric pit is continuous with that of a gastric gland. In the fundic and body regions of the stomach the gastric glands are formed mainly by two types of cells:

parietal cells - large, round, pink/orange staining cells that secrete hydrochloric acid chief cells - smaller, pale lavender/purple staining cells that produce pepsinogen.

Lab 8 p.2

A submucosa, muscularis externa of smooth muscle, and a serosa form the remainder of the wall of the stomach.

Lab 8 p.3

4. slide: Ileum

Villi are specific structures present only in the small intestine. They are fingerlike projections of the mucosa, which provide a greater surface area for digestion and absorption. The villi are composed of a simple columnar epithelium and an underlying lamina propria of loose connective tissue. The apical, (lumenal) surface of the columnar epithelial cells bears numerous extensions of the cell membrane called microvilli which increase the surface area of the cells for digestion and absorption. Collectively the microvilli form the striated border. Goblet cells are also present in the epithelium.

Intestinal glands are narrow invaginations of the epithelium located at the bases of the villi.

Note the muscularis externa of smooth muscle.

(5. slide: Pancreas

The pancreas is organized into lobules separated by connective tissue. It contains light-staining aggregations of cells called pancreatic islets, which produce hormones, including insulin. The islets are surrounded by numerous serous-secreting units called pancreatic acini (singular = acinus), which produce digestive enzymes.

Lab 8 p.4

6. slide: Liver

The liver is organized into lobules. In the pig, the lobules are very distinct, as the connective tissue of the septa between the lobules is abundant, thereby delineating each lobule. Identify the lobules. Notice the presence of a central vein and cords of hepatocytes (liver cells) that radiate outward from the central vein. (In 3D, the hepatocytes are actually arranged as plates of cells; these appear as cords of cells in histologic section.) The plates of hepatocytes are separated by sinusoids.

Lab 8 p.5

“Stuff to Know” Lab Practical #2

Lab 5

1. Sagittal section of head, human model skull brain spinal cord cervical vertebrae frontal sinus sphenoidal sinus hard palate soft palate uvula oral cavity tongue nasal bone nostril nasal cavity

superior, middle, and inferior conchae superior, middle, and inferior meatus

nasopharynx pharyngeal tonsil opening of the auditory tube

oropharynx palatine tonsil lingual tonsil

laryngopharynx esophagus hyoid bone larynx:

epiglottis vocal folds (true vocal cords) vestibular folds (false vocal folds)

trachea 2. Thoracic organs, human model

heart superior vena cava inferior vena cava diaphragm esophagus

esophageal hiatus thyroid gland larynx:

epiglottis vocal folds (true vocal cords) vestibular folds (false vocal cords) thyroid cartilage

cricoid cartilage

trachea right primary bronchus left primary bronchus

Lungs: apex base hilus right lung

superior lobe middle lobe inferior lobe

left lung superior lobe inferior lobe cardiac notch

3. Torso Model, Human: Viscera of the

Thoracic Cavity

right lung superior lobe middle lobe inferior lobe

left lung superior lobe inferior lobe

right primary bronchus left primary bronchus esophagus heart superior vena cava inferior vena cava pulmonary trunk right pulmonary artery left pulmonary artery pulmonary veins aorta diaphragm

Lab 6: Histology of the Respiratory System

1. slide: Trachea & Esophagus, x.s. pseudostratified epithelium hyaline cartilage

“Stuff to Know” p.1

2. slide: Lung bronchus bronchiole alveoli (singular is “alveolus”)

Lab 7: I. GASTROINTESTINAL TRACT MODEL

Sagittal section of the Head: frontal sinus sphenoidal sinus hard palate soft palate uvula oral cavity tongue nasal bone nostril (external naris) nasal cavity

superior, middle, and inferior conchae superior, middle, and inferior meatus

nasopharynx pharyngeal tonsil (adenoid) opening of the auditory tube (Eustachian tube)

oropharynx palatine tonsil lingual tonsil

larynx: epiglottis

vocal folds (true vocal cords) vestibular folds (false vocal cords)

esophagus trachea

Digestive Organs esophagus upper esophageal sphincter lower esophageal sphincter stomach:

cardia fundus body pylorus

pyloric sphincter pancreas pancreatic ducts liver

gall bladder cystic duct spleen small intestine:

duodenum jejunum ileum

ileocecal valve large intestine:

cecum appendix ascending colon transverse colon descending colon sigmoid colon rectum anus

II. ABDOMINAL CAVITY: TORSO MODEL, HUMAN

peritoneum visceral peritoneum parietal peritoneum

peritoneal cavity abdominal cavity diaphragm descending aorta inferior vena cava esophagus

esophageal hiatus liver hepatic portal vein hepatic artery gall bladder cystic duct common hepatic duct common bile duct

stomach cardiac region fundic region body pyloric region

“Stuff to Know” p.2

lower esophageal sphincter Estimate the pyloric sphincter location of these

spleen small intestine

duodenum pancreas large intestine

cecum appendix

colon ascending colon transverse colon descending colon sigmoid colon

right kidney left kidney renal artery renal vein

adrenal gland ureters urinary bladder

Lab 8: Histology of the Digestive System

1. slide: Tongue, rabbit, taste buds stratified squamous epithelium

taste buds skeletal muscle

2. slide: Esophagus and Trachea, x.s. esophagus:

stratified squamous epithelium muscularis externa

3. slide: Stomach, fundic region simple columnar epithelium gastric pits gastric gland

parietal cells chief cells

muscularis externa

4. slide: Ileum villi simple columnar epithelium

striated border goblet cells

intestinal glands muscularis externa

5.. slide: Pancreas pancreatic islet pancreatic acini

6. slide: Liver lobules

central vein hepatocytes sinusoids

“Stuff to Know” p.

Please

study !