Download Digestive System

Anatomy & Physiology 120
Lab 14: Digestive System
www.med.umich.edu/
1libr/aha/aha_digestiv
_art.htm
What you need to know
• Identify gross anatomy of the digestive system
– We have lots of models and manikins today
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Pancreas
gall bladder
Sagittal section-head
Duodenum
manikins
• Know the functions of each structure
What we are doing today
• Model Identification & Labeling Lab Diagrams
• Mouse Metabolism Experiment
The digestive system
The mechanical & chemical digestion of food
• 4 Stages
– Ingestion (eating = oral cavity)
– Digestion (brake down of food )
– Absorption (digested product  circulatory system
– Elimination (waste products)
Today we will be:
• Taking a walk through the alimentary canal
Using the Manikin &
Sagittal Sectioned Head
• Oral Cavity – Entrance to the digestive system
• Hard Palate – Front part of the upper mouth (grinding surface)
• Soft Palate & Uvula –
Rise during swallowing, blocks the entry
of food into the nasal cavity
• Oropharynx – Area of pharynx behind the oral cavity
• Parotid Gland – Anterior & inferior to each ear
Found between the skin & masseter muscle
1 of 3 Salivary glands (moistens & brakes down food)
• Submandibular Gland – Floor of the mouth both sides
2 of 3 Salivary glands
• Sublingual Gland – Floor of the mouth inferior to the tongue
3 of 3 Salivary glands
• Esophagus – Channels food from pharynx to stomach
Posterior or dorsal to the trachea
• Stomach – (divided into four regions)
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1) Cardiac– Sm. area adj. to the esophageal opening
2) Fundic –Expanded area superior to the cardiac region (stores food)
3) Body – Lg. area between the fundic and pyloric region
4) Pyloric – Sm. Area at the end (converges with the sm. Intestine)
– Esophageal (Cardiac) sphincter –
regulates the movement of food between esophagus and stomach
– Pyloric sphincter –
regulates movement between stomach and small intestine
– Lesser and greater curvatures – Rugae – lines the walls (increases surface area)
Absorption – Water, alcohol, some salts, some lipid & soluble drugs
• Mesentery - anchors the sm. intestine to the back of the
abdominal wall (part of the peritoneum)
• Small intestine (divided into three regions)
– 1) Duodenum – (C shaped &10 inch long) receives chyme
– 2) Jejunum – (3ft long) most nutrients are digested and absorbed
– 3) Ileum – (6-7 ft long) Cont. minimal nutrient absorption & delivers
undigested material to the ……….. Ileocecal valve
• Ileocecal valve – “See above” and “Below”
• Appendix – at the Ileocecal valve joins the lg. and sm. intestine
(packed with white blood cells … though to help fight infection)
• Cecum - pouch connected to the large intestine and the ileum
• Colon - (Lg. intestine - about 5 ft long)
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Ascending – going up
Transverse - Across
Descending – going down
Sigmoid – S shaped
Haustra - sacculations in the wall of the colon produced by
adaptation of its length to that of the tenia coli, or by the
arrangement of the circular muscle fibers.
– Teniae coli – A ribbon-like band of tissue or muscle.
• Rectum – Short term reservoir for feces
• Anal canal – terminal opening of the digestive system
• Liver – produces bile salts (stored in Gallbladder)
carbohydrate protein and lipid metabolism,
storage and detoxifications
– Two Lobes (Right & Left)
• Gallbladder
– Stores & delivers bile salts to the duodenum
• Pancreas –
– Secretes digestive juices into duodenum
– & secretes insulin & glucagon
Duodenum Model
• Mucosa – Surface epithelium -sm. amount of smooth muscle
Protects the tissue beneath it (Secre & Absorb)
• Submucosa – Carries away absorbed material
• Muscularis – Produces movements of the tube
– Circular – Constricts diameter (diameter decreases)
– Longitudinal – Tube shortens
• Serosa – Visceral peritoneum (outer covering)
• Villi – tiny, fingerlike projection (increase surface area)
• Lymph nodule – Found in the mucosa layer
• Capillaries – inside villi & carry nutrients away
• Intestinal Gland – located in between villi
• Lacteal – located in the villi with the capillaries
carries nutrients and minerals away to a lymph node
Liver – Gallbladder Model
• Cystic duct – gallbladder to the duodenum
• Pancreas – secretes digestive juices and is closely
associated with the duodenum (also produces insulin)
• Pancreatic duct – leads from the pancreas to
the duodenum
• Common bile duct – both cystic and hepatic duct which
leads to the …..
• Right & Left Hepatic Duct – two ducts (one from each
lobe of the liver) joins the cystic duct & goes to…
• Duodenum – What does it do?………..
Mandible
Total = 32
• Teeth – break food into sm. pieces (increase surface area)
• Incisors – chisel-shaped (bite off lg. pieces of food)
(8)
• Canines – grab & tear food (cuspids)
(4)
• Premolaers – Grinding food (bicuspids)
(8)
• Molars – Grinding food (polycuspids)
(12)
• Crown – exposed portion of the tooth (thick enamel)
• Root – Portion of the tooth below the gum (gingiva)
• Enamel – covers the crown (calcium salts) hardest
thing on the body
• Dentin – like bone but harder surrounds the pulp
cavity
• Pulp cavity – center of the tooth & contains blood
vessles, nerves, & connective tissue
• Root canal – blood vessels reach the pulp cavity
through the root canal.
• Cementum – thin layer of bone like material
(encloses the root)
Sm. Mammal Metabolism
Determine the metabolic rate of a mouse
Metabolic rate can be measured by O2 consumption rate
What is the definition of a Calorie?
________________________________________
What is a Kilocalorie?
You will be using a Metabolic Chamber
(See Lab Handout)
Notes to Remember
• Make sure to wet the pipette before putting in the soap
– You will not need to redo this every time ………
• Weigh the mouse & record the data
• Make note of the temp. & record
(**make sure the temp is stable**)
• You will do 3 trials
– Time how long it takes the mouse to use 5 ml of O2
– Remember “remove rubber stopper after each trial
The Math: Always use the UNITS
Step 1: Covert to minutes
_____ seconds / 60 seconds = ______ Min
Step 2: Find the average
Ave # of Min to
_____ Total Min / 4 Trials = ______ consume 5 ml
of O2
Step 3: Finding Cal/ min /gram
We will do this on the board
Step 4: Cleaning up
Used Soda Lime (into used jar)
Clean Up Thoroughly (spray down desks …)