A&P 2 Test 3 Flashcards
1
Q
The digestive system consists of the _____ and is assisted by various _____
A
muscular digestive tract
accessory organs
2
Q
6 digestive functions
A
- ingestion
- mechanical processing
- digestion
- secretion
- absorption
- excretion
3
Q
What are the 8 components of the digestive tract
A
- oral cavity
- pharynx
- esophagus
- stomach
- small intestines
- large intestines
- rectum
- anus
4
Q
What functions do the oral cavity, teeth, and tongue play in the digestive tract?
A
- Mechanical processing of food
- Moistening of food
- Mixing food with salivary secretions
5
Q
What is the function of the liver in the digestive tract?
A
- Secretes bile
- Stores nutrients
6
Q
What is an important lipid for digestion?
A
Bile
7
Q
What is the function of the gallbladder in the digestive tract?
A
Stores and concentrates bile
8
Q
What is the function of the pancreas in the digestive tract?
A
- Exocrine cells: secrete buffers and digestive enzymes
- Endocrine: secrete hormones
9
Q
What is the function of the large intestines in the digestive tract?
A
- Dehydrates and compacts indigestible materials
- Prepares for elimination
10
Q
What is the function of the salivary glands in the digestive tract?
A
-Secretes lubricating fluid which also contains enzymes which breaks down carbs
11
Q
What is the function of the pharynx in the digestive tract?
A
-Provides muscular propulsion of food into the esophagus
12
Q
What is the function of the esophagus in the digestive tract?
A
-Transports food from the mouth to the stomach
13
Q
What is the function of the stomach in the digestive tract?
A
- Breaks down food chemically with acid and enzymes
- Muscles contract to mechanically process and break down food
14
Q
What is the function of the small intestines in the digestive tracts?
A
- Digests food further using enzymes
- Absorbs water, organic substrates, vitamins, and ions
15
Q
What are the four histological layers of the digestive tract?
A
- Mucosa
- Submucosa
- Muscularis externa
- Serosa
16
Q
Describe the mucosa histological layer of the digestive tract
A
- Epithelium
- Lamina propria (connective tissue)
17
Q
Describe the submucosa histological layer of the digestive tract
A
- connective tissue
- nerves
- blood vessels
18
Q
Describe the muscularis externa histological layer of the digestive tract
A
-loose connective tissue cover (adventitia)
19
Q
Describe the serosa histological layer of the digestive tract
A
- in the peritoneal cavity
- continuous with mesentery
20
Q
The structure of the digestive tract:
A
slide 6 & 7
21
Q
How does food move through the digestive tract?
A
Involuntary control and contraction of smooth much of the muscularis externa
22
Q
What are the two types of movement of food through the digestive tract?
A
Peristalsis
Segmentation
23
Q
Describe peristalsis
A
Food is propelled along the digestive tract
24
Q
Describe segmentation
A
Food is churned in the small intestines
25
The steps of contraction of muscles moving food along the digestive tract:
*slide 9-12*
26
What are the functions of the oral cavity?
- Sensory analysis of potential foods
- Mechanically process food using the teeth, tongue and palate
- lubricate food using mucus in saliva
- Begins enzymatic digestion with saliva
27
What is another name for the oral cavity?
Buccal cavity
28
What forms the floor of the oral cavity?
The tongue
29
What forms the roof of the oral cavity?
Hard and soft palate
30
What forms the walls of the oral cavity
Buccal mucosa
31
What is the epithelium of the buccal mucosa?
Stratified squamous
32
What are the specific functions of the tongue?
- Mechanically processes food
- Manipulates food to assist in chewing and swallowing
- Provides sensory analysis (taste and texture)
- Participates in speech
33
The anatomy of the oral cavity:
*slides 16 & 17*
34
What are the three pairs of salivary glands?
- Parotid
- Sublingual
- Submandibular
35
What are the functions of saliva?
- Lubricates and cleanses oral cavity
- Dissolves chemicals
- Suppresses bacterial growth
36
Location of salivary glands:
*slide 19*
37
What is the function of teeth
Mastication of food
38
Mastication
Chewing
39
What ligament anchors teeth to bone?
Periodontal ligament
40
What forms the basic shape of teeth?
Dentin
41
What covers the crown of teeth?
Enamel
42
What covers the root of teeth?
Cementum
43
How many deciduous teeth are humans born with?
20
44
Deciduous teeth
Baby teeth
45
How many secondary teeth do humans have?
32
46
Secondary teeth
Adult teeth
47
The basic structure of teeth:
*Slides 21-23*
48
What are the functions of the pharynx?
- Passageway for food, drink and air
| - Food is propelled along the esophagus towards the stomach during swallowing by pharyngeal muscles
49
Describe the esophagu
- Muscular tube
| - 25 cm long
50
What is the epithelial lining of the esophagus?
Stratified squamous
51
Where is the esophagus in relation to the trachea?
Posterior
52
Where does the esophagus penetrate the diaphragm at the?
Esophageal hiatus
53
What two structures does the esophagus possess?
Upper and lower esophageal sphincters
54
A circular band of muscle that can pinch close to a muscular tube
Sphincter
55
What are the three steps of swallowing?
- Oral Phase
- Pharyngeal Phase
- Esophageal Phase
56
What happens during the oral phase of swallowing?
- Compaction of bolus
| - Food enters the pharynx
57
What happens during the pharyngeal phase of swallowing?
- Elevation of the larynx
- Bending of the epiglottis
- Closing of the glottis
58
What happens during the esophageal phase of swallowing?
-Peristalsis pushes the bolus toward the stomach
59
Steps of swallowing:
*slides 27-32*
60
What are the functions of the stomach?
- Temporarily stores ingested food
- Mechanically breaks down food
- Breaks down chemical bonds in food using acid and enzymes
- Production of the intrinsic factor
61
What occurs during the mechanical breakdown of food in the stomach?
Chyme is formed and liquid suspension occurs
62
Why is intrinsic factor important?
Required for vitamin B12 absorption
63
What are the 4 regions of the stomach?
- Cardia
- Funus
- Body
- Pylorus
64
What region of the stomach is closest to the heart?
Cardia
65
What region of the stomach is the "hump" on top of the stomach?
Fundus
66
What region of the stomach is shaped like the letter "C"?
Body
67
What region of the stomach is guarded by a guarded by a sphincter at the exit of the stomach?
Pylorus
68
What sphincter guards the exit of the stomach?
Pyloric sphincter
69
The regions of the stomach:
*slides 34 & 35*
70
What glands in the stomach are involved in secretions?
Gastric Glands
71
What cells are in the gastric glands?
- Parietal
- Chief
- Goblet
- Endocrine
72
The anatomy of the stomach:
*slides 37 & 38*
73
What do parietal cells secrete?
HCl
74
What is HCl involved in?
Intrinsic factor
75
What do chief cells secrete?
Pepsinogen (an inactive enzyme)
76
What turns pepsinogen into pepsin?
HCl
77
What do goblet cells produce?
mucus
78
What do endocrine cells produce?
Gastrin ( a hormone)
79
What are the three phases of regulating gastric activity?
- Cephalic phase
- Gastric phase
- Intestinal phase
80
What occurs during the cephalic phase?
CNS prepares the stomach to receive food
81
When does gastric phase occur?
When food enters the stomach
82
What does the intestinal phase do?
Controls the pace of gastric emptying
83
Phases of gastric secretion:
*slides 40-43*
84
What is the stomach lined with?
Highly mitotic cells
85
What is a short summary of the stomach?
The stomach provides for the physical breakdown of food that must precede chemical digestion. Pepsin and acid begin the digestion of proteins. For a variable period of time after food arrives in the stomach, starch continues the digestion that began with salivary amylase
86
What are the regions of the small intestines?
- Duodenum
- Jejunum
- Ileum
87
What sphincter marks the junction between small and large intestines?
Ileocaecal valve
88
The segments of the small intestines:
*slide 46*
89
The mucosa of the intestinal wall has transverse folds called...
Plicae circulares
90
Small projections of pilcae
Villi
91
What are the functions of the plicae and villi?
Increases surface area of mucosa for absorption
92
Each villus has a ____ which is called ____
Lymphatic capillary
| A lacteal
93
The small intestinal wall:
*slide 50*
94
Two forms of peristalsis in the small intestines
Small-scale and large-scale
95
Describe small-scale peristalsis
Periodic contractions of the muscularis extera
96
Describe large-scale peristalsis
Coordinated by gastroenteric or gastrocolic reflex
97
What are the 3 types of intestinal secretions
- Intestinal juice
- Mucus
- Hormones
98
What does intestinal juice do?
- Moistens chime
- Buffers stomach acid
- Dissolves digestive enzymes
- Dissolves products of digestion
99
What are some intestinal hormones in the small intestines?
- Gastrin
- Secretin
- Cholecystokinin
- Gastric Inhibitory Peptide
100
What part of digestion happens in the small intestine?
Most enzymatic digestion and absorption
101
What organs release enzymes and buffers for digestion in the small intestines?
- Pancreas
- Liver
- Gall Bladder
102
What is a brief summary of the small intestines?
The small intestine receives chyme from the stomach and raises its pH. It then absorbs water, ions, vitamins, and the products released from food molecules by the action of digestive enzymes produced by intestinal glands and the pancreas.
103
Where do the pancreatic ducts enter?
Duodenum
104
What do pancreatic ducts deliver?
Pancreatic juice
105
Pancreatic ducts branch ___
Repeatedly
106
Where do fine pancreatic duct branches end?
Pancreatic acini
107
What cells are found among the acini of the pancreas?
Endocrine cells
108
Anatomy of the pancreas:
*slide 59*
109
What are the two types of secretions from the pancreas?
- Endocrine (hormones)
| - Exocrine (digestive)
110
What are some hormones are secreted by the pancreas?
- insulin
| - glucagon
111
What are some digestive secretions which come from the pancreas?
- Water
- Ions
- Enzymes
112
What are some enzymes secreted by the pancreas
- Carbs
- Lipases
- Proteases
- Nucleases
113
What occurs to control pancreatic secretion?
-Chyme enters the duodenum which triggers hormone release, hormones then trigger the release of pancreatic juices
114
Secretin being secreted by the pancreas triggers...
Water and bicarbonate
115
CCK being secreted by the pancreas triggers...
Enzymes like Amylas, lipase, proteases
116
Brief summary of the pancreas
The exocrine pancreas produces a mixture of buffers and enzymes essential for normal digestion. Pancreatic secretion is stimulated by hormones (secretin and CCK) released from the duodenum.
117
What is the largest visceral organ?
Liver
118
How many known functions does the liver have?
Over 200
119
What are the 4 lobs of the liver?
- Right (largest)
- Left
- Caudate
- Quadrate
120
Anatomy of the liver
*slides 65 & 66*
121
What is a basic functional unit of the liver?
Liver lobule
122
Where is the blood supply of the liver coming from?
- Hepatic artery
| - Hepatic portal vein
123
In the liver, blood flows past sheets of
Hepatocytes
124
What are the blood channels of the liver?
Sinusoids
125
Where does blood collect in the liver?
Central vein
126
What carries bile towards of the bile ducts in the liver?
Bile Canaliculi
127
Where are bile ducts located in the liver?
Each lobe has a duct
128
What is formed when liver bile ducts unite?
Common Hepatic duct
129
What ducts carry bile from the liver to the gall bladder?
Cystic duct
130
What duct carries bile from the liver to the duodenum?
Common bile duct
131
How does the liver regulate metabolism?
- Stores absorbed nutrients and vitamins
| - Releases nutrients as needed
132
How does the liver carry out hematological regulation?
- Produces plasma proteins
| - Removes old RBCs
133
Why does the liver produce bile?
It is required for fat breakdown
134
What is the function of the gallbladder?
Stores and concentrates bile for release into duodenum
135
How does bile enter the small intestine from the gallbladder?
The hepatopancreatic sphincter relaxes
136
Briefly describe the gallbladder
The liver is the body’s center for metabolic regulation. It produces bile that will be ejected by the gallbladder into the duodenum under stimulation of CCK. Bile is essential for the efficient digestion of lipids; it emulsifies fats so that individual lipid molecules can be readily attacked by digestive enzymes
137
Know the anatomy of the gallbladder
Slides 75 & 76
138
Describe the large intestines?
- Reabsorbs water and compacts feces
- Absorbs vitamins made by bacteria
- Stores feces before defecation
139
What are the three parts of the large intestines?
- Cecum
- Colon
- Rectum
140
Functions of the cecum
- Collects and stores material from ileum
- Begins process of compaction
- Attaches to vermiform appendix
141
Describe the anatomy of the colon
- Larger diameter, thinner wall than small intestine
- Bears haustra (pouches)
- Possesses taenia coli (longitudinal bands of smooth muscle)
142
Describe the rectum?
- Expandable for temporary storage of feces
- Terminates in anal canal
- Leads to anus
- Circular muscle forms internal anal sphincter
- Encircled by skeletal muscle
143
What forms the external anal sphincter?
The rectum
144
Know the anatomy of the large intestines
Slides 81 & 82
145
What does the large intestine absorb?
```
Water
Ions
Vitamins
Organic wastes
Bile salts
Toxins
```
146
What triggers feces to move from the colon to the rectum?
Stretching of stomach and duodenum
147
What controls the movement of feces towards the anus?
Sphincters
148
What does the stretching of the rectum do?
Defecation of reflex
149
Release of feces requires....
Relaxation of external anal sphincter
150
Brief description of the large intestines
The large intestine stores digestive wastes and reduces their volume by reabsorbing water. Bacteria that live in the large intestine are an important source of vitamins, especially vitamin K, biotin, and vitamin B5
151
What are the two steps of processing nutrients?
Mechanical
| Chemical
152
Processing to break down physical structure of foods
Mechanical processing
153
Processing to break the covalent bonds between food subunits
Chemical processing
154
What catalyzes mechanical processing?
Enzymes
155
Chemical processing activates....
The hydrolysis of large food molecules
156
How are starches/carbs broken down?
Amylases
157
What breaks initial disaccharides & trisaccharides into monosaccharides
Enzymes
158
Carb absorption is facilitated by
facilitated diffusion or co-transport
159
Describe what happens during the processing and absorption of fats
- Bile emulsifies fats to small droplets
- Lipase hydrolyzes triglycerides into fatty acids and monoglycerides
- Lipid products form micelles
- Lipids diffuse into epithelial cells
- Triglycerides are reformed
- Secreted as chylomicrons into lacteals
- Transported in lymph to thoracic duct
160
What are the three things the urinary system eliminates?
Nitrogenous wastes
Toxins
Drugs
161
How does the urinary system regulate to maintain homeostasis?
- Water balance
- Electrolytes
- Acid-base balance in the blood
- Blood pressure
- Red blood cell production
- Activation of vitamin D
162
Organs of the urinary system
- Kidneys
- Ureters
- Urinary bladder
- Urethra
163
Describe the location of the kidneys
- Against the dorsal body wall
- At the level of T12 to L3
- The right kidney is slightly lower than the left
- Attached to ureters, renal blood vessels, and nerves at renal hilus
- Atop each kidney is an adrenal gland
164
What are the coverings of the kidneys?
Renal capsule
| Adipose capsule
165
Surrounds each kidney
Renal Capsule
166
Surrounds the kidney
Provides protection
Keeps the kidneys in the correct locations
Adipose Capsule
167
Outer region of the kidney
Renal Cortex
168
Inside the cortex of the kidney
Renal Medulla
169
Inner collecting tube of the kidney
Renal pelvis
170
Triangular regions of tissue in the medulla of the kidney
Medullary pyramids
171
Extensions of cortex-like material inward of the kidneys
Renal Columns
172
Cup-Shaped structures that funnel urine towards the renal pelvis in the kidneys
Calyces
173
The structural and functional units of the kidneys
Nephrons
174
What structure of the kidneys are responsible for forming urine?
Nephrons
175
What are the two main structures of nephrons?
Glomerulus
| Renal Tubule
176
A specialized capillary bed in the kidney which attaches to arterioles on both sides of the kidneys
Glomerulus
177
What are the arterioles in the kidneys which are attached to the glomerulus
Large Afferent Arteriole
| Narrow Efferent Arteriole
178
What are capillaries in the glomerulus covered with?
Podocytes from the renal tubule
179
Where does the glomerulus sit?
Within a glomerular capsule
180
Know anatomy of the renal tubule
Slide 178
181
Types of nephrons
Cortical
| Juxtamedullary
182
Describe cortical nephrons
- Located entirely in the cortex
| - Includes most nephrons
183
Describe Juxtamedullary nephrons
Found at the boundary of the cortex and medulla
184
Describe peritubular capillaries
Arise from efferent arteriole of the glomerulus
Normal, low pressure capillaries
Attached to a venule
Cling close to the renal tubule
Reabsorb (reclaim) some substances from collecting tubes
185
What are the three steps of the urine formation processes?
- Filtration
- Reabsorption
- Secretion
186
Describe filtration
Nonselective passive process
Water and solutes smaller than proteins are forced through capillary walls
Blood cells cannot pass out to the capillaries
Filtrate is collected in the glomerular capsule and leaves via the renal tubule
187
Describe Reabsorption
The peritubular capillaries reabsorb several materials
Some reabsorption is passive, most is active
Most reabsorption occurs in the proximal convoluted tubule
188
What do peritubular capillaries reabsorb?
- Some water
- Glucose
- Amino Acids
- Ions
189
What materials are not reabsorbed
- Urea
- Uric Acid
- Creatinine
- Excess water
190
Reabsorption in reverse
secretion
191
During secretion, some materials move from the peritubular capillaries to
renal tubules
192
What is secreted?
Hydrogen and potassium ions
| Creatinine
193
Materials left in the renal tubule move...
toward the ureter
194
What are the characteristics of urine used during medical diagnosis?
```
Colored somewhat yellow due to the pigment urochrome (from the destruction of hemoglobin) and solutes
Sterile
Slightly aromatic
Normal pH of around 6
Specific gravity of 1.001 to 1.035
```
195
Describe ureters
Slender tubes attaching the kidney to the bladder
Runs behind the peritoneum
Peristalsis aids gravity in urine transport
196
The ureters are continuous with the
renal pelvis
197
Where do ureters enter the bladder?
Posterior aspect
198
Describe the urinary bladder wall
Three layers of smooth muscle (detrusor muscle)
Mucosa made of transitional epithelium
Walls are thick and folded in an empty bladder
Bladder can expand significantly without increasing internal pressure
199
Describe the Urethra
Thin-walled tube that carries urine from the bladder to the outside of the body by peristalsis
Release of urine is controlled by two sphincters
200
What are the two sphincters in the urethra
Internal Urethral sphincter
| External Urethral Sphincter
201
Involuntary urethra sphincter?
Internal
202
Voluntary urethral sphincter
External
203
Female urethra length and location
3-4cm (1 in)
| Along the wall of the vagina
204
Male urethra length and location
```
20 cm (8 in)
Through the prostate and penis
```
205
Females function of the urethra
Only carries urine
206
Males function of the urethra
Carries urine and is passageway for sperm cells
207
Normal amount of water in a young adult female
50%
208
Normal amount of water in a young adult male
60%
209
Normal amount of water in babies
75%
210
Normal amount of water in elderly
45%
211
Micturition
Voiding
212
What must happen to allow voiding
both sphincter muscles must relax
213
Describe voiding
The internal urethral sphincter is relaxed after stretching of the bladder
Activation is from an impulse sent to the spinal cord and then back via the pelvic splanchnic nerves
The external urethral sphincter must be voluntarily relaxed
214
Where is intracellular fluid
inside cells
215
Where is extracellular fluid
Outside cells
216
What are examples of extracellular fluid
interstitial fluid
| Blood plasma
217
Describe the link between water and salt
Changes in electrolyte balance causes water to move from one compartment to another
218
Describe maintenance of water balance
-water intake must equal water output
219
Sources for water instake
- ingested foods and fluids
| - water produces from metabolic processes
220
Sources of water output
- Vaporization out of the lungs
- lost in perspiration
- leaves the body in the feces
- urine production
221
If water intake is excessive...
Dilute urine is produced
222
If large amounts of water are lost....
Less urine (concentrated) is produced
223
Proper concentrations of various electrolytes....
must be present in urine
224
Regulation of water and electrolyte is primarily due to
```
Antidiuretic hormone (ADH) prevents excessive water loss in urine
Aldosterone regulates sodium ion content of extracellular fluid
```
225
Cells in the kidneys and hypothalamus are active monitors
water and electrolyte reabsorption
226
Blood pH must remain between....
7.35-7.45
227
pH too high
Alkalosis
228
pH too low
Acidosis
229
Most ions originate as....
Byproducts of cellular metabolism
230
Most acid-base balance is maintained by...
the kidneys
231
Blood buffers and respiration are
acid-base controlling systems
232
Describe blood buffers
Molecules react to prevent dramatic changes in hydrogen ion (H+) concentrations
Bind to H+ when pH drops
Release H+ when pH rises
233
Three major chemical blood buffer systems
Bicarbonate buffer system
Phosphate buffer system
Protein Buffer System
234
Describe renal mechanisms of Acid-base balance
Excrete bicarbonate ions if needed
Conserve or generate new bicarbonate ions if needed
Urine pH varies from 4.5 to 8.0
235
Functional kidneys are developed by...
month three
236
Urinary system of a newborn
bladder is small
| Urine cannot be concentrated
237
When does the control of the voluntary urethral sphincter start?
18 mos.
238
What are the only common issue with the urinary bladder before old age
UTI
239
Describe aging and the urinary sytem
There is a progressive decline in urinary function
The bladder shrinks with aging
Urinary retention is common in males
