Unit 5 Lec S Flashcards
(164 cards)
1
Q
What is the function of the Human Digestive System?
A
Food Processing
The digestive system processes food to extract nutrients and energy.
2
Q
What characteristic does the Digestive System have in numerous organs?
A
Form that MAXIMIZES Surface Area
This characteristic increases the amount of diffusion that occurs.
3
Q
Is the Stomach responsible for the most amount of Digestion in the body?
A
No
4
Q
Is the Small Intestine responsible for the most amount of Digestion in the body?
A
Yes
5
Q
What three general anatomical features give the Small Intestine a large Surface Area?
A
- Extreme length and folds
- Villi projections of tissue layers
- Microvilli
6
Q
What dietary mode do Humans utilize?
A
Omnivore
7
Q
What three things must be acquired in a Nutritional Diet?
A
- Energy
- Atoms (to build molecules)
- Essential Nutrients (i.e. things we can’t build)
8
Q
What are Essential Amino Acids?
A
Amino acids that cannot be synthesized by the body
Diets that can risk deficiencies include vegetarian or vegan diets.
9
Q
What are Essential Fatty Acids?
A
Fatty acids that must be obtained from the diet
Deficiencies in these are not common.
10
Q
What are Essential Vitamins?
A
Organic compounds required for various bodily functions
Examples include Vitamin C, Vitamin D, and B vitamins.
11
Q
What are Essential Minerals?
A
Inorganic elements necessary for health
Examples include calcium, iron, and potassium.
12
Q
How does Chemical Digestion work at the molecular level?
A
Breaking bonds
13
Q
What two classes of organs makeup the Digestive System?
A
- Digestive Organs
- Accessory Organs
14
Q
What are the SIX general processes performed by the Digestive System?
A
- Ingestion
- Mechanical Digestion/Breakdown
- Chemical Digestion
- Propulsion
- Absorption
- Defecation
15
Q
What additional process is sometimes included in the functions of the Digestive System?
A
Secretion (of Mucus, Enzymes, etc.)
16
Q
What is the Enteric Nervous System?
A
A complex network of neurons that governs the function of the gastrointestinal system
It operates independently but also interacts with the central nervous system.
17
Q
How are the Ganglia in the Enteric Nervous System arranged?
A
In Enteric Plexuses
These plexuses are located between the layers of the gastrointestinal tract.
18
Q
What are Short-Reflexes?
A
Reflexes that are internal to the Digestive System
They involve local circuits within the Enteric Nervous System.
19
Q
What are Long-Reflexes?
A
Reflexes that are external to the Digestive System
They involve the central nervous system and can affect distant parts of the body.
20
Q
What are the effectors of the Enteric Nervous System?
A
Glands and Smooth Muscle
These effectors execute the responses initiated by the Enteric Nervous System.
21
Q
What general functions of the Digestive System are performed in the Oral Cavity?
A
Ingestion, Mechanical Digestion/Breakdown, Chemical Digestion, Propulsion
These functions prepare food for further digestion and absorption.
22
Q
Why does the Oral Cavity have thick squamous epithelia?
A
To protect against abrasion from food
This structure helps in withstanding mechanical forces during eating.
23
Q
What is Keratin?
A
A protein that provides strength and protection in epithelial cells
In the Oral Cavity, it helps protect against physical damage.
24
Q
What are the roles of Saliva?
A
Moistening food, chemical digestion, and oral hygiene
Saliva contains enzymes and antimicrobial agents.
25
What is in Saliva?
Water, electrolytes, enzymes, and antimicrobial substances
## Footnote
Salivary components facilitate digestion and protect oral health.
26
Where is Saliva produced?
In salivary glands
## Footnote
Major salivary glands include parotid, submandibular, and sublingual glands.
27
What is Salivary Amylase?
An enzyme that breaks down starches into sugars
## Footnote
It initiates the process of carbohydrate digestion in the mouth.
28
Where is Salivary Amylase produced?
In the salivary glands
## Footnote
It is secreted into the oral cavity during the process of eating.
29
What are the roles of the Tongue?
Taste, manipulation of food, and aiding in swallowing
## Footnote
The tongue also plays a role in speech.
30
What type of dentition do Humans have?
Heterodont dentition
## Footnote
This means humans have different types of teeth for different functions.
31
What is Enamel?
The hard, outer layer of a tooth
## Footnote
Enamel is not capable of being replaced once damaged.
32
What is Dentin?
The layer beneath enamel that forms the bulk of the tooth
## Footnote
Dentin can regenerate to some extent and contains odontoblasts.
33
What are Odontoblasts?
Cells that produce dentin
## Footnote
They are located at the boundary between the dentin and the pulp.
34
Identify the structure: Mouth.
The opening through which food enters the digestive system
## Footnote
It is involved in ingestion and initial digestion.
35
Identify the structure: Gingiva.
Gum tissue surrounding the teeth
## Footnote
It provides support and protection to the teeth.
36
Identify the structure: Teeth.
Hard structures used for biting and chewing food
## Footnote
Different types include incisors, canines, premolars, and molars.
37
Identify the structure: Hard Palate.
The bony front part of the roof of the mouth
## Footnote
It separates the oral cavity from the nasal cavity.
38
Identify the structure: Soft Palate / Uvula.
The soft tissue at the back of the roof of the mouth
## Footnote
It aids in swallowing and speech.
39
Identify the structure: Palatine Tonsil.
Lymphoid tissue located on both sides of the throat
## Footnote
It plays a role in the immune response.
40
Identify the structure: Parotid Gland.
The largest salivary gland located near the ear
## Footnote
It produces saliva rich in amylase.
41
Identify the structure: Sublingual Gland.
A salivary gland located under the tongue
## Footnote
It produces a mucous type of saliva.
42
Identify the structure: Submandibular Gland.
A salivary gland located beneath the jaw
## Footnote
It produces both serous and mucous saliva.
43
Identify the structure: Filiform Papilla.
Small, cone-shaped projections on the tongue
## Footnote
They provide texture and help with the mechanical aspect of taste.
44
Identify the structure: Fungiform Papilla.
Mushroom-shaped projections on the tongue
## Footnote
They contain taste buds and are involved in the sense of taste.
45
Identify the structure: Vallate Papilla.
Large, dome-shaped projections at the back of the tongue
## Footnote
They house numerous taste buds.
46
Identify the structure: Foliate Papilla.
Folds of tissue on the sides of the tongue
## Footnote
They are involved in taste sensation.
47
Identify the structure: Lingual Tonsil.
Lymphoid tissue located at the base of the tongue
## Footnote
It plays a role in immune function.
48
What act of Propulsion does the Cephalic Phase end with?
Swallowing
49
Does Swallowing involve Voluntary or Involuntary Muscles?
Both
50
What type of muscle controls the Voluntary part of Swallowing?
Skeletal
51
What type of muscle controls the Involuntary part of Swallowing?
Smooth
52
Do Long-Reflexes or Short-Reflexes control the Voluntary part of Swallowing?
Long-Reflexes
53
Do Long-Reflexes or Short-Reflexes control the Involuntary part of Swallowing?
Short-Reflexes
54
What is Smooth Muscle?
Muscle typically arranged in two perpendicular layers: Longitudinal and Circular
55
How do the PERPENDICULAR layers work in Smooth Muscle to conduct Propulsion?
They contract alternately to create wave-like motion
56
What is Peristalsis?
Wave-like forward motion used for moving food through the digestive tract
57
What layers work in Peristalsis?
Circular & Longitudinal
58
What is Segmentation?
Mechanical digestion/mixing process in the digestive tract
59
What layers work in Segmentation?
Circular ONLY
60
What are the two types of CONTRACTIONS that Smooth Muscle can perform?
* Long-lasting Tonic Contractions * Short-acting Phasic Contractions
61
What are the Interstitial Cells of Cajal (ICCs)?
Pacemaker Cells for Smooth Muscle CONTRACTION
62
Where are the Interstitial Cells of Cajal (ICCs) located?
In the Myenteric Plexus
63
Where is the Myenteric Plexus located?
Between Circular and Longitudinal Layer
64
What connects ICCs and Smooth Muscle Cells?
Gap Junctions
65
How are Smooth Muscle Cells different than Skeletal Muscle Cells?
Lack striations, have dense bodies, gap junctions, no T-tubules, varicosities
66
What are the general steps of Swallowing?
Buccal Phase, Involuntary Phase
67
What is the Buccal (Voluntary) Phase?
The initial phase of swallowing initiated by the tongue
68
What is the Involuntary Phase?
Phase that brings food down the Esophagus through reflex actions
69
What Propulsion brings food down the Esophagus?
Peristalsis, Phasic Contraction
70
What Propulsion allows food into the Stomach?
Sphincter, Tonic Contraction
71
What general functions of the Digestive System are performed in the Stomach?
Mechanical Breakdown, Chemical Digestion, Propulsion
## Footnote
No Absorption occurs in the Stomach.
72
What is another function of the Stomach?
Storage
73
What is the Fundus?
The upper part of the Stomach
74
What do the Cardia/Gastroesophageal Sphincter and Pyloric Sphincter do?
Control the entry and exit of food in the Stomach
75
What is the primary Chemical Digestion enzyme in the Stomach?
Pepsin
76
What type of molecule is broken down by Pepsin?
Proteins
77
What is the pH level of the Stomach?
pH = ~2
78
How is the Muscularis Externa different in the Stomach?
Contains an Oblique Muscle Layer
79
What is the function of the Oblique Muscle Layer?
Extra Mechanical Digestion
80
What are Gastric Pits and Gastric Glands?
Structures in the Stomach that contain specialized cells
81
What do Parietal Cells do?
Secrete H+ and Cl- to make HCl acid
82
What do Chief Cells do?
Secrete Pepsin precursor, Pepsinogen
83
What do Mucous Cells do?
Secrete Mucus
84
What do Enteroendocrine Cells (G-Cells) do?
Secrete Gastrin
85
What is Gastrin?
Hormone secreted by the Stomach and other organs
86
What is the Ileocecal Valve?
A valve that regulates the flow from the small intestine to the large intestine
87
How does Gastrin get to the Ileocecal Valve?
Through the bloodstream
88
What does Gastrin make the Ileocecal Valve do?
Regulates the passage of chyme
89
What does Gastrin stimulate in regard to pH?
Stimulates Parietal Cells to make HCl
90
What hormones act to slow down Stomach Emptying?
Secretin and CCK
91
What is Bile?
A digestive fluid that helps break down fats
92
What type of macromolecules does Bile break down?
Fats
93
Where is Bile produced?
Liver
94
Where is Bile stored?
Gallbladder
95
What role does Bile play in breaking down 'Fatty Meals'?
Emulsifies fats for easier digestion
96
What signals are involved in the process of bile secretion?
Hormones like CCK and Secretin
97
What is the role of the Vagus Nerve?
Facilitates Basal Responses to food in Duodenum
98
What stimulates Secretin release from the Duodenum?
Acidic Chyme
99
What stimulates CCK release from the Duodenum?
Fatty Acids
100
What does Secretin stimulate?
Pancreatic Duct Cells to make Bicarbonate
101
What does CCK stimulate?
Pancreatic Acinar Cells to make Lipase
102
Increased Bile Salts in the blood stimulate what?
Hepatocytes to produce more Bile
103
How do high levels of CCK affect the Gallbladder?
Cause stronger contractions
104
How do high levels of CCK affect the Duodenal Ampulla?
Relax the Sphincter
105
What is the overall purpose of these physiological processes?
Regulate physiology to adapt to a HIGH-FAT Meal
106
Once the 'Fatty Meal' is broken down, what can continue?
Stomach Clearing
107
What general functions of the Digestive System are performed in the Small Intestine?
Chemical Digestion, Absorption, Propulsion, Mechanical Breakdown
## Footnote
These functions are crucial for processing food and nutrients.
108
Is the Small Intestine the primary organ for both Absorption AND Digestion?
Yes
## Footnote
The Small Intestine plays a critical role in both breaking down food and absorbing nutrients.
109
What are the three regions of the Small Intestine?
Duodenum, Jejunum, Ileum
## Footnote
Each region has distinct functions in digestion and absorption.
110
Which section of the Small Intestine receives enzymes from Accessory Organs?
Duodenum
## Footnote
The Duodenum is the first section and plays a major role in mixing digestive juices.
111
What is the 'Brush Border'?
Microvilli on enterocytes that increase surface area for absorption
## Footnote
The Brush Border is essential for maximizing nutrient absorption.
112
What morphological features make the Brush Border good at Absorption?
Microvilli increase surface area
## Footnote
This adaptation allows for more efficient nutrient uptake.
113
What is the difference between Circular Folds, Villi and Microvilli?
Circular Folds are large folds, Villi are finger-like projections, Microvilli are tiny projections on epithelial cells
## Footnote
Each structure enhances the absorptive capacity of the Small Intestine.
114
What are Intestinal/Mucosal Glands?
Glands in the Mucosa that secrete Mucus
## Footnote
These glands help lubricate and protect the intestinal lining.
115
What are Duodenal/Brunner's Glands?
Glands in the Submucosa that secrete Mucus
## Footnote
They play a protective role in the Duodenum by neutralizing stomach acid.
116
What are Peyer's Patches?
Mucus Associate Lymphatic Tissue (MALT) located in the Ileum that plays a role in immunity
## Footnote
They help monitor intestinal bacteria and prevent pathogenic growth.
117
What are the steps associated with Glucose Absorption in the Small Intestine?
1. Pancreatic Amylase breaks down starches to disaccharides 2. Brush Border Enzymes convert disaccharides to monosaccharides 3. Glucose is absorbed into enterocytes
## Footnote
This process is essential for providing energy to the body.
118
How is Pancreatic Amylase involved in Glucose Absorption?
Converts starches to disaccharides
## Footnote
This enzyme initiates the breakdown of carbohydrates.
119
How are Brush Border Enzymes involved in Glucose Absorption?
Convert disaccharides to monosaccharides
## Footnote
This conversion is necessary for glucose absorption.
120
What is Glucose Absorption into Enterocytes 'coupled' to?
Diffusion of Na+ into the enterocyte
## Footnote
This coupling is important for actively concentrating glucose in the cell.
121
How is the Na+ gradient maintained for Na+ Diffusion?
Na+/K+ Pump
## Footnote
This pump actively transports sodium out of the cell to maintain the gradient.
122
When does Glucose undergo Diffusion?
High to Low Gradient into Blood
## Footnote
This process allows glucose to enter the bloodstream efficiently.
123
What is the Ileocecal Valve, and how is it opened?
A sphincter that relaxes from reflex due to stretch receptors in the Stomach and gastrin hormone
## Footnote
This mechanism regulates the flow of material from the Small Intestine to the Large Intestine.
124
What molecule does the Large Intestine absorb in large quantities?
H2O
## Footnote
Water absorption is crucial for maintaining hydration and electrolyte balance.
125
What are the roles of the Cecum?
Fermentation and Absorption
## Footnote
The Cecum aids in the digestion of fibrous materials.
126
What do symbiotic bacteria in the Large Intestine do?
Fermentation
## Footnote
These bacteria break down undigested carbohydrates and produce short-chain fatty acids.
127
Why are bacteria in the Digestive System important?
Fats, Vitamins, Plant Material
## Footnote
They assist in digesting complex nutrients and synthesizing certain vitamins.
128
Does the Immune System need to 'regulate' symbiotic bacteria in the GI-Tract?
Yes
## Footnote
Regulation is necessary to prevent overgrowth of harmful bacteria.
129
What is the role of the Appendix?
Unknown, but may play a role in immune function
## Footnote
The Appendix is thought to serve as a reservoir for beneficial gut bacteria.
130
What are the roles of the remaining parts of the Large intestine, i.e., colon?
Fermentation, Absorption Plant Material, Absorption Vitamins, Absorption Water
## Footnote
The colon is essential for processing waste and recovering nutrients.
131
What is a Gene?
A segment of DNA that encodes a functional product, typically a protein
## Footnote
Genes are the basic units of heredity.
132
What is an Allele?
Different versions of a gene that can exist at a particular locus
## Footnote
Alleles can be dominant or recessive.
133
What is a Chromosome?
A structure composed of DNA and proteins that carries genetic information
## Footnote
Chromosomes are found in the nucleus of eukaryotic cells.
134
What does it mean to be Diploid?
Having two complete sets of chromosomes, one from each parent
## Footnote
Diploid cells are represented as 2n.
135
What does it mean to be Haploid?
Having one complete set of chromosomes
## Footnote
Haploid cells are represented as n.
136
What are Homologous Chromosomes?
Chromosome pairs, one from each parent, that are similar in shape, size, and genetic content
## Footnote
Homologous chromosomes carry the same genes but may have different alleles.
137
Do Diploids or Haploids have Homologous Chromosomes?
Diploids
## Footnote
Haploid cells do not have homologous pairs.
138
Are most cells in the body Diploid?
Yes
## Footnote
Somatic cells are typically diploid.
139
Are sex-cells, i.e. gametes Haploid?
Yes
## Footnote
Gametes include sperm and eggs.
140
How many Autosomal chromosome pairs do humans have?
22
## Footnote
Autosomes are non-sex chromosomes.
141
How many Sex Chromosome pairs do humans have?
1
## Footnote
The sex chromosomes determine an individual's sex.
142
What are Sex Chromosomes?
Chromosomes that determine the sex of an individual
## Footnote
In humans, these are X and Y chromosomes.
143
Why are Sex Chromosomes important?
They determine the biological sex and influence sexual development
## Footnote
They carry genes important for sex differentiation.
144
What combination of Sex Chromosomes determine Male Sex?
XY
## Footnote
Males typically have one X and one Y chromosome.
145
What combination of Sex Chromosomes determine Female Sex?
XX
## Footnote
Females typically have two X chromosomes.
146
What is the SRY Gene?
A gene located on the Y chromosome that triggers male sex determination
## Footnote
SRY stands for Sex-determining Region Y.
147
In Males, do the X and Y behave like Homologous Chromosomes in Meiosis?
Yes
## Footnote
They pair during meiosis despite being different in structure.
148
Sex is determined by the gametes of which parent?
Father
## Footnote
The father's sperm determines the sex of the offspring.
149
Do you need at least one X Chromosome to survive/live, in general?
Yes
## Footnote
An X chromosome is essential for normal development.
150
Do you need at least one Y Chromosome to survive/live, in general?
No
## Footnote
Females can survive without a Y chromosome.
151
What is nondisjunction?
The failure of homologous chromosomes or sister chromatids to separate properly during cell division
## Footnote
This can lead to aneuploidy.
152
What disorders can nondisjunction result in?
Down syndrome, Turner syndrome, Klinefelter syndrome
## Footnote
These are examples of chromosomal abnormalities.
153
Describe how gene dosage is handled in XX-females.
Through the formation of Barr Bodies
## Footnote
One X chromosome is inactivated to balance gene dosage.
154
How can Sex-Linked genes in XX-females express in 'mosaic' patterns?
Due to X-inactivation, where different cells express different alleles of the X chromosomes
## Footnote
This leads to a mix of phenotypes in females.
155
At what stage of Embryonic Development is the 'Sex Indifference Stage'?
5-weeks
## Footnote
This is the period before sexual differentiation occurs.
156
What is the 'default' developmental state?
XX
## Footnote
This is the typical pathway for female development.
157
What are Gonads?
Organs that produce gametes; ovaries in females and testes in males
## Footnote
Gonads also produce sex hormones.
158
What are Mullerian Ducts?
Structures that can develop into female reproductive organs
## Footnote
They are present in both male and female embryos initially.
159
What are Wolffian Ducts?
Structures that can develop into male reproductive organs
## Footnote
They are also present in both sexes during early development.
160
Generally, how does the SRY Gene operate to 'activate' Male Development?
By initiating the formation of testes, which produce male hormones
## Footnote
This leads to the development of male characteristics.
161
What is Testes Determining Factor (TDF)?
A protein encoded by the SRY gene that triggers male sex differentiation
## Footnote
TDF promotes the development of male gonads.
162
How do Sertoli Cells and Leydig Cells influence Male Development?
Sertoli cells support spermatogenesis, and Leydig cells produce testosterone
## Footnote
Both cell types are crucial for male reproductive development.
163
What hormones do Sertoli Cells and Leydig Cells secrete during Male Development?
Sertoli cells secrete inhibin and Leydig cells secrete testosterone
## Footnote
These hormones play key roles in male reproductive function.
164
What common structures develop into Male and Female Sex Organs during development, depending on the presence or absence of Testosterone?
Gonads and genital ducts
## Footnote
Testosterone influences the differentiation of these structures.
