Digestive System Flashcards
(125 cards)
1
Q
How does the cardiac sphincter differ in rabbits and horses
A
90degree angle to stomach so can’t through up
2
Q
Digestive enzyme produced in stomach
A
Pepsin
3
Q
Species that don’t have a gall bladder and why
A
Horses
gall bladder produces bile to breakdown carbs but horse dont eat carbs
4
Q
Name the 2 ducts that form the common bile duct
A
Hepatic duct and cystic duct
5
Q
Where does common bile duct enter digestive tract
A
First merges with pancreatic duct then enters the duodenum
6
Q
Role if Caecum
A
Breaks down fibre. All true herbivores have this
7
Q
Where in the abdomen would you find the caecum
A
Caudal aspect of abdomen
8
Q
Caecotroph
A
Species that eats its faeces (rabbits)
Reabsorb nutrients
9
Q
Which vessels and organs transport blood around the body
A
Arteries
Veins
Capillaries
The heart
10
Q
Digestive system also known as
A
Gastrointestinal system
Extracts nutrients from our food and excretes waste
11
Q
5 stages of digestion
A
Ingestion
Digestion
Absorption
Metabolism
Excretion
12
Q
Ingestion
A
Taking food into body via mouth
13
Q
Digestion
A
Breaking food down by contracting stomach/small intestine
Mechanical = physically breakdown (teeth/mouth/stomach)
Chemical = digestive juice/acid (stomach and SI)
14
Q
Absorption
A
Nutrients pass into blood (small intestine)
15
Q
Metabolism
A
Nutrients converted into energy (liver)
every cell in the body creates energy
16
Q
Excretion
A
Getting rid of waste via anus, rectum, kidneys
17
Q
3 major nutrients of food
A
Proteins
Carbohydrate
Lipids/fats
18
Q
Proteases
A
Enzyme that breaks down proteins into amino acids
19
Q
Amylase
A
Enzyme breaks down carbohydrates into simple sugars (monosaccharides)
20
Q
Lipases
A
Enzyme breaks down lipids into fatty acids (unsaturated and saturated fats)
21
Q
Main organ parts of digestive system
A
Oral cavity (mouth)
Pharynx
Oesophagus
Stomach
SI
LI
22
Q
Accessory glands of digestive system
A
Salivary glands
Pancreas
Liver (gall bladder)
23
Q
Oral cavity role
A
To pick up food break it down (masticate/chew) lubricate with saliva
24
Q
Which bones of the skull form the oral cavity
A
Mandible bone
Incisive bone
Palatine bone
Maxilla bone
25
Enamel
Top surface of tooth
Harder than bone
26
Crown of tooth
Exposed part of tooth covered in enamel for protection
27
Gingiva
The gums
28
Dentin
Surround pulp cavity softer than enamel
29
Neck
Part of the tooth sat under gum/gingiva line
30
Root
Embedded in bone
31
Cementum
Calcified mineralised tissue layer covering root of tooth which sits inside the gum socket
32
Pulp cavity
Contains blood vessels and nerves
33
Periodontal ligament
Keeps roots in bone
34
How many teeth do dogs have
42
12 incisors 6 top + bottom
4 canine 2 top + bottom
16 premolars 8 top + bottom
10 molars 4 top + 6 bottom
35
Carnassial tooth in dogs
Upper 4th premolar and lower 1st molar
36
How many teeth does cat have
30
12 incisors 6 top + bottom
4 canine 2 top + bottom
10 premolars 6 top + 4 bottom
4 molars 2 top + bottom
37
Cats carnassial tooth
Upper 3rd premolar and lower 1st molar
38
How many teeth does horse have
36-42 days teeth depending on age and sex
12 incisors 6 top + bottom
4 canines 2 top + bottom (males)
12 premolars 6 top + bottom
12 molars 6 top + bottom
4 Wolf teeth not always present (pointless - sit infrint of pre molars)
39
Diastema
Gap between incisors and premolars
Where bit sits
40
Triadan system
How teeth are numbered
Dental charts
41
Small mammals teeth
Teeth continuously grow need wearing down with diet/chewing
Hamsters and chipmunks have well developed cheek pouches to store food
42
Check pouches
For storing food (hamsters and chipmunks)
43
Salivary glands
Paired glands that produce saliva
Ducts connect the glands to the oral cavity
Saliva contains amylases (digest carbs) EXCEPT CARNIVORES
44
Dog salivary glands
Zygomatic glands (x2) - only found in Carnivores
Sublingual gland
Partridge gland
Madibular gland
45
Degluition (action of swallowing)
Food is rolled into a bolus (mush) by tongue and cheeks
Pharyngeal muscles contract pushing bolus to oesophagus
Epiglottis closes to prevent food entering larynx
Peristalsis pushed food down oesophagus
Epiglottis opens once food has passed
46
What is the peristalsis
A simple tube lines with smooth muscle that carries food from oral cavity to stomach by contracting in a wave like manner to push the food down
47
Where is the perostalsis
It lies dorsal to the heart
Passes through the thorax through the diaphragm to enter abdominal cavity
48
How long does it take food to pass to stomach
15-30 seconds
49
How long does it take liquids to pass into stomach
Couple of seconds
50
Monogastric stomach anatomy
Sac like organ with smooth muscle walls located in the cranial abdomen
51
Role of the stomach
Break up food
Mechanically - stomach muscles contract
Chemically - gastric juices secreted by glands
52
Adaptations to the stomach
Folded walls to allow stomach to stretch when full known as rugae
Mucus and acid producing cells in the walls
53
How much can the stomach expand
Expands to 3rd of the size of the abdomen
54
Mucus membrane of the stomach
Folded into rugae and contains gastric pits
55
3 main cell types that gastric pits contain
Goblet cells
Parietal cells
Chief cells
56
Goblet cells
Secrete mucus to lubricate food and protect stomach wall from acid (auto digestion where stomach eats itself)
57
Parietal cells
Secrete hydrochloric acid (HCl)
Controlled by D and G cells
58
Chief cells
Secrete pepsinogen (precursor to the enzyme pepsin)
59
D cells
Secrete somatostatin which inhibits acid secretion
60
G cells
Secrete gastrin which stimulate acid secretion
61
pH of HCl
1.5 to 3.5
62
Gastric emptying times liquid and solid
Liquid 30mins
Solid 3 hours
63
Lower oesophageal/cardiac sphincter
Between the oesophagus and the stomach (oesophagus enters here)
There to stop food coming back up
In horses and rabbits it’s very well developed thick muscular ring
64
Fungus
The bulge at the top/cranial part of the stomach
65
Area to the opening of the stomach
Cardia
66
Body of stomach
Majority of the stomach
67
Pylorus
Area prior to the exit of the stomach
68
Pyloric antrum
Area prior to pylorus
69
Pyloric sphincter
Exit to the stomach comes after the pylorus (very sensitive to acid so opens when stomach is full)
When detects acid on small intestine side it will close
70
Margo plicatus
Visible line in horses stomach splitting the two sides
71
Top part of horse stomach
Nonglandular region lined with squamous epithelium
Doesn’t secret acid or mucus so not protected and prone to autodigestion leading to gastric ulcers (open sores)
Storage area for food
72
Bottom half of horses stomach
Glandular region lined with glandular epithelium
Secrets acid and mucus
Less prone to ulcers
Most digestion happens here
73
Duodenum
Beginning part of intestine
74
Birds digestive system components
Crop
Proventriculus
Ventriculus (gizzard)
Small intestine
Colon
Cloaca
75
Crop
Enlargement/pouch of the oesophagus
Stores food
Pigeons/doves can produce crop milk for young
76
2 stomach like structures of birds
Proventriculus (acid secreting stomach)
Ventriculus /gizzard - highly muscular (in seed eating birds) or sac like (raptors) to help grind food (stones)
77
Reflux in birds
When food moves between the 2 stomachs
78
Small intestine role
Enzymatic digestion and absorption
79
Small intestine parts
Duodenum - c shaped ring comes first
Jejunum - comes second
Ileum - empties into LI (first part is the caecum)
80
Epithelial lining of the small intestine
Folded into villi structures similar to stomach folds (rugae)
Finger like projections
81
What organs drain into the small intestine
Liver and spleen
82
What is inside the villus
Network of capillaries
A lacteal (lymphatic vessel)
83
Types of water soluble vitamins
Vitamin B
Vitamin C
These enter the blood
84
Types of fat soluble vitamins
Vitamin A
Vitamin D
Vitamin E
Vitamin K
These enter the lymph
85
What does the villus do
Absorbs the breakdown products of digestion
86
Which products go to the liver from the villus
Amino acids (proteins)
Simple sugars (carbs)
enter capillaries to the hepatic portal vein
87
Which products of digestion enter lymphatic system
Fatty acids (lipids) and fat soluble vitamins (too large to enter blood) get absorbed by the lacteal which merge with lymph the form ‘chyle’
88
Largest gland in the body
Liver (made up of lobes)
89
Where is the liver located
Right cranial abdomen caudal to diaphragm
90
What does the liver do
Energy store
Carbs, protein, fat metabolism
FORMING/STORING BILE
Destroys old rbc
Stores vitamins (A,D,K) and iron
DETOXIFICATION
91
What is the falciform ligament
Ligament running through centre of the liver is the remnants of the foetal citculation
92
Gall bladder role
Stores bile and empties into cystic duct combining with hepatic duct to form the common bile duct emptying into SI
HORSES DONT HAVE GALL BLADDER
93
Hepatic lobules
Hexagonal squares - cluster of cells
94
Hepatocytes
Liver cells usually displayed in rows of
95
Carbohydrate metabolism
Liver stores glucose as glycogen
96
Protein metabolism
Formation of blood proteins (albumin and blood clotting proteins)
Regulating amino acids (protein building blocks)
Breaking down surplus amino acids from urea (waste product of protein metabolism
97
Fat metabolism
Breaking down fats and making useful products such as phospholipids for cell membranes
98
Forming and storing bile for digestion
Bile made up of Fats (including cholesterol)
Bile acids (bile salts)
bilirubin (breakdown product of rbc)
99
Bile emulsification
Bile salts break down large fats/lipids into smaller droplets and surrounds each droplet to increase surface area for lipase enzymes
100
What is the pancreas
An extrinsic gland (accessory gland that sits outside the normal GI tract)
A mixed gland due to 2 functions (exo and endocrine)
101
Exocrine function of pancreas
Secretes digestive enzymes/ pancreatic juices into small intestine (duodenum) via pancreatic duct
This is closer hence exocrine
102
Endocrine function of pancreas
Secretes hormones into the blood
Target organs are further away hence endocrine
103
Snakes pancreas
Spleen and pancreas fuse together to form splenopancreas to save space
104
What are the digestive enzymes released in pancreas
Bicarbonate (to neutralise acidity)
Proteases (trypsin) breakdown protein
Lipases (assisted and activated by bile) breakdown fat
Amylases break down carbs
105
Large intestine
Similar to SI but shorts in cats and dogs and wider in diameter
No villi
Produces more mucus than SI
Water soluble vitamins absorbed here (b and c)
106
What are the 3 parts of the Large intestine
Caecum - junction between ileum ( SI) and ascending colon (found in true herbivores no funtion in cats and dogs)
Colon (larger in horses as storing large faeces)
Rectum
107
Caecum
Full of bacteria breaking down complex carbs (fibre) from grass
108
Ascending colon starting from caecum
Right ventral
Sternal flexure
Left ventral
Pelvic flexure (food gets stuck here due to 360 twist)
Left dorsal
Diaphragmatic flexure
Right dorsal
109
Large colon parts
Ascending and transverse colon
110
Small colon parts
Just the descending colon
111
Small mammals digestive system
Rabbits are similar to horses but the tract allows rapid passage of food and elimination of fibre (short colon)
112
Coprophagia guinea pigs and chinchillas
Eat own faeces driectly from anus to obtain nutrients produced by microbial fermentation
They eat caecotrophs (soft pellets/faeces)
113
Birds digestive system
Short large intestine/colon
No caecum in most species (Parrots and pigeons) if it is, it is paired and elongated
114
Rectum
Feacal storage and compose of
Water and fibre
Bacteria
Intestinal cells
Mucus
Anal sac contents
Stercobilin (product of bilirubin breakdown)
115
Anus
Hole on outside where faces exit
116
Anal sac
Empty very close to anus and should do so every time they defecate due to pressure from stool
Easily infected as close to outside
117
Internal anal sphincter
Smooth muscle controlled by brain (involuntary)
118
External anal sphincter
Skeletal muscle animal controls (voluntary) and is attached to pelvis
119
Endocrine function of pancreas
Hormones produced by groups of cells in pancreas called “islets of langerhans” in response to blood glucose levels
120
What are the hormones secreted by the islets of langerhans
Insulin from beta cells
Glucagon from alpha cells
Somatostatin from delta cells
121
Regulation of blood glucose why
Glucose in blood needs to remain stable
Pancreatic hormones regulate levels
Glucose released increases levels (digestion)
When we haven’t eaten levels decrease
Homeostasis can’t be too high or too low
122
Somatostatin
Has a regulatory role inhibiting the release of glucagon and insulin
Stops wild fluctuations in blood glucose levels which could damage tissue
123
Regulation of blood glucose when eating
Blood sugar levels are high so
Pancreas releases hormone insulin which makes the cells take up sugar from the blood
The liver stores this sugar as glycogen (inactive form of glucose)
Reduces appetite (feeling full)
GLYCONEOGENESIS -creation of glycogen
124
Regulation of blood glucose between meals
Blood glucose is low
Pancreas releases glucagon hormone (opposite effect of insulin)
This makes the liver release stored glycogen and turns it back into glucose
Triggers hunger
GLUCONEOGENESIS - creation of glucagon
125
Range of glucose blood levels
4mmol/L to 6mmol/L
