Digestive system Flashcards

1
Q

The four digestive processes explained

A

Ingestion – The process of taking food into the body.

Digestion – The process of breaking down food into its component parts in the stomach and small intestine.

Absorption – Occurs in the small intestine and large intestine – the process of transferring nutrients from the intestine into the bloodstream.

Excretion – Removal of indigestible material as faeces.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Order of the digestive tract

A

Oral Cavity
Oropharynx
Oesophagus
Stomach
Duodenum
Jejunum
Ileum
Caecum
Colon
Rectum
Anus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Name the four accessory digestive structures

A

Salivary Glands,
Liver,
Gall Bladder,
Pancreas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Describe four functions of the oral cavity

A
  • Picking up food with the lips and tongue.
  • Chewing to break up food into smaller boluses to aid swallowing.
  • Lubrication of food with mucus and saliva.
  • Digestion of carbohydrates in the mouth by salivary amylase (omnivores and herbivores only).
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

six functions of the tongue

A
  • To aid ingestion
  • To carry receptors for taste
  • To form a bolus from food for swallowing
  • Grooming
  • Thermoregulation – flattening of the tongue and increased blood supply to the capillaries of the tongue allows saliva to evaporate and cooling of the body.
  • Vocalisation – complex movements of the tongue allow an animal to vocalise.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

The tongue is made of (1) allowing complex voluntary movement, with its root attached to the (2)

A

Striated muscle
Hyoid bone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

the membrane which covers the gums is known as

A

the gingival membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

incisor shape and function

A

small, chisel shaped with single root
Used for nibbling, cutting and grooming

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Canine shape and function

A

pointed, curved, single root
grasping, gripping and piercing prey

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Molar and pre molar

A

premolar<3>molar roots
Flatter surface with cusps
Shearing flesh with cusps,
flattened surfaces used for crushing and grinding.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

saliva - structure and source

A

consists of 99:1 water:mucus
produced in salivary glands

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

function of soft palate

A

divide the naso/oro-pharynx

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What system is the tonsil part of and what is its function

A

lymphatic system - protects the animal from disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

five steps of swallowing

A
  • Food is rolled into a bolus by the tongue and is passed to the back of the mouth.
  • The muscles of the pharynx contract, pushing the food bolus to the osophagus
  • The epiglottis closes, preventing food entering the larynx.
  • A wave of peristalsis pushes food down the osophagus.
  • The epiglottis opens allowing respiration to begin again.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Function and location of esophagus

A

The osophagus carries food from the pharynx to the stomach. It lies dorsal and slightly to the left of the trachea. As it passes through the thorax it runs through the mediastinum, dorsal to the heart and between the lungs.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

oesophogus structure

A

The osophagus is a tubular structure containing longitudinal and circular bands of smooth muscle. It is lined by stratified squamous epithelium.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

structure and location of stomach within body

A

The stomach is a c-shaped sac-like organ which lies on the left side of the abdomen. it lies caudal to the diaphragm and cranial to the liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

stucture of stomach wall (4)

A

The stomach wall is lined by mucosa and has deep folds called rugae.

Within the wall are gastric pits containing:
- Goblet cells which produce mucus to protect the stomach wall from acid and digestive enzymes

  • Chief cells which produce pepsinogen.
  • Parietal cells which produce gastric (hydrochloric) acid.
18
Q

three main functions of stomach

A
  • To act as a reservoir for foods.
  • To break up food and mix it with gastric juices
  • To begin protein digestion
19
Q

which movements take place within the stomach and their purpose

A
  • Peristalsis – to propel food material through the stomach
  • Rhythmic segmentation – to break up and mix food boluses.
20
Q

processes which occur in the small intestine

A

digestion and absorbtion

21
Q

The stomach breaks food down to a substance known as

A

Chyme

22
Q

Small intestine consists of 3 parts;

A

Duodenum, Jejunum and Ileum

23
Q

which structures empty into the first part of the small intestine

A

the pancreatic duct and the common bile duct

24
Q

Describe parts of the ileocaecocolic junction

A

The ileocaecocolic (or ileocaecal) junction, at which location the ileum, caecum and colon meet.

25
Q
  1. What is the function of the villi in the wall of the small intestine?
A

To improve efficiency of digestion and absorption of the nutrients from the small intestine by increasing the surface area.

26
Q

properties of intestinal villi which aid with absorption

A
  • Large Surface Area
  • Excellent blood supply from a network of internal capillaries
  • They have a thin layer of cells lining their wall
  • Surface area is further increased by the presence of microvilli on the surface of the epithelial cells lining the villi.
27
Q

Which two structures are located within the villi to transports absorbed substances

A
  • Capillary Network – absorb carbohydrates and proteins to relay them to the hepatic portal vein
  • Lacteal – to absorb fat in the form of chyle (the product of fat digestion) and relay it to the lymphatic system (specifically to the cisterna chyli).
28
Q
  1. Name and describe (in terms of function) the four structures which make up the large intestine
A
  • Caecum – a short blind ending tube. This is used for bacterial fermentation in hind-gut fermenting herbivores but has no significance in carnivores.
  • Colon – made up of the ascending, transverse and descending. Water, vitamins and electrolytes are absorbed here.
  • Rectum – found within the pelvic cavity, stores faeces before release.
  • Anal Sphincter – controls the passage of faeces out of the body.
29
Q

eight functions of liver

A
  • Metabolism of carbohydrates and storage of glycogen
  • Metabolism of proteins – including manufacture of plasma proteins, regulation of amino acids and production of urea from surplus amino acids.
  • Metabolism of fat
  • Bile formation which is subsequently stored in the gall bladder
  • Destruction of old red blood cells
  • Formation of new red blood cells
  • Storage of vitamins (mainly fat soluble ones)
  • Storage of iron
  • Production of heat for the body
  • Detoxification
30
Q

where is the pancreas located

A

within the ‘U’ of the duodenum

31
Q

function of bicarbonate

A

To neutralise the acid found in chyme.

32
Q

function of trypsinogen

A

A precursor to trypsin which is activated in the small intestine.

33
Q

function of typsin

A

Breaks down proteins and peptides into amino acids

34
Q

function of lipase

A

converts fats into fatty acids and glycerol

35
Q

function of amylase

A

breaks down starch into maltose

36
Q

explain the process of trypsin

A

Active trypsin is not normally present in the pancreas, instead, the enzyme precursor trypsinogen is found in the pancreas. Activation of trypsinogen to trypsin is prevented in the pancreas by a trypsin inhibitor.
Trypsin becomes activated once it reaches its destination; the small intestine

37
Q

where is bile made and stored

A

made in the liver and stored in gall bladder

38
Q

function of bile

A

emulsify fat globules (to increase surface area for lipase to act)

39
Q

function of mucus

A

Lubricates food and protects the stomach wall from auto-digestion.

40
Q

function of hydrochloric acid

A

Begins the breakdown of proteins and creates a low pH to facilitate digestion

41
Q

function of pepsinogen

A

A precursor to pepsin which is not active so prevents damage to the stomach wall, where it is produced

42
Q

pepsin function

A

Breaks down proteins into peptides (is activated from pepsinogen in the acidic environment of the stomach).