Animal nutrition Flashcards
1
Q
five main processes in nutrition
A
- ingestion- the intake of food into the alimentary canal
- digestion- by chemical and mechanical digestion
- absorption- the end product absorbed into the blood steam
- assimilation- the cells absorbs the nutrients from the blood and uses it to build new cell structures and compounds
- egestion- undigested remains removed through the anus
2
Q
importance of food
A
- provides energy
- growth and repair of damaged tissues
- regulation of body processes
3
Q
consumers are divided into 3 groups
A
herbivores, carnivore and omnivores
4
Q
what is a food web
A
number of food chain that are interlinked
5
Q
how are the teeth of herbivores adapted for their survival
A
- incisors are broad and flattened for clipping blades
- molars and premolars are large and flat for grinding the grass
- diastema occurs between the incisors and premolars to enable the tongue to move around during chewing
- canines are absent. if present, the are short and used for protection
6
Q
how are teeth of carnivores adapted for their survival
A
- incisors are short and pointed to tear food into small pieces
- canines are long,curved and pointed to pierce and kill the prey
- molars are blade shaped , sharp and jaggared
7
Q
how are teeth of omnivores adapted for their survival
A
- canines are long pointed and curved
* molars are blade shaped,sharp and flattened
8
Q
the digestive system is made up of 2 parts
A
the alimentary canal and the associated organs
9
Q
which parts make up the alimentary canal
A
- mouth and the mouth cavity
- pharynx
- esophagus
- stomach
- small intestine
- large intestine
- anus
10
Q
what makes up the mouth cavity
A
- 2 lips in front
- tongue and teeth of lower aw making up the floor of the mouth cavity
- palate and teeth of upper jaw making up the roof
- a mucus membrane made up of epithelial connective tissue
11
Q
define the pharynx
A
it is the area where the nasal passage and the alimentary canal intersect each other
- it serves both the alimentary canal and the respiratory tract
12
Q
how is the pharynx adapted to suit its function
A
- the trachea has an opening called the glottis
- the pharynx leads to the respiratory tract via the glottis with a covering called the epiglottis
- when swallowing occurs, the glottis is called by the epiglottis preventing food from going down the trachea
- this prevents choking
13
Q
the esophagus
A
- it is a long muscular tube that lies behind the trachea leading from the pharynx to the stomach
14
Q
the stomach
A
it is a sac like organ with thick muscular walls located in the abdominal cavity below the diaphragm
15
Q
cardiac sphincter valve
A
the valve between the stomach and the esophagus
16
Q
pyloric sphincter valve
A
the valve between the stomach and the small intestine
17
Q
describe the small intestine and gow it is adapted to suit its fuction in details
A
- it is a long muscular tube(2,5-4,5 m) that is made up of 3 parts
- the 3 parts are the duodenum, the jejunum and the ileum
- the HEPATIC-PANCREATIC DUCT opens into the duodenum, the first part of the digestive system
- jejunum is a small tube found between the duodenum and the ileum
- ileum is the last and longest part of the small intestine
- the wall of the small intestine are made up of 4 layers :the serosa, muscle layer, submucosa and mucosa
- the mucosa is a columnar epithelium tissue with goblet cell and villi
- the goblet cells secret mucus and the villi increase the absorption surface area of digestive food
- the Cripst of Lieberkuhn and the Brunner Glands secrete an alkali mucus protecting the small intestine from stomach acids burns
- the peristalsis movements helps the food to move along the small intestine and ensure that the food is thoroughly mixed with the digestive juices
18
Q
explain the 4 wall layers of the small intestine
A
- serosa- outer most layer
- muscular layer- made up of an outer layer of longitudinal muscle and an inner layer of circular muscle
- sub-mucosa -made up of connective tissues that include blood vessels, lymph vessels and nerves
- mucosa- the inner most layer that is lines by columnar epithelium with goblet cells and villi
- goblet cells secrets mucus while the villi increases absorption surface area
19
Q
Cripst of Lieberkuhn
A
located between the villi
20
Q
Brunner glands
A
special compound glands located between the villi of the duodenum
21
Q
function of the mucus in the small intestine
A
- serves as lubricant , allowing for the easy movement of food along the small intestine
- it also protects the lining of the small intestine from the acidic chyme coming from the stomach
22
Q
describe the large intestine
A
- made up of 3 parts,the Caecum ,the Colon and the rectum
- the caecum is the first part of the large intestine that is a sac-like portion into which the ileum opens into
- the appendix is attached to the caecum
- the colon is the second part and is also made up of 3 parts: the ascending colon, the transverse con, the descending colon
- the rectum is the last past . It opens to the outside via the anus
23
Q
the Hepato-Pancreatic duct
A
Formed when the pancreatic duct joins the common bile duct
24
Q
the structure of the tongue
A
the tongue is a movable muscular organ attached at its back
25
the 5 functions of the tongue
1. it pushes the food between the teeth for chewing
2. helps in mixing food with saliva
3. it assists in forming the food into a bolus
4. helps in swallowing
5. it has taste buds that serves at taste organs
26
the number of teeth adults have
32
27
what are the 4 types of teeth
* incisors
* canines
* premolars
* molars
28
the dental teeth formulae
- tells us the number and type of teeth in 1 half of each jaw
- 2.1.2.3/2.1.2.3
29
how to calculate the total number of teeth in humans
(2+1+2+3) x4
| multiply one row by 4 after adding them together
30
the number of pointed cups in premolars
2
31
the number of pointed cups in molars
3-5
32
the 3 types of salivary glands
1. parotid salivary glands (below the ear)
2. sub-mandibular salivary glands (in the lower jaw)
3. sublingual salivary glands(under the tongue)
33
why are salivary glands called exocrine glands
it is because their secretion are carried by ducts
34
what do salivary glands secrete
salivia
35
describe the pancreas
it is a tongue shaped gland located below the stomach
36
the 2 type of cells the pancreas is composed of
1. pancreatic cells
| 2. the islet of Langerhans
37
normal pancreatic cells
they secrete the pancreatic juice[ a type of digestive juice]
38
the islets of Langerhans
- they are specialized cells that are found amoung the pancreatic cells
- they secrete 2 hormones: insulin and glucagon
39
the islets of Langerhans
- they are specialized cells that are found among the pancreatic cells
- they secrete 2 hormones: insulin and glucagon
40
why are the islets of Langerhans endocrine
they secrete insulin and glucagon directly into he blood stream
41
the function of the pancreas
1. secretes pancreatic juice with enzymes which play a role in digestion
2. secrete insulin and glucagon which controls the blood glucose levels in the body
42
the liver
the largest gland in the body that ism located under the diaphragm
43
the number of lobes a liver has
2 lobes
| the large right lobe and small left lobe
44
liver cells
formed from tiny lobules in each liver lobe
45
bile
Bile is produced by
46
what do liver cells produce
Bile.
| it is the transported away from the liver via the common hepatic duct
47
the common bile duct
formed when the common hepatic duct and the cystic duct join
48
what are the functions of the liver
* produces bile
* converts glucose into glycogen
* stores excess glycogen as fats
* de-amination occurs when the liver breaks down excess amino acids into urea and glucose
* acts as a detoxifying organ that absorbs and neutralizes certain toxins
* stores minerals like Fe and imp. vitamins like K,D,E,
* liver synthesizes heparin which prevents blood clotting
49
the gall bladder
- it is a muscular sac located below the liver lobes
| - it contracts to release bile into the cystic duct when it is stimulated
50
the function of the gall bladder
it stores and releases bile that is produced in the liver
51
describe bile in details
* it is a yellow green liquid that alkali and has enzyme
* secreted by the liver cells stored in the gall bladder
* when needed...the bile is transported by the common bile duct
52
functions of the bile
1. the water in the bile keeps the food fluid enabling easy movement along the alimentary canal
2. the bile salts neutralize the acid food coming from the stomach
3. they also break up the fatty into tiny droplets. this increases the surface area for enzymes action
4. bile salts helps in the absorption of fats and fat soluble vitamin D,E,A and k
5. bile prevents the decomposition of food in the alimentary canal because it is antiseptic
53
2 types of digestion
mechanical digestion and chemical digestion
54
mechanical digestion
it is a physical process that food is broken down into smaller particles
55
explain what happens during mechanical digestion
* mastication-food is broken down into smaller particles by teeth and tongue
* bolus forming- the chewed food mixed with saliva and rolled into a bolus using the tongue. the tongue pushes the bolus through the pharynx
* churning movements- these takes place by contracting and relaxing the muscles of the stomach wall
* peristaltic movements- a rhythmic contraction and relaxation of the muscles in the wall of the alimentary canal
56
chemical digestion
it is the breaking down of large insoluble food into smaller, soluble molecules using enzymes by addition of water
57
what is the catalyst chemical digestion reaction known as
hydrolysis
58
what is an enzyme
it is a biological catalyst that accelerates a chemical reaction by lowering the activation energy without being changed by the reaction
59
the role of water during digestion
- acts as a lubricant and facilitates the chewing and swallowing
- acts as a solvent for the digested food
- transports digested food
- it is a medium in which digestion occurs in
- the reagent for hydrolysis
60
where does most absorption take place
small intestine
61
how is the small intestine structurally adapted for maximum absorption
+ the length of the small intestine ensures the food remains for long periods,allowing enough time for maximum absorption
+ the transverse folds and a millions of villi in the mucosa of the wall of the small intestine , increase the absorption surfaces
+ the soluble nutrient are mainly absorbed in the villi
+ the villus is structurally adapted for efficient absorption of nutrients
62
how is the villus is structurally adapted for efficient absorption of nutrients
* the columnar epithelium is one cell layer thick for easy and fast diffusion
* it is richly supplied with blood capillaries for the absorption of glucose, amino acids, vitamins and mineral salts and water
* has a central lacteal for the absorption of fats
* goblet cells in the columnar epithelium secrete mucus , a medium in which nutrients can dissolve
* columnar epithelium has many mitochondria which provides energy for active transport
* micro-villi increase the absorption surface
63
active transport
requires a lot of energy and often is a carrier of molecules as it occurs against the concentration gradient
64
passive transport
occurs spontaneously and does not require energy as it occurs down the concentration gradient
65
open the summary table for absorption
study it know
66
how are vitamins and minerals transported
amino acids and glucose are absorbed into blood capillaries of the villi in the small intestine > capillaries join together to form large venules that forms hepatic portal vein, which transports amino acids and glucose to the liver > glucose and amino acids flows through hepatic vein to the heart > the liver converts excess glucose to glycogen and stores it > excess amino acids are de-aminated by the liver to form urea and are removed from the body
67
what is assimilation
it is the corporation of a absorbed nutrients into the cells of the body for building compounds and cell structures from the blood
68
what happens during the assimilation process
- the liver plays a vital role in the assimilation of nutrients
- the liver is responsible for the metabolism of glucose, de-amination of amino acids, the break down of alcohol ,drugs and hormones
69
what occurs during the process egestion
- large amounts of water are absorbed from from the semi-solid waste in the colon which reduces the liquidity of the content
- the undigested and indigestible waste(faeces) are temporarily stored in the rectum
- defecation is the process where muscle contraction of the rectum and relaxation of the circular muscle of the anus cause faeces to be expelled to the outside
