Gastrointestinal System (digestive)

Question 1

Nurients (6) and function

Answer 1

1. Salts
2. Carbs (-CHO): energy source
3. Proteins: build cells and tissues
4. Fats (energy + membrane formation), & Lipids (hormone production)
5. Vitamins
6. Minerals & Trace elements: used to help assemble structures e.g. bones + enzymes

Question 2

Structures (10)

Answer 2

1. Oral/Buccal Cavity
2. Throat
3. Oesphagus
4. Stomache
5. Duodenum
6. Pancreas
7. Jejunum + Illeum (small intestine)
8. Large Intestine
9. Rectum
10. Liver + Gallbladder

Question 3

Steps (5)

Answer 3

1. Ingestion
2. Mechanical Digestion
3. Chemical Digestion
4. Absorption
5. Egestion (waste removal)

Question 4

Parts of the oral cavity (4) + function

Answer 4

1. Teeth: mechanically break down food
2. Buccal-lining: non-keratinised stratified squamous epithelium helping to cope with frictional ware and kept moist via saliva
3. Tongue: has intristic (altering shape) and extrinstic muscles (altering position), taste buds
4. Salivary Glands: secrete saliva which clenses mouth, dissolves food chemicals (taste), moistens food so bolus can be formed, contains digestive enzymes

Question 5

Throat parts (2)

Answer 5

Oropharynx and larynopharynx

Question 6

Functions of throat

Answer 6

epithelium rich with mucous glands which smooth passageway for bolus, skeletal mucsles run longitudinally and circumferencly to propel food down oesphagus via. pharyngeal constriction

Question 7

oesphagus

Answer 7

a muscular tube running from throat through diaphragm (via oesphageal hiatus) to gastroespohageal sphincter where it meets the stomache

Question 8

muscle layers in oesphagus (5, in->out)

Answer 8

1. Epithelial
2. Mucosa: smooth muscle, connective tissue
3. Muscularis: skeletal muscle running vertically and circumferenly
4. Sub-mocosa: connective tissue
5. Serosa: connective tissue membrane

Question 9

Stomach muscle overiew structure

Answer 9

musclular sack made of 3 layers of muscle which can expand and contract in size

Question 10

tissue type in stomache

Answer 10

simple columar epithelium with gastric pits and glands in mucosa outer layer

Question 11

stomache connections w/in digestive system

Answer 11

1. cardiac part sphincter between lower oesphagua and stomach
2. pyloric sphincter between stomache and duodenum

Question 12

gastric pits: what they produce + components (3)

Answer 12

produce gastric juice (HCl)

Made of: parietal cells , chief cells , enteroendocrine cells

Question 13

stomache mucosa

Answer 13

mucus glands producing alkaline muscle to form a layer over epithelium protecting tissue from acidic enviroment

Question 14

Pyloric regioin and sphinchter in stomache

Answer 14

break down food into small chunks and cause emptying of stomache via waves into duodenum

Question 15

duodenum

Answer 15

1st segment of small intestine where secretion from pancreas and gall bladder enter the digestive chain

Question 16

type of tissue in duodenum + compoenets of tissue (4)

Answer 16

simple columar eptithelium
made of :
1) absorption cells (producing digestive enzymes)
2)goblet cells (producing mucus)
3)endocrine cells (regulating hormone production)
4)intestinal glands

Question 17

pancreas

Answer 17

produces endocrine and exocrine secretions which enter the digestive tract in duodunum

Question 18

Jejunum + Illeum (small intestine)

Answer 18

made of villus epithelium w. micro-villi to allow the absorption of nurients into BS

Question 19

Villus Epithelium cells of small intestine (4)

Answer 19

1. Absorptive cells
2. Mucus secreting cells
3. Cells excreting water + electrolytes to aid molecule absorption
4. Cells studded with enzymes to aid final digestion

Question 20

process of Absorption of nurients +fats

Answer 20

MAJORITY OF NURIENTS…..
absorped by cells in s.intestine, released into BS, passes to liver via hepatic vein
FATS…………..
cross cell-membrane and enter lymph system which drains into blood

Question 21

Large intestine

Answer 21

a longitudinal muscles modified to form 3 layers of smooth muscle. Mucus is thickened in crypts which aid movement of faeces to rectum during contractional waves

Question 22

Parts of large intestine (5)

Answer 22

food enters via ileoncael valve, ascending colon, transverse colon, descending colon, exits via sigmoid colon

Question 23

Rectum

Answer 23

straight muscular tube from sigmoid colon to anal canal, lined with simple columar epithelium, under voluntary & involuntary control

Question 24

Anal canal parts & tissue

Answer 24

Internal Sphincter: smooth muscle (simple columar epithelium)
External Sphincter: skeletal muscle (stratified squamous epithelium)

Question 25

how does Defaeceation occur

Answer 25

simultaneous relaxation of skeletal and smooth muscles of anal canal sphincters

Question 26

Liver parts

Answer 26

R+L lobes which are sperated by connective tissue, quadrate + caudate lobes, feed by hepatic artery and inferior vena cava

Question 27

Liver lobules parts

Answer 27

heptocytes, heoatic artery, hepatic portal vein, hepatic duct (bile duct)

Question 28

direction of blood & bile flow

Answer 28

opposite directions

Question 29

functions of Kupffer/heptatic cells (liver) (3)

Answer 29

1. Bile production
2. Metabolism
3. detoxification of blood (haematological management)

Question 30

bile

Answer 30

a alkaline solution synthesised in liver, stored in gall bladder, and excreted in duodenum. Contains water, electrolytes, bilirubin, cholesterol and bile salts