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Flashcards in EAC The Digestive System Deck (32):
1

3 basic food groups

Carbohydrates

Proteins

Fats

in addition minerals and vitamins are also absorbed

2

how are the basic food groups used by the body?

to build and repair the body

as fuel to produce heat and energy

to provide raw materials for the body's chemical activities

to help maintain health

3

4 stages of the digestive process

Ingestion

Digestion

Absorption

Elimination

4

define:
Ingestion

food is taken into the alimentary tract

5

define:
Digestion

food is broken down mechanically by chewing and chemically by enzymes secreted by glands in the digestive system.

6

define:
Enzyme

a chemical substance which causes, or accelerates, a chemical change in another substance without being changed itself

7

define:
Absorption

food which has been digested passes through the walls of some organs of the alimentary tract into the bloodstream to be used by the body tissues

8

define:
Elimination

Undigested components of food are excreted from the bowel as faeces

9

define:
Peristalsis

rhythmic muscular contraction of the walls of the tract which pushes the food through in one direction. This involuntary action is known as peristalsis

10

Components of the Digestive System

Digestive processes:
Mechanical process - chewing
Chemical Process - saliva, stomach acid

Alimentary Tract or Cana/Gastro-Intestinal/GI tract: Actively transports the flow of food through the whole of the digestive process


Accessory organs of digestion: these organs produce some of the chemicals necessary for digestion and include; salivary glands, liver, gall bladder, pancreas

11

Function of Digestion

The digestive system is made up of organs which convert solid and liquid foods into forms of essential, basic nutrients which the body tissues can use

It also helps to remove the bodies waste products

12

define:
Mouth

also referred to as the oral or buccal cavity

Tongue
Teeth
3 pairs of salivary glands: parotid, sub-lingual and sub-mandibular

13

define:
Pharynx

pharynx or throat is an expanded muscular tube lying behind the nose and mouth

shared with the respiratory tract

divided into 3 parts:
Nasopharynx
Oropharynx
Laryngopharynx

14

define:
Epiglottis

A leaf-shaped plate of yellow fibro-elastic cartilage located at the entrance of the larynx

its main function is to prevent food entering the larynx during the act of swallowing

15

define:
Oesophagus

oesophagus or gullet is a collapsable, muscular tube

descends form the pharynx above to the cardiac orifice of the stomach below

approx. 25cm long

movement of a food bolus along it is by peristalsis action

smooth muscle, elastic tissue and mucous membrane

16

define:
Stomach

muscular bag like organ

walls are lined with mucous membrane

contains the cardiac sphincter at its connection with the oesophagus which helps prevent regurgitation

is able to contract in a variety of ways to help churn up food. this helps mix food with gastric juices containing hydrochloric acid, water and enzyme

chyme is produced which then passes into the duodenum via the pyloric sphincter, which helps prevent regurgitation back into the stomach

17

define:
Duodenum

first part of the small intestine

25cm long

both bile duct and pancreatic duct (endocrine glands) empty into the duodenum

bile, pancreatic and intestinal juices complete the conversion of chyme into amino acids

18

define:
Small Intestine

6 metres long

Muscular tube lined with connective tissue and mucous membrane

Comprises of the duodenum, jejunum and ileum

Continuos with the duodenum above and the large intestine below

outer covering is formed by the peritoneum

large surface area for digestion and absorption

Nutrients pass through the inner lining and are absorbed by blood vessels contained in the wall of the intestine

19

define:
Large intestine/Colon

1.5 metres long

absorbs water

absorbs electrolytes, vitamins

storage of faecal material

expulsion of faeces

synthesis of vitamins K, B by using symbiotic bacteria

20

divisions of the Large Intestine/Colon

Caecum
Vermiform appendix
ascending colon
transverse colon
descending colon
sigmoid colon
rectum
anus

21

define:
Peritoneum

serous membrane that lines the abdominal cavity

covers abdominal organs

prevents friction

helps hold the organs in position

carries blood vessels that help fight infection

22

functions of:
Liver

generates heat
carbohydrate, lipid and protein metabolism
Processing of drugs and hormones
excretion of bilirubin
synthesis of bile salts
storage for vitamins and minerals
phagocytosis - RBC's, WBC's and some bacteria
Activation of vitamin D

23

functions of:
Pancreas

oblong in shape

dual function organ

12-15cm long

connected to the duodenum by 2 ducts

secretes pancreatic juices (enzymes)

secretes insulin and glucagon (hormones)

24

function of:
Gall Bladder

stores and concentrates bile

releases bile into the small intestine

25

function of:
Kidneys

filters blood to help remove waste products
regulates acid base balance and pH of the blood
regulates blood volume
regulates blood pressure
regulates salt water balance
produces hormones
regulation of blood glucose levels
excretes urine: urine contains the end products of metabolism, drugs, toxins and other harmful chemical substances

26

function of:
Ureters

two fine tubes 25-30cm long

they pass from the kidneys to the bladder

they carry urine

27

function of:
Bladder

the bladder is a muscular bag
it acts as a reservoir for urine passed via the ureters from the kidneys
it lies behind the pubis in the pelvic cavity
it normally holds 300ml
maximum capacity 800ml (smaller in women)
when full it rises up into the abdominal cavity

28

function of:
Urethra

urine is passed form the bladder via the urethra in the penis and vagina during the act of Micturition

the canal leading from the bladder to the outside of the body

29

define:
Uterus

positioned in the centre of the pelvic cavity

lies between the bladder and rectum

two uterine tubes (fallopian tubes) connect the ovaries to the uterus

30

define:
Ovaries

2 small glands about the size and shape of an almond

they produce the female ova

ova are released into these uterine tubes, moving on to the uterus where they are either fertilised or passed out from the body during the menstrual cycle

31

be able to label...

digestive system diagram

Male/female genital diagram

32

relationship between Digestive System, circulatory system, respiratory and renal system

DS breaks food down into energy used with oxygen intake from RS and water from DS/RS to make ATP in cells that they use to function. the CV system uses ATP to function and pump blood around the body allowing it to collect nutrients, oxygen and water.

Waste products are filtered and eliminated by the Renal System