Nutrients And Gas Requirments-Iq:1 Flashcards
Respiratory system enables
The gas exchange between organisms and it’s environment
Gas exchange surfaces
Large SA
- enhanced by folding,branching/flattening
- faster rate of infusion
Moist, thin surfaces
- dissolved gases for easier diffusion
- decreases distance that gases have to travel
Alveoli
Gaseous exchange surfaces located in the lungs.
Air sac that is connected to external environment
Surround by capillaries
Gills
Gills can extract maximum possible amount of O2 from water
Water flows in 1 direction over gills
Gas exchange occurs at gills
Spiracles
Breathing pores
Take in and expel air
Have valves
Tracheal tubes
Branching air tubes
Branch into tracheoles
Tracheoles
Very large surface area
Bring air directly to and from cells
Fluid in tracheoles transport gases
Digestion
Breaking down of large, complex food particles into smaller particles for easier absorption
Mechanical Digestion
- physical breakdown
- starts with teeth.
- stomach churns
- aim is to start breaking food into smaller pieces to increase SA to aid chemical digestion
Chemical digestion
Using digestive enzymes to breakdown large complex molecule to smaller, simpler molecules
Starts with saliva
Mouth
Mechanical digestion by teeth
Chemical digestion of CHO by amylase(enzyme)
Tongue forms bolus( mixture of chewed food and saliva)
Oesophagus
Muscular contractions move bolus down oesophagus
Chemical digestion of CHO by amylase still occurring.
Stomach
Movement of substances in and out of stomach is controlled
Relaxation and contraction of walls continue mechanical digestion
Bolus combines with gastric juices to form chyme.
Bolus
Chewed food and saliva
Chyme
Bolus combined with stomach juices
Small intestine
What are the three main regines
- duodenum(start)
- jejunum(middle)
- ileum( end)
Duodenum
Release of pancreatic juices and bicarbonate ions
Bile released to emulsify fats into smaller particles
Bile
Produced by liver, stored in gall bladder
Why does mucus line the walls of our stomach?
Prevents acidic conditions from eating away the walls
Pepsinogen concerted into pepsin
Breaks down large proteins into short chained peptides
Breaks down nucleic acids into nucleotides
Peptides
a compound consisting of two or more amino acids linked in a chain, the carboxyl group of each acid being joined to the amino group of the next by a bond of the type
Pepsinogen
A substance which is secreted by the stomach wall and converted into the enzyme pepsin by gastric acid.
Jejunum
Most absorption occurs
Absorption occurs by diffusion and active transport
Walls lined with villi that are very close to capillaries
Villi
any of the fingerlike or threadlike projections from the surface of certain membranous structures, typically serving to increase surface area and facilitate the passage of fluid or nutrients.
Capillaries
Capillaries are tiny blood-containing structures that connect arterioles to venules. They are the smallest and most abundant form of a blood vessel in the body. Capillaries are small enough to penetrate body tissues, allowing oxygen, nutrients, and waste products to be exchanged between tissues and the blood.
Liver
Absorbed digested food in blood moved to liver
Keeps sugars, glycogen, protein levels balanced
Detoxifies blood
Large intestine
Contains undigested material
There are two sections- colon and rectum
Colon
Water, salts and vitamins A,K absorbed back into blood stream.
Rectum
Faeces moves into rectum for egestion
