animal systems Flashcards
Transport system
must include ability to reach all cells
components of circulatory system
Fluid which materials are transported
system of interconnected blood vessels or spaces through out the body in which fluid moves
Muscular pump, usually heart, that pushes the fluid through the blood vessels or spaces
open circulatory system
Fluid circulates freely in body cavity in which it bathes the cells.
fluid called haemolymph because blood mixed wt interstitial fluid
Contraction of one or more muscular hearts pumps haemolymph through open areas into spaces surrounding organs.
relaxation draws haemolymph back to pump from organs
Valves in pores close to prevent back flow of circulating fluid to ensure one-way flow
heart is tubular or sac-like
Gastrovascular cavity
central cavity with single opening that functions to transport and digest substances
Simple organisms have this
diffusion and gastrovascular cavity enough to provide substances needed
Closed circulatory system
fluid flows through enclosed vessels
Fluid called blood
interstitial fluid outside enclosed vessels
One or more hearts hump blood into large vessels
smaller vessels are site for diffusion
Single circulatory system
contain one circuits
Found in sharks and bony fish
blood pumped to gills
Blood proceeds from gills straight to tissue
one pump, atrium and ventricle
Double circulatory system
2 circuits: pulmonary circuit, blood to lungs. Systemic circuit transports oxygenated blood around body and back to heart.
In mammals, no mixing of oxygenated and deoxygenated
in amphibians and reptiles, heart lacks septum therefore 2 atrium 1 ventricle. Oxygenated and deoxygenated slightly mix.
Functions of circulatory system
transportation of H20, O2, CO2.
Distribution of nutrients and removal of wastes
maintenance of body temp
Circulation of hormones
blood
Plasma, erythrocytes, leukocytes, platelets
considered connective tissue
RBC and O2 transport
RBC produced in bone marrow
Nucleus breaks down before release from bone into circulation, making them pliable and elastic to twist and flex when going through vessels, allows more space for O2
haemoglobin
Red pigment
allows to carry more O2
Blood and CO2 transport
CO2 dissolves in water to form carbonic acid, slow reaction, in RBC, enzyme carbonic anhydrase speeds up reaction.
Carbonic acid produced diffuses into plasma and carried to lungs, 70% carried in plasma as carbonic acid, 7% as CO2 in plasma, 23% attaches to haemoglobin.
Blood and CO2 transport (at lungs)
Carbonic acid turns to CO2 and H2O.
CO2 leaves internal environment of blood to external environment of the lungs where both CO2 and H2O are exhaled.
Heart
made of muscle
4 chambers, atria and ventricles
Systemic circulation
system of blood vessels that circulate blood to most of the body
Pulmonary circulation
system of vessels that carries blood to and from the lungs
Atrioventricular valves
valve between atrium and ventricle
Pulmonary valve
between ventricle and pulmonary artery
Aortic valve
between aorta and ventricle
Lymphatic system
Collect fluid that is pushed out of vessels due to high pressures and rejoins it to the circulatory system.
lymph vessels
Have valves
collect lymph
Gas exchange
diffusion of O2 from external to the internal environment and diffusion of carbon dioxide from internal to external environment
Surface for gas exchange needs to be
moist so gases can dissolve into water and diffuse from one side of the membrane to other
Be thin and permeable, so gas molecules can move across easily and quickly
have large surface area in relation to the volume of the organism, so as to adequately provide the gaseous requirements
Have a greater concentration of gas on one side of the membrane than the other, so that a concentration gradient is maintained
be highly vascularised
Spiracles
tracheal system
Opening at body surface leading to trachea
trachea branches into tracheoles, carrying air directly to cells for gas exchange
Gills
in aquatic animals
Must have water passing through them
dissolved O2 in water rapidly dissolved into bloodstream
Alveoli
Lungs in mammals
Gas exchange at surface of alveoli
Sac-like, air flows into them
skin
In amphibians
gas dissolves across cell membrane
Dense network of capillaries lies below skin
gas exchange in amphibians
Tadpole, use gills and skin
Adults, use simple lungs and skin, lungs not as good as mammals as diaphragm not as developed, must push air into lungs
Gas exchange in mammals
diaphragm contracts to expand the volume of thoracic cavity
Rate of breathing controlled mainly in response to CO2 in blood
inhalation, diaphragm and intercostal muscles contract
Exhalation, diaphragm and most intercostal muscles relax
endothermic
Use heat energy generated by own metabolic reactions to maintain internal body temp
gas exchange in fish
Gills rely on buoyancy of water, emmerses in water to expand surface area, thus exposes animal’s blood supply to oxygen drenched water.
gills rely on water flowing through it
Fish can force water out mouth through gills, bigger fish can’t therefore must maintain movement and swim with mouth open
Excess CO2 washed away by water
operculum
Covering over gills
protects gills
Moves water into and out of opercular cavity
gills
Composed of 2 layers of leaf-like filaments, which project from gill arch
upper and lower layer contain gill plates, greatly increasing surface area
Gill arch contains an artery bringing deoxygenated blood to gill
gill plates have capillaries
fish out of water
Gills collapse as air doesn’t have same support as water
surface area decreases and gills lose moisture
Concurrent flow
water flows in one direction, blood flows in opposite
Maximises gas exchange as concentration gradient maintained along whole structure
alimentary canals
Specialised pathway food takes in complex animals
mechanical digestion
Large pieces of food broken down into smaller pieces through chewing or muscular movement in stomach
increases surface area of food exposed to enzymes.
Chemical digestion
when enzymes break down complex substances into their simplest forms
Ingestion
acquisition of nutrients
Digestion
breakdown of complex organic molecules into smaller compounds by mechanical and chemical means
Absorption
the taking up of digested molecules into the internal environment of the cells of the digestive tract
egestion
The removal of undigested waste food materials from the body
gastrovascular
Only one opening
simple animals
Alimentary canal
mout to anus
Passage: mouth, oesophagus, stomach, small intestine, large intestine, rectum, anus
ingestion (steps)
Starts at mouth
mechanical and chemical digestion
Molars grind food
tongue moves food
Amylase secreted from salivary glands, chemical breakdown of carbs into simpler carbohydrates
digestion and secretion
Once ready for swallowing, food moves to back of mouth, tongue helps push it to oesophagus
epiglottis closes off trachea, preventing food from entering trachea
Some chemical digestion continues until reaches stomach
Peristalsis
Unidirectional muscular contractions that enable food to move down oesophagus
in stomach
Potential to stretch significantly
mechanical digestion: stomach churns food, allows enzymes easy access
Presence of food stimulates secretions of gastric juice from cells lining stomach wall
substance contains: mucus, water, hydrochloric acid, pepsin enzyme.
Sphincter
regulate movement of food into and out of the stomach
When it contracts, openings close
in small intestine
Peristalsis required from stomach to small intestine
sphincter at bottom of stomach controls how much is entering small intestine
Human adult: 7m long, surface are of 4500m squared
duodenum
First part of small intestine
site of high levels of chemical digestion
Secretions from pancreas enter duodenum
secretions known as pancreatic juice, contain mixture of enzyme amylase, trypsin and lipase
Bile
produced in liver
Passes down bile duct into duodenum
stored in gall bladder if no food present
Mechanical breakdown of fats, emulsifies fats into small droplets
lipase
Enzyme produced by pancreas
chemically breakdown fat into fatty acids and glycerol
Trypsin
enzyme produced by pancreas
breaks long-chain polypeptides, breaking them into shorter-chain peptides
Erepsin
enzyme produced by pancreas
Breakdown shorter peptides into individual amino acids
from duodenum
Food enters rest of small intestine
digestion of all food nutrients continues
Proteins: broken down into amino acids and absorbed into bloodstream
Carbohydrates: broken into simple sugars and absorbed into bloodstream
Absorption (steps)
smaller products in that (external environment), transported across cell membrane into bloodstream (internal membrane)
What is absorbed: glucose, amino acids, fatty acids, glycerol
villi
Lining of small intestine
finger like projections
Increases surface area
rich in blood vessels
Glucose, amino acids absorbed into capillary network
fatty acids, glycerol enter lymphatic system
egestion (steps)
Large intestine: colon and rectum
main function: compact undigested food material, absorb water and some salts back into body
Colon
bacteria in colon act on undigested material producing vitamin A and K
Vitamins absorbed into lining of large intestine
peristalsis pushes material into rectum
Rectum
storehouse of waste material
Waste eliminated from body through Anus
faeces
Waste material
specialisation of alimentary canal
Diet of animal affects which features are present
Dentition
vertebrates
Teeth different for diets
Herbivores
eat plants, harder to digest
Alimentary canal longer than carnivores
cellulase
Enzyme to break down cellulose
produced by micro-organisms in gut, not alimentary canal
Cow
enlarged stomach
Abomasum, true stomach
ground materials grounded by molars and transported to reticulum, forms a ball of cud, which is regurgitated and chewed again.
When cud swallowed, passes into rumen, largest chamber, cud mixes wt cellulose digesting bacteria and saliva.
rumen
Fermentation chamber
Cellulose chemically digested, releases CO2 and Methane
contents of rumen empty out into duodenum via omasum
Omasum
soluble products of digestion are absorbed by omasum
Carnivores
protein easy to digest therefore shorter alimentary canal and no enzymes in saliva
Omnivores
eat plant and animal matter
Lack specialised structures of herbivores and carnivores
have simple stomachs
Intestine larger then carnivores
animals without digestive system
Microscopic and simple animals
have high surface area to volume ratio
Size of cell membrane sufficient to service total volume of cytoplasm
relies on diffusion
All functions take place inside boundary of cell membrane
