BIOL113 animals

Definition of animal

multicellular , heterotrophic eukaryotes, heterotrophic, two types of tissues (nervous system and muscle tissue)

evolutionary origin from colonial, flagellated protists

ancestors of animals were single celled, flagellated protists, lived in aquatic environments

Parazoa

no true tissues, asymmetrical, some bilateral symmetry, sponges

Eumztaeoa

true tissue, radial or bilateral symmetry, two or three germ layers

Radiata

radial symmetry, diploblastic, ectoderm and endoderm

Bilateria

bilateral symmetry, triploblastic, has dorsal and ventral side, anteriroi and posterior end, ectoderm, endoderm, mesoderm

Protostomia

coelom from cell masses, cleavage is spiral and determinate, solid masses of mesoderm split and form coelem, mouth develops from blastopore

Deuterostomia

coelon from digestive tube, cleavage is radial and indeterminate, folds of archenteron form coelom, anus develops from blastopore

Porifera structure

asymmetric, no true tissue, lack nerves or muscles, more are filter feeders

Porifera feeding

flagellated chanocyte, or collar cells line the internal water chambers create a flow of water through the sponge with their flagella and trap food with their collars.

Reproduction of porifera

gametes arise from choanocytes or amoebocytes, eggs retained sperm are carried out of occulum by water current, sperm are drawn to neighbouring individuals and fertilised eggs in the mesophyll, zygotes develop into flagellated larvae and disperse, when larvae find suitable subtrsatum it develops into a sessile adult

Cnidaria structure

diploblastic, radial symmetry, eumztaeoa, can be sessile polyp or floating medusa, carnivores use tentacles to capture prey and push to gastrovascular, movements controlled by non centralised nerve net.

polyp stage of the lifecycle

sessile, can stick to substratum

Medusa stage of the lifecycle

drift and get moved can also contract bodies and move

Hydrozoa class

polyp only, asexually reproduce in favourable environmental conditions, sexually reproduce in unfavourable conditions

Scyphoza class

small polyp stage if coastal, mostly medusa in open water

Cuboza class

box jellyfish, medusa and polyp stage

Anthozoa class

only polyp, solitary in colonial forms and secretes external calcium carbonate skeleton, each generation builds on previous generation

Phylum Platyhelminths characteristics

eumetazoa, bilateral, triploblastic, acoelomate, no circulatory system, gastrovascular cavity with one opening, lack specialised organs for gas exchange and circulation

Turbellaria class

non parasitic, planarians, nearly all free living, cells close to top and fine branching system distirbutes food through animal, use cillia on ventral episdermis to move, eyespots detect light, lateral flaps function for smell, reproduce asexually through regeneration

Trematoda class

alternation through sexual and asexual stages, many require intermediate host where larvae develop before infecting final host

monogenea class

ectoparasite, have suckers to attatch to host, no intermediate host, tough protective covering, usually on skin or gills of fish or in bladder of hosts

Cestoidea class

adults live mostly in vertebrates, suckers and hooks anchor worm in the digestive tract and chemicals stop it from being digested, absorbs food molecules, external surface of microvillae, eggs leave via hosts feces, eggs in contaminated food and water are ingested by intermediate hosts, eggs develop into larvae that encysts in the muscles of their hosts

Blood fluke

trematoda called schistosomiasis, human secretes it and penetrates skin of birds to then go to intermediate host before attempting to penetrate the skin of humans

Liver fluke

trematoda, intermediate hosts are freshwater fish, adults live in veins around pancreas

polystoma inegerrium

monogenea, lives in bladder of frog, produces egg when frog spawns, larvae attach to internal gills of tadpoles, passes down gut of frog to bladder

Phylum annelida

segmented bodies (metemeres), triploblastic, coelom formed hydrostatic skeleton, longitudinal and circular muscles, have setae that anchor segments during locomotion, closed circulatory system that transports oxygen, nutrients, hormones and metabolic wastes, excretion is carried out by metanephrida this filters coelomic fluid, reabsorbs useful substances and removes nitrogenous waste and helps osmoregulation

Oligochaeta

reduced head, no parapodia, setae present, coelom portioned by septa

Locomotion of worms

when the circular muscles contract the segment extends and stretches worm forward, the setae anchor the worm into the substratum to allow for movement, when the longitudinal muscle contract the segment shortens and this pulls rest of body forward

role of segmentation and hydrostatic skeleton in worms

body is divided into segments called metameres each segments contains muscles, coelmic fluid, excretory structure and nerves, this allows body to move independantly while being coordinated, allows for better burrowing. The coelom is a fluid filled cavity that acts as a hydrostatic skeleton, provides support and maintains body shape. Body space for storage and complex organ development, cushions internal structures, segmentation allows for high degree of specialisation

Polychaeta class

each segment has parapodia, each parapodia has several chitinous setae, serpentine locomotion which is driven by longitudinal muscles, propulsion from parapodia and setae dig in. Can slow walk, rapid crawl or swim.

Hirudinea class

feed on invertebrates, bladelike jaws attatch to skin, some secrete enyzmes that digest a hole through skin, secretes an anti coagulant which allows it to suck as blood as it can hold, 34 segments with no setae

Leech locomotion

attach by posterior sucker, extends body (circular muscles), anterior suckers attacher, repositions posterior sucker and then contracts (longitudinal muscles)

Phylum Mollusca

Muscular foot for locomotion, radula to eat food, mantle secretes shell over visceral mass which creates mantle cavity, high level of cephalisation, visceral mass (internal organs)

Polyplacophora class

8 dorsal plates, muscular foot to grip rocky substrate, use radula to ingest algae

Gastropoda class

most protected by shells, distinct heads with eyes at tips of tentacles, move by rippling motion of foot, move by ciliary propulsion, muscles move against hamocoel hydrostatic skeleton, muscles are longitudinal oblique and transverse

Bivalvial

flattened shell, two valves, reduced head, no radula, filter feeders, can burrow as foot is specialised for this and use circular and longitudinal muscles, can swim in short bursts by flapping shells

Cephalapoda

tentacles with suckers, locomotion by propulsion, mantle but no shell, food modified tentacles, closed circulatory system, mantle covers visceral mass, contraction of mantle fires a stream of water through excurrent siphon

Locomotion of molluscs

waves of muscular contraction passing along foot, direction - posterior to anterior, indirect - anterior to posterior, dietetic - each side is out of phase with other

Phylum Arthropoda

exooskeleton, body segmentation, biggest phylum, joint appendages, open circulatory system, extensive cephalisation, antennae for touch and smell, body is covered by cuticle, protein and chitin

Classes of Anthropoda

Arachnida, diplopoda, chilopoda, insecta, crustacea

Millipedes

diplopoda, 2 pairs of legs per segment

Centipedes

head has antennae and three pairs of appendages modified as mouth parts

Crustaceans

jaw like mandibles, 2 pairs of antennae, compound eyes, branches appendages

Uniramians

jaw like mandibles, 1 pair of antennae, compound eyes, unbranched appendages

advantages of arthropod cuticle

reduce water loss in air, allows mobility of the body, provides protection

disadvantages of arthropod cuticle

prevents growth, requires special sense organs, prevents passage of material both in and out of body therefore needs special respiratory and excretory

Locomotion of arthropods

limbs move backwards and forwards, effective stroke down with leg in contact with ground and close to body, recovery stroke is slower leg leaves ground swinging before next stroke. Different lengths ti avoid overlap

Phylum Echinodermata

sessile, slow moving, bilateral symmetry in larvae form, tube feet, skeletal bumps on skin

Asteroidea class

starfish such as crown of thorn starfish, five arms from central disk, use tube feet to move, feeds on closed bivalves it inverts its stomach through its mouth and into the narrow opening between the shells of bivalves

Ophiuroidea class

brittle stars, tube feet lack suckers, move by serpentine motion, central disk and long arms, some suspension feeders, some scavengers and predators

echinodea class

sea urchins and sand dollars, no arm, five rows of tube feet for locomotion, mouth part called aristoltles lantern, seaweed eaters

crinodea class

sea lillies and feather stars, suspension feeders, crawl using long flexible arms, slow evolution

halothyroidea class

sea cucumber, lack spines, endoskeleton is reduced, five rows of tube feet

Tube feet

small muscular extensions ending in a suction cup, water is forced into tube feet extending them, attach to surfaces using suction. In starfish can open bivalves and help extend stomach out of body, allow diffusion of oxygen and carbon dioxide

open circulatory system

hemolymph is not always confined to vessels, it is a low pressure system, slow transport good for small or low metabolism animals

closed circulatory system

blood goes through network of vessels, high pressure, fast transport of oxygen and nutrients, higher energy cost, good for bigger and high metabolism animals

Two chambered heart

found in fish, 1 atrium, 1 ventricle, single loop, low energy cost, not suitible for high metabolic activity or terrestrial life

three chambered heart

found in amphibians, 2 atria and one ventricle, double circulation, pulmonary circuit (lungs and skin) and systemic circuit (body), improved oxygen delivery, mixing of oxygenated and deoxygenated blood in ventricle

partially seperated four chambered heart

reptiles, 2 atria and 2 ventricles, more separation of oxygenated and deoxygenated blood, supports higher metabolic activity, additional shunt of deoxygenated blood for going underwater

fully separated four chambered heart

mammals, 2 atria and 2 ventricles complete separation of deoxygenated and oxygenated blood, supports high energy demands, high energy demand to maintain pressure

hepatic portal system

when blood returns from digestive tract it goes through hepatic portal system before heart so it goes to liver for detoxification before going to heart

Respiratory pigments

binds to oxygen molecules allowing blood to carry more oxygen and maintain diffusion gradients

why is water a poor respiratory medium

low oxygen content, high density and viscosity so difficult to move around and get oxygen out of water

diffusion

net movement of a substance from a high-concentration to a low-concentration

cutaneous diffusion

across body surface only, animals must be small and thin, oxygen diffuses directly into into cells and CO2 diffuses out, sponges, hydras

Cutaneous diffusion with a circulatory system

oxygen diffuses across skin into blood vessels, circulatory system transports oxygen to tissues, CO2 carried back to skin for release, earthworms

Internal gills

water pumped over the gills surface, oxygen diffused into the blood, CO2 diffuses into the water, gills are protected by from damage and have a large surface area, counter current exchange, relies on water currents to ventilate

External gills

water flows directly over gills, oxygen diffuses into blood vessels within the gills, large surface area, easily damaged

water lungs

sea cucumbers, takes huge amount of energy to move water, respiratory trees

Opercular

double action pump that creates a continuous flow of water over the gills, allows fish to ventilate their gills even when not swimming

Counter current exchange

water flows over gills in one direction, blood flows through gill capillaries in the opposite direction, oxygen continues to diffuse from water into blood along the entire length of the gill

Tracheal systems

circulatory system not involved, segments called spiracles which diffusion happens from, gas exchange happens through tracheoles, oxygen gets delivered by diffusion to cells

Air as a respiritory medium

larger oxygen content compared to water making respiration more efficient

Lungs

air enters lungs through respiratory passages, oxygen diffuses across respiratory surfaces into blood, carbon dioxide is exhaled, inflate through negative pressure

Diffusion lungs

air diffuses into pneumostome, circulatory system get oxygen to tissues, used for organisms with low energy requirements

Tidally ventilated

same passage used for both inhalation and exhalation, buccal pumping in frogs, no continuous unidirectional flow

unidirectionally ventilated

bird lungs, air sacs create on way flow of air through lungs, goes to posterior air sacs to anterior, cross current movement, 2 cycles to get to lungs

function of excretory system

to remove nitrogenous waste, allows reabsorption and secretion

Protonephridia

excretory and osmoregulatory, found in flatworms, cilia of flame bulb moves fluid through tubes

Metanephridia

more advanced than protonephridia, open system for urine formation, surrounded by a network of blood vessels to adjust composition of urine, each segment in work has a pair of metanephridia

Malpighian tubules

blind ended, no filtration, active transport, water follows by osmosis, found in insects like grasshoppers

Kidneys

have millions of nephrons, key in osmoregulatory processes, a lot of reabsorption takes place

what is a nephron

the functional unit of a kidney

what is bowmans capsule and what does it do

afferent arteriole brings blood to bowmans capsule, smaller molecules filter through, water, amino acids, salt and sugars filter out, blood leaves by efferent arteriole and goes to proximal tubule

what is proximal tubule

important site for reabsorption, bicarbonate and water diffuse back back in

what does the descending loop of henle do

filter out water

collecting duct purpose

reabsorption is hormonally driven by antidiruetic hormones (ADH)

what does it mean if there is more ADH hormone

means more permeability, more water reabsorption and more concentrated urine

what does a long loop of henle do?

allows for more water reabsorption, adaption in dry environments.

Kangaroo rat kidney

long loops on henle to maintain steep osmotic gradient

Beaver kidney

short loops of henle and little ability to concentrate urine as dehydration is not an issue

Bird kidneys

shorter loops of henle so water conservation is an issue, however they produce ureic acid which does not need to be dissolved in water

Reptile kidneys

no loops of henle so can’t concentrate urine so produce ureic acid and reabsorb water

trout kidney

hyperosmotic to surrounding so have excess water uptake and produce very dilute urine

amphibian kidney

excrete dilute urine in freshwater but reabsorb water across the bladder when on land to conserve water

Tuna

hypoosmotic to seawater, lose water across gills and gain salt, very few nephrons, consume lots of water and produce little urine to get rid of excess salts

Vampire bat kidney

once they have a large meal they can’t fly as they’re too heavy, after feeding they produce very dilute urine so they can fly, when roosting they produce very concentrated urine to get rid of nitrogenous waste

Blood flow through heart

inferior/superior vena cava, right atrium, tricuspid valve, right ventricle, pulmonary valve, pulmonary arteries, lungs, pulmonary veins, left atrium, bicuspid valve, left ventricle, aortic valve, aorta, body