Animals

Animal Types

• All animals are grouped as either an invertebrate or a vertebrate.– 95% of all animals are invertebrate organisms.• The animals do not have a backbone or vertebral

column.

– 5% of all animals are vertebrates.• These animals do have a backbone.

InvertebratInvertebrate groupse groups

Porifera – ex. SpongePorifera – ex. Sponge

Osculum of

Sponge

Porifera• Oldest of the animal phyla• No symmetry or consistent body shape• Water flows through its body which is full of

canals• Spicules act as a skeleton to give it structure• No locomotion (stationary animals)• Contain specialized cells but they are not

organized into tissues, organs, or organ systems

Cnidaria – ex. Sea AnenomeCnidaria – ex. Sea Anenome

Tentacles of Sea Anemone

7

More CnidariansMore Cnidarians

Brain Coral

Red jellyfish

Cnidarians

• First phyla to have a nervous system– Contain a nerve net: interconnected neurons without

a brain or cephalization

• Some have stinging cells called nematocysts for stunning prey

• Live in two forms: free swimming medusa or non-swimming polyp

• Digestive tract with the entrance being the exit• Tentacles are used for obtaining food

Platyhelminthes – ex. flatwormsPlatyhelminthes – ex. flatworms

Planarian

Marine Flatworm

Platyhelminthes

• Hemaphroditic – worms have both male and female parts

• Simplest animals with bilateral symmetry• Tubular mouth of pharynx for taking in food• Digestive tract with the entrance being the exit• Most members are parasitic• Light sensitive cells make up their “eyes” called

eyespots• A group of nerve cells for a ganglia which acts like a

brain

Nematoda – ex. roundwormsNematoda – ex. roundworms

Nematode

Nemotoda

• Have flattened bodies with bilateral symmetry• Many are parasitic• Breathe through their skin• Digestive tract with two ends: mouth and

anus

Annelida – ex. Segmented wormsAnnelida – ex. Segmented worms

Leech (segmented worm)

Annelida

• Bilateral symmetry and segmented bodies• Complete digestive tract with two ends:

mouth and anus• Fluid filled skeleton (hydrostatic skeleton)

helps them move• Closed circulatory system with 5 “hearts”• Hair-like bristles on each segment help them

move

Mollusca (With and Without Shells)

snailscallop

nautilusnudibranch

octopus

Mollusca• Feeding device like a toothed, scraping tongue

called a radula• Most have a calcium based shell• Muscular foot can allow the animal to slide, dig,

or jump• Some propel themselves in the water using their

siphon as a jet• Mantle of tissue covers the body and secretes

calcium• Digestive tract with two ends: mouth and anus

Arthropoda (insects, spiders, crustaceans, horseshoe crab)

Dung beetle

Horseshoe crab

crayfishspider

Arthropoda

• Jointed segmented body• Nervous system with a brain• Exoskeleton made of chitin• Tend to metamorphasize/molt• Largest animal phyla

EchinodermsEchinoderms

Sea cucumber

Sand dollar

starfish

Brittle star

Sea fan (crinoid)

Echinodermata

• Five part radial symmetry in adults• Tube feet directed by a water vascular system

help them move and eat• Hard but flexible bodies with plates of calcium

under the skin• All members are marine – live in ocean• The name means “spiny skin”• Digestive tract with two ends: mouth and anus

VertebratVertebrate Groupse Groups

All vertebrates belong to Phylum Chordata

• Have a notochord which develops into vertebrae that protect the spinal cord

• Have an internal skeleton that allows them to grow without molting

• Made up of fish and tetrapods (land-dwelling animals with legs)

FishFish

lanceletray

anglerfish

damselfish

AmphibiaAmphibia

toad

newt

frog

salamander

ReptiliaReptilia

Turtle

Snake

Alligator

Lizard

Birds - AvesBirds - Aves

hummingbird ostric

hlovebirds

MammaliaMammalia

Section 26-1

have are carry out

with such as

What do animals do to survive?

AllAnimals

Feeding Respiration Circulation Excretion Response Movement Reproduction

Eukaryoticcells Heterotrophs Essential

functions

No cell walls

In order to survive, animals need to maintain homeostasis

• Homeostasis is the balance between the internal environment and the changing external conditions

• This is achieved through feedback – the control of a process or system by its results

– In positive feedback, the results of the process make it happen: a “chain reaction”.– In negative

feedback, the process is shut down by its products.

In mammals such as humans, homeostasis is maintained through interactions between organ

systems

• Atoms make up biomolecules• Biomolecules make up organelles• Organelles make up cells• Cells make up tissues• Tissues make up organs• Organs make up organ systems• Organ systems make up organisms

Early Development

• During the early development of animal embryos, cells divide to produce a hollow ball of cells called a blastula.

• The cells continue to divide to form three germ layers:– Ectoderm: forms skin, nerves, and sense organs– Mesoderm: forms muscles and other systems– Endoderm: forms liver and lungs

Nervous and Endocrine Systems

• The nervous system and the endocrine system provide the means by which organ systems communicate

• The body’s communication systems help maintain homeostasis

• The nervous system controls thoughts, movement, and emotion.

• The endocrine system controls growth, development, and digestion.

Nervous System

• The nervous system works quickly, using chemical and electrical signals. – interconnected network of cells– signals move through cells– divided into central nervous system (CNS) and peripheral

nervous system (PNS)

Endocrine System

• The endocrine system works more slowly.– only chemical signals

(hormones)– signals move through

bloodstream (circulatory system)

– physically unconnected organs

Worksheets

• Nervous system – p. 838, 847 - 852• Endocrine system – p. 858 - 863

Circulatory and Respiratory Systems

• The respiratory and circulatory systems work together to maintain homeostasis.

• The respiratory system moves gases into and out of the blood.

Oxygen-poor blood

Oxygen-rich blood

nose

sinus

mouthepiglottis

trachea

lungs

• The circulatory system transports blood and other materials– Brings supplies to cells– Carries away wastes– Separates oxygen-poor and oxygen-rich blood

• The respiratory system is where gas exchange occurs– Pick up oxygen from inhaled air– Expels carbon dioxide and water

Gas Exchange

• Oxygen and carbon dioxide are carried by the blood to and from the alveoli.– oxygen diffuses from

alveoli into capillary– oxygen binds to

hemoglobin in red blood cells

– carbon dioxide diffuses from capillary into alveoli

Blood Flow

• Pulmonary circulation occurs between the heart and the lungs.– oxygen-poor blood

enters lungs– excess carbon dioxide

and water expelled– blood picks up oxygen– oxygen-rich blood

returns to heart

• Systemic circulation occurs between the heart and the rest of the body.– oxygen-rich blood goes

to organs, extremities by through arteries

– oxygen-poor blood returns to heart through veins

Worksheets

• Respiratory – p. 870 - 873• Circulatory – p. 877 - 880

Digestive and Excretory Systems

• The digestive system breaks down food into simpler molecules, and the excretory system removes wastes and helps maintain homeostasis.– The digestive system breaks down food into

energy cells can use.– After digestion is complete, nutrients are

absorbed and transported to all cells.– Undigested materials are eliminated as liquid and

solid wastes through the excretory system.

Digestive System

• Digestion of carbohydrates begins in the mouth.

• Digestion of proteins occurs in the stomach.

• Digestion of fats and sugars occur in the small intestine.

• Digestion is completed in the small intestine.– Pancreas helps digest fat and

protein– Bile from the liver/gallbladder

helps digest fats

Digestion

• Peristalsis moves food through the organs

esophagus

muscles contract

muscles relax

food

stomach

Villi increase surface area for absorption of nutrients.

Excretory System• In addition to removing waste produced from the

digestive system, the excretory system removes nonsolid waste.

• Nonsolid wastes are eliminated through lungs, skin, and kidneys.

• Lungs exhale carbon dioxide and water vapor.• Sweat glands in skin release excess water and salts.• Kidneys filter and clean the blood to produce urine.

• The excretory system helps maintain homeostasis by controlling water loss and filtering the blood.– Dialysis is used to filter

blood in people with damaged kidneys

Other systems protect, support, and move the body.

• The skeletal system allow for movements, supports the body, and protects tissues.

• The muscular system moves substances throughout the body.– bones of the skeletal system– food through digestive system– blood through circulatory system– fluids through excretory system

• The integumentary system (hair, skin, oil glands, etc.) surrounds the body and organs and removes substances (water, salt, and urea).

Immune System

• The immune system is the body system that fights off infection and pathogens.

• Many other tissues and systems help the immune system.– Skin is a physical barrier to infection.– Mucous membranes trap pathogens entering the

body.– The circulatory system transports immune cells.

Cells and proteins fight the body’s infections.

• White blood cells attack infections inside the body.– Phagocytes engulf and destroy

pathogens.– T cells destroy infected cells.– B cells produce antibodies.

• Three types of proteins fight off invading pathogens.– Complement proteins weaken

pathogen membranes.– Antibodies make pathogens

ineffective.– Interferons prevent viruses from

infecting healthy cells.

antibody

pathogens

Immunity prevents a person from getting sick.

• Passive immunity occurs without an immune response.– Mother’s milk– Genetics

• Active immunity occurs after a specific immune response

• Vaccines produce acquired immunity– stimulates a specific immune response– allows immune system to respond quickly to infection – causes memory cells to be produced– has such a fast response, a person will not get sick

Allergies occur when the immune system responds to harmless anitgens.• Allergies are caused by

allergens.– Allergens are antigens

that cause an allergic reaction.

– Allergens cause inflammation responses.

– May be food, airborne, or chemical

– Can cause anaphylaxis

In autoimmune diseases, white blood cells attack the body’s healthy cells.

• Autoimmune diseases are failures of the immune system.– White blood cells cannot

recognize healthy cells.– White blood cells attack

healthy body cells. – Tissues fail because of

attack.