17A Body Systems in Vertebrate Animals Introduction: Animals in the vertebrate group: Have...

17A Body Systems in Vertebrate

Animals Introduction:

Animals in the vertebrate group: Have vertebrae Skulls Skeletons that are alive (they are made if cells

and require energy to grow) Endoskeleton – made of a combination of

bone and cartilage Animals with endoskeletons have their

primary support inside their bodies


Animals Bone gives vertebrates a strong support system

Cartilage is also strong, but more flexible than bone Example: the end of your nose is cartilage

Bone and cartilage are living tissues that grow with the organism

All skeletons have a vertebral column and skull

Most vertebrates have ribs as well as other skeletal structures supporting their limbs (may be fins, arms, legs, or wings)


Animals They also have joints between various

bones and cartilage pieces that permit them to move

Muscles pulling on the bones or cartilage cause the limbs to move at the joints

Vertebrates testify to the greatness of God

See Psalm 104:24-25


Animals Vertebrates have more in common than just

their skeletal similarities

God designed them with organ systems that meet their needs for energy, response, movement, and nutrition

17A.1 Circulatory System Blood

All vertebrates have blood (aka “the river of life”) Circulates throughout the body by the pumping of

the heart


Animals It brings food to cells that are far away from the

digestive system Transports oxygen to and carries carbon dioxide

from the cells that are distant from the lungs or gills

Wastes, control chemicals, and many other necessary substances travel to and from the body’s cells in the blood

See Figure 17A-1 Red – oxygenated blood – carries oxygen Blue – deoxygenated blood – had given oxygen away

and now carries carbon dioxide The blood of all vertebrates is red. They only differ

slightly in redness YOU DO NOT HAVE BLUE BLOOD!!


Animals 17A.1 Circulatory System

Heart Chambers Vertebrate hearts contain spaces called chambers The walls of the chambers are made up of heart muscle The walls contract (squeeze), forcing the blood to move

out. One-way valves prevent the blood from returning to the

previous chamber Thus, a heart contracts over and over again, pumping

blood in one direction ARTERIES - blood vessels that carry blood AWAY from

the heart VEINS – blood vessels that carry blood TOWARD the

heart


Animals Different vertebrates have different numbers of

chambers Fish – two chambers

One receives blood, the other pumps it to the body The blood that leaves goes first to the gill to become

oxygenated and then travels to the rest of the body Then eventually returns to the heart

Most reptiles and adult amphibians – three chambered hearts One collects oxygenated blood from the lungs Another collects deoxygenated blood from the rest of

the body Both of these empty into a third chamber where the

two types of blood are mixed


Animals Birds and Mammals – four chambered hearts

Chambers on one side only pump oxygenated blood

The other side pumps deoxygenated blood to the lungs, where it becomes oxygenated

The oxygenated blood returns from the lungs to the other side of the heart

The oxygenated side pumps the blood throughout the body

In healthy animals with four chambered hearts, oxygenated and deoxygenated blood mix


Animals 17A.2 Respiratory System

Gills Many vertebrates live their entire life underwater Gills take oxygen from the water and give off

carbon dioxide Fish gills are shaped like tiny fingers and are richly

supplied with capillaries Blood circulating near the surface of the gills make

them appear red Capillaries – microscopic blood vessels in which

blood often exchanges gases and other materials In gills, deoxygenated blood becomes oxygenated



Lungs Vertebrates that have lungs are able to breathe

air Lungs are air chambers inside the body where

blood can obtain oxygen and give off carbon dioxide

The lungs of reptiles, birds, and mammals are all different

All lungs have many capillaries in which deoxygenated blood becomes oxygenated

Breathing moves air into and out of the lungs



Lungs There are several different methods that animals

use to breathe Frog – fills its mouth with air and then forces the

air into its lungs Birds – move air through their lungs by using

muscles to control the size of connecting air sacs Mammals and humans – have diaphragms to

help them breathe Diaphragm – a thin later of muscle that

separates the chest chamber from the abdomen


Animals 17A.3 Nervous System

Vertebrate nervous systems consist of two main divisions: the central ad peripheral nervous

Central nervous system – made up of the brain, which is protected by the skull, spinal cord (which is protected by bones of the vertebral column),

Peripheral nervous system – made up of nerves which branch off the central nervous system

Sensory organs – sensory receptors scattered throughout the body; they are a major collection of sensory receptors and various supporting structures


Animals 17A.3 Nervous System

Normally, a sensory organ only senses one environmental factor

Cranial nerves – nerves that branch from the brain These connect the brain with sensory organs of the head

Spinal nerves – nerves that branch from the spinal cord These transmit impulses from the spinal cord to various

muscles and internal organs An organism’s reactions are controlled in the central

nervous system The central nervous system also controls many

internal processes


Animals 17A.4 Digestive System

Food enters the body through the mouth and passes through short, tubular esophagus into the stomach

Muscles in the stomach walls squeeze the stomach walls in and out to mix food with digestive enzymes

When it is mixed, it moves into the small intestine In the small intestine has different enzymes to digest

– here food is broken down into molecules small enough to be absorbed into the blood stream

Two organs attached to the small intestine produce additional enzymes: Liver and pancreas


Animals 17A.4 Digestive System Liver – produces a greenish fluid called bile, which

contains substances to help breakdown fats Bile released by the liver is stored in the gallbladder

until it is needed Pancreas – smaller organ that makes and releases

enzymes into the small intestine; these break down sugar, starches, proteins, and fats

Small intestine wound in curves and loops in order to fit inside the animals body

Large intestine – Food that cannot be digested passes through here; also where excess water is absorbed.

Undigested food leaves the digestive tract through the anus


Animals 17A.5 Excretory System All vertebrates have kidneys to filter wastes from their

blood Various waste products, including urea, are picked up by

the blood as it passes through the body’s tissue Kidneys have tiny tubes surrounded by capillaries Wastes leave the blood and enter the tubes In each kidney, the wastes flow through these tubes into

one large tube called the ureter Urinary bladder – where fluid is collected and stored

before it passes out of the body Birds – wastes pass out of the body with indigestible

materials Some amphibians, most reptiles, and all mammals and

humans, wastes form urine

17B Fish Fish have fins, gills, and usually scales

They live in fresh or salt water Ectothermic

Ectothermic – their body temperatures change with their surroundings

A fish’s activity changes with the temperature

17B.1 Fish Anatomy A fish propels itself by flexing its entire body Paired fins control movements Streamlined body shape to move easily through the water Some have a swim bladder (helps them float at a

constant depth) Swim bladder – an air filled organ that a fish uses to

adjust to different water depths

17B Fish 17B.1 Fish Anatomy

Fish have: closed circulatory system

two chambered heart and blood vessels Blood pumped from the heart to the gills, through the

body, and back to the heart When blood passes through capillaries in the gills,

oxygen diffuses into the blood stream Using Figure 17B-1 – Trace the flow of blood through a

fish Scales – overlapping to give the fish some protection

They grow larger as the fish grows Lateral line – located on each side of the fish; a string of

sensory structures Can detect vibrations and pressure

17B Fish 17B.1 Fish Anatomy

Nostrils of a fish are NOT used for breathing; used for smelling

Most fish reproduce by spawning During spawning – female fish release millions of

eggs which are then fertilized by the male However, only a few survive to become adult

fish Most fall prey to predators

A few fish, guppies, reproduce by giving birth to live fish rather than spawning

17B Fish 17B.2 Fish Groups

Jawless Fish Have no jaws No scales or paired fins Worm-like creatures with skeletons composed of cartilage Examples: lampreys and hagfish

Some species of lamprey are parasites, feeding on the body fluids of other fish

Hagfish are scavengers

Cartilage Fish Have endoskeletons made of cartilage Have jaws, scales, and paired fins Examples: Sharks, skates, and rays Sharks have to keep water moving over their gills to ensure oxygen supply

They swim with their mouths open

They lack a swim bladder; instead they have a large oily, liver that is less dense than water

Skates and rays rest on the ocean floor

17B Fish 17B.2 Fish Groups

Bony Fish The largest group of fish Includes: catfish, bass, flounder, goldfish,

guppies, and trout Endoskeleton made of bone Have jaws, paired fins Most have scales Some grow no longer than the width of a

pencil; others can reach 4.3 meters Some live in salt water; others in fresh Some warm water of the tropics; some frigid

polar temps

17C Amphibians Amphibians are ectothermic

Live in water when young, but can live on land as adults

The name comes from the greek word that means, “double life”

The name reflects two ways of living: in water and on land

17C Amphibians 17C.1 Amphibian Development

Metamorphosis – the process that changes an amphibian from a gilled, aquatic organism to an air-breathing organism

Young amphibians possess gills, but adults usually have lungs

Gills and lungs are not the only organs used for respiration

Most have thin, moist skin They can exchange gases through their skin (carbon

dioxide and oxygen) because they have tiny blood vessels close to the surface

Other changes metamorphosis includes: Two chambered heart to three chambered Growth of two pairs of limbs Gradual loss of a tail

17C Amphibians 17C.1 Amphibian Development

Though many adults live on land, they still live near water, for all must return to water or moist places to lay their eggs

17C.2 Amphibian Groups There are two major groups of amphibians – with a tail and

without Tailless Amphibians

Frogs and toads Frogs have smooth, moist skin and are usually near water Toads have rough, dry, bumpy skin and can be found far

from water Most lay jelly-coated eggs in water, where they are fertilized

externally They hatch to become tadpoles Tadpoles have gills and tails, but during metamorphosis,

they develop lungs and their tail gradually dissolves

17C Amphibians 17C.2 Amphibian Groups

Frogs and toads are ectothermic Temperature of their surroundings affect their

activity They are less active in the cool (autumn and winter) Frogs usually bury themselves in the mud at the

bottom of a lake of stream during the winter Toads burrow in soft, moist soil Hibernation – the winter state of inactivity During hibernation, the animal’s life processes slow

down and energy supplies stored during the summer months are used up

A similar period of activity called ESTIVATION sometimes occurs during hot, dry weather


Frogs eat insects, worms, slugs, snails, and other small animals It will attack anything that moves and is small enough to fit into

its mouth A large North American bullfrog will eat young water birds,

ducklings, young turtles, and even small fish Some will even eat other small frogs! A frog catches its food with its tongue

Its tongue is short, thick, and attached to the front of the mouth

When it sees food, it flicks its tongue out and stretches it out The tip of it is sticky When it touches food, the frog flips its tongue

Frogs have two sets of teeth They do not use them for chewing, rather for keeping prey from

escaping


One set of teeth forms a ridge of tiny maxillary teeth around the rim of the upper jaw

The other set, the vomerine teeth, is located in two spots at the front of the roof of the mouth

The frog swallows by blinking and bulging its eyes

When the frog closes its eyes, they push down into the frog’s mouth, forcing the food back into the esophagus


Tailed Amphibians Salamanders They have tails into adulthood The young usually have gills and develop lungs

later They also have thin, moist skin to help with gas

exchange The Appalachian region of the US has more

salamander species than any other region on earth Most are small and less than 15 cm (6 in) long One Japanese salamander species can grow to be

1.5 m (5 ft) long!

17D Reptiles All reptiles breathe air and do not experience the

life-changing metamorphosis

17D.1 Reptile Characteristics Ectothermic Dry, scaly skin Lay eggs with leathery shells Most have a three-chambered heart – but one chamber is

partially divided The have lungs their entire lives Can be found in both wet and dry environments The scaly skin protects it from drying out The leathery eggs allow eggs to be laid on land far from

water They fertilize eggs internally, within the female’s body

17D Reptiles 17D.2 Reptile Groups

The most famous – extinct dinosaurs Living reptiles can be divided into four groups:

Snakes and lizards Alligators and crocodiles Turtles Tuataras


Snakes and Lizards Snakes have no legs, ear openings, and

immovable eyelids Most lizards have four legs, ear openings, and

moveable eyelids Both shed their skin periodically in a process

called molting Snakes do not hear. They also have poor vision Their immoveable eyelids are actually clear

scales that are shed each time it molts


What snakes lack in sight they make up in other sense organs

Snakes have a keen sensitivity to molecules When a snake flicks its tongue, it is sensing the air

– helps it to detect food or danger Some snakes can detect body heat of its prey Pit vipers – such as rattlesnakes – have small pits

on their heads that contain organs that can detect heat

Snakes are meat-eaters Benefit to humans –

Eat insect pests, rats, and mice


Most snakes are nonpoisonous Poisonous ones inject poison through hollowed

fangs or grooved teeth Nonpoisonous coil around prey and squeeze! They are capable of swallowing prey much larger

in diameter They swallow food whole – they cannot chew! They have double hinged jaws Its throat is elastic


Snakes are found in almost every environment Most lizards are found in hot or warm

environments; dry Lizards can grow quite large – komodo dragon – up

to 10 ft! Some lizards can change skin color!


Crocodiles and Alligators Can be found in and near shallow waters of warm streams,

rivers, swamps, and lakes Usually found in tropical and subtropical environments Few crocodiles venture into salty water Use their large tails to propel themselves through the water Raised eyes and nostrils allow them to keep them above

water while the rest of the body is submerged Diet includes: fish, turtles, various large and small mammals

(usually attacked while drinking), others of their own kind and occasionally humans

Alligators and crocodiles can be distinguished by their snouts – Alligators – broad, rounded snouts Crocodiles – narrow, pointed snouts


Crocodiles and Alligators The alligator is found all over the southeast Crocodiles are restricted to southern Florida

Turtles Sea turtles – live in the ocean Tortoises – live on land Terrapins – freshwater turtles that may venture onto land Sea turtles have paddle-shaped legs used in swimming Other turtles have clawed legs They have two hard, bony shells to cover their bodies The shell is composed of bony plates covered with large

scales It serves as a good defense Some have a hinged lower shell to close tightly for protection

17A Body Systems in Vertebrate Animals Introduction: Animals in the vertebrate group: Have...

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