3.1 Animal Cells and 3.1 Animal Cells and TissuesTissues

Cardiac cells

Review… just a littleReview… just a little

In single-celled organisms (like In single-celled organisms (like bacteria), the cell has to be able bacteria), the cell has to be able to do everything that is needed to do everything that is needed to surviveto survive

In multicellular organisms (like In multicellular organisms (like humans), the tasks needed for humans), the tasks needed for the organism to survive is done the organism to survive is done by groups of by groups of specialized cells specialized cells called called tissues tissues that perform a that perform a similar functionsimilar function– there are 75 – 100 trillion cells in

the human body, all with specific functions

Cells Cells Tissues Tissues Organs Organs System System

Types of Animal TissuesTypes of Animal Tissues

Although there are millions of Although there are millions of different animals on Earth, all have different animals on Earth, all have the same 4 types of tissues:the same 4 types of tissues:

1.1. Epithelial Epithelial

2.2. Muscle Muscle

3.3. Nervous Nervous

4.4. Connective Connective

Epithelial TissueEpithelial Tissue Line the surfaces of the bodyLine the surfaces of the body

– body covering (exterior)body covering (exterior)– between organs (interior)between organs (interior)

Made of cells with strong connections, Made of cells with strong connections, which form a barrierwhich form a barrier

Types:Types: skinskin

– thin, flat cells that form sheetsthin, flat cells that form sheets– act as a semi-permeable barrier to the environmentact as a semi-permeable barrier to the environment

columnarcolumnar – columns of cells that line the stomach, intestines, etc.columns of cells that line the stomach, intestines, etc.

SKIN

COLUMNAR

Muscle TissueMuscle Tissue Moves parts of the body Moves parts of the body

– achieved by contracting or relaxing bundles of achieved by contracting or relaxing bundles of muscle cellsmuscle cells

Types:Types: skeletalskeletal

– cells line up in the same direction, giving a striated (striped) cells line up in the same direction, giving a striated (striped) looklook

– attaches to boneattaches to bone– found in limbs and where body needs supportfound in limbs and where body needs support

smoothsmooth – cells are tapered (thinned out) at both endscells are tapered (thinned out) at both ends– found in blood vessels, walls of inside organs like the found in blood vessels, walls of inside organs like the

esophagus, stomach, …esophagus, stomach, … cardiaccardiac

– found only in the heartfound only in the heart– unevenly stripedunevenly striped– contract all at the same timecontract all at the same time

Nervous TissueNervous Tissue Co-ordinates movement to keep the body Co-ordinates movement to keep the body

functioning properly functioning properly – have finger-like projections that receive & have finger-like projections that receive &

transfer signalstransfer signals Cells that make up nervous tissue Cells that make up nervous tissue

are called are called neuronsneurons Types are varied:Types are varied:

some relay signals from the brainsome relay signals from the brain others detect info from their environment and others detect info from their environment and

trigger the body’s responses (e.g., remove hand trigger the body’s responses (e.g., remove hand from a hot object)from a hot object)

Connective TissueConnective Tissue Strengthens, supports, protects, and Strengthens, supports, protects, and

connects tissuesconnects tissues Cells are in a matrix that ranges from a Cells are in a matrix that ranges from a

liquid to elastic materials to mineral depositsliquid to elastic materials to mineral deposits Many types, here are some:Many types, here are some:

bonebone– cells are surrounded by calcium-hardened tissuecells are surrounded by calcium-hardened tissue– needed for support & protectionneeded for support & protection

fat (aka fat (aka adiposeadipose tissue) tissue)– made of large, tightly-packed cellsmade of large, tightly-packed cells– needed for energy storage, padding, and insulationneeded for energy storage, padding, and insulation

bloodblood– includes RBCs, WBCs, platelets, & plasmaincludes RBCs, WBCs, platelets, & plasma– transports nutrients, including Otransports nutrients, including O22

– clots when skin is cutclots when skin is cut– attacks invaders like bacteria & virusesattacks invaders like bacteria & viruses

Random Diddies About theRandom Diddies About theHuman BodyHuman Body

The largest cell in the human body is the female egg and The largest cell in the human body is the female egg and the smallest is the male sperm. Go figure!the smallest is the male sperm. Go figure!

A full bladder is roughly the size of a soft ball A full bladder is roughly the size of a soft ball It takes food seven seconds to get from your mouth to your It takes food seven seconds to get from your mouth to your

stomach stomach A woman’s heart beats faster than a man’s A woman’s heart beats faster than a man’s Side by side, 2000 cells from the human body could cover Side by side, 2000 cells from the human body could cover

about one square inch about one square inch There are about one trillion bacteria on each of your feet There are about one trillion bacteria on each of your feet It takes twice as long to lose new muscle if you stop It takes twice as long to lose new muscle if you stop

working out than it did to gain itworking out than it did to gain it Your ears secrete more earwax when you are afraid Your ears secrete more earwax when you are afraid

(stressed) than when you aren’t(stressed) than when you aren’t If the average male never shaved, his beard would be 13 If the average male never shaved, his beard would be 13

feet long when he died feet long when he died Your body uses 300 muscles to balance itself when you’re Your body uses 300 muscles to balance itself when you’re

standing still standing still