1 Ch. 8 Cell Structure & Function Lesson 2 How are Cells Specialized?
2 Different Cells for Different Jobs All multicellular organisms have specialized cellsthat work together.Complex organisms have many types of cells.Each cell has special structures that allow it tocarry out specific tasks.A group of cells that has a common structurefunction is called a tissue.Epithelial tissues:*sheet of cells thatcover surfaces*line certain bodycavities and blood vessels*usually smooth
3 Connective tissues:*join other tissues together*stores fat and makes blood cells*includes bone, blood, and cartilage*made of specialized cells and fibersthat stick to living cellsMuscle tissues:*work together to move body*create movement in one direction only (eithergetting longer or shorter)Nervous tissue:*produces electrical impulses and sends signals*routed through nervous tissue*some send signals while others protect andprovide with nutrients
4 Body functions performed by special structures called organsOrgans:*made up of several tissue types that worktogether to perform one or more functions*example-plant’s leaves, roots, flowersThree human organs:*brain-*heart-*liver-*skin-protect from injury and retain moistureSome organs perform more than one function*kidneys-remove waste and control bloodpressure
5 Relationship among cells, tissues, and organs *tissues are groups of cells withcommon structures and functions*organs are made of different types oftissues that work togetherOrgan SystemsGroups of organs that work together to performcomplex tasksThe more complex the organism,the greater the number of organsystems needed to survive.Humans have 11 organ systems.Some work for more than oneorgan system.
6 Circulatory systemCarries hormones made in the endocrine systemthroughout the bodyCarries blood and oxygen to the body andremoves carbon dioxide and other wastesHelps keep body temperature constantIncludes heart, arteries, veins, and bloodConnects to the Urinary system at the kidneys*helps regulate water and salt in blood, aswell as remove liquid wastesMusculoskeletal systemSupports all parts of body andallows movement of different partsBones anchor body parts and provide structure
7 Contracting your muscles make body parts move Generates warmth for body (reason why you feelwarmer when you exercise)Nervous systemBrain is headquarters ofnervous systemSenses feed information intobrainBrain process and responds to information bysending signals down nerves to musclesBrain control other organ systemsRespiratory systemBrings oxygen into bodyRemoves carbon dioxide from body
8 Endocrine SystemChemical messenger system that makes andsends out hormones throughout the bodyHormones have many functions*act as messages*travel through bloodstream*picked up only by certain cells*regulating growth and blood sugarGrowth hormone-causedramatic changes in musclesand bones as you growPlants use hormones to controlgrowth and other functions
9 What makes a multi-celled organism different from one that is single-celled?Only multi-celled organisms have cells that work together to form specific functions.