the hierarchy of structural organization in an animal copyright © 2009 pearson education, inc
TRANSCRIPT
20.1 Structure fits function at all levels of organization in the animal body
Anatomy—structure
Physiology—function
Animals consist of a hierarchy of levels or organization
Copyright © 2009 Pearson Education, Inc.
20.2 EVOLUTION CONNECTION: An animal’s form reflects natural selection
Sharks, seals, and penguins have streamlined, tapered bodies
Copyright © 2009 Pearson Education, Inc.
Video: Galápagos Sea Lion
Video: Shark Eating a Seal
Cellular levelMuscle cell
Tissue levelMuscle tissue
Organ levelHeart
A B
C
D Organ system levelCirculatory system
Cellular levelMuscle cell
Tissue levelMuscle tissue
Organ levelHeart
Organ system levelCirculatory system
Organism levelMany organ systemsfunctioning together
A B
C
D
E
20.3 Tissues are groups of cells with a common structure and function
Copyright © 2009 Pearson Education, Inc.
Animals have four main categories of tissues
– Epithelial tissue
– Connective tissue
– Muscle tissue
– Nervous tissue
20.4 Epithelial tissue covers the body and lines its organs and cavities
Epithelial cells come in three shapes
– Squamous—like a fried egg
– Cuboidal—as tall as they are wide
– Columnar—taller than they are wide
Copyright © 2009 Pearson Education, Inc.
Apical surface ofepithelium
Cellnuclei
Underlyingtissue
Basallamina
Simple squamous epithelium(air sacs of the lung)
Simple cuboidal epithelium(kidney)
Simple columnar epithelium(intestine)
Stratified squamousepithelium(esophagus)
Pseudostratifiedciliated columnarepithelium(respiratory tract)
A
B
C
D
E
20.5 Connective tissue binds and supports other tissues
Connective tissue can be grouped into six major types
The tissue consists of a matrix which can be hard, semi soft or fluid in which are embedded cells.
Copyright © 2009 Pearson Education, Inc.
Fatdroplets
Adiposetissue
Whitebloodcells
Redbloodcell
Blood
Plasma
Loose connectivetissue (underthe skin)
Elasticfibers
Collagenfiber
CellFibrous connectivetissue (forminga tendon)
Collagenfibers
Cellnucleus
Cartilage(at the end of a bone)
Matrix
Cartilage-formingcells
Centralcanal
Matrix
Bone-formingcellsBone
B
AF
E
D
C
20.6 Muscle tissue functions in movement
Skeletal muscle causes voluntary movements
Cardiac muscle pumps blood
Smooth muscle moves walls of internal organs, such as the intestines
Copyright © 2009 Pearson Education, Inc.
Unit ofmusclecontraction Muscle
fiber
Nucleus
Nucleus
Musclefiber
Junction betweentwo cells
NucleusMuscle fiber
Cardiac muscle
Smooth muscle
Skeletal muscle
C
B
A
20.7 Nervous tissue forms a communication network
Neurons carry signals by conducting electrical impulses
Supporting cells insulate axons and nourish neurons
Copyright © 2009 Pearson Education, Inc.
20.8 Organs are made up of tissues
Each tissue performs specific functions
The heart has epithelial, connective, and nervous tissues
– Epithelia line the heart chambers
– Connective tissues make the heart elastic
– Neurons regulate contractions
Copyright © 2009 Pearson Education, Inc.
Small intestine
Lumen
Epithelial tissueConnective tissue
Smooth muscletissue (2 layers)
Connective tissue
Epithelial tissue(columnar epithelium)
Lumen
Artificial skin
Used to heal burns
20.9 CONNECTION: Bioengineers are learning to produce tissues and organs for transplants
Copyright © 2009 Pearson Education, Inc.
20.11 CONNECTION: New imaging technology reveals the inner body
New technologies show body organs without surgery
X-rays help to see bones and teeth
Copyright © 2009 Pearson Education, Inc.
Magnetic resonance microscopy (MRM)
– Provides three-dimensional images of very small structures
Copyright © 2009 Pearson Education, Inc.
20.11 CONNECTION: New imaging technology reveals the inner body
Positron-emission tomography (PET)
– Helps identify metabolic processes at specific body locations
Copyright © 2009 Pearson Education, Inc.
20.11 CONNECTION: New imaging technology reveals the inner body
20.10 Organ systems work together to perform life’s functions
An organ system usually consists of many organs
Each organ system has one or more functions
Copyright © 2009 Pearson Education, Inc.
Endocrine system controls body functions
Skeletal and muscular systems support and move the body
Circulatory system transports the food and oxygen
Respiratory system absorbs oxygen and releases carbon dioxide
Integumentary system covers and protects the body
Copyright © 2009 Pearson Education, Inc.
20.10 Organ systems work together to perform life’s functions
Circulatorysystem
Heart
Bloodvessels
Respiratory systemNasal cavityLarynx
TracheaBronchusLung
Muscularsystem
Integumentarysystem
Hair
Nails
Skin
Skeletalmuscles
Cartilage
Bone
Skeletalsystem
Adrenalgland
PancreasTestis(male)
Ovary (female)
Hypothalamus
Pituitary gland
Thyroid gland
Parathyroidgland
Endocrinesystem
C D
F
E
BA
Excretory system disposes of certain wastes
Lymphatic and immune systems protect the body from infection and cancer
Reproductive system perpetuates the species
Digestive system absorbs food
Nervous system controls body functions
Copyright © 2009 Pearson Education, Inc.
20.10 Organ systems work together to perform life’s functions
Lymphatic andimmune systems
G, H
Thymus
Bonemarrow
Spleen
Oviduct
Ovary
FemaleLymph nodes
Lymphaticvessels
Uterus
Vagina
Urinarysystem
Male
Brain
Seminal vesicles
Prostate gland
Vas deferens
Penis
Urethra
Testis
Sense organSpinalcord
Nervoussystem
Nerves
Esophagus
LiverStomachSmallintestine
Digestivesystem
Largeintestine
Anus
Mouth
Kidney
Ureter
Urinarybladder
Urethra
K
J
I
L
Reproductivesystem
20.12 The integumentary system protects the body
The skin consists of two layers
– Epidermis, at the surface
– Dermis, inner layer
Copyright © 2009 Pearson Education, Inc.
Epidermis
Dermis
Hypodermis
Adipose tissue
Blood vessels
Hair follicle
Oil gland
Sweatgland
Sweatpore
Hair
Muscle
Nerve
Skin has many functions
– Epidermis
– Resists damage
– Decreases water loss
– Prevents penetration by microbes
– Dermis
– Sensory information
– Synthesis of vitamin D
– Temperature regulation
Copyright © 2009 Pearson Education, Inc.
20.12 The integumentary system protects the body
20.13 Structural adaptations enhance exchange between animals and their environment
Animals must exchange materials with the environment
Respiratory system exchanges gases
Digestive system acquires food and eliminates wastes
Excretory system eliminates metabolic waste
Copyright © 2009 Pearson Education, Inc.
External environment
MouthFood
Animal
CO2 O2
Respiratorysystem
d
Bloo
Digestivesystem
Heart
Nutrients Circulatorysystem
Intestine
Urinarysystem
Bodycells
Interstitialfluid
Anus
Unabsorbed matter (feces)
Metabolic wasteproducts (urine)
Adaptations that increase surface area promote exchanges with the environment
Copyright © 2009 Pearson Education, Inc.
20.13 Structural adaptations enhance exchange between animals and their environment
Homeostasis is an internal steady state
20.14 Animals regulate their internal environment
Copyright © 2009 Pearson Education, Inc.
Humans promote homeostasis by
– Adding clothing when we are cold
– Drinking water when we are dehydrated
– Eating when our calories are running low
– Urinating when our bladders are full
Copyright © 2009 Pearson Education, Inc.
20.14 Animals regulate their internal environment
Negative feedback mechanisms permit only small fluctuations around set points
20.15 Homeostasis depends on negative feedback
Copyright © 2009 Pearson Education, Inc.
Animation: Negative Feedback
Animation: Positive Feedback
Sweat glands secrete sweatthat evaporates, cooling body
Blood vessels inskin dilate andheat escapes
Temperaturedecreases
Thermostat shuts offcooling mechanisms
Temperature risesabove normal
Temperature fallsbelow normal
Thermostat shuts offwarming mechanisms
Homeostasis:Internal body temperatureof approximately 36–38°C
Temperatureincreases
Blood vessels in skinconstrict, minimizingheat loss
Skeletal musclesrapidly contract,
causing shivering,which generates heat
Thermostat inbrain activateswarming mechanisms
Thermostat in brainactivates cooling
mechanisms
Epithelial (20.4) Connective (20.5) Muscle (20.6) Nervous (20.7)
Neurons withbranchingextensions
Long cells (fibers)with contractileproteins
Sparse cells inextracellularmatrix
Sheets of closelypacked cells
Protection,exchange,secretion
Binding andsupport ofother tissues
Movement ofbody parts
Transmission ofnerve signals
Fu
nct
ion
Str
uc
ture
Tis
sue
You should now be able to
1. Explain the relationship between anatomy and physiology
2. Describe the structural hierarchy of the body from cell to organism
3. Explain how an animal’s form is influenced by its environment
4. Describe an example of convergent evolution
5. Describe the general structures and functions of the major tissues of the human body
Copyright © 2009 Pearson Education, Inc.
6. Describe several recent advances of bioengineering
7. List and describe the functions of the major systems of the body
8. Explain how materials are exchanged between an organism and its environment
9. Define homeostasis and describe several examples
Copyright © 2009 Pearson Education, Inc.
You should now be able to