biology sylvia s. mader michael windelspecht chapter 31 animal organization and homeostasis lecture...
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BiologySylvia S. Mader
Michael Windelspecht
Chapter 31 Animal Organization and
HomeostasisLecture Outline
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31.1 Types of Tissue
• Tissues are: Collections of specialized cells organized to
perform a common function
The four tissue types are:
Epithelial Connective Muscular Nervous
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Types of Tissue
• Epithelial Tissue (epithelium) Forms a continuous layer over body surfaces Lines body cavities Forms glands Epithelial cells may be connected to one another by
• Tight junctions• Adhesion junctions• Gap junctions
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Functions of epithelial tissue include:
ProtectionSecretionAbsorptionExcretionFiltration
3 types of epithelial tissue
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1. Simple
2. Stratified
3. glandular
Types of Tissue
• Simple Epithelia - A single layer of cells
Classified according to cell type:
• Squamous epithelium – flattened cells• Cuboidal epithelium – cube-shaped cells• Columnar epithelium – cells resembling columns
Glandular Epithelia
• - Secretes a product A gland can be a single epithelial cell or can contain
many cells Exocrine glands - Secrete products into ducts or
cavities Endocrine glands - Secrete products directly into the
bloodstream
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Stratified Epithelia –
Layers of cells
Types of Epithelial Tissues in the Vertebrates
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Simplesquamous
Simple cuboidal
basement membranebasement membrane
• lining of lungs, blood vessels• allows diffusion
• lining of kidney tubules, various glands• absorbs molecules
(All): © Ed Reschke
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Types of Epithelial Tissues in the Vertebrates
cilia
Simple columnar• lining of small intestine, oviducts• absorbs nutrients
Pseudostratified,ciliated columnar• lining of trachea• sweeps impurities toward throat
Stratified squamous• lining of nose, mouth, esophagus, anal canal, vagina• protects
basement membrane
basementmembrane
goblet cellsecretesmucus
goblet cellsecretesmucus
basementmembrane
(All): © Ed Reschke
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• Connective tissue functions: Establishing a structural framework Transporting fluids and dissolved materials Protecting delicate organs Supporting, surrounding and interconnecting
tissues Storing energy reserves Defending the body from microorganisms
• Connective tissue: Specialized cells Ground substance - Noncellular material Protein fibers
• Collagen fibers - contain collagen providing strength and flexibility
• Reticular fibers – contain thinly branched collagen fibers
• Elastic fibers – contain elastin
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Three categories of connective tissueFibrous
Supportive
Fluid
Types of Connective Tissue in Vertebrates
15(a, b); (c): © The McGraw-Hill Companies,Inc. Dennis Strete, Photographer
Loose fibrousconnectivetissue
fibroblast
a.
elasticfiber
collagenfiber
b. c.
nucleus
50 µm 400xcollagen
fibersnuclei of
fibroblasts
Adiposetissue
Dense fibrousconnectivetissue
50 µm
• has collagenous fibers closely packed.• in dermis of skin, tendons, ligaments.• functions in support.
• cells are filled with fat.• occurs beneath skin, around heart and other organs.• functions in insulation, stores fat.
• has space between components.• occurs beneath skin and most epithelial layers.• functions in support and binds organs.
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Types of Connective Tissue in Vertebrates
(d, e): © Ed Reschke
Hyalinecartilage
Compact bone
osteoncentral canal
d. e.
320xchondrocytewithin lacunae matrix
50 µmosteocyte
within a lacunacanaliculi
• has cells in lacunae.• occurs in nose; in the walls of respiratory passages; at ends of bones, Including ribs.• functions in support and protection.
• has cells in concentric rings.• occurs in bones of skeleton.• functions in support and protection.
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Fibrous Connective Tissue consist of:
• Fibroblast cells
• A matrix containing collagen and elastic fibers
Loose fibrous connective tissue• Allows organs to expand
Adipose tissue• Stores energy
• Insulates the body and provides padding
Dense fibrous connective tissue• Strong connective tissue
• Tendons – connect muscle to bone
• Ligaments – connect bones to other bones at joints
Diagram of Fibrous Connective Tissue
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Blood vessel
Adipose cell:stores fat
Groundsubstance: fillsspaces betweencells and fibers
Elastic fiber:branched andstretchable
Stem cell: divides toproduce other typesof cells
Collagen fiber:unbranched, strongbut flexible
Fibroblast: divides toproduce other typesof cells
Reticular fiber:branched, thin, andforms network
White blood cell:engulfs pathogensor produces antibodies
Cartilage• Classified according to type of collagen and elastic fibers
found in the matrix (hyaline cartilage, elastic cartilage, fibrocartilage)
• Cartilage cells lie in small chambers (lacuna) in the matrix
Bone• Matrix is inorganic salts deposited around protein fibers
• Bone cells are located in lacunae
• Lacunae arranged in concentric circles within osteons around tiny tubes (central canals)
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Supportive Connective Tissue
Blood• A connective tissue in which cells are embedded in a liquid
matrix (plasma)– Red blood cells – oxygen transport– White blood cells – immune response– Platelets – involved in the clotting process
• Functions– Transports nutrients and oxygen to cells– Removes carbon dioxide and other wastes
Lymph• A fluid connective tissue located in lymphatic vessels
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Fluid Connective Tissues
Blood, a Liquid Tissue
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b. Blood smear
plasma
white blood cell
platelets
red blood cell
plasma
white blood cells(leukocytes)
red blood cells(erythrocytes)
a. Blood sample after centrifugation
Muscular (contractile) Tissue
Contractile cells containing actin and myosin filaments Cells are called muscle fibers Three types of muscle tissue:
• Skeletal Muscle– Voluntary - Long, striated fibers, multinucleated
• Smooth (visceral) Muscle– Involuntary - No striations
• Cardiac Muscle– Striated, but mostly involuntary– Cells are bound to each other by intercalated disks– Relies on pacemaker cells for regular contraction
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Muscular Tissue
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Cardiac muscleSkeletal muscle Smooth muscle
400 250nucleus
nucleusnucleus
a.
striationintercalated disksmooth muscle
b. c.
• has striated cells with multiple nuclei.• occurs in muscles attached to skeleton.• functions in voluntary movement of body.
• has spindle-shaped cells, each with a single nucleus.• cells have no striations.• functions in movement of substances in lumens of body.• is involuntary.• is found in blood vessel walls and walls of the digestive tract.
• has branching, striated cells, each with a single nucleus.• occurs in the wall of the heart.• functions in the pumping of blood.• is involuntary.
a, c: © Ed Reschke; b: © McGraw-Hill Higher Education, Dennis Strete, photographer
cell
Nervous system (functions):
Sensory input• Sensory receptors detect changes• Transmit information to the spinal cord and brain
Data integration• Spinal cord and brain integrate data• Decision is made regarding appropriate response
Motor output• Response is transmitted to effector (gland or
muscle)• Effector initiates the actual response
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Nervous Tissue
Conducts electrical impulses
Conveys information from one area to another
Nervous tissue includes:• Neurons
– Transmit information
– Consist of dendrites, a cell body, and an axon
– Outside the brain and spinal cord, fibers bound by connective tissue form nerves.
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Neuroglia• Support and nourish neurons
• Neuroglia in brain include– Microglia
– Astrocytes
– Oligodentrocytes
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Nervous Tissue
Neurons and Neuroglia
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axon
cell body
axon
a. Neuron and neuroglia
dendrite
Neuronnucleus
MicrogliaAstrocyte
Oligodendrocyte
myelin sheath
Capillary
b: © Ed Reschke
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
b. Micrograph of a neuron 200×
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Regenerative Medicine
• In humans, axons outside the brain and spinal cord can regenerate, but not those inside these organs.
• Injured neurons in CNS degenerate Permanent loss of nervous function.
• In cold-water fishes and amphibians axon regeneration in the CNS does occur. Several proteins play role in axon
regeneration
Creating a New Type of Salamander for Limb Regeneration
31.2 Organs, Organ Systems, and Body Cavities
• Organ Composed of two or more tissue types
working together for a particular function
• Organ System Composed of various organs that cooperate
to carry out a general process• Ex: the digestion of food
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Body Cavities
1.Dorsal cavity (toward the back) • Contains the cranial cavity and the vertebral canal
• The brain is in the cranial cavity, and
• The spinal cord is in the vertebral canal
2. Ventral cavity (toward the front) is divided into
• The thoracic cavity (includes heart and lungs),
• The abdominal cavity (most other internal organs), and
• The pelvic cavity (certain reproductive organs)31
Mammalian Body Cavities
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diaphragm
a.
Cranialcavity:contains brain
DorsalcavityVertebral
cavity:containsspinal cordThoracic
cavity:contains heart,lungs, andesophagus
Abdominalcavity:contains stomach,liver , spleen,pancreas,and intestines
Ventralcavity
Pelviccavity:contains certainreproductiveorgans
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Mammalian Body CavitiesCopyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
b.
Thoracic cavity:contains esophagus,heart, and lungs
Abdominal cavity:contains digestive and other organs
Pelvic cavity:contains reproductiveand other organs
31.3 The Integumentary System
• Functions of skin Covers and protects underlying body regions
Regulates body temperature, and
Contains sensory receptors
• Skin and its derivatives make up the integumentary system
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Regions of the Skin
Epidermis Dermis Subcutaneous Layer
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- Outer, thinner region
Stratified squamous epithelium
New cells are pushed outward, become keratinized, and are sloughed off
Melanocytes produce melanin (pigment)
UV radiation can cause mutations in the DNA of skin cells, leading to skin cancer.
Dermis - Deeper and thicker than epidermis
• Fibrous connective tissue containing elastic and collagen fibers contains:
– Receptors
– Nerve fibers
– Blood vessels
Subcutaneous Layer - Loose, connective tissue located below dermis
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The Integumentary System• Accessory Structures of Human Skin:
Nails
Hair follicles
Hair follicles
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Nails
Grow from nail root and form protective covering of distal portion of fingers and toes
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Hair follicles
Begin in the dermis and continue through the epidermis
Contain oil glands (sebaceous glands) which secrete sebum
Lubricates the hair within the follicle as well as the skin
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Hair follicles
Begin in the dermis and continue through the epidermis
Contain oil glands (sebaceous glands) which secrete sebum
Lubricates the hair within the follicle as well as the skin
Human Skin Anatomy
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Dermis
Epidermis
Subcutaneous layer
nerve
arteryvein
adipose tissue
sensory receptor
hair root
sweat gland
arrector pili muscle
oil gland
free nerve endings
hair shaft
hair follicle
melanocytes
capillaries
sweat pore
The Epidermis
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Ep
ider
mis
a. Photomicrograph of skin c. Melanoma
Der
mis
flattened anddead cells
cells undergoingkeratinization
b. Basal cell carcinoma
stem cellsand melanocytes
dermalprojection
a: © John D. Cunningham/Visuals Unlimited; b: © Ken Greer/Visuals Unlimited; c: © James Stevenson/SPL/Photo Researchers, Inc.
31.4 Homeostasis
• The organ systems of the human body contribute to homeostasis:
The ability of an organism to maintain a relatively constant internal environment
Animals vary to the degree in which they can regulate internal variables.
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The organ systems of the human body contribute to homeostasis
1.The digestive system• Takes in and digests food• Provides nutrient molecules that replace used nutrients
2.The respiratory system• Adds oxygen to the blood • Removes carbon dioxide
3.The liver and the kidneys• Store excess glucose as glycogen• Later, glycogen is broken down to replace the glucose used• The hormone insulin regulates glycogen storage
4.The kidneys• Under hormonal control as they excrete wastes and salts
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Homeostasis
• Homeostatic Control
Partially controlled by hormones
Ultimately controlled by the nervous system
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Negative feedback is the primary homeostatic mechanism that keeps a
variable close to a set value
• Sensor detects change in environment
• Regulatory center initiates an action to bring the conditions back to normal
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Regulation of Room Temperature Using Negative Feedback
stimulus
stimulus
Homeostasistoo cold
too hot
Control center
68°F set point
Sensor
Sensor
68°F set point
sends data tothermostat
directs furnaceto turn off
negative feedbackand return tonormal temperature
70Ftoo hot
negative feedbackand return tonormal temperature
directs furnaceto turn on sends data to
thermostat
66°Ftoo cold
furnace off
furnace on
Control center
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Regulation of Body Temperature by Negative Feedback
Control center
Control center
Sensor
SensorEffect
Effect
stimulus
stimulus
Normal body temperature
above normal
below normal
98.6F set pointsends data tocontrol center
directs responseto stimulus
Blood vessels dilate;sweat glands secrete.
negative feedbackand return to normaltemperature
negative feedbackand return to normal
Blood vessels constrict;sweat glands are inactive.
directs responseto stimulus sends data to
control center
98.6F set point
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Positive feedback
• is a mechanism that brings about an ever greater change in the same direction Childbirth process
• Positive Feedback Does not result in equilibrium Does not occur as often as negative feedback
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Positive FeedbackCopyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
uterus
pituitary gland
2. Signals cause pituitary gland to release the hormone oxytocin. As the level of oxytocin increases, so do uterine contractions until birth occurs.
1. Due to uterine contractions, baby’s head presses on cervix, and signals are sent to brain.
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