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Transcript of Copyright 2010 Pearson Education, Inc. Chapter 16 Tissues, Organs, and Organ Systems Organ...
Copyright © 2010 Pearson Education, Inc.
Chapter 16
Tissues, Organs, and Organ Systems
Organ Donation
Copyright © 2010 Pearson Education, Inc.
16.1 Tissues
Tissues = group of similar cell types that perform a common function.
Four basic types of tissue:1. Epithelial2. Connective3. Muscle4. Nervous
Copyright © 2010 Pearson Education, Inc.
16.1 Tissues - Epithelial Tissue
Epithelium is tightly packed sheets of cells
cover organs and outer surfaces
line insides of hollow organs, vessels, and body cavities.
Figure 16.1
(a) Examples of organs lined with epithelialtissue:
(b) Epithelial cells in skin
Heart and blood vessels
Respiratory tract
Digestive tract
Urogenital tract
Epidermis
(c) Epithelial cells liningthe small intestine
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16.1 Tissues - Epithelial Tissue
Epithelia are polar anchored on one surface, but free on another
The free side is typically exposed to the environment or body fluids
Can be single layer or many layers thick
Function in protection, secretion, and absorption
Epithelial cells are continuously sloughing off and are replaced by cell division
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16.1 Tissues - Connective Tissue
Connective Tissue Loosely organized and composed of cells
embedded in a matrix Cells
Blood cells, adipocytes, fibroblasts, chondrocytes, osteocytes
Matrix is composed of two things1. Ground substance
Liquid, gel-like, rubbery or solid2. Fibers
Collagen, elastin, reticular fibers
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16.1 Tissues - Connective Tissue
Connective Tissue Usually binds organs or tissues to one another Six different types:
Loose connective tissue Adipose tissue Blood Fibrous connective tissue Cartilage Bone
Copyright © 2010 Pearson Education, Inc. Figure 16.2a
16.1 Tissues - Connective Tissue
Most widespread tissue in animal body
Matrix composed of collagen and elastin fibers
It is called “loose” because fibers are loosely woven together
Binds epithelia to tissues, pads skin, and holds organs in place
Loose Connective Tissue
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16.1 Tissues - Connective Tissue
Adipose Tissue AKA Fat Primarily adipose
cells; small amount of matrix
Functions Used for storage of
energy (fat) Insulation Padding for organs
Figure 16.2b
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16.1 Tissues - Connective Tissue
Blood Cellular component
red blood cells, white blood cells and platelets
Matrix is the plasma Functions include
carrying oxygen and nutrients; fighting infection
Figure 16.2c
Redblood cell
Platelet
Whiteblood cell
Plasma
(c) Blood
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16.1 Tissues - Connective Tissue
Fibrous Connective Tissue Forms tendons and
ligaments Matrix is collagen
fibers running in parallel
Figure 16.2d
Fibroblastcell
Parallelcollagenfibers
(d) Fibrous connective tissue (tendon)
Copyright © 2010 Pearson Education, Inc. Figure 16.2e
MatrixMatrix
Chondro-cytes
(e) Cartilage(at the end of a bone)
16.1 Tissues - Connective Tissue
Cartilage Chondrocytes
Secrete rubbery matrix, collagen and elastin
Cartilage cushions joints, forms support for ears and nose
Not vascularized, so takes a long time to heal if injured
Copyright © 2010 Pearson Education, Inc. Figure 16.2f
Matrix
Osteocytes
Centralcanal
(f) Bone
16.1 Tissues - Connective Tissue
Bone Rigid connective tissue Osteocytes
secrete matrix of collagen fibers and calcium salts
Bone marrow produces blood cells
Body can make use of calcium from bones if dietary levels are too low
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16.1 Tissues - Muscle Tissue
Muscle is contractile tissue Long, thin cylindrical cells called muscle
fibers Two proteins – actin and myosin –
interact to cause contraction of muscle fibers
Three types of muscle:1. Skeletal2. Cardiac3. Smooth
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16.1 Tissues - Muscle Tissue
Skeletal Muscle Usually attached to bone Produces all voluntary movements Striated Long, thin, cylindrical shape
Figure 16.3aMuscle fiber Nucleus
(a) Skeletal muscle (biceps)
Copyright © 2010 Pearson Education, Inc. Figure 16.3b
(b) Cardiac muscle (heart)
Muscle fiber Nucleus
16.1 Tissues - Muscle Tissue
Cardiac Muscle Only found in
heart tissue Striated involuntary,
undergoes rhythmic contractions to produce heartbeat
Branched, interlocking cells propagate signal to contract almost simultaneously
Copyright © 2010 Pearson Education, Inc. Figure 16.3c
Muscle fiber Nucleus
(c) Smooth muscle (intestine)
16.1 Tissues - Muscle Tissue
Smooth Muscle Not striated Spindle-shaped cells Musculature of
organs, blood vessels, digestive tract
Involuntary Contracts more slowly and for longer than
skeletal muscle
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16.1 Tissues - Nervous Tissue
Nervous Tissue Neurons conduct electrical signals Primary cells of the brain and spinal cord Main function of neurons is to:
Sense stimuli Process stimuli Transmit signals
Most cells of nervous system do not undergo cell division
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16.1 Tissues - Tissue Donation
Brain death and Tissue Donation Injuries from motor vehicle accidents, burst
blood vessels, and drowning are common causes of brain death Once dead, brain cells cannot recover Tissues can be harvested to help others
> One person’s tissues can improve the lives of as many as 50 people.
Copyright © 2010 Pearson Education, Inc. Figure 16.5
16.2 Organs and Organ Systems
Organs are composed of two or more tissue types Organs that act
together form an organ system
All the organ systems of a body form an organism
Muscle cell
Muscle tissue
Heart organ Circulatory system Organism
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16.2 Organs and Organ Systems
Figure 16.8
12 Organ Systems
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16.2 Organs and Organ Systems –
The Liver as a Model Organ The liver sits below the
diaphragm comprised of four
lobes associated with the
gall bladder.
Figure 16.6
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16.2 Organs and Organ Systems
The Liver as a Model Organ The liver is an important component of the
digestive and the circulatory system As part of the circulatory system, the liver:
Synthesizes blood clotting factors Detoxifies Regulates blood volume Destroys old red blood cells
As part of the digestive system, the liver: Produces bile Metabolizes and stores nutrients
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16.2 Organs and Organ Systems
Liver Structure Epithelia
Hepatocytes Lining blood vessels Lining bile ducts
Connective Tissue Loose connective
tissue Kupffer cells
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16.2 Organs and Organ Systems - The Liver as a Model Organ
Liver transplants can be made from living donors or from brain dead ones Unlike many organs, liver can regenerate
itself Portion can be taken from living donor and
implanted in patient Liver in donor and patient will regrow to
normal size
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16.2 Organs and Organ Systems
The Digestive System
Figure 16.8
Mouth• Teeth reduce the size of food, increasing surface area available for digestion by enzymes.• Amylase enzymes in saliva start breaking down carbohydrates.
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16.2 Organs and Organ SystemsThe Digestive System
Figure 16.8
Esophagus• The esophagus transports food to stomach by rhythmic waves of muscle contractions called peristalsis.
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16.2 Organs and Organ SystemsThe Digestive System
Figure 16.8
Stomach• HCl starts breaking down foods.• The enzyme pepsin breaks down proteins.• Mucous prevents gastric juices from digesting stomach.• Pyloric sphincter regulates movement offood from stomach to small intestine.
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16.2 Organs and Organ SystemsThe Digestive System
Figure 16.8
Small intestine• Most digestion of carbohydrates, proteins,and fats occurs here.• Nutrients are absorbed into the bloodstream.
Large intestine• Water is reabsorbed
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16.2 Organs and Organ Systems - The Digestive System
Villi and microvilli increase the surface area of the intestines to allow nutrient absorption
Figure 16.9
VillusLumen
Mucosal folds
Small intestine One villus Micrograph
Bloodcapillaries
ArterioleVenule
Lymphaticvessel
Microvilli
Nutrients in small intestine
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16.2 Organs and Organ SystemsThe Digestive System
Figure 16.8
Accessory Organs
Liver• Produces bile which aids absorption of fats
Gall bladder• Stores bile and empties into small intestine
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16.2 Organs and Organ SystemsThe Digestive System
Figure 16.8
Accessory Organs
Pancreas• Produces LOTS of digestive enzymes• Produces a bufferthat neutralizes stomach acid• Enzymes & buffer are released into small intestine
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16.2 Organs and Organ Systems
An organ system consists of many organs working together
Failure of one organ may compromise the entire system Intestine transplants and pancreatic
transplants are becoming more common Gall bladder and stomach transplants are
rarely done Organ failure can also disrupt multiple
systems
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16.2 Organs and Organ Systems
Animation—The Digestive SystemPLAY
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16.2 Organs and Organ Systems
Evolution of the Digestive System Paramecia use digestive food vacuoles Hydra have an extracellular digestive sac Earthworms have alimentary canal
Allows for ‘assembly line’ like specialization
Figure 16.9
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Homeostasis
Homeostasis a dynamic state of equilibrium in which
internal conditions remain relative stable (Steady State)
homeostasis regulates conditions in the internal environment
A homeostatic control system has a receptor a control center a set point an effector
James M. HutcheonGeorgia Southern University
PowerPoint lecture prepared by
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LE 40-11Response
No heatproduced
Roomtemperaturedecreases
Roomtemperature
increases
Set point
Toohot
Set point
Heaterturnedoff
Toocold
Set point
Control center:thermostat
Heaterturnedon
Response
Heatproduced
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16.3 Regulating the Internal Environment
Homeostasis Negative feedback is when the outcome
of a process inhibits that process.
Figure 16.11
Pancreassecretes insulin.
Glucose
Liver converts glucoseto glycogen.
Liver breaks down glycogeninto glucose and releasesglucose into bloodstream.
Glycogen
GlucoseGlycogen
Liver
LiverPancreas secretes glucagon.
(a) If blood glucoselevel rises...
Blood glucoselevel falls.
Glucose levels rise.(b) If blood glucoselevel falls...
HomeostasisNormal blood glucose level
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16.3 Regulating the Internal Environment
Homeostasis Positive feedback occurs when the outcome of
a process increases or intensifies that process. During childbirth, hormones cause muscles of
uterus to contract Uterine contractions cause even more hormones
to be released, which intensify the contractions
> In animals, regulation is usually by negative feedback because positive feedback often results in amplification – away from homeostasis
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16.3 Regulating the Internal Environment –
Organ Donation The best candidates to donate organs are
those who have died of brain injury. In cardiac death, organs deteriorate due to
lack of oxygen, and thus are less suitable for transplant.
Thousands of lives are saved each year through organ donation.
The decision to become a donor now can save families from making difficult decisions later.