Transcript Chapter 16: Tissues, Organs, and Organ Systems

Chapter 16
Tissues, Organs, and Organ Systems
Organ Donation
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Chapter 16 Section 1
Tissues
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16.1 Tissues
Levels of organization:





Cells
Tissues
Organs
Organ Systems
Organisms
Smallest
Largest
Tissues = group of similar cell types that
perform a common function.
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16.1 Tissues
Tissues = group of similar cell types that
perform a common function.
Four basic types of tissue:
1.
2.
3.
4.
Epithelial
Connective
Muscle
Nervous
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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.
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(a) Examples of organs lined with epithelial
(b) Epithelial cells in skin
tissue:
Heart and blood vessels
Epidermis
Respiratory tract
Digestive tract
Urogenital tract
(c) Epithelial cells lining
the small intestine
Figure 16.1
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
 Examples include: Blood cells, adipocytes,
fibroblasts, chondrocytes, osteocytes
 Matrix is composed of two things
1. Ground substance
 May be liquid, gel-like, rubbery or solid
2. 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:
1.
2.
3.
4.
5.
6.
Loose connective tissue
Adipose tissue
Blood
Fibrous connective tissue
Cartilage
Bone
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16.1 Tissues - Connective Tissue
Loose Connective Tissue
 Most widespread tissue in
animal body
 Matrix composed of
collagen and elastin fibers
 Cells are fibroblasts and
adipocytes
 It is called “loose” because
fibers are loosely woven
together
 Binds epithelia to tissues,
pads skin, and holds organs
in place
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Figure 16.2a
16.1 Tissues - Connective Tissue
Adipose Tissue
 AKA Fat
 Primarily adipocytes;
small amount of matrix
 Functions
 Used for storage of
energy (fat)
 Insulation
 Padding for organs
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Figure 16.2b
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
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(c) Blood
Platelet
Red
blood cell
Plasma
White
blood cell
Figure 16.2c
16.1 Tissues - Connective Tissue
Fibrous Connective
Tissue
 Forms tendons and
ligaments
 Matrix is collagen
fibers running in
parallel
 Cells are fibroblasts
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(d) Fibrous connective tissue (tendon)
Fibroblast
cell
Parallel
collagen
fibers
Figure 16.2d
16.1 Tissues - Connective Tissue
Cartilage
 Cells are chondrocytes
 Cells 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
(e) Cartilage
(at the end of a bone)
Chondrocytes
Matrix
injured
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Figure 16.2e
16.1 Tissues - Connective Tissue
Bone
 Rigid connective tissue
 Cells are osteocytes
 Cells 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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(f) Bone
Central
canal
Matrix
Osteocytes
Figure 16.2f
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. Skeletal
2. Cardiac
3. Smooth
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16.1 Tissues - Muscle Tissue
Skeletal Muscle




Usually attached to bone
Produces all voluntary movements
Striated – due to overlap of actin & myosin
Long, thin, cylindrical shape
(a) Skeletal muscle (biceps)
Muscle fiber Nucleus
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Figure 16.3a
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
(b) Cardiac muscle (heart)
Muscle fiber
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Nucleus
Figure 16.3b
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
(c) Smooth muscle (intestine)
Muscle fiber
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Nucleus
Figure 16.3c
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
 Other tissues can be harvested to help others
 > One person’s tissues can improve the
lives of as many as 50 people.
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End Chapter 16 Section 1
Tissues
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Chapter 16 Section 2 Part 1
Organs and Organ Systems
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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
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Muscle cell
Muscle tissue
Heart organ
Circulatory system
Organism
Figure 16.5
16.2 Organs and Organ Systems
12 Organ Systems
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Figure 16.8
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.
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Figure 16.6
16.2 Organs and Organ Systems
The Liver as a Model Organ
 The liver is an important component of the
circulatory and the digestive system.
 As part of the circulatory system, the liver:
 Synthesizes blood clotting factors
 Removes and breaks down toxins
 Regulates blood volume
 Destroys old red blood cells
 As part of the digestive system, the liver:
 Metabolizes and stores nutrients
 Produces bile
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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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End Chapter 16 Section 2 Part 1
Organs and Organ Systems
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Chapter 16 Section 2 Part 2
The Digestive System
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16.2 Organs and Organ Systems
The Digestive System
Alimentary canal
1 Mouth
• Teeth reduce the size of food,
increasing surface area available
for digestion by enzymes.
• Enzymes in saliva then start
breaking down carbohydrates.
Accessory organs
of the digestive
system
Liver
• Produces bile
which aids
absorption of
fats
Gall bladder
• Stores bile and empties
into small intestine
Pancreas
• Produces digestive
enzymes
• Produces a buffer
that neutralizes
acidity of stomach
acid
2 Pharynx
• Epiglottis blocks the opening to the
windpipe when we swallow, so that our
food goes into our esophagus rather than
our lungs.
3 Esophagus
• The esophagus transports food to stomach
by rhythmic waves of muscle contractions
called peristalsis.
4 Stomach
• Acidic gastric juices start breaking down
foods.
• The enzyme pepsin breaks down proteins.
• Mucous prevents gastric juices from
digesting stomach.
• Pyloric sphincter regulates movement of
food from stomach to small intestine.
5 Small intestine
• Most digestion of carbohydrates, proteins,
and fats occurs here.
• Nutrients are absorbed into the
bloodstream.
6 Large intestine
• Water is reabsorbed.
7 Anus
• Undigested materials are excreted
as feces.
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Figure 16.8
16.2 Organs and Organ Systems
The Digestive System
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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Figure 16.8
16.2 Organs and Organ Systems
The Digestive System
Esophagus
• The esophagus
transports food to stomach
by rhythmic waves of
muscle contractions called
peristalsis.
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Figure 16.8
16.2 Organs and Organ Systems
The Digestive System
Stomach
• HCl starts breaking down
foods.
• The enzyme pepsin breaks
down proteins.
• Mucous prevents gastric juices
from digesting stomach.
• Pyloric sphincter regulates
movement of food from stomach
to small intestine.
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Figure 16.8
16.2 Organs and Organ Systems
The Digestive System
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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Figure 16.8
16.2 Organs and Organ Systems - The
Digestive System
Internal Specializations
 Mucosal folds, villi and microvilli
increase the surface area of the intestines
to allow nutrient absorption
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Figure 16.9
16.2 Organs and Organ Systems
The Digestive System
Accessory Organs
Liver
• Produces bile which
aids absorption of fats
Gall bladder
• Stores bile and
empties into small
intestine
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Figure 16.8
16.2 Organs and Organ Systems
The Digestive System
Accessory Organs
Pancreas
• Produces LOTS of
digestive enzymes
• Produces a buffer
that neutralizes stomach
acid
• Enzymes & buffer are
released into small
intestine
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Figure 16.8
16.2 Organs and Organ Systems
Organ Systems = many organs working
together
 Failure of one organ may compromise the
organ 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
PLAY
Animation—The Digestive System
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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
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Figure 16.9
End Chapter 16 Section 2 Part 2
The Digestive System
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Chapter 16 Section 3
Regulating the Internal Environment
Organ Donation
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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
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LE 40-11
Response
No heat
produced
Heater
turned
off
Room
temperature
decreases
Set
point
Too
hot
Set point
Control center:
thermostat
Too
cold
Room
temperature
increases
Set
point
Heater
turned
on
Response
PowerPoint lecture prepared by
Heat
James M. Hutcheon
produced
Georgia Southern University
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16.3 Regulating the Internal Environment
Homeostasis
 Negative feedback is when the outcome
of a process inhibits that process.
(a) If blood glucose
level rises...
Liver converts glucose
to glycogen.
Pancreas
secretes insulin.
(b) If blood glucose
level falls...
Glucose
Glycogen
Liver
Blood glucose
level falls.
Homeostasis
Normal blood glucose level
Glucose levels rise.
Glucose
Glycogen
Pancreas secretes glucagon.
Liver
Liver breaks down glycogen
into glucose and releases
glucose into bloodstream.
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Figure 16.11
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
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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.
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End Chapter 16 Section 3
Regulating the Internal Environment
Organ Donation
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End Chapter 16
Tissues, Organs, and Organ Systems
Organ Donation
Copyright © 2010 Pearson Education, Inc.