Download Bio 20 Ch 4 Tissues, Organs and Organ Systems

Chapter 4
Tissues, Organs, and
Organ Systems
Cecie Starr | Beverly McMillan
Tissues, Organs, and Organ Systems
Key Concepts
• Types of Body Tissues
• Organs and Organ Systems
• Homeostasis
4
Tissues, Organs, and Organ Systems
4
• Stem cells
– Embryonic stem cells:
controversy
– Adult stem cells
p67
4.1 Epithelium: The Body’s Covering and Linings
Types of Body Tissues
• Epithelial tissues cover the body surface or line it’s
cavities and tubes
4.1 Epithelium: The Body’s Covering and Linings
There are two basic types of epithelia.
• Epithelium
– Simple: one layer of cells
– Stratified: several layers of cells
• Shape of the cells at the tissue’s free surface
– Squamous epithelium
– Cuboidal epithelium
– Columnar epithelium
• Basement membrane
4.1 Epithelium: The Body’s Covering and Linings
free surface of
epithelium
Flattened simple squamous epithelium
simple
squamous
epithelium
Squarish simple cuboidal epithelium
basement
membrane
connective
tissue
Tall simple columnar cells
Figure 4-1 p68
4.1 Epithelium: The Body’s Covering and Linings
Glands form from epithelium.
• Gland
– Make and release specific products
– Derived from epithelial tissue
• Classification
– Exocrine gland
• Substances released through ducts or tubes
– Endocrine gland
• Substances released directly into the extracellular fluid
4.1 Epithelium: The Body’s Covering and Linings
Endocrine gland
Take home message
blood
vessel
cell that secretes
hormone
What are epithelial tissues?
Exocrine gland
parotid gland
(secretes saliva)
parotid duct (delivers
saliva to mouth)
thyroid gland
(secretes
hormones into
blood)
Figure 4-2 p69
4.2 Connective Tissue: Binding, Support, and Other
Roles
• Connective tissue connects, supports, and anchors the
body’s parts
• Makes up more of your body than any other tissue
• Fibrous and specialized types
• Matrix
– Ranges from hard to liquid
4.2 Connective Tissue: Binding, Support, and Other
Roles
Fibrous connective tissues are strong and stretchy.
• Fibrous connective tissue
• Loose connective tissue
– Flexible
• Dense connective tissues
– Less flexible; stronger
• Elastic connective tissue
– Stretchy due to elastin
Table 4-1 p69
Table 4-2 p70
4.2 Connective Tissue: Binding, Support, and Other
Roles
collagenous fiber
fibroblast
elastic fiber
collagenous
fibers
Type Loose connective tissue
Description Fibroblasts, other cells,
Type Dense, irregular connective tissue
Description Collagenous fibers,
plus fibers loosely arranged in
semifluid matrix
Common Locations Under the skin
and most epithelia
Function Elasticity, diffusion
fibroblasts, less matrix
Common Locations
In skin and capsules around some organs
Function Support
Figure 4-3 p70
4.2 Connective Tissue: Binding, Support, and Other
Roles
Special connective tissues include cartilage, bone, adipose
tissue, and blood.
• Cartilage
– Hyaline cartilage
– Elastic cartilage
– Fibrocartilage
• Bone tissue
• Adipose tissue
• Blood
4.2 Connective Tissue: Binding, Support, and Other
Roles
collagenous
fibers
fibroblast
Type Dense, regular connective tissue
Description Collagen fibers in parallel
bundles, long rows of fibroblasts, little
matrix
Common Locations Tendons,
ligaments
Function Strength, elasticity
ground substance with
very fine collagen
fibers
cartilage cell
(chondrocyte)
Type Cartilage
Description Cells embedded in pliable,
solid matrix
Common Locations Ends of long bones,
nose, parts of airways, skeleton of embryos
Function Support, flexibility, low-friction
Figure 4-3 p70
surface for joint movement
4.2 Connective Tissue: Binding, Support, and Other
Roles
compact
bone tissue
blood vessel
bone cell
(osteocyte)
Type Bone tissue
Description Collagen fibers, matrix
hardened with calcium
Common Locations Bones of skeleton
Function Movement, support, protection
Figure 4-3 p70
nucleus
cell bulging
with fat
droplet
Type Adipose tissue
Description Large, tightly packed fat cells
occupying most of matrix
Common Locations Under skin, around heart,
kidneys
Function Energy reserves, insulation, padding
4.3 Muscle Tissue: Movement
• Cells in muscle tissue can contract, allowing
muscle to move body parts
• Muscle tissue- contracts and shortens when
stimulated by an outside signal
4.3 Muscle Tissue: Movement
• Skeletal muscle- striated; usually attached to
bone; voluntary; multinucleated
• Smooth muscle- tapered; walls of internal organs;
involuntary; uninucleated
• Cardiac muscle- cardiac wall; branching: special
cellular junctions (intercalated discs); involuntary;
uninucleated
Take home message
What is muscle tissue?
white blood cell
platelet
red blood cell
Figure 4-4 p71
4.3 Muscle Tissue: Movement
VOLUNTARY
INVOLUNTARY
nucleus
nucleus
adjoining
ends of
abutting
cells
A Skeletal muscle
B Smooth muscle
C Cardiac muscle
Figure 4-5 p72
4.4 Nervous Tissue: Communication
• Nervous tissue makes up the nervous system
– Neurons (nerve cells)
– Neuroglia (support cells)
• Communication lines; carry messages
4.4 Nervous Tissue: Communication
• Glial cells (neuroglia)
– 90% of the cells of the
nervous system
– Bring nutrients to the
neurons
– Physically support neuron
– Remove debris
– Myelin Sheath
(Schwann cells)
• Provide insulation
p73
4.4 Nervous Tissue: Communication
• Neurons have a cell
body that contains a
nucleus and
cytoplasm
• Cell processes
– Dendrites
– Axons
Take home message
What is nervous tissue?
p73
4.5 Healing with Stem Cells and Lab-Grown Tissues
• “Reverse engineering”
mature cells to convert
them back to stem cells
stem
cell
• Introduce “cured” stem
cells to replace faulty stem
cells
• Use stem cells from bone
marrow and umbilical
cords
• Use a cultured skin
substitute
cell
type 1
or
stem
cell
cell
type 2
stem
cell
or
stem
cell
stem
cell
cells divide
cell
type 3
cells specialize
p73
Figure 4-6 p73
4.6 Cell Junctions: Holding Tissues Together
• Junctions between the cells in a tissue knit the
cells firmly together, stop leaks, and serve as
communication channels
4.6 Cell Junctions: Holding Tissues Together
• Tight junctions
– Block leaking between adjoining cells
• Adhering junctions
– Desmosomes
– Cement cells together
• Gap junctions
– Channels that connect the cytoplasm of neighboring cells
– Abundant in smooth and cardiac muscle
Take home message
What do cell junctions do?
4.6 Cell Junctions: Holding Tissues Together
cell
basement
membrane
Figure 4-7 (top) p74
4.6 Cell Junctions: Holding Tissues Together
cytoskeleton
filaments
plasma
membrane
of one cell
A Tight Junction
B Adhering Junction
channel
C Gap Junction
Figure 4-7 p74
4.7 Tissue Membranes: Thin, Sheet-like Covers
• Thin, sheet-like membranes cover many body
surfaces and cavities
– Some provide protection
– Others both protect and lubricate organs
4.7 Tissue Membranes: Thin, Sheet-like Covers
• Cutaneous membranes
• Mucous membranes
– Designed to secrete and/or
absorb substances
– Most have glands
– Line tubes and cavities
• Serous membranes
– Occur in paired sheets; line
the thoracic cavity and
enclose the heart and lungs
– Secrete a fluid; no glands
– Dry membrane; skin
• Synovial membranes
– Line cavities of the body’s
movable joints
– Lubricate the ends of moving
bones
– Prevent friction between a
bone and a moving tendon
Take home message
What are the functions of membranes?
4.7 Tissue Membranes: Thin, Sheet-like Covers
A mucous membrane
B serous membrane
C cutaneous
membrane (skin)
D synovial membrane
Figure 4-8 p75
4.8 Organs and Organ Systems
Organs and Organ Systems
• Organ
• Body cavities
–
–
–
–
–
Cranial cavity
Spinal cavity
Thoracic cavity
Abdominal cavity
Pelvic cavity
4.8 Organs and Organ Systems
Organ system:
A set of organs that
interacts to carry out a
major body function
Organ:
Body structure that integrates different
tissues and carries out a specific function
Stomach
Epithelial tissue:
Connective tissue:
Protection, transport,
Structural support
secretion, and absorption
Figure 4-9a p76
Muscle tissue:
Movement
Nervous tissue:
Communication,
coordination, and
control
4.8 Organs and Organ Systems
cranial
cavity
spinal
cavity
thoracic
cavity
abdominal
cavity
pelvic
cavity
Figure 4-9b p76
4.8 Organs and Organ Systems
Organ systems:
Integumentary
System
Nervous
System
Muscular
System
Skeletal
System
Circulatory
System
Endocrine
System
Figure 4-10a p77
4.8 Organs and Organ Systems
Organ systems:
Lymphatic
System
Respiratory
System
Digestive
System
Urinary
System
Reproductive
System
Figure 4-10a p77
4.9 The Skin: An Example of an Organ System
Skin and structures that develop from it make up the
integument- the body’s covering.
• Skin
– Largest surface area of any organ
– Functions
• Oil glands
• Sweat glands
• Hair
• Nails
4.9 The Skin: An Example of an Organ System
Epidermis and dermis are the skin’s two layers.
• Epidermis
– Stratified squamous
epithelium
– Keratinocytes
– Melanocytes
• Role in skin color
– Langerhans cells
– Granstein cells
• Dermis
– Dense connective tissue
– Elastin and collagen fibers
– Blood vessels and nerve
endings
– Oil and sweat glands
– Hair follicles
4.9 The Skin: An Example of an Organ System
hair
duct of
sweat
gland
blood
vessel
pressure
sensitive
sensory
receptor
smooth
muscle
sweat
gland
hair
follicle
sebaceous
gland
epidermis
stratified
squamous
epithelium
dermis mainly
dense
connective
tissue
hypodermis
mainly adipose
tissue and
loose
connective
tissue
Figure 4-11a p78
4.9 The Skin: An Example of an Organ System
outer flattened
epidermal cells
epidermis
stratified
squamous
epithelium
cells being
flattened
dermis
dividing cells
mainly
dense
connective
tissue
dermis
Figure 4-11b p78
4.9 The Skin: An Example of an Organ System
• Hypodermis: layer beneath dermis
– Loose connective
– Fat: insulator and cushion
4.9 The Skin: An Example of an Organ System
Sweat glands and other structures develop from
epidermis.
• Sweat glands
– Location of glands
– Chemical composition of sweat
– Role in evaporative cooling
• Oil glands
– Location
– Sebum: softens and lubricates hair
– Effect on bacteria
• Hair
– Keratinized cells
4.9 The Skin: An Example of an Organ System
Skin disorders are common.
• Blisters
• Acne
• Cold sores
• Vitiligo
Take home message
What is the integumentary system?
• Cancer
– Squamous cell carcinoma
– Malignant melanoma
Squamous cell carcinoma
• Effect of ultraviolet radiation
on the skin
Figure 4-12 p79
Malignant melanoma
p79
4.10 Homeostasis: The Body in Balance
• Cells and more complex body parts function properly
only when conditions inside the body are stable
4.10 Homeostasis: The Body in Balance
The internal environment is a
pool of extracellular fluid.
Cell
Interstitial
(tissue) fluid
Blood
• Extracellular fluid
– ~15 liters
– Mostly interstitial fluid
– Blood plasma
Blood
vessel
• Homeostasis
– Mechanisms to maintain
stability in the volume and
chemical makeup of
extracellular fluid
Extracellular fluid
p80
Sensors: Cells in
the eyes, ears, skin,
and elsewhere
Integrator:
The brain
Effectors: Muscles
and glands
Figure 4-13 p80
4.10 Homeostasis: The Body in Balance
Homeostasis requires the interaction of sensors,
integrators, and effectors.
• Sensory receptors
– Translate the stimulus into a signal that can be sent to
the brain
• Stimulus
– Specific change in the external and internal
environment
• Integrator
– Brain
• Effectors
– Muscles and glands
4.10 Homeostasis: The Body in Balance
Stimulus
(change in the
environment)
Sensor
(for example,
nerve ending
in the skin)
Integrator
(such as
the brain)
Effector
(a muscle
or a gland)
Response
In negative feedback, the
response of the system
cancels or counteracts the
effect of the original change.
Figure 4-14 p81
4.10 Homeostasis: The Body in Balance
Negative feedback is the most common control
mechanism in homeostasis.
• Negative feedback
– An activity alters a condition in the internal
environment and triggers a response that reverses the
altered condition
– Example: keeping body temperature within a normal
range
4.10 Homeostasis: The Body in Balance
Homeostasis
Positive feedback is the plays a role outside of
homeostasis.
• Positive feedback
– A chain of events intensify a change from the original
condition that reverses the change
– Example: childbirth
Take home message
What are homeostatic controls?
4.11 How Homeostatic Feedback Maintains the
Body’s Core Temperature
• Controls over the body’s core temperature provide
good examples of negative feedback loops
4.11 How Homeostatic Feedback Maintains the
Body’s Core Temperature
Body’s core temperature.
• Humans are endotherms.
• Core temperature
– 37°C (98.6°F)
– Controlled by metabolic activity and negative
feedback loops
• What happens to enzyme activity if the body gets too
hot? Too cool?
4.11 How Homeostatic Feedback Maintains the
Body’s Core Temperature
Change in skin temperature
Change in core temperature
central
thermoreceptors
in hypothalamus,
abdominal organs,
and elsewhere
peripheral
thermoreceptors
in skin
hormonal signals from
“thermostat” centers
in hypothalamus
motor
neurons
skeletal
muscles
voluntary
changes in
behavior
adjustments in heat
gain or heat loss
muscle tone,
shivering
smooth muscle in
arterioles in skin
vasoconstriction,
vasodilation
adjustments in muscle
adjustment in loss
activity (in metabolic heat or conservation of
output)
metabolic heat
sweat
glands
sweating
adjustment in
heat loss
Figure 4-15 p82
4.11 How Homeostatic Feedback Maintains the
Body’s Core Temperature
Excess heat must be eliminated.
• Hypothalamus- neurons and endocrine cells
• Peripheral vasodilation
• Activation of sweat glands followed by evaporation of the
sweat
• Hyperthermia
– Heat exhaustion
– Heat stroke
Table 4-3 p83
4.11 How Homeostatic Feedback Maintains the
Body’s Core Temperature
Several responses counteract cold.
• Hypothalamus
• Peripheral
vasoconstriction
• Pilomotor response
• Non-shivering heat
production and “brown
fat”
• Hypothermia and frostbite
Metabolic activity
at 22°C (72°F)
Metabolic activity after
two hours at 16°C
(61°F)
Take home message
How is body temperature regulated?
Figure 4-16 p83
Table 4-4 p85