Biology
Concepts and Applications | 9e
Starr | Evers | Starr
Chapter 28
Animal Tissues and
Organ Systems
© Cengage Learning 2015
© Cengage Learning 2015
28.1 How Are Animal Bones Organized?
• Tissue found in all vertebrate bodies:
– Epithelial tissue: covers body surfaces; lines
internal cavities
– Connective tissue: holds body parts together;
provides structural support
– Muscle tissue: moves the body or its parts
– Nervous tissue: detects stimuli; relays
information
© Cengage Learning 2015
Levels of Organization
A Cell
(muscle
cells)
B Tissue
(cardiac muscle)
C Organ
(heart)
D Organ System
(circulatory system)
© Cengage Learning 2015
E Organism
(human)
An Internal Environment
• An animal body consists mainly of water
with dissolved salts, proteins, etc.
– Most of this fluid resides inside cells
– The rest is extracellular fluid: internal
environment in which body cells live
• In vertebrates, extracellular fluid consists mainly of
interstitial fluid: fluid in spaces between body cells
© Cengage Learning 2015
Types of Connective Tissue
• Cartilage: cells surrounded by a rubbery
matrix of their own secretions
• Adipose tissue: cells that make and store
triglycerides; specialize in fat storage
• Bone tissue: cells surrounded by a
mineral-hardened matrix of their own
secretions
• Blood: plasma and cellular components
(red cells, white cells, platelets)
© Cengage Learning 2015
Types of Connective Tissue
© Cengage Learning 2015
28.5 What Are Muscle Tissues?
• Muscle tissue: cells that contract (shorten)
in response to stimulation
– Coordinated contractions of layers or rings of
muscles move the body or propel material
through
© Cengage Learning 2015
Skeletal Muscle
• Skeletal muscle tissue: helps move and
maintain the positions of the body and its
parts
– Contains parallel arrays of long, cylindrical
muscle fibers
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Cardiac Muscle
• Cardiac muscle tissue: found only in the
heart wall
– Appears striated
– Has branching cells, each with a single
nucleus
© Cengage Learning 2015
28.6 What Is Nervous Tissue?
• Nervous tissue:
– Allows an animal to collect and integrate
information about its internal and external
environment
– Controls the activity of glands and muscles
– Main tissue of the vertebrate brain and spinal
cord, and of the nerves that extend through
the body
© Cengage Learning 2015
What Is Nervous Tissue?
• Neurons: cells that transmit electrical
signals along their plasma membrane and
send chemical messages to other cells
– Central cell body: contains nucleus and other
organelles
– Cytoplasmic extensions project from the cell
body; function to receive and send
electrochemical signals
© Cengage Learning 2015
What Is Nervous
Tissue?
signalreceiving
extensions
cell body
of neuron
signal-sending
extension
neuroglial cell
wrapped around
a signal-sending
cytoplasmic
extension of
the neuron
© Cengage Learning 2015
What Are Vertebrate Organs and How Do
They Interact?
• Integumentary system: skin and skinderived structures (e.g., hair and nails)
• Nervous system: body’s main control
center (brain, spinal cord, nerves, sensory
organs)
• Endocrine system: controls other organ
systems
© Cengage Learning 2015
What Are Vertebrate Organs and How Do
They Interact?
• Muscular system: moves the body and its
parts; regulates body temperature
• Skeletal system: protects internal organs;
stores minerals and produces blood cells
• Circulatory system: heart and blood
vessels; delivers oxygen and nutrients and
clears wastes
© Cengage Learning 2015
What Are Vertebrate Organs and How Do They Interact?
food, water intake
oxygen inhaled
Digestive
System
nutrients,
water,
solutes
Respiratory
System
oxygen
carbon
dioxide
exhaled
carbon
dioxide
Urinary
System
Circulatory System
water,
solutes
excretion
of food
residues
© Cengage Learning 2015
transport of
materials to
and from cells
elimination of soluble
wastes, excess water,
and salts
What Are Vertebrate Organs and How Do
They Interact?
• Lymphatic system: moves fluid (lymph)
from tissues to blood and organs; protects
the body against pathogens
• Respiratory system: lungs and airways;
delivers oxygen from air to blood and
expels carbon dioxide
• Digestive system: takes in and breaks
down food; delivers nutrients to blood and
eliminates undigested wastes
© Cengage Learning 2015
What Are Vertebrate Organs and How Do
They Interact?
• Urinary system: kidneys, bladder, etc.;
removes wastes from blood and adjusts
blood volume and solute composition
• Reproductive system: gamete-making
organs (ovaries or testes)
– In females the uterus is the organ in which
offspring develop
© Cengage Learning 2015
28.8 How Does Skin Structure Affect Its
Function?
• Components of human skin:
– Epidermis: stratified squamous epithelium
with an abundance of adhering junctions
• Human epidermis consists mainly of keratinocytes
that make the waterproof protein keratin
– Dermis: consists primarily of dense
connective tissue with stretch-resistant elastin
fibers and supportive collagen fibers
• Blood vessels, lymph vessels, and sensory
receptors weave through the dermis
© Cengage Learning 2015
Sun and the Skin
• Melanin: protects skin by absorbing
ultraviolet (UV) radiation
– Some UV exposure is a good thing; it
stimulates skin to produce a molecule that the
body converts to vitamin D
• Variations in skin color among human
populations probably evolved as
adaptations to differences in sunlight
exposure
© Cengage Learning 2015
Cultured Skin Products
• Skin is the only organ that is grown
artificially for widespread medical uses
– Cells from infant foreskins are grown in
culture to produce thin sheets of cells that can
be used to cover wounds, burns, or sores
© Cengage Learning 2015
28.9 How Do Organ Systems Interact in
Homeostasis?
• In vertebrates, homeostasis involves
interactions among sensory receptors, the
brain, and muscles and glands
– Sensory receptor: responds to a specific
stimulus (e.g., temperature or light)
– Negative feedback mechanism: change
causes a response that reverses the change
• Important for homeostasis
© Cengage Learning 2015
28.10 Application: Growing Replacement
Tissues
• Animals commonly replace tissues lost to
injury
• Invertebrates have the greatest capacity
for regeneration
• Example: some sea stars can regrow an
entire body from a single arm and a bit of
the central disk
© Cengage Learning 2015
Biology
Concepts and Applications | 9e
Starr | Evers | Starr
Chapter 29
Neural Control
© Cengage Learning 2015
© Cengage Learning 2015
29.1 What Are the Types of Nervous
Systems?
• Cell-to-cell communication is important for
an animal body to function as an
integrated whole
• Neurons make up the communication lines
of nervous systems
– Neurons transmit electrical signals and send
chemical messages to other cells
– Neuroglial cells support the neurons
© Cengage Learning 2015
Nerve Net
• Animals with radial symmetry have a mesh
of interconnected neurons, a nerve net
– Information flows in all directions among cells
– Sea anemones and other cnidarians are
simple animals with nerve net
– Echinoderms have nerve net + nerves
• Nerve: bundle of neuron fibers (cytoplasmic
extensions) wrapped in connective tissue
© Cengage Learning 2015
Getting a Head
• Cephalization: evolutionary trend whereby
neurons became concentrated at the
“head” of bilateral animals
• Planarian flatworms have a simple
nervous system
– A pair of ganglia (cluster of neurons) in the
head serves as an integrating center
– The ganglia connect to a pair of nerve cords
(may nerve fibers)
© Cengage Learning 2015
Getting a Head
• Annelids and arthropods have paired
nerve cords that connect to a simple brain
– Brain: central control organ of nervous system
© Cengage Learning 2015
The Vertebrate Nervous System
• A dorsal nerve cord is one of the defining
features of chordate embryos
• Central nervous system: brain and spinal
cord (evolved from dorsal cord)
• Peripheral nervous system: nerves that
carry signals between the central nervous
system and the rest of the body
© Cengage Learning 2015
The Vertebrate Nervous System
Brain
cranial nerves
(twelve pairs)
cervical nerves
(eight pairs)
Spinal Cord
thoracic nerves
(twelve pairs)
ulnar nerve
(one in
each arm)
sciatic nerve
(one in each leg)
lumbar nerves
(five pairs)
sacral nerves
(five pairs)
© Cengage Learning 2015
coccygeal nerves
(one pair)
How Does Neuron Structure Relate to
Function?
receptor
endings
peripheral cell axon axon
axon
body
terminals
cell
body
axon
cell
body
axon
dendrites
dendrites
A
© Cengage Learning 2015
B
C
axon
terminals
How Does Neuron Structure Relate to
Function?
• Structure of a neuron:
– Cell body: contains nucleus and other
organelles
– Axon: transmits electrical signals and
releases chemical signals at its terminal
– Dendrites: receive chemical signals from
other neurons
© Cengage Learning 2015
Conduction Along an Axon
axon
© Cengage Learning 2015
myelin sheath
around axon
node (unsheathed region
of the axon)
29.5 What Happens at a Synapse?
• Action potentials cannot pass directly from
a neuron to another cell
• Signaling molecules (neurotransmitters)
relay signals between a neuron and
another cell
– Synapse: region where axon terminals
transmit neurotransmitters to another cell
© Cengage Learning 2015
29.6 How Do Drugs Act at Synapses?
• Psychoactive drugs alter brain function:
– Mimic a neurotransmitter’s effect on a
postsynaptic cell (e.g., morphine and heroin)
– Stop neurotransmitter action (e.g., caffeine)
– Inhibit neurotransmitter release (e.g., alcohol)
– Block reuptake of neurotransmitter (e.g.,
cocaine)
– Slow reuptake of neurotransmitter (e.g.,
antidepressants)
© Cengage Learning 2015
29.7 What Is the Peripheral Nervous
System?
• Peripheral nervous system: all nerves
outside the brain or spinal cord
• Each nerve has outer layer of connective
tissue surrounding bundles of axons
• Two major functional divisions of the
peripheral system:
– Somatic nervous system
– Autonomic nervous system
© Cengage Learning 2015
What Is the Peripheral Nervous System?
• Somatic nervous system: controls skeletal
muscles; relays sensory signals about
movements and external conditions
• Autonomic nervous system: relays signals
to and from internal organs and glands
– Parasympathetic neurons: encourage
digestion and other “housekeeping” tasks
– Sympathetic neurons: activated during stress
and danger
© Cengage Learning 2015
Biology
Concepts and Applications | 9e
Starr | Evers | Starr
Chapter 31
Endocrine Control
© Learning
Cengage
© Cengage
2015Learning
2015
31.1 What Are Animal Hormones?
• Animal hormones: intercellular
communication molecules that are
secreted by endocrine cells
– Distributed by the blood; typically act at a
distant site from their source
• Only cells with the appropriate receptors
(target cells) can respond to a specific
hormone
© Cengage Learning 2015
31.2 What Are the Components of the
Human Endocrine System?
• Endocrine glands: aggregations of
epithelial cells that produce and secrete
hormones into the blood
– Collectively make up the endocrine system
• Portions of the endocrine system and
nervous system are closely linked
– Most organs respond to hormones and
signals from the nervous system
© Cengage Learning 2015
What Are the
Components of the
Human Endocrine
System?
© Cengage Learning 2015
Hormonal Growth Disorders
• Growth hormone production surges during
teenage years, causing a growth spurt,
then declines with age
• Oversecretion of growth hormone during
childhood leads to pituitary gigantism
• Too little growth hormone during childhood
can cause pituitary dwarfism
© Cengage Learning 2015
Hormones, Stress, and Health
• Long-term elevation of cortisol is
unhealthy (example: Cushing’s syndrome):
– Interferes with immunity, memory, and sexual
function
– Raises the risk of cardiovascular problems
• Abnormally low levels of cortisol (example:
Addison’s disease)
– Fatigue, depression, weight loss, and
darkening of the skin
© Cengage Learning 2015
31.7 What Are Sex Hormones?
• Sex hormones: steroid hormones
produced by the gonads
– Essential to reproductive function
– Influence secondary sexual characteristics
• Traits that differ between the sexes, but do not
function directly in reproduction
© Cengage Learning 2015
What Are Sex Hormones?
© Cengage Learning 2015
What Are Sex Hormones?
• Testosterone: responsible for development
of male sex organs and secondary sexual
characteristics
• Estrogens: function in reproduction and
cause development of female secondary
sexual characteristics
• Progesterone: prepares a female body for
pregnancy and helps maintain a
pregnancy
© Cengage Learning 2015
How Does the Pancreas Regulate Blood
Sugar?
• Beta cells secrete insulin when blood
glucose levels rise
– Insulin causes its target cells to take up and
store glucose
– Encourages synthesis of fats and proteins
and inhibits their breakdown
– Lowers blood glucose levels
© Cengage Learning 2015
How Does the Pancreas Regulate Blood
Sugar?
• Alpha cells secrete glucagon when blood
glucose levels fall
– Glucagon binds to receptors on liver cells:
activates enzymes that break glycogen into
glucose subunits
– Raises the level of glucose in blood
© Cengage Learning 2015
How Does the Pancreas Regulate Blood
Sugar?
• The regulation of blood glucose is
disrupted in diabetes mellitus
• Type 1 diabetes: autoimmune response
destroys insulin-secreting beta cells
– Symptoms usually appear in childhood and
adolescence
• Type 2 diabetes: target cells do not
respond to insulin
– Symptoms typically start in middle age
© Cengage Learning 2015
31.9 Do Invertebrates Have Hormones?
• Some components of the endocrine
system occur in invertebrates
– Example: roundworms, annelids, and
mollusks make steroid hormones
© Cengage Learning 2015
Do Invertebrates Have Hormones?
• Invertebrates do not have the same glands
as vertebrates do, but they produce the
homologous hormones in other glands
– Example: octopuses produce estrogens,
progesterone, and cortisol in a gland near
their eye
© Cengage Learning 2015
Do Invertebrates Have Hormones?
• Hormone-signaling systems unique to
invertebrates have also evolved
– Example: a hormone unique to arthropods
called ecdysone controls molting (periodic
shedding of the exoskeleton)
© Cengage Learning 2015
31.10 Application: Endocrine Disrupters
• Endocrine disrupters:
– DDT (a pesticide)
– PCBs (used to make electronic products,
caulking, and solvents)
– Phthalates (found in plastics and scented
products) – these chemicals are still in wide
use
© Cengage Learning 2015
The CDC had found BPA in the urine of
95% of adults sampled in 1988–1994 and
in 93% of children and adults tested in
2003–04
• Wednesday 9/24 Chap 33,34,35,36
• Friday 9/26 Chap 37,38
• Wednesday 10/1 EXAM #1