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Chapter 20
Tissues and Homeostasis
Anatomy and Physiology are the studies of the structure and function of organisms.
Examples: feathers on the wings of birds, muscles and bones on a gecko’s legs. Structure
and function are closely related and work hand in hand such as the muscles and bones in
a bird’s wing.
All animal bodies have structural hierarchy.
Cellular level -- tissue-- organ - organ system -- organism
Tissue:
Animals have four major types of tissues:
Epithelial tissue:
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Epithelium is found as
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Example is the epidermis, outermost covering of the skin
Lining of the GI tract, lungs, kidneys
One side, called the ------------------------- forms the lining of the passageways. The
other side is more densely packed, made of sticky polysaccharides and proteins, and
is anchored to the underlying tissue, called ------------------------------------------------.
These two surfaces form a barrier between tissues and cells
These tissues are named according to the shape and number of cells they have
------------------------------------------ has one layer of cells; ----------------------------------------------------- has multiple layers.
Shape of the cell can be -----------------------------------------------------------------------Every cell structure has a unique function
Stratified squamous epithelium
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Simple squamous epithelium
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Cuboidal and columnar cells
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Connective tissues:
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Main function is to ---------------------------------Six different types that are found scattered in a matrix of fluid
------------------------------------------- is the most common type. Collection of fibers of
collagen that hold other tissues in place.
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------------------------------- mainly stores fats. It insulated
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Blood is a
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Fibrous connective tissue
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Cartilage is made
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Bone
Muscle tissues:
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Made of bundles of long muscle fibers.
Most abundant type of tissue in animals
Three types of muscles:
Skeletal muscles are
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Cardiac muscles cause involuntary contraction of the heart.
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Smooth muscles
Nervous tissues:
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A communication network by transmitting nerve signals.
Made of nerve cells ----------------------------A neuron is made of a --------------------------, which has the nucleus, extensions called
--------------------------, which send the signal to the cell body, and axons, which
transmit the signal away from the cell body.
Nerve tissues also contain cells that cover the axons, and many cells that support the
neurons.
Signals are made of a set of chemicals that are exchanged between the neurons.
Several tissues together that can perform specific functions form --------------------------- heart is made of mainly ------------------------------------------------------------------------------------------------------------------------- Small intestine has three types of tissues. Epithelial, connective, and smooth
muscles.
Many organs make up an organ system, which cooperate together to allow the body to
function properly.
There are twelve organ systems in vertebrates.
 Digestive system: digests food; mouth, esophagus, stomach.
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Respiratory system: exchanges gases like ------------- and ------------------ between
the body and the environment. Nose, mouth, larynx, trachea, bronchi, and lungs.
Circulatory system: heart which pumps blood to different organs, and blood vessels.
Lymphatic and immune systems: small vessels that carry lymph (fluid from blood
vessels) and take it to the blood and lymph nodes. Immune system protects the body
from infection and consists of lymphocytes and antibodies. Bone marrow, thymus,
and spleen.
Excretory system: removal of -----------------------------. Kidneys, bladder, urethra.
Endocrine systems: involves the production of hormones that regulate the function
of several body organs. Glands such as the pancreas, thyroid, pituitary, adrenal, testis
and ovaries.
Reproductive system: produce gametes for reproduction, not essential for survival.
Ovaries produce eggs and testis produce sperms.
Nervous system: brain receives information to allow for reaction to stimuli. Brain,
spinal cord, nerves.
Muscular system: all the skeletal muscles in the body. Allows for movement.
Integumentary system: consists of skin, hair, and nails. Protection of internal
organs.
Organisms are in constant contact with their external environments allowing for the
exchange of materials, gases and fluids. Need to obtain material and excrete material into
their environments.
In simple animals, like a hydra, exchange involves -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------In more complex animals, they rely on specialized surfaces to do the exchanges. Direct
exchange does not occur between the blood and cells, there is a solution called ------------------------------------------- that bathes cells and allows for this exchange to occur.
Homeostasis: is the ability --------------------------------------------------------------------- --------------------------------------------------------------. Examples: regulation of blood
sugars, maintain salt and water levels, and a constant internal temperature.
Homeostasis is controlled by ---------------------------------------Maintaining a constant blood tempr. Is based on these types of controls. The
hypothalamus senses the tempr. of the body and raises or lowers it by sending signals to
sweat glands and blood capillaries to either dilate or constrict (sweating or shivering).