Chapter 19
Homeostasis and the Organization of the Animal Body
What is homeostasis?
ho·me·o·sta·sis (hō'mē-ō-stā'sĭs)
n.
The
ability or tendency of an organism or cell to maintain internal equilibrium by
adjusting its physiological processes.
Negative Feedback
Reverses the Effects of Changes
Tissues
Cells group
together in the body to form tissues - a collection of similar cells that group
together to perform a specialized function.
There are 4
primary tissue types in the human body: epithelial tissue, connective tissue,
muscle tissue and nerve tissue.
How Do Tissues Differ?
Four
Main Kinds of Animal Tissues:
Epithelial
Tissue: Covers the Body and Lines Its Cavities
Connective
Tissues: Diverse, Support and Bind Other Tissues
Muscle Tissue:
Has the Ability to Contract
Nerve Tissue:
Transmits Electrical Signals
Epithelial tissues
Some Epithelial Tissues Form Glands
Glands:
specialized cells that are specialized to secrete substances.
Two types:
Exocrine:
connected to epithelium by ducts- sweat, sebaceous, salivary glands
Endocrine
:become separated from epithelium:
Exocrine
Sweat and sebaceous glands
Endocrine glands
Like pituitary
glands, pancreas, adrenal glands ovaries and testes
Connective Tissues Have Diverse Structures
and Functions
Connective tissue typically
has a large extra-cellular component
Matrix
Proteins
Types
Fibrous : tendons, ligaments, lots of
collagen
Cartilage: flexible,
resilient: few cells thick matrix
Bone- cell embedded in hard matrix, calcium
phosphate
Adipose tissue: store
energy, insulate
Blood : matrix is plasma, white
& red cells, platelets
Muscle Tissue Has the Ability to Contract
Muscle tissue
consists of contractile cells called muscle fibers
Three Kinds of Muscle tissue
Skeletal
voluntary
Cardiac
Heart only
involuntary
Smooth
Lines internal tubes
Involuntary
Slow sustained contractions
Nerve Tissue Transmits Electrical Signals
A nerve cell
Nervous tissue
Two types of
cells
Neurons
Glial cells support and protect neurons, regulate
composition of extracellular fluid
How Are Tissues Combined into Organs?
An organ is a structure that contains at
least two different types of tissue functioning together for a common purpose.
Ex: Heart
Organ Systems
Consist of Two or
More Interacting Organs
Major Vertebrate
Organ Systems
Major Vertebrate Organ Systems
Circulatory
Lymphatic/immune
Digestive
Excretory
Respiratory
Endocrine
Nervous
Muscular
Skeletal
Reproductive
Integumentary
How Are Tissues Combined into Organs?
The Bodys Organ
Systems Act in Concert Digestion Example
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