animal tissues and organ systems chapter 20. key concepts types of tissues –four tissues types...
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Animal Tissues andOrgan Systems
Chapter 20
Key Concepts
• Types of tissues– Four tissues types organized into organs
• Epithelial• Connective• Muscle• Nervous
• Organ systems– Three embryonic tissues are source of all
adult organs– Each organ system has specialized
function
Stem Cells
• Undifferentiated cells with potential to develop into many cell types– Embryonic stem cells,
more versatile– Adult stem cells, less
versatile
Body Organization
• Tissue– Group of cells performing same task
• Organ– Two or more tissues performing same task
• Organ system– Two or more organs performing same task
Tissues
• Groups of cells and intercellular
substances that interact in one or more
tasks
• Example: muscle tissue
Organs
• Group of tissues organized to perform a task or tasks
• Example: Heart is an organ that pumps blood through body
• Heart consists of muscle tissue, nervous tissue, connective tissue, and epithelial tissue
Organ Systems
• Groups of organs that interact
physically and/or chemically to perform
a common task
• Example: Circulatory system includes
heart, arteries, and other vessels that
transport blood through the body
Homeostasis
• Stable operating conditions in the internal environment
• Brought about by coordinated activities of cells, tissues, organs, and organ systems
4 Types of Tissues
• Epithelial tissues
• Connective tissues
• Muscle tissues
• Nervous tissues
Type 1: Epithelial Tissues
• Sheet-like, line body surfaces,
cavities, ducts, and tubes
• One free surface faces a body fluid or
the environmentsimplesquamousepithelium
basementmembrane
connective tissue
Glands
Secretory organs derived from epithelium
• Exocrine glands have ducts or tubes– Salivary and sweat glands– Secrete to the OUTSIDE
• Endocrine glands are ductless– Adrenals and pituitary – Secrete to the INSIDE
exo = out endo = in
Type 2: Connective Tissues• Most abundant tissues in the body
• Different types– Soft
• Beneath skin, encapsulates organs– Specialized
• Cartilage• Bone• Adipose (fat)• Blood
• Fibroblasts– Secrete “ground substance” forming
polysaccharides– Secrete collagen, the most abundant protein in the
human body
Soft Connective Tissues• Loose connective tissue
• Dense, irregular connective tissue
• Dense, regular connective tissue
red blood cell
white blood cell
platelet
Fig. 20-3g, p.342
Type 3: Muscle Tissue
• Cells contract when stimulated
• Moves body and specific body parts
• 2 types, 3 classes– Striated
• Skeletal• Cardiac
– Not striated • Smooth
Skeletal Muscle
• Attaches to and moves bones
• Long, cylindrical cells
• Striated cells
• Voluntary control
nucleus
Cardiac Muscle
• Present only in heart
• Cells are branching– Ends joined by
communication junctions
• Cells striated
• Not under voluntary control
where cells meet
Smooth Muscle
• Located in soft internal organs and blood vessels
• Cells taper at ends
• Cells not striated
• Not under voluntary control
cell nucleus
Type 4: Nervous Tissue• Detects stimuli, integrates information,
and relays commands for response
• Consists of excitable neurons and supporting neuroglial cells
Neurons
• “Excitable” cells
This means that:
• Stimulus sends electrical impulse along plasma membrane because of specific proteins
This allows the cells to:
• Transmit information to other neurons, muscles or glands
11 Major Organ Systems
• Integumentary
• Nervous
• Muscular
• Skeletal
• Circulatory
• Endocrine
• Lymphatic
• Respiratory
• Digestive
• Urinary
• Reproductive
I promise that you will be tested on these 11 systems. At the very least, you will need to know the functions of each system. All of this info is on page 344.
Nervous System
Muscular System
Skeletal System
Circulatory System
Endocrine System
Fig. 20-6, p.344a1
Integumentary System
11 Major Organ Systems
Lymphatic System
Respiratory System
Digestive System
Urinary System
Reproductive System
Fig. 20-6a2, p.344
11 Major Organ Systems
Skin: An Organ SystemIntegumentary
• Epidermis: Stratified epithelium
• Dermis: Dense connective tissues
• Hypodermis: Loose connective tissue and adipose tissue
Functions of Human Skin
• Protects body from injury, dehydration, UV radiation, and some pathogens
• Helps control temperature
• Receives external stimuli
• Involved in vitamin D production
Important stuff, this
Sun Damages Skin
• UV light stimulates melanin production– tans skin
• Tan protects inner layers against UV damage
• UV exposure causes– elastin fibers to clump– skin to age prematurely– skin cancer
The Epidermis is an Epithelial Tissue
Porphyria and vampirism
Where do Tissues and Organ Systems Come From?
Primary Tissues
Three primary tissues in vertebrate embryos give rise to all adult tissues:
Ectoderm
Mesoderm
Endoderm
ecto=out meso=middle endo=inside
Primary Tissues (cont’d)
• Ectoderm– Outer layer of skin– Nervous tissue
• Mesoderm– Muscles, bones and most of the
circulatory, reproductive and urinary systems
• Endoderm– Lining of the digestive tract, as well as the
liver, lungs and pancreas
5 Major Body Cavities
• Cranial cavity
• Spinal cavity
• Thoracic cavity
• Abdominal cavity
• Pelvic cavity