1. Animal Tissues and Organ Systems
Chapter 20

2. Stem Cells
Undifferentiated cells with potential to develop into many cell types
Embryonic stem cells, more versatile
Adult stem cells, less versatile

3. Body Organization Tissue Organ Organ system
Group of cells performing same task
Organ
Two or more tissues performing same task
Organ system
Two or more organs performing same task

4. Tissues
Groups of cells and intercellular substances that interact in one or more tasks
Example: muscle tissue

5. 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

6. 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

7. Homeostasis Stable operating conditions in the internal environment
Brought about by coordinated activities of cells, tissues, organs, and organ systems

8. 4 Types of Tissues Muscle tissues Nervous tissues Epithelial tissues
Connective tissues
Muscle tissues
Nervous tissues

9. Epithelial Tissues Line body surfaces, cavities, ducts, and tubes
One free surface faces a body fluid or the environment
simple
squamous
epithelium
basement
membrane
connective tissue

10. free surface of epithelium
simple epithelium
basement membrane
connective tissue

11. Glands Secretory organs derived from epithelium
Exocrine glands have ducts or tubes
Endocrine glands are ductless

12. Cell Junctions Tight junctions prevent leaks
Gap junctions connect abutting cytoplasms
Adhering junctions cement cells together
Tight junctions
Adhering junction
Gap junctions

13. Connective Tissues Most abundant tissues in the body
Fibroblasts secrete
polysaccharide “ground substance” that surrounds and supports cells
fibers of collagen and/or elastin

14. Soft Connective Tissues
Loose connective tissue
Dense, irregular connective tissue
Dense, regular connective tissue

15. Specialized Connective Tissues
Cartilage
Bone tissue
Adipose tissue
Blood

16. cells and platelets of blood
white blood cell
platelet
red blood cell
cells and platelets of blood
Fig. 20-3g, p.342

17. Muscle Tissue Cells contract when stimulated
Moves body and specific body parts
3 types
Skeletal
Cardiac
Smooth

18. Skeletal Muscle Attaches to and moves bones Long, cylindrical cells
Striated cells
Voluntary control
nucleus

19. Smooth Muscle Located in soft internal organs and blood vessels
Cells taper at ends
Cells not striated
Not under voluntary control
where abutting cells meet

20. Cardiac Muscle Present only in heart Cells are branching
ends of cells joined by communication junctions
Cells striated
Not under voluntary control
cell nucleus

21. Nervous Tissue
Detects stimuli, integrates information, and relays commands for response
Consists of excitable neurons and supporting neuroglial cells

22. Functional zones of a motor neuron
Neurons
Functional zones of a motor neuron

23. Neurons Excitable cells
Stimulus sends electrical impulse along plasma membrane
Transmits information to other neurons, muscles or glands

24. Neuroglia Neuroglial cells make up more than half of nervous tissue
Protect and support neurons

25. 11 Major Organ Systems Integumentary Nervous Muscular Skeletal
Circulatory
Endocrine
Lymphatic
Respiratory
Digestive
Urinary
Reproductive

26. 11 Major Organ Systems Integumentary System Nervous System
Muscular System
Skeletal System
Circulatory System
Endocrine System
Fig. 20-6, p.344a1

27. 11 Major Organ Systems Lymphatic System Respiratory System
Digestive System
Urinary System
Reproductive System
Fig. 20-6a2, p.344

28. Position References: Animals
dorsal surface
midsagittal plane
anterior
posterior
transverse plane
frontal plane
ventral surface
Fig. 20-6b, p.345

29. Position References: Humans
frontal plane
(aqua)
transverse plane
(yellow)
midsagittal plane (green)

30. Major Body Cavities Cranial cavity Spinal cavity Thoracic cavity
Abdominal cavity
Pelvic cavity

31. cranial cavity spinal cavity thoracic cavity abdominal cavity
pelvic cavity
Fig. 20-6d, p.345

32. Primary Tissues
Three primary tissues in vertebrate embryos give rise to all adult tissues:
Ectoderm
Mesoderm
Endoderm

33. Skin: An Organ System Epidermis: Stratified epithelium
Dermis: Dense connective tissues
Hypodermis: Loose connective tissue and adipose tissue

34. hair epidermis dermis sensory neuron hypodermis (below skin,
not part of it)
sweat gland
oil gland
hair follicle
smooth muscle
blood vessels
Fig. 20-7a, p.346

35. outermost epidermal layer (all dead cells) keratinized cells being
flattened
rapidly
dividing
cells of
epidermis
dermis
Fig. 20-7b, p.346

36. 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

37. 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

38. Langerhans Cells White blood cells in skin Attack viruses and bacteria
Stimulate immune system
Are damaged by UV exposure

39. Epithelial Tissues