1. Animal Tissues and Organ Systems
Chapter 33
Animal Tissues and Organ Systems
AP Biology
Spring 2011

2. Chapter 33.4
Nervous Tissue

3. Nervous Tissue
Nervous Tissue: composed of neurons and a variety of cells (called neuroglia), that structurally and functionally support them

4. Nervous Tissue
Neurons: kind of excitable cell that makes up the communication lines in most nervous systems

5. Motor Neuron Neuron: highly excitable in a specific way
When stimulated, propagates a message along its plasma membrane, all the way to some outpoint zone, without altering it
Message triggers release of signaling molecules called neurotransmitters
Signals diffuse to another cell that is almost but not quite touching the neuron that sent them

6. Neurons Interneurons: neurons in your brain and spinal cord
Receive and integrate sensory information, store the bits that hold meaning, and coordinate the body’s short-term and long-term responses to stimuli
Motor Neurons: relay commands from brain and spinal cord to muscle cells

7. Overview of Major Organ Systems
Chapter 33.5
Overview of Major Organ Systems

8. Organ Systems Germ cells give rise to sperm or egg
Fertilization  zygote forms
Mitotic cell divisions  three primary tissue layers
Forerunners of all adult tissues and organs

9. Three Primary Tissue Layers
Ectoderm: the outer layer, is the first to form
Gives rise to epidermis and the nervous system
Mesoderm: middle layer, start of muscles, bones, and most of circulatory , urinary, and reproductive systems
Endoderm: inner primary tissue layer, start of lining of digestible tract and organs derived from it

10. Division of Labour
Division of Labor: organ systems of multicelled body show this compartmentalization of function
Help body survive in ways no one tissue can offer

11. Division of Labor
Organ systems divide up tasks of securing, processing, and distributing materials, and expelling wastes, protecting the body, integrating its activities, and reproducing

12. Organ Systems Integumentary Systems
Protects body from injury, dehydration, and some pathogens; controls its temperature; excretes certain wastes, receives some external stimuli

13. Organ Systems Nervous System:
Detects external and internal stimuli; controls and coordinates the response to stimuli; integrates all organ system activities

14. Organ Systems Muscular System:
Moves body and its internal parts; maintains posture; generates heat and increases metabolic activity

15. Organ Systems Skeletal System:
Supports and protects body parts; provides muscle attachment sites; produces red blood cells; stores calcium, phosphorous

16. Organ Systems Circulatory System:
Rapidly transports many materials to and from cells; helps stabilize internal pH and temperature

17. Organ Systems Endocrine System:
Hormonally controls body functioning; works with nervous system to integrate short-term and long-term activities

18. Organ Systems Lymphatic System:
Collects and returns some tissue fluid to the bloodstream; defends the body against infection and tissue damage

19. Organ Systems Respiratory System:
Rapidly delivers oxygen to the tissue fluid that bathes all living cells; removes carbon dioxide wastes of cells; helps regulate pH

20. Organ Systems Digestive System:
Ingests food and water; mechanically, chemically breaks down food and absorbs small molecules into internal environment; eliminates food residues

21. Organ Systems Urinary System:
Maintains the volume and composition of internal environment; excretes excess fluid and blood borne wastes

22. Organ Systems Reproductive System:
Female: produces eggs; after fertilization affords a protected, nutritive environment for the development of a new individual
Male: produces and transfers sperm to the female; hormones of both systems also influence other organ systems

23. Cavities Cranial cavity Spinal cavity Thoracic cavity Abdominal cavity
Pelvic cavity

24. Directional Terms and Planes
Direction: dorsal, ventral, posterior, anterior

25. Directional Terms and Planes
Planes: frontal, midsagittal , transverse

26. Directional Terms and Planes
Anterior: at or near front of body
Posterior: at or near back of body
Superior: of two body parts, the one closest to the head
Inferior: of two body parts the one farthest from the head
Proximal: closest to trunk or point of origin of a body part
Distal: farthest from trunk or from point of origin of a body part

27. Vertebrate Skin: An Example of an Organ System
Chapter 33.6
Vertebrate Skin: An Example of an Organ System

28. Skin Outer body covering has the largest surface area
Two layers: underlying dermis and outer epidermis

29. Dermis
Dense connective tissue with many fibers of stretch resistant elastin and supportive collagen
Blood vessels, lymph vessels, sensory receptors thread through it
Rest on hypodermis:
not part of skin,
contains loose
connective tissue
and adipose tissue

30. Dermis Dermis contains exocrine glands Sweat glands
Oil glands (except on palms and soles)

31. Epidermis
Stratified squamous epithelium with an abundance of adhering junctions and no extracellular matrix
Ongoing mitotic cell divisions in the deepest layers push previously formed cells to the surface

32. Epidermis
Wear and tear from surface and pressure from growing mass, flatten and kill cells before they reach the surface
Dead one are flaked off
Main types: keratinocytes, melanocytes, dendrite cells

33. Epidermis
Keratinocytes: sectret keratin, tough, water resistant protein, makes skin water proof and more durable
Dead, flattened keratinocytes make up hair

34. Epidermis
Melanocytes: produce brownish-black pigment melanin (gives up pigments to keratinocytes)
Body’s barrier to UV radiation
Variations in skin colour result from differences in the distribution and activity of melanocytes

35. Epidermis Langerhans: migrate through epidermis
Engulf bacteria or viruses, communicate with immune system
UV radiation damages these cells and skin will be more vulnerable to viral outbreaks

36. Epidermis
Lab-grown epidermis: used to protect tissues and aid wound healing in some patients
A new tattoo removal procedure developed by the Wake Forest Institute in North Carolina for Regenerative Skin Treatment was recently used by rapper Pharrell Williams. The procedure involves the patient providing a sample of his/her skin from which is grown in a laboratory  enough new skin to cover the tattooed area. Supposedly the new skin is stitched over the tattoo and does not leave any scars. Once the skin has healed, new tattoos can be done.

37. Suntans and Shoe-Leather
UV light stimulates melanocytes in skin to make melanin and gives skin “tan” look
Chronic UV damage causes skin to be less resilient and starts to look like shoe leather
UV attacks DNA causing skin cancer

38. Suntans and Shoe-Leather
As we age, epidermal cells divide less often
Skin thins, becomes less elastic as collagen and elastin fibers become sparse
Glandular secretions dwindle, wrinkles deepen

39. Vitamin Connection UV stimulates vitamin D production
Helps body absorb calcium
UV aids breakdown of folate (B vitamin)
Variations in skin colour may be adaptations to differences in sunlight xposure