2. Immagini e concetti della biologia Sylvia S. Mader
Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

3. C1 - Organization and Homeostasis
Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

4. Four levels of biological organization
Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

5. Epithelial tissue
Epithelial cells are connected to each other by tight junctions, adhesion junctions and gap junctions.
Epithelium lies on a basement membrane, which acts as a scaffolding and anchors the epithelial tissue to the underlying connective tissue.
Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

6. Functions of the epithelium
Epithelial tissue
Functions of the epithelium
SECRETION
PROTECTION
SELECTIVE ABSORPTION
Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

7. Cells of the epithelium
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8. Cells of the epithelium
Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

9. Cells of the epithelium
Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

10. Cells of the epithelium
Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

11. Connective tissue
Connective tissue connects, protects and supports other tissues.
The most abundant tissue in vertebrates-
Connective cells are separated by a collagen-rich fluid called matrix which varies from solid (in bones) to semifluid (in cartilage) to fluid (in blood).
Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

12. Types of Connective Tissue
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13. Types of Connective Tissue
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14. Blood is different from the other connective tissues
Plasma
RBC
WBC
Platelets
Blood has different functions as:
Transport of oxygen
Transport of nutrients
Body heat regulation
pH regulation
Protection
Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

15. Muscular tissue
Muscular cells contains contractile filaments, actin and myosin, that move past each other and change the size of the cell.
Major functions:
Locomotion of the organism;
Movement of internal organs.
Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

16. Muscular tissue
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17. Nervous tissue Major functions: Sensory input Sensory output
Communication within organs
Control of muscles and glands
Homeostasis
Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

18. Neurons transmit impulses
axon
dendrite
cell body
Neuron cells are composed of:
A cell body (contain nucleus)
Dendrites (for input signals)
An axon (for output signals)
Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

19. microglia
oligodendrocyte
astrocyte
Neuroglia cells
Neuroglia cells assist propagation of the impulse and provide nutrients to the neuron.
Neuroglia cells include microglia (destroy bacteria and remove dead cells), astrocytes (supply nutrients) and oligodendrocytes (insulate neurons).
Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

20. Organs and organ systems
Organs combine several tissues that function together and cooperate in organ systems.
An organ has a precise structure and performs a specific function.
Organs exist in all higher biological organisms.
Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

21. The skin covers and protects
In humans the skin is divided into two strata: the epidermis (stratified epithelium) and the dermis (dense fibrous connective tissue).
A subcutaneous layer, the hypodermis (connective tissue) connects the dermis with underlying structures.
Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

22. Organ systems work in homeostasis
Several organs of a system work together to carry out a complex function as:
Control
Sensory input and motor output
Transport
Maintenance
Reproduction
Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

23. Control
Nervous system coordinates the body actions and transmits signals between different locations.
Endocrine system regulates the hormones secretion.
Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

24. Sensory input and motor output
Integumentary system is the attachment site for sensory receptors and provides environmental information.
Skeletal and muscular systems are responsible for locomotion in response to nervous system instructions.
Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

25. Transport
Cardiovascular system transports nutrients, gases, hormones and other substances through the body.
Lymphatic system is a network of conduits carrying the lymph which returns protein and lipids in excess to the circulation.
Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

26. Maintenance
Digestive, Respiratory and Urinary systems are responsible for maintaining the body efficient and constant through the transformation of nutrients or gases and purifying the organism.
Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

27. Reproduction
Organs of the reproductive system include the genitalia (penis and vulva) and a number of internal organs as the gamete producing gonads (testicles and ovaries).
Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

28. Homeostasis
Homeostasis is the maintenance of stable, constant conditions of the body’s internal environment which consists of blood and interstitial fluid (tissue fluid).
EQUILIBRIUM
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29. Homeostasis
All organ systems contribute to maintain within normal limits the internal conditions as body temperature, water content, pH, glucose and CO2 concentrations.
Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018

30. Negative feedback
The negative feedback mechanisms is the principal mechanism in homeostasis and is composed of a sensor and a reaction center (i.e. blood glucose levels).
effect
Control center
Sensor
Sylvia S. Mader, Concepts of Biology © Zanichelli editore, 2018