- •Content
- •Preface
- •Biology as Science and Important Part of Our Life
- •Applying Life Science to Your Life
- •Careers, hobbies and element of personal culture
- •The scientific method
- •1. Basics of organisation of life
- •1.1. Nature and Properties of Life. Cell Theory
- •1.2. Energy and Energy Conversions. Chemistry aspects of life organisation
- •Ionic bonds
- •Ice floats
- •1.3. Life as Phenomenon of Universe
- •Fig. 1.6. Dna structure
- •2. Elements of general biology
- •2.1. Introduction to Cell Biology
- •Internal membranes
- •Pumping Molecules Through Cell Membranes (active transport)
- •Fig. 2.1. Diffusion into and out of cells
- •Fig. 2.2. Active transport of two different ions
- •Autotrophic and Heterotrophic Organisms
- •Stored energy from the sun
- •The role of photosynthetic pigments
- •Identifying Photosynthetic Reactants and Products
- •Respiration in the cells
- •Comparison of photosynthesis and respiration.
- •2.2. Introduction in Genetics
- •Fig. 2.3. Normal human (female) karyotype
- •Fig. 2.4. Dna ladder separates to form two identical dna ladders
- •Mitosis
- •Incomplete Dominance is Neither Dominant nor Recessive
- •X Chromosomes & y Chromosomes
- •Fig. 2.5. Process of meiosis
- •Fig. 2.6. Process of meiosis (continuation)
- •Inheritance of Blood Types
- •Variations and Mutations
- •Initiation of transcription requires a promoter and rna polymerase
- •2.3. The Introduction to Theory of Evolution
- •2.3.3. Classification and Identification
- •The system of Linnaeus
- •The scientific name
- •Bases of Modern Classification
- •Categories of Classification
- •Subdivisions of the Five Kingdoms
- •Identifying Photosynthetic Reactants and Products
- •3. Aspects of biology of viruses, monera, protists, algae, fungi and lichens
- •3.1. Viruses
- •3.1.1. Discovery of viruses. Sizes of viruses
- •Viruses differ greatly in size. They range in length from 0.01 to over 0.3 micrometers; yet over 500 of them can fit on the point of the pin.
- •3.1.2. Characteristics of viruses
- •3.1.3. Kinds of viral infections
- •3.1.4. Defenses against viral infections
- •3.2. Kingdom Monera. Bacteria
- •3.2.1. Bacteria are organisms
- •3.2.2. Main groupes of bacteria Archaebacteria
- •Photosynthetic bacteria
- •Chemosynthetic bacteria
- •Cyanobacteria
- •Some bacteria are helpful
- •Some bacteria are harmful
- •Prevention and control of bacterial disease
- •3.3. Plantlike Protists. Kingdom Protista
- •3.4. Algae
- •Plants that live in water
- •Economic importance of algae
- •3.5. Fungi
- •3.5.1. Terrestrial molds
- •3.5.2. Water molds
- •3.5.3. Slime molds
- •3.5.4. Club fungi
- •3.5.5. Sac fungi
- •3.5.6. Imperfect fungi
- •3.5.7. Fungi and habitats
- •3.5.8. Adaptations to life on land
- •3.5.9. Ecological and economic roles
- •3.6. Lichens
- •3.6.1.Structure
- •3.6.2. Habitats
- •3.6.3. Nutrition
- •3.6.4. Ecological role
- •3.6.5. Reproduction
- •Summary and test questions
- •4. Botany
- •Nonvascular and vascular plants
- •Seed plants
- •4.1. Bryophytes and Mosses
- •4.1.2. Mosses
- •4.2. Ferns
- •4.2.1. Physical structure
- •4.2.2. Life cycle of ferns
- •4.3. Gymnosperms
- •4.3.1. Conifers
- •Importance of conifers
- •4.3.2. Cycads
- •4.3.3. Ginkgoes
- •4.3.4. Gnetales
- •4.4. Angiosperms
- •Kinds of plant tissues
- •Root structure
- •Flowers and sexual reproduction
- •Leaves and water loss
- •Table 4.1 Comparative characteristics of monocots and dicots
- •5.1. Phylum Protozoa
- •5.1.4. Class Sporozoa
- •5.2. Phylum Porifera: Sponges
- •5.3. Phylum Coelenterata
- •5.4. Phylum Plathelminthes. Flatworms
- •5.5. Phylum Nemathelminthes: Roundworms
- •5.6. Phylum Annelids
- •5.7. Phylum Molluska: Mollusks
- •5.8. Phylum Arthropoda
- •Incomplete Metamorphosis
- •5.9. Phylum Chordata
- •Classification and Characteristics of Amphibians
- •The 4,500 species of mammals live throughout the world. Mammals can live in different environments because their flexible body plan has allowed the various species to undergo many special adaptations.
- •5.10. Classification of Kingdom Animalia
- •6. Human Biology
- •Introduction
- •6.1. The skeleton system
- •6.2. The muscular system
- •6.3. The integumentary system
- •6.4. The respiratory system
- •6.5. The excretory system
- •6.6. Nervous control and coordination
- •Introduction
- •6.7. Sense organs
- •Introduction
- •Vision, Hearing, and Balance
- •6.8. Endocrine system
- •Introduction
- •6.9. Circulatory system
- •Introduction
- •Immune Response
- •Immunity
- •6.10. Nutrition and digestion
- •Vitamins
- •Vitamins and Minerals
- •6.11. Reproduction and development
- •Introduction
- •Influence of external environmental factors on human health
- •6.12. World populationand its regulation
- •World population, total quantity and annual increase, 1950–2000 (us Bureau, 2001)
- •7. Biodiversity as phenomenon of life
- •Introduction
- •7.1. Biodiversity and problems of its preservation
- •Biodiversity components and levels (Global, 1995)
- •Quantitative assessment of the species diversity of the planet (Global, 2001)
- •7.2. Biodiversity conservation in Ukraine: conceptual developments and challenges
- •7.3. Protected Areas and Econet of Ukraine as instruments of conservation and innovation
- •7.4. Transboundary protected areas and opportunities for cooperation
- •Carpathians case (successful story)
- •The greening of local environment
- •Conclusion
- •Annex 1. Classification of living organisms
- •Bibliography
- •Additional references
- •Other information resources
- •Terms and definition index
6.3. The integumentary system
Bones, muscles, and body organs are covered by the largest single organ, the skin. The skin is also called the integument. Along with the hair and nails, it makes up the integumentary system.
Functions of the integumentary system
The skin performs many functions for the body, the most important of which is protection. The unbroken skin prevents harmful organisms from entering the body. It also cushions the body against physical injury. The skin is a sense organ containing receptors for touch, heat, cold, pressure, and pain. It is also an organ of elimination because it reds the body of certain waste and so helps control body temperature. Blood vessels near the skin’s surface also allow heat to escape. When exposed to direct sunlight, components of the skin produce vitamin D. In addition, skin acts as a waterproof covering that keeps fluids inside the body.
Structure of the integumentary system
Skin consists of all 4 types of body tissue: nervous, muscle, connective, and epithelial. As a result, it is elastic, flexible, and responsive. Its thickness depends upon its function. For example, an extremely thin layer of skin covers the eardrums, which must be sensitive to sound waves. In contrast, thick skin covers the soles of the feet.
Layers of Skin
The skin consists of 2 layers. The skin outer layer is called the epidermis. The thick inner layer is called the dermis.
The epidermis itself has 2 layers. The top one is actually about 20 layers of dead, scale like, flattened cells. These cells die quickly because they are cut off from their food supply. They contain a protein called keratin, which makes them waterproof. The body loses several thousand of these cells each day, and new cells are produced by mitosis in the lower epidermal layer. As the surface cells disappear, those in the lower layer become the outer surface. It takes about 27 days for all of the outer skin cells to be replaced. In addition to these skin-generating cells, the lower layer has cells that contain melanin, the pigment that makes skin dark. Every person has approximately the same number of these cells. Therefore, skin color differences result from variations in the amount of pigment produced by these cells.
The dermis is composed mainly of connective tissue, which gives the skin its strength and elasticity. Blood vessels, nerves, hair roots, and oil and sweat glands are all located in the dermis.
Subcutaneous layer
A protective layer of loose fatty tissue and dense connective tissue called the subcutaneous layer attached the dermis to the bones and muscles. Although not technically part of the skin, the subcutaneous layer, like skin, helps protect the body against injury and heat loss.
Glands
Sebaceous glands, or oil glands, secrete sebum, an oil that reaches the skin’s surface through the places where hair emerges from the skin. The oil prevents hair and skin from drying out and helps waterproof the skin. A condition called acne commonly occurs during adolescence. Acne occurs when oil mixes with dead cells and plugs up pores in the skin, causing blackheads. In addition, inflammation of oil glands causes pimples. Acne may be related to hormonal changes that take place during adolescence.
More than 2,5 million sweat glands exist in the dermis. Most consist of a tiny duct that opens to the skin’s surface and rids the body of excess water and certain wastes. The evaporation of sweat also acts to cool the body when it becomes overheated.
Hair and nails
Hair is present on the skin over the entire body, except on the soles of the feet, the palms of the hands, and the lips. Hair is manufactured in hair follicles, which are small folds of epidermis that extend into the dermis. Tiny blood vessels at the base of the follicle nourish the hair root. A group of actively dividing cells near the base produces new hair. The hair shaft, which extends above the skin’s surface is composed of dead epidermis.
Nails are mainly dead cells composed of keratin that protect the tips of fingers and toes. At the base of the hard nail plate is a whitish, semicircular area called the lunula. Cell division takes place in the root of the nailbed.