BIOL 1080 Chapter Notes -Cartilage, Chondrocyte, Dermis
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BIOL*1080 Biological Concepts of Health
Chapter 1a Humans in the World of Biology
Basic Characteristics of All Living Things
•Living things contain nucleic acids, proteins, carbohydrates, and lipids.
oThe nucleic acid DNA is especially important because DNA molecules can make copies of
themselves, an ability that enables organisms to reproduce.
•Living things are composed of cells.
•Living things grow and reproduce.
•Living things use energy and raw materials.
oThe term metabolism refers to all chemical reactions that occur within the cells of living things.
•Living things respond to their environment.
•Living things maintain homeostasis.
oHomeostasis is the relatively constant and self-correcting internal environment of a living
•Populations of living things evolve and have adaptive traits.
Classification by Evolutionary Relationship
•Organisms with the greatest similarity are grouped together.
•One system recently favored by many biologists recognizes three domains.
•Two of the domains, Bacteria and Archaea, consist of the various kinds of prokaryotes – all very small,
single-celled organisms that lack a nucleus or other internal compartments.
•All other organisms, including humans, belong to the third domain, Eukarya.
•Eukarya have eukaryotic cells, which contain a nucleus and complex internal compartments called
•Domain Eukarya is subdivided into four kingdoms – protists, fungi, plants, and animals.
•Human characteristics include a large brain size relative to body size and a two-legged gait.
•But nothing distinguishes humans more than culture.
•Culture may be regarded as a set of social influences that produce an integrated pattern of knowledge,
belief, and behaviour.
Levels of Biological Organization
•A population is individuals of the same species (individuals that can interbreed) living in a distinct
•A community is all living species that can potentially interact in a particular geographic area.
•The biosphere is that part of Earth where life is found.
•Is a way of learning about the natural world by applying certain rules of logic to the way information is
gathered and conclusions are drawn.
•Develop a testable hypothesis – an explanation of your observation.
•Make a prediction based on your hypothesis and test it with a controlled experiment.
oA controlled experiment, the research subjects are randomly, divided into two groups.
oOne group is designated as the control group and the other is designated as the experimental
oBoth groups are treated in the same way except for one factor, called the variable, whose effect
the experiment is designed to reveal.
•Draw a conclusion based on the results of the experiment.
oA conclusion, which is an interpretation of the data.
•Statistical significance of the data, which is a measure of the possibility that the results were due to
•Inductive and Deductive Reasoning
oIn inductive reasoning, facts are accumulated through observation until the sheer weight of the
evidence allows some logical general statement to be made.
oDeductive reasoning, begins with a general statement that leads logically to one or more
deductions, or conclusions.
oThe process can usually be described as an “if then” series of associations.
oResearchers look at patterns that occur within large populations.
1d: Body Organization and Homeostasis
From Cells to Organ Systems
•A tissue is a group of cells of similar type that work together to serve a common function
•Human tissues have four primary types
oEpithelial Tissue: Covers body surfaces, lines body cavities and or organs and forms glands
oConnective Tissue: Serves as a storage site for fat, plays an important role in immunity and
provides the body and its organs with protection and support
oMuscle Tissue: Responsible for body movement and the movement of substances throughout the
oNervous Tissue: Conducts nerve impulses from one part of the body to another
oHave a free surface and basement membrane
Free surface: Specialized for protein and secretion/absorption
Basement membrane: Noncellular layer that binds epithelial cells to underlying
connective tissue resists stretching
oFree surface has three basic shapes of cells
Squamous: Flattened, scale-like cells that form linings in the blood vessels of lungs and
allows for O2 and CO2 to diffuse
Cuboidal: Cube shaped cells that are found in many glands and is the lining of kidney
tubules. Provides some protection and are specialized for secretion and absorption.
Columnar: Elongated, column-shaped cells that are specialized for absorption and
secretion and line the small intestine
•A gland is an epithelial tissue that secretes a product
•An exocrine gland secretes their products into ducts leading to body surfaces, cavities or organs
(produce digestive enzymes)
•An endocrine gland lacks ducts. They secrete their products/hormones into spaces just outside the cells
(hormones diffuse into bloodstream)
oBinds tendons and ligaments and supports other tissue (cartilage+bone)
oMost abundant and widely distributed tissue in body
oAll connective tissue contain cells embedded in an extracellular matrix
oMatrix consists of protein fibers and a noncellular material called ground substance
oGround substance may be solid (bone), fluid (blood) or gelatinous (cartilage)
Ground substance is secreted by the connective tissue or other cells near by
oMatrix contains three types of fibers
Collagen: Strong and ropelike fibers that withstand pulling because of their great tensile
Elastic: Random coils that can stretch and recoil like a spring (i.e. skin, lung, blood
Reticular: Thin strands of collagen that are interconnecting networks suitable for
supporting soft tissue (support liver+spleen)
•All three types of fibers are produced by cells called fibroblasts in the connective tissue
•Fibroblasts repair tears in body tissue and have two broad categories
oConnective Tissue Proper: Loose and dense connective tissue that contains many cells but has
fewer and more loosely woven fibers
oSpecialized Connective Tissue: Cartilage, bone and blood. Provides support and protection and
helps transport CO2, O2 and nutrients, helps fight infection
•Connective Tissue Proper has 3 types
oAreolar Connective Tissue: Functions as a universal packing material between other tissues
(found in muscles) , permits muscles to move freely and anchors the skin to underlying tissues
oAdipose Tissue: Contains cells that are specialized for fat storage, insulation and shock absorber
oDense Connective Tissue: Forms strong bands because of its amounts of tightly woven fibers,
and is found in ligaments, tendons and dermis
•Specialized Connective Tissue has 3 types
oCartilage: Strong but flexible, cushioning between certain bones and helps maintain the
structure of certain body parts (ears, nose). Cells in cartilage (chondrocytes) sit within spaces of
the matrix called lacunae. It lacks blood vessels/nerves. Nutrients reach cartilage cells by
diffusion, and the cartilage heals slower than bone
3 types of cartilage
Hyaline: Most abundant/support/flexibility. Known as gristle and is found at the end of
large bones. It forms part of the nose, ribs and contains collagen fibers
Elastic: More flexible that Hyaline. Large amounts of wavy elastic fibers found in the
external ear to provide strength and elasticity
Fibrocartilage: Fever cells than other cartilage and contains collagen fibers. Forms
cushioning layers in the knee joint as well as the outer part of the shock-absorbing disks
between vertebrae of spine. Can withstand pressure
oBone: Apart of skeletal system and is a living/actively metabolizing tissue with good blood
supply. Protection and support for internal structures, movement and storage of lipids/fats and
produces blood cells. Made from hardened Ca for rigid support, and collagen fibers for strength
oBlood: Consisting of a liquid matrix and fibers in the blood are soluble in proteins. Transports
various substances. Red blood cells transport O2 to cells and carries CO2 away. White blood
cells fight infection and protect the body
oComposed of muscle cells (muscle fibers) that contract when stimulated
oThree types of muscle tissue
Skeletal: Usually attached to bones and is described as a voluntary muscle. Long,
cylinder shaped cells each containing several nuclei. Actin and Myosin interact to cause
Cardiac: Found only in walls of heart, and contractions are responsible for pumping
blood to rest of body (involuntary muscle). Resembles branching cylinders and have
striations and typically 1 nucleus. Special junctions at the plasma membranes of these
cells that strengthen cardiac tissue and promote rapid conduction of impulses throughout
Smooth: Involuntary muscle found in the walls of blood vessels and airways and also in
walls of organs. Contractions reduce the flow of blood/air. Helps organs in mixing and