Download Levels of Organization

Levels of Organization
Subatomic Particles – electrons, protons, neutrons
Atom – hydrogen atom, lithium atom
Molecule – water molecule, glucose molecule
Macromolecule – protein molecule, DNA molecule
Organelle – mitochondrion, Golgi apparatus, nucleus
Cell – muscle cell, nerve cell
Tissue – simple squamous epithelium, loose connective
tissue
Organ – skin, femur, heart, kidney
Organ System – skeletal system, digestive system
Organism - human
1
Levels of Organization
2
Anatomy and Physiology
Anatomy – study of structure
(Greek – “a cutting up”)
Physiology – study of function
(Greek – “relationship to nature”)
Structure is always related to function
3
Homeostasis
Body’s maintenance of a stable internal environment
Homeostatic Mechanisms – monitor aspects of the
internal environment and corrects any changes
•Receptors - provide information about stimuli
•Control center - tells what a particular value should be
(includes a set point)
•Effectors - elicit responses that change conditions in the
4
internal environment
Homeostatic Mechanisms
5
Body Cavities
6
Thoracic & Abdominal
Membranes
Visceral layer – covers an organ
Parietal layer – lines a cavity or body wall
Thoracic Membranes
•Visceral pleura
•Parietal pleura
•Visceral pericardium
•Parietal pericardium
Abdominopelvic Membranes
•Parietal peritoneum
•Visceral peritoneum
7
Serous Membranes
8
Serous Membranes
9
Table 01.02
10
Anatomical Terminology
Anatomical Position – standing erect, facing forward,
upper limbs at the sides, palms facing forward
Terms of Relative Position
• Superior versus Inferior
•Anterior versus Posterior
•Medial versus Lateral
•Ipsilateral versus Contralateral
•Proximal versus Distal
•Superficial versus Peripheral
•Deep
11
Body Sections
•Sagittal / Midsagittal or Median / Parasagittal
•Transverse or Horizontal
•Coronal or Frontal
•Cross section, Oblique, Longitudinal
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Body Sections
13
Body Sections
14
Body Sections
15
Abdominal Subdivisions
16
17
Body Regions
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Major Directional Terms
21
Structure of Matter
Matter – anything that takes up space and has weight;
composed of elements
Elements – composed of chemically identical atoms
• bulk elements – required by the body in large
amounts
• trace elements – required by the body in small
amounts
Atoms – smallest particle of an element
222-3
Atomic Structure
Atoms - composed of
subatomic particles:
• protons – carry a
positive charge
• neutrons – carry no
electrical charge
• electrons – carry a
negative charge
Nucleus
• central part of atom
• composed of protons and
neutrons
• electrons move around the
nucleus
232-4
Atomic Number and
Atomic Weight
Atomic Number
• number of protons in the
nucleus of one atom
• each element has a unique
atomic number
• equals the number of
electrons in the atom
Atomic Weight
• the number of protons
plus the number of
neutrons in one atom
• electrons do not
contribute to the weight of
the atom
242-5
Isotopes
Isotopes
• atoms with the same atomic numbers but
with different atomic weights
• atoms with the same number of protons
and electrons but a different number of
neutrons
• oxygen often forms isotopes (O16, O17,
O18)
• unstable isotopes are radioactive; they
emit subatomic particles
252-6
Molecules and Compounds
Molecules – particle formed when two or more atoms
chemically combine
Compound – particle formed when two or more
atoms of different elements chemically combine
Molecular formulas – depict the elements present
and the number of each atom present in the molecule
H2
C6H12O6
H2O
262-7
Electrons
• found in regions of space called electron shells (energy shells)
• each shell can hold a limited number of electrons
• for atoms with atomic numbers of 18 or less, the following rules apply:
• the first shell can hold up to 2 electrons
• the second shell can hold up to 8 electrons
• the third shell can hold up to 8 electrons
• lower shells are filled first
• if the outermost shell is full, the atom is stable
272-8
Ions
Ion
• an atom that has gained or lost an electron(s)
• an electrically charged atom
• atoms form ions to become stable
Cation
• a positively charged
ion
• formed when an atom
loses an electron(s)
Anion
• a negatively charged ion
• formed when an atom gains an
electron(s)
282-9
Ionic Bond
Ionic Bond
• an attraction between a cation and an anion
• formed when electrons are transferred from one atom
to another atom
292-10
Covalent Bond
Formed when atoms share electrons
•Hydrogen atoms form single bonds
•Oxygen atoms form two bonds
•Nitrogen atoms form three bonds
•Carbon atoms form four bonds
H―H
O=O
N≡N
O=C=O
302-11
Polar Molecules
Polar Molecule
• molecule with a slightly negative end and a slightly positive
end
• results when electrons are not shared equally in covalent
bonds
• water is an important polar molecule
312-13
Hydrogen Bonds
Hydrogen Bond
• a weak attraction between the positive end of one polar
molecule and the negative end of another polar molecule
• formed between water molecules
• important for protein and nucleic acid structure
322-14
Types of Chemical Reactions
Dehydration Synthesis Reaction (Anabolism) –
chemical bonds are formed with the removal of
water
Hydrolysis/Decomposition Reaction (Catabolism) –
chemical bonds are broken with addition of water
332-16
Acids, Bases, and Salts
Electrolytes – substances that release ions in water
NaCl  Na+ + Cl-
Acids – electrolytes that release hydrogen ions in water
HCl  H+ + Cl-
Bases – substances that release ions that can combine with
hydrogen ions
NaOH  Na+ + OH-
Salts – electrolytes formed by the reaction between an
acid and a base
HCl + NaOH  H2O + NaCl
342-17
Acid and Base Concentrations
pH scale - indicates the
concentration of hydrogen ions in
solution
Neutral – pH 7; indicates
equal concentrations of H+
and OH-
Acidic – pH less than 7;
indicates a greater
concentration of H+
Basic or alkaline – pH
greater than 7;
indicates a greater concentration
of OH-
352-18
Organic Versus Inorganic
Organic molecules
• contain C and H
• usually larger than inorganic molecules
• dissolve in water and organic liquids
• carbohydrates, proteins, lipids, and nucleic acids
Inorganic molecules
• generally do not contain C
• usually smaller than organic molecules
• usually dissolve in water or react with water
to release ions
• water, oxygen, carbon dioxide, and inorganic
salts
362-19
Inorganic Substances
Water
• most abundant compound in living material
• two-thirds of the weight of an adult human
• major component of all body fluids
• medium for most metabolic reactions
• important role in transporting chemicals in the body
• can absorb and transport heat
Oxygen (O2)
• used by organelles to release energy from nutrients
• necessary for survival
372-20
Inorganic Substances
Carbon dioxide (CO2)
• waste product released during metabolic reactions
• must be removed from the body
Inorganic salts
• abundant in body fluids
• sources of necessary ions (Na+, Cl-, K+, Ca2+, etc.)
• play important roles in metabolic processes
382-21
Organic Substances
Carbohydrates
• provide energy to cells
• supply materials to build cell structures
• water-soluble
• contain C, H, and O (CH2O)n
• ratio of H to O to 2:1 (C6H12O6)
• monosaccharides – glucose, fructose
• disaccharides – sucrose, lactose
• polysaccharides – glycogen, cellulose
•subunits linked by glycosidic bonds
392-22
Organic Substances
Carbohydrates
402-23
Organic Substances
Lipids
• soluble in organic solvents
• fats (triglycerides)
• used primarily for energy
• contain C, H, and O but less O than carbohydrates (C57H110O6)
• building blocks are 1 glycerol and 3 fatty acids per molecule
• saturated and unsaturated
412-24
42
Organic Substances
Lipids
• phospholipids
• building blocks are 1 glycerol, 2 fatty acids, and 1 phosphate per
molecule
• hydrophilic and hydrophobic
• major component of cell membranes
432-25
phospholipid
44
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Organic Substances
Lipids
• steroids
• connected rings of carbon
• component of cell membrane
• used to synthesize hormones
• cholesterol
462-26
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Organic Substances
Proteins
• structural material
• energy source
• hormones
• receptors
• enzymes
• antibodies
• building blocks are amino acids
• amino acids held
together with
peptide bonds
482-27
Organic Substances
Proteins
Four Levels of Structure
492-28
Organic Substances
Nucleic Acids
• constitute genes
• play role in protein synthesis
• building blocks are nucleotides
• DNA (deoxyribonucleic acid) – double polynucleotide
• RNA (ribonucleic acid) – single polynucleotide
502-29
Organic Substances
Nucleic Acids
512-30
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Clinical Applications
Radioactive Isotopes Reveal Physiology
• injected into the body
• different types taken up by different organs
• can be detected in the body using a scintillation
counter
• can be used to destroy specific tissues
• commonly used
• iodine-131 for thyroid function
• thallium-201 for heart function
• gallium-67 and cobalt-60 for cancer
• others used to assess kidney functions, measure hormone
levels and bone density changes
532-31
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Epithelial Tissues-Must Know!
General characteristics
 classified according to cell shape and number of cell layers
• line body cavities
• line hollow organs
• have a free surface
• cover organs and the body
• have a basement membrane
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5-3
Epithelial Tissues-Must Know!
General characteristics
• avascular
• cells readily divide
• cells tightly packed
• cells often have desmosomes
• function in protection, secretion, absorption, and
excretion
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5-3
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58
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Epithelial Tissues
Simple squamous
• single layer of flat cells
• substances pass easily through
• line air sacs
• line blood vessels
• line lymphatic vessels
Simple cuboidal
• single layer of cube-shaped cells
• line kidney tubules
• cover ovaries
• line ducts of some glands
60
5-4
Epithelial Tissues
Simple columnar
•single layer of elongated cells
• sometimes possess cilia
• sometimes possess microvilli
• often have goblet cells
• line uterus, stomach, intestines
Pseudostratified columnar
•single layer of elongated cells
• appear stratified
• often have cilia
• often have goblet cells
• line respiratory passageways
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5-5
Epithelial Tissues
Stratified squamous
• many cell layers
• top cells are flat
• can accumulate keratin
• outer layer of skin
• oral cavity, throat
• vagina, anal canal
Stratified cuboidal
• 2-3 layers
• cube-shaped cells
• ducts of mammary glands
• sweat glands
• salivary glands
• pancreas
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5-6
Epithelial Tissues
Stratified columnar
• top layer of elongated cells
• cube-shaped cells in deeper layers
• line vas deferens, male urethra, and part of pharynx
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5-7
Epithelial Tissues
Transitional
• many cell layers
• cube-shaped and elongated cells
• line urinary bladder, ureters, and some of urethra
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5-7
Glandular Epithelium
Composed of cells that are specialized to produce and secrete
substances
Endocrine glands are ductless
Exocrine glands have ducts
Unicellular exocrine gland
• composed of one cell
• goblet cell
Multicellular exocrine gland
• composed of many cells
• sweat glands, salivary glands, etc.
65
5-8
Types of Glandular Secretions
Merocrine glands
Apocrine glands
Holocrine glands
• fluid product
• salivary glands
• pancreas
• sweat glands
• cellular product
• portions of cells
• mammary glands
• ceruminous glands
• secretory products
• whole cells
• sebaceous glands
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5-10
67
Connective Tissues-Must Know
General characteristics
• most abundant tissue type
• many functions
• bind structures
• provide support and protection
• serve as frameworks
• fill spaces
• store fat
• produce blood cells
• protect against infections
• help repair tissue damage
• have a matrix
• have varying degrees of vascularity
• have cells that usually divide
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5-11
69
Connective Tissue Major Cell Types
Fibroblasts
• fixed cell
• most common cell
• large, star-shaped
• produce fibers
Macrophages
• wandering cell
• phagocytic
• important in defense
Mast cells
• fixed cell
• release heparin
• release histamine
70
5-12
Connective Tissue Fibers
Collagenous fibers
• thick
• composed of collagen
• great tensile strength
• abundant in dense CT
• hold structures together
• tendons, ligaments
Elastic fibers
• microfibrils embedded in elastin
• fibers parallel or branch
• elastic
• vocal cords, air passages
Reticular fibers
• very thin collagenous fibers
• highly branched
• form supportive networks
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5-13
Connective Tissues
Connective tissue proper
• loose connective tissue
• adipose tissue
• dense connective tissue
Specialized connective tissue
• cartilage
• bone
• blood
72
5-14
Connective Tissues
Loose connective tissue
Adipose tissue
• mainly fibroblasts
• fluid to gel-like matrix
• collagenous fibers
• elastic fibers
• bind skin to structures
• beneath most epithelia
• between muscles
• adipocytes
• cushions
• insulates
• store fats
• beneath skin
• behind eyes
• around kidneys and heart
73
5-15
Connective Tissues
Dense connective tissue
• packed collagenous fibers
• elastic fibers
• few fibroblasts
• bind body parts together
• tendons, ligaments, dermis
• poor blood supply
74
Connective Tissues
Bone
• solid matrix
• supports
• protects
• forms blood cells
• attachment for muscles
• skeleton
• osteocytes in lacunae
75
5-17
Connective Tissues
1. Hyaline cartilage
Cartilage




rigid matrix
chondrocytes in lacunae
poor blood supply
three types
1. hyaline
2. elastic
3. fibrocartilage
• most abundant
• ends of bones
• nose, respiratory passages
• embryonic skeleton
2. Elastic cartilage
• flexible
• external ear, larynx
3. Fibrocartilage
• very tough
• shock absorber
• intervertebral discs
• pads of knee and pelvic girdle
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5-18
Connective Tissues
Three types of cartilage
1. Hyaline cartilage
2. Elastic cartilage
3. Fibrocartilage
77
5-19
Connective Tissues
Blood
• fluid matrix called plasma
• red blood cells
• white blood cells
• platelets
• transports
• defends
• clotting
• fills blood vessels
• heart
78
5-20
Muscle Tissues
1. Skeletal muscle
General characteristics
•
•
•
muscle cells called muscle
fibers
contractile
three types
1. skeletal
2. smooth
3. cardiac
• attached to bones
• striated
• voluntary
2. Smooth muscle
• walls of organs
• skin
• walls of blood vessels
• involuntary
• not striated
3. Cardiac muscle
• heart wall
• involuntary
• striated
• intercalated discs
79
5-21
80
Muscle Tissues
1. Skeletal muscle
2. Smooth muscle
3. Cardiac muscle
81
5-22
Nervous Tissues
• found in brain, spinal cord, and peripheral nerves
• basic cells are neurons
• neuroglial cells are supporting cells
• sensory reception
• conduction of nerve impulses
82
5-23
Types of Epithelial Membranes
Serous
• line body cavities that lack openings to outside
• reduces friction
• inner lining of thorax and abdomen
• cover organs of thorax and abdomen
• secrete serous fluid
Mucous
•line tubes and organs that open to outside world
•lining of mouth, nose, throat, etc.
•secrete mucus
83
5-24