Chapter 1-4 Study Guide and answers
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Transcript of Chapter 1-4 Study Guide and answers
BIOL 131Week 1 CHPTS 1-4 Study Guide
CHAPTER 1-4 Study GuideInstructions:1.) Save this document with your last name first initial Study Guide (smithj Study Guide)- Points will be deducted for an incorrect file name
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Chapter 1: The Nature of Disease: How to Think about Illness
Introduction to Human Physiology
What is physiology?
– Physiology: The study of the normal functioning of a living organism and
its component parts.
Pathology is the science that deals with the function of organs and systems and the way they do this functions.
Man and the environment
• External environment
• The environment man lives in, interacts with (benefits and hazards)
• Major environmental factors are: oxygen, water, food, physical factors,
social factors, micro organisms and parasites.
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BIOL 131Week 1 CHPTS 1-4 Study Guide
The internal environment
• The human body consists of organs& tissues that are formed of cells.
• The cell is the smallest unit of life.
• The cell is surrounded by tissue fluid (Internal Environment).
• The composition of the internal environment should remain constant within
narrow limits.
Internal environment
• Claude Bernard stated that all the life processes have only one goal, that
is to keep the internal environment constant, and this fixity of the internal environment is necessary condition for life
Homeostasis
• Cells live a fairly constant environment
• The cells in turn constitute the tissues which provide the environment
Body-Fluid Compartments
• 60% of total body weight H20
• In a 65kg man, there is 40 liters, distributed as:
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BIOL 131Week 1 CHPTS 1-4 Study Guide
o Intracellular compartment: Fluid inside the cell & 25L
o Extracellular compartment: 15 L & 2 Subdivisions: Blood plasma
3L & Interstitial fluid 12L
Extracellular fluid:
15L
2 Subdivision:
Blood plasma 3L
Interstitial Fluid 12L
• It is the internal environment that immediately surround the units of life of
the whole body
• Intravascular : within the vascular system
• Interstitial : lies between the cells
• Transcellular : secreted by epithelial lining e.g., CSF, pleural
fluid ,peritoneal fluid, joint fluid,….
• Large volumes are present in disease states, pleural effusion , ascites.
• Large losses in diarrhea and vomiting leads to dehydration and electrolyte
disturbances.
Homeostasis:
• It is all the physological processes that are carried out by all body systems.
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BIOL 131Week 1 CHPTS 1-4 Study Guide
• It is to insure that chemical and physical structure of the internal environment is kept constant in spite of external (e.g.: temp, oxygen tension, pressure) or internal
(e.g.: increased muscular activity) changes.
• It deals with all automatic reactions which take place to correct all deviations from normal
• It is a necessary condition for the existence
• Failure of homeostasis often leads to diseases and death.
Homeostasis
• This is the name for the process which keeps the condition and
environment of the tissues in the proper condition to sustain life
Composition of the human body
• Water: 60%
• Protein: 18%
• Fats: 18%
• Minerals: 4%
Body water
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BIOL 131Week 1 CHPTS 1-4 Study Guide
• 60%
• Varies with age (newborn 82, old age 52).
• Varies with fat content (males have more water than females)
Body protein
• It is the second largest components
• It is found in the structure of all tissues
• The largest amount is found in the skeletal muscle.
Body fat
• Triglycerides in adipose tissues: found in the subcutaneous tissue and
surrounding the abdominal viscera, energy stores, in females, it is one of the secondary sex characters
• Phospholipids : in the cell membrane
• In the structure of CNS.
Minerals
• Small quantity with the exception of Ca2+
• Ca2+ is about 1.2 kg in young adult, found in bones
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BIOL 131Week 1 CHPTS 1-4 Study Guide
• Ca2+ is functionally significant in tissue fluids.
• Iron 3-4gm: in heme, stores,
transport forms, and in enzymes.
• Other minerals are closely regulated to maintain the composition of the
internal environment
Minerals
• The concentration of the minerals in the intracellular fluid is different from
the concentration of them in the extra cellular fluid.
• This difference depends on :
– Active transport
– Passive diffusion according to concentration gradient and electrical
charges distribution.
Fluid exchange
• The intravascular fluid and the interstitial fluid are in continuous exchange.
Estimated to be 100L/ h.
• Aim: to renew tissue fluid and maintain its constancy (Homeostasis) by
supplying materials needed by the cells, and removing wastes produced by cell metabolism.
Fluid Exchange
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BIOL 131Week 1 CHPTS 1-4 Study Guide
• i) hydrostatic pressure: filtration force, it moves the fluid out of the
capillaries
• ii) colloid osmotic pressure: osmosis (suction) force, it draws the fluid back
into the capillaries
• These two forces act in opposite directions.
• The colloid osmotic is uniform throughout the capillary length.
• The hydrostatic pressure
Forces
• Fluid exchange between the plasma & ISF is governed by algebric sum of
hydrostatic & osmotic forces on either sides of the capillaries
• Pcap is due to pumping action of the heart
• High hydrostatic in the arterial end of the capillary P=35mmHg
• Low hydrostatic pressure in the venous side of the capillary P=15mmHg
• Opposed by osmotic pressure of plasma proteins: пcap= 25mmHg
• Mainly opposed by пcap, without opposing forces the plasma would
rapidly transferred into the interstitium
• The osmotic pressure is uniform throughout the capillary length
• The hydrostatic pressure falls from the arteriolar end to the venular end
• At arterial end the filtration force exceeds the osmotic force→35-
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BIOL 131Week 1 CHPTS 1-4 Study Guide
25=10mmHg filtration
• At the venular end the osmotic force exceeds the filtration force
→25-15=10mmHg reabsorption
Chapter 2: Cell Injury, Adaptation, and Death
Concept of Injury and Cellular Response to Injury
• Cells are constantly exposed to a variety of stresses.
• When stress is too severe, injury results.
• Injury alters the preceding normal steady state of the cell.
What hurts cells?
Causes of Cell Injury/Lesions
• oxygen deprivation (anoxia)
• physical agents
• chemical agents
• infections agents
• immunologic reactions
• genetic defects
• Nutritional imbalances
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BIOL 131Week 1 CHPTS 1-4 Study Guide
• Aging
Disease
• Dis + Ease = Disease.
• “Discomfort due to Structural or functional abnormality”
• Disease is caused by an agent.
• Causes (etiology) can be
– External / Environmental. E.g.. Heat, Bacteria.
– Internal E.g. stress, genes, ageing.
Cellular Injury & Adaptation
• Normal cell is in a steady state “Homeostasis”
• Change in Homeostasis due to stimuli - Injury
• Injury - Reversible / Irreversible
• Adaptation / cell death
Response to Injury
• Adaptations (reversible)
– Hydropic degeneration
– Hypertrophy
– Hyperplasia
– Atrophy
– Accumulations - hyaline, fat, etc.
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BIOL 131Week 1 CHPTS 1-4 Study Guide
• Necrosis (irreversible) – cell death.
Terminology
• Necrosis : Morphologic changes seen in dead cells within living tissue.
• Autolysis : Dissolution of dead cells by the cells own digestive enzymes. (not seen)
• Apoptosis : Programmed cell death. Physiological, for cell regulation.
Types of Necrosis
• Coagulative – Eg. Infarction
• Liquifactive - Brain, abscess
• Caseous - Bacterial / Tuberculosis
• Gangrene - With infection
Sequels of Necrosis
• Cell Death
• Necrosis
• Autolysis
• Phagocytosis
• Organization & fibrous repair.
Aging
“Progressive time related loss of structural and functional capacity of cells leading to death”
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BIOL 131Week 1 CHPTS 1-4 Study Guide
• Senescence, Senility, Senile changes.
• Ageing of a person is intimately related to cellular ageing.
Factors affecting Ageing
• Genetic – Clock genes, (fibroblasts)
• Diet – malnutrition, obesity etc.
• Social conditions -
• Diseases – Atherosclerosis, diabetes etc.
Cellular mechanisms of aging
• Cross linking proteins & DNA .
• Accumulation of toxic by-products.
• Aging genes.
• Loss of repair mechanism.
• Free radical injury
• Telomerase shortening.
Ageing –changes
• Gradual atrophy of tissues and organs.
• Dementia
• Loss of skin elasticity
• Graying and Loss of hair
• BV damage – atherosclerosis/bruising.
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BIOL 131Week 1 CHPTS 1-4 Study Guide
• Loss of Lens elasticity opacity vision
• Lipofuscin pigment deposition – Brown atrophy in vital organs.
Factors affecting ageing
• Stress
• Infections
• Diseases
• Malnutrition
• Accidents
• Diminished stress response
• Good health
Conclusions
• Cellular Injury - Various causes
• Reversible Injury Adaptations
– Hypertrophy, Hyperplasia, Atrophy
– Accumulations - Hydropic, hyaline, fat..
• Irreversible Injury - Necrosis
– Coagulative, Liquifactive, Caseous
• Ageing - Causes, Changes, Factors
Chapter 3: Inflammation: The Reaction to Injury
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BIOL 131Week 1 CHPTS 1-4 Study Guide
Why is it necessary to determine the mechanism of injuries? Important for the diagnosis, rehabilitation and prevention of injuries.
Distant Effects of Inflammation
• Systemic effects
• Involvement of the lymphatic system
• Production of reactant proteins
The Consequences of Acute Inflammation
• Complete resolution
• Scarring
• Abscess
• Chronic inflammation
Injury Mechanism
• Depends persons perspective
• Mechanism often acts in combination
• Establish cause and effect relationship
Mechanical Loading
• Loads greater than physiological lead to injuries
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BIOL 131Week 1 CHPTS 1-4 Study Guide
• Chronic injuries
– Cumulative trauma
– Repetitive stress
• Acute injuries
Principles of Injuries
• Catch-all terms
– shinsplints
– tennis elbow
– jumper’s knee
• Level of dysfunction
– catastrophic injuries
• Progression
– untreated or lack to time to heal lead to more severe injuries
Assessment of Severity
• Clinical classifications help assign common characteristics to injuries
• Severity linked to amount of tissue damage
• Mild & moderate: partial disruption, tissue is able to accept loads
• Ligaments grade 1 mild: negligible structural & minimal time loss
grade 2 moderate: partial rupture & swelling tenderness & up to 6 wk time
grade 3 severe: complete, gross swelling & 8 wk min
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BIOL 131Week 1 CHPTS 1-4 Study Guide
Injury Principles
• Micro vs macrotrauma
• Primary: direct consequence of trauma
• Secondary
– injury surface after original trauma
– accommodation to primary injury (adaptation of loads)
• Tissue structure
Contributing factors
• Age– acute injuries: young– chronic: older• Gender• Genetics• Fitness level• nutrition • Psychological• Human interaction• Fatigue– physical & mental• Environment
Tissue Injury
• Inflammation: pathological process– vascular response– increase capillary permeability (swelling)
• Pain: swelling related pressure on nerve endings (more in confined spaces)
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BIOL 131Week 1 CHPTS 1-4 Study Guide
Tissue Injury
• vasodilatory phase– flow of fluid/plasma proteins into tissue
• Plasma proteins– fibrinogen
• Functions– dilutes & inactivates toxins– nutrients to inflammatory cells– antibodies, proteins
• Control of inflammation
– Chemicals Mediators– histamines , serotonin, bradykin, prostagladins, plasmin etc.
– Other Cells– phagocytes (fungal and bacterial infection)
– lymphocytes (antigens)
Why inflam0mation?
Body’s first line of defense against injuries
The Inflammatory Response to Infection
Infection and inflammation
• Bacteria
• Parasites
• Viruses
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BIOL 131Week 1 CHPTS 1-4 Study Guide
Bone
• Any conditions that affects osteocyte performance
• Osteonecrosis : cessation of blood flow
– vessel disruption
– occlussion
– injury or pressure to arterial walls
• matrix, bone strength likelihood of fracture
Bone
• Osteoporosis
• Major public health issue
• Affect mostly trabercular bone
• Bone of axial skeleton
• Multifactor
• Clinical conditions
Bone
• Fracture (break): applied loads exceeds bone’s ability
• Resistance– material properties– geometry– anisotropic effects– porosity
• Type of loading– acute vs chronic
Fractures
• Indirect or direct
• Risk and type of bone
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BIOL 131Week 1 CHPTS 1-4 Study Guide
• Diagnosis– site– extent of injury– configuration– fragments (displaced)– environmental (open closed)– complications– etiological
Fractures
• Healing phases:– inflammation
– union of bony ends (3wk)
– callus remodeling (6 wks)
Articular Cartilage
• Excessive loading
– loss of cartilage matrix
– chondral fractures
– osteochondral fracture
• Inability to repair
Articular Cartilage
• AO– non inflammatory
– weight bearing joints
– deterioration of AC
– osteophytes formation
– cartilage fibrillation
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BIOL 131Week 1 CHPTS 1-4 Study Guide
• Artificial Joints – cemented or non
Joint Injuries
• Excessive loading
• Dislocation (luxation)
• Partial dislocation (subluxation)
• Synovitis
• Arthritis
– OA
– RA
– Gouty
Fibrocartilage
• Distributes forces at joints
• Shock absorber
• Improve joint fit
• menisci
• intervertebral disks
Tendon
• Force transfer
• Injuries
– direct (cuts)
– indirect (excessive loads applied to unit)
• Musculotendinous injuries: strain
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BIOL 131Week 1 CHPTS 1-4 Study Guide
– Mild, moderate, severe
– severe: precede by microdamage
Tendon
• Repetitive overloading: inflammatory response or tendinitis
• Also could affect tendon sheath, peritenon etc.
• Healing
– inflamation
– Synthesis of collagen and GAG (matrix)
– Cyclic loading (2-3 wk)
– Progressive stress
• Peritenonitis
• Tendinosis (intratendinous degeneration dut ot atrophy)
• Tendinitis (Symptomatic degeneration vascular disruption and inflammation
Ligaments
• Ligament injuries
– sprain
– partial tears
– complete tears
• Healing
– bleeding & inflamation (fibrin, fibroblas scar cells)– proliferation of building material (scar tissue)– matrix remodeling • smaller fibers
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BIOL 131Week 1 CHPTS 1-4 Study Guide
• lack organization
Muscle
• Injuries– acute muscular strain• Over stretching or overloading• force, rate, application• moderate: partial tear• severe: complete tear, hemorrhage,swelling– contusions• intramuscular bleeding• myositis ossificans – exercise induced injury• DOMS 24-72 hr after exercise• Eccentric
Skin
• Abrasions
• Contusions
• Penetrating wounds– obscure deeper damage
• Lacerations
• Infection
• Excessive bleeding
Nervous tissue
• Not musculoskeletal
• Greatest potential for dysfunction
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BIOL 131Week 1 CHPTS 1-4 Study Guide
• Injuries
• chemical
• thermal
• ischemic
• mechanical
• entrapment
• trauma: compressive or tensile
• Temporary or complete axonal discontinuity• Motor impairment can lead to secondary injuries
Nervous Tissue
• Compartment or entrapments of nerves or vessels– increase pressure transmitted– Enclosed spacing• Symptoms– numbness, tingling & pain– decreased vessel perfusion• Inflammation: positive feedback loop
Chapter 4: Repair: Recovery from Injury
Chapter 4
• is the body’s collective attempt to restore normal structure and function to the injured site.
• is one type of repair and is the complete or nearly complete
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BIOL 131Week 1 CHPTS 1-4 Study Guide
restoration of normal anatomy and function by the regrowth of normal parenchymal cells and supporting tissue; little or no scarring is present.
• is another type of repair that occurs when regeneration is partial or not possible; some scarring is always present.
The Repair Process
– In tissues capable of regeneration (those with stem cells), repair of mild injury takes place by means of regeneration of new functional (parenchymal) cells and the restoration of normal anatomy.
– Repair of severe injury occurs by means of regeneration of new functional cells and partly by scarring (fibrous repair).
– In tissues not capable of regeneration (without stem cells), repair of injury takes place only by scarring.
Types of cells according to their ability to regenerate
– Labile cells , which divide continuously from a pool of stem cells
– Stable cells , which have a reserve of stem cells, and which divide very slowly until stimulated by injury, after which they divide rapidly
– Permanent Cells , which are highly specialized and have no reserve of stem cells, and which are incapable of division and regeneration
The Scaffolding for Cell Regeneration
• Basement membranes is a thin, filmy membrane under the epithelium, it provides the surface upon which epithelial cells grow.
• Extracellular matrix is a mixture of collagen elastin fibers creates by fibrolasts, it creates a structural meshwork t o support cell growth.
Cell Migration into the Wound
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BIOL 131Week 1 CHPTS 1-4 Study Guide
• Wound : A wound is the injury resulting from short term injury at a discrete site
• Steps in fibrous repair (scarring)
– Fibrocyte migration : raw material for repair
– Angioneogensis : growth of new blood cells
– Scar development: synthesis of excellular matrix proteins and deposition of collagen followed by contraction, reshaping and strengthening
Scar Development
• Scar development follows angioneogenesis and occurs in several overlapping steps
• Granulation tissue is a mixture of new blood vessels, fibrous tissue, and residual edema and leukocytes that is at its peak a few days into wound healing.
Healing by First intention vs Second intention
• First intentions : – Wounds with closely approximated edges; surgical incisions are an example. – Healing by first intention: inflammation first, followed by macrophage clean-up, neovascularization, and scarring.
• Second intentions : – Wounds with widely separated margins heal by; for example, skin or intestinal ulcers.– Healing by second intention is much the same as healing by first intention: inflammation first, followed by macrophage clean-up, neovascularization, and scarring. However, the volume of necrotic tissue to be removed is greater, and reepithelialization of the surface is slower because the wound is wider.
Host Factors Interfering with Wound Healing
• Infection is the most common obstacle to normal repair
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BIOL 131Week 1 CHPTS 1-4 Study Guide
• Other obstacles
– Poor nutrition
– Steroid drugs
– Diabetes
– Poor vascular supply
– Foreign objects
– Mechanical forces
Pathologic Wound Repair
• A keloid is a hyperplastic scar that is prominent, raised, or nodular and that contains excess collagen.
• Pyogenic granuloma is a localized, highly vascular collection of persistent
granulation tissue.
Recaps
• Distinguish between repairs, regeneration and healing
• Name the types of cells according to their ability to regenerate
• List the component steps in fibrous repair
• What is meant by “healing by first and second intention”
• What are ostavles to normal repair
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