Transcript Exam 3 Review - Iowa State University

Exam 3 Review
Immune and Endocrine Systems
AN S 214 Supplemental Instruction
3/31/13
Immune System Outline
• Cells of Immune System
• Innate Defenses
– Surface Barriers
– Internal Defenses
• Injury to Healing Flow Chart
• Adaptive Defenses
– Cell Mediated Immunity
– Humoral Immunity
– Forms of Immunity
• Words to Know
Cells of Immune System
Innate Defenses
• Surface Barriers
– Skin
• Acidity
• Enzymes
• Mucin
• Defensins
• Lipids
• Keratin
– Mucus Membranes
• Internal Defenses
– Natural Killer Cells (Police)
• Large granular
lymphocyte
• Induce apoptosis
• Non-specific
– Fever
– Inflammation
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Heat
Redness
Swelling
Pain
Impairment of Function
– Phagocytes
Phagocyte Mobilization
• Leukocytosis –
Neutrophils enter blood
from bone marrow
• Margination –
Neutrophils cling to
capillary wall
• Diapedesis – Neutrophils
flatten and squeeze out of
capillaries
• Chemotaxis – Neutrophils
follow chemical trail
Mechanism of Phagocytes
1. Phagocyte adheres to
pathogens or debris
2. Phagocyte forms pseudopods
that eventually engulf the
particles forming a phagosome
3. Lysosome fuses with the
phagocytic vesicle, forming a
phagolysosome
4. Lysosomal enzymes digest the
particles, leaving a residual
body
5. Exocytosis of the vesicle
removes indigestible and
residual material
Injury to Healing Flow Chart
Adaptive Defenses
• Cell Mediated Immunity
– T Cells
• Humoral Immunity
– B Cells
• Specific
• Systemic
• Has memory
Cell Mediated Immunity
• CD4 + MHC II = Clones
 Helper T Cells
– Activate immune
response
• Stimulate B cells
• CD8 + MHC I = Clones
 Cytotoxic T Cells
– Release perforin and
granzymes
Humoral Immunity
• Antigen + Naïve B Cell = Clones
 Memory B Cells + Plasma B
Cells
• Plasma B Cells
– Antibodies
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Precipitation
Lysis by Complement
Agglutination
Neutralization
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IgM
IgA
IgD
IgG
IgE
Forms of Immunity
• Primary
– Mostly IgM, lag period, antibodies don’t last as long
• Secondary
– Mostly IgG, faster and larger response, antibodies last
longer
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Active, Natural – Infection
Active, Artificial – Vaccine
Passive, Natural – Colostrum
Passive, Artificial – Injection of antibodies
Words to Know
• Antigen – substance that can mobilize the adaptive defenses and
provoke an immune response
• Antigenic Determinant – part of the antigen that induces an
immune response
• Apoptosis – Cell death
• Haptens – not immunogenic by themselves, immunogenic when
attached to body proteins
• Immunocompetence – (lymphocytes) able to recognize and bind to
a specific antigen
• Immunogenicity – ability to stimulate proliferation of specific
lymphocytes and antibodies
• Reactivity – ability to react with activated lymphocytes and
antibodies released
• Self-Tolerance – (lymphocytes) unresponsive to self antigens
Endocrine System Outline
• Types of Stimuli
• Pituitary Hormones
– Thyroid Hormone
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Blood Glucose Levels
Hormonal Abnormalities
Blood Calcium Levels
Blood Calcium Abnormalities
Mechanisms of Hormone Action
– Water-Soluble Hormones
– Lipid-Soluble Hormones
• Words to Know
Types of Stimuli
• Humoral Stimuli
– Changing blood levels of
ions and nutrients directly
stimulates secretion of
hormones
• Neural Stimuli
– Nerve fibers stimulate
hormone release
• Hormonal Stimuli
– Hormones stimulate other
endocrine organs to
release their hormones
Pituitary Hormones
• Anterior Pituitary Hormones (Adenohypophysis)
• Posterior Pituitary Hormones (Neurohypophysis)
Hormone
GH
FSH
LH
PRL
TSH
ACTH
Oxytocin
ADH
Secreted from
Triggered by… (which
Effects
(cell type?)
hormone?)
Somatotrophs GHRH (stimulate)
Direct: Fat and carbohydrate metabolism
GHIH (somatostatin) (inhibit) Indirect: Stimulates the release of IGFs,
which affects skeletal and extraskeletal
Gonadotrophs GnRH
Stimulates gamete production
Gonadotrophs GnRH
Stimulate gonadal hormone production
Lactotrophs PRH (stimulate)
Stimulates milk production
PIH (dopamine) (inhibit)
Thyrtrophs TRH
Stimulates thyroid development
Corticotrophs CRH
Regulates to response to stress
Stimulates the adrenal cortex to release
corticosteroids
Hypothalamus XXXXXXXXXXXXXXXXXXXXXXX Stimulates milk ejection
XXXXXXXXXXXXXXXXXXXXXXX Stimulates uterine contractions
Hypothalamus XXXXXXXXXXXXXXXXXXXXXX Inhibits urine production
Thyroid Hormone
A – Thyroglobulin synthesized/discharged into
follicle lumen
B – Iodide (I-)is actively transported in
Not labeled – Iodide is oxidized to Iodine
C – Iodine is attached to tyrosine in colloid
D - Iodinated tyrosines are linked to form T3
& T4
E - Thyroglobulin colloid is combined with
lysosome
F - Enzymes cleave T3 & T4 from
thyroglobulin colloid and hormones
diffuse into blood
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Major metabolic hormone
Maintenance of blood pressure
Regulation of tissue growth
Development of skeletal and nervous
systems
Reproductive capabilities
T3 is ten times more active than T4
Blood Glucose Levels
• Pancreas
– Insulin
• Decreases blood
glucose levels
– Glucagon
• Increases blood
glucose levels
Hormone Abnormalities
• Growth Hormone
– Hypersecretion
• In children
results in
gigantism
• In adults results
in acromegally
– Hyposecretion
• In children
results in
pituitary
dwarfism
• Insulin
– Hypersecretion
• Excessive insulin
secretion results
in hypoglycemia,
disorientation,
unconsciousness
• Type II
– Hyposecretion
• Insufficient
insulin results in
polyuria,
polydipsis,
polyphagia
• Type I
• Thyroid Hormone
– Hypersecretion
• Grave’s disease
– Hyposecretion
• In Infants
results in
cretinism
• In adults results
in myxedema
or endemic
goiter if due to
lack of iodine
Blood Calcium Levels
• Parathyroid Hormone
– Produced by parathyroid gland
– Increases blood calcium levels
• Calcitrol (Activated Vitamin D)
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UV radiation and epidermal
keratinocytes convert steroid
derivative to cholecalciferol –
D3
Liver converts it to calcidiol
Kidney converts that to calcitrol
– Increases blood calcium levels
• Calcitonin
– Produced by parafollicular
cells
– Decreases blood calcium
levels
Blood Calcium Abnormalities
• Hypercalcemia
– Excess blood calcium
• Hypocalcemia
– Deficiency in blood calcium
• Milk Fever Prevention
– Stimulate cow’s calcium
mobilization before calving
– Feeding a transition diet 3
weeks before calving
– Increase dietary calcium
immediately after calving
– Avoid fat cows at calving
– Administering vitamin D
injection 2-8 days before
calving
Mechanisms of Hormone Action
• Target cell must have specific receptors to
which the hormone binds
– Water-soluble hormones
– Lipid-soluble hormones
Water-Soluble Hormones
• Amino-acid based hormones
1. Hormone binds receptor (1st
messenger)
2. Receptor activates G protein
3. G protein activates adenylate
cyclase
4. Adenylate cyclase converts
ATP to cAMP (2nd messenger)
5. cAMP activates protein
kinases
Lipid-Soluble Hormones
• Steroid-based hormones and
Thyroid Hormone
1. The steroid hormone diffuses
through the plasma membrane
and binds an intracellular
receptors
2. The receptor-hormone complex
enters the nucleus
3. The receptor-hormone complex
binds a hormone response
element (a specific DNA
sequence)
4. Binding initiates transcription of
the gene to mRNA
5. The mRNA directs protein
synthesis
Words to Know
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Antagonism – one or more hormones opposes the action of another hormone
Autocrine – chemicals that exert effects on the same cells that secrete them
Gluconeogenesis – synthesis of glucose from lactic acid and noncarbohydrates
Glycogenolysis – breakdown of glycogen to glucose
Half life – the time required for a hormone’s blood level to decrease by half
Homeostasis – The tendency of an organism or a cell to regulate its internal conditions,
usually by a system of feedback controls, so as to stabilize health and functioning,
Hormones – long-distance chemical signals that travel in the blood or lymph
Negative Feedback – feedback that reduces output of a system
Paracrine – locally acting chemicals that affect cells other than those that secrete them
Permissiveness – one hormone cannot exert its effects without another hormone being
present
Positive Feedback – feedback that enhances the output of a system
Rickets – bones don’t mineralize properly
Synergism – more than one hormone produces the same effects on a target sell
Tropic Hormones – regulate the secretory action of other endocrine glands