Midterm #2 Flashcards
(102 cards)
1
Q
how does ADH affect water retention?
A
- ADH increases the amount of water in the body by causing insertion of water channels called aquaporins in the plasma membrane of the cells forming the kidney tubules
- Water can enter the cells via aquaporins
- Aquaporins allow water in the tubules to enter the cytosol of the kidney cells by osmosis, reducing the amount of water in the tubules
- From the cytosol water into the interstitial fluid and then into blood capillaries
- Net effect of ADH is to return water to the blood that would have otherwise been eliminated from the body as urine - decreases the formation of urine
2
Q
Anterior Pituitary Hormones (FLAT PiG)
A
Follicle Stimulating Hormone Luteinizing Hormone Adrenocorticotropic hormone (ACTH) Thyroid-Stimulating Hormone (TSH) Prolactin Growth Hormone (GH)
3
Q
Prolactin
A
- Stimulates growth of mammary glands, the initiation and maintenance of milk production
- Suckling of an infant triggers it
4
Q
Luteinizing Hormone (LH)
A
- One of two hormones known as gonadotropins
- Stimulate testes (testosterone) and ovaries (estrogen and progesterone)
- Triggers the release of an oocyte (egg)
5
Q
Follicle Stimulating Hormone (FSH)
A
- Gonadotropin
- In males: FSH stimulates the testes to produce chemicals that bind and concentrate testosterone
- In females: triggers the production of estrogen, and triggers maturation of ovarian follicles (houses developing oocytes)
6
Q
Adrenocorticotropic Hormone (ACTH)
A
- Increased levels of cortisol and aldosterone
- Stimulates the development of the adrenal glands and their synthesis of steroid hormones
7
Q
short term effects of growth hormone
A
- Promotion of fat breakdown
- Production of new glucose by the liver
- Inhibition of glucose uptake by muscle fibers
- These effects increase the conc. Of glucose and fatty acids in the blood allowing cells to use them as fuel for growth
8
Q
which cells produce calcitonin
A
parafollicular cells
9
Q
which cells produce parathyroid hormone
A
chief cells
10
Q
parathyroid hormone
A
- increases Ca+ concentration
- Increasing release of calcium ions from bone by stimulating osteoclasts
- Increasing absorption of dietary calcium ions by the small intestine
- Prevent the loss of calcium ions during the formation of urine (Increasing reabsorption of calcium ions from the fluid in the kidney)
- Stimulates calcitriol hormone synthesis in the kidney
11
Q
calcitonin
A
- decreases Ca+ concentration
- Calcitonin decreases the blood calcium ion concentration by inhibiting osteoclasts so osteoblasts are unopposed and can build bone (using up calcium from the blood which decreases the blood calcium ion concentration)
12
Q
3 zones of adrenal cortex
A
- outer zona glomerulosa
- middle zone fasiculata
- inner zona reticularis
13
Q
zona glomerulosa
A
- make mineralocorticoids (aldosterone)
- influence sodium levels
- fluid and electrolyte homeostasis
14
Q
zona fasiculata
A
- makes glucocorticoids (hydrocortisone, cortisol)
- influence glucose levels
- metabolic homeostasis
15
Q
zona reticularis
A
- makes androgenic steroids (testosterone, estrogen) –> sex hormones
- makes small amount of glucocorticoids (cortisol)
16
Q
aldosterone
A
- Maintaining the concentration of extracellular sodium and potassium ions within their normal ranges
- Regulating extracellular fluid volume
- Maintaining blood pressure
- Maintaining acid-base homeostasis (maintains the pH of the blood)
Activates hydrogen ion pumps in kidney tubules which transports hydrogen ions from the extracellular fluid into the fluid in the tubules, which is excreted as urine. This lowers the hydrogen ion concentration, which increases pH of the blood to its normal alkaline level. (this is why urine is acidic)
17
Q
cortisol
A
- help mediate the body’s response to stress through the regulation of blood glucose
- Effects of cortisol (primary target tissues: liver, muscle, adipose)
- Gluconeogenesis (glucose molecule production) in the liver → increases blood glucose
- Release of amino acids from muscle tissue (skeletal muscle breakdown) → can be converted to glucose by gluconeogenesis
- Release of fatty acids from adipose tissue → can be converted to glucose
- Also acts as an anti-inflammatory agent by decreasing levels of leukocytes (inflammatory cells)
18
Q
androgenic steroids (sex hormones)
A
- Androgenic steroids - sex hormones that affect reproductive organs, or gonads
- Majority of androgenic steroids are produced by gonads but they are also synthesized in small amounts by adrenal cortex
- Can be converted to testosterone or estrogen
19
Q
hormones of the adrenal medulla
A
- catecholamines (norepinephrine & epinephrine)
Increase rate and force of heart contractions
Dilating the bronchioles
Constricting blood vessels supplying the skin, digestive organs, and urinary organs
Dilating blood vessels supplying skeletal muscles
Dilating pupils
Decreasing digestive and urinary functions
20
Q
cells of the adrenal medulla that make catecholamines
A
- chromaffin cells
21
Q
delta cells
A
- secrete somatostatin
- inhibits pancreatic hormone secretion
22
Q
what hormones does the thymus gland produce
A
- thymosin
- thymopoietin
23
Q
progesterone
A
- Progesterone production peaks after ovulation and during pregnancy (pro=for)
- Progesterone helps prepare the body for pregnancy and support fetal development
- Target tissue: smooth muscle, body temperature, blood clotting, metabolism, bone tissue
24
Q
Atrial Natriuretic Peptide (ANP)
A
- released in response to stretch sensitive ion channels opening more widely (increased blood volume)
- Triggers relaxation of smooth muscle cells in blood vessels (vasodilation) → enhances excretion of sodium ions from kidneys (natriuresis) (and water excretion) → lower blood volume → decrease blood pressure
25
Erythropoietin (EPO)
- Secreted by the kidney in response to a decreased level of oxygen in the blood
- EPO acts on red bone marrow where it stimulates the development of erythrocytes, which increases the oxygen carrying capacity of blood
26
cardiac tamponade
Penetrating wounds of the pericardium/heart
Bleeding (or fluid) occurs into the pericardial cavity
Compression of heart
Circulation is greatly compromised
Veins of the face and neck become engorged owing to compression of the SVC as it enters the inelastic pericardium
Beck triad - collection of the clinical signs of cardiac tamponade
- low blood pressure (weak pulse)
- muffled heart sounds
- distended neck veins
27
the great vessels
- superior and inferior vena cava
- pulmonary trunk
- pulmonary veins
- aorta
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right coronary artery
splits into:
- right marginal artery
- posterior interventricular artery
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left coronary artery
splits into:
- anterior inter ventricular artery
- circumflex artery
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coronary veins
- great cardiac vein
- small cardiac vein
- middle cardiac vein
31
pacemaker cell action potentials
- slow initial depolarization
- full depolarization
- repolarization
- minimum potential phase
32
conduction of action potentials through the heart
1) The SA node generates an action potential, which spreads to atrial cells (via gap junctions) and the AV node
2) After the AV node delay (time it takes for the ap to spread from the SA node to the AV bundle), the action potential is conducted to the AV bundle and then to the right and left bundle branches
3) The action potential spreads from the bundle branches along the purkinje fibers to the contractile cells of the ventricles
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contractile cells action potentials
- rapid depolarization
- initial repolarization
- plateau phase
- repolarization
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P-R interval
atrial depolarization + AV node delay
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Q-T interval
entire duration of a ventricular action potential
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S-T segment
ventricular plateau phase
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events of cardiac cycle
1) ventricular filling phase
2) isovolumetric contraction phase
3) ventricular ejection phase
4) isovolumetric relaxation phase
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3 factors that influence stroke volume
- The preload imposed on the heart before it contracts
- The heart's contractility (ability to generate tension)
- The afterload against which the heart pumps as it contracts
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frank starling law
the more the ventricular muscle cells are stretched (more blood enters the ventricle/greater preload) the more forcefully they contract
40
Chronotropic agents
factors that influence the rate at which the SA node depolarizes
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other factors that influence cardiac output
- Blood volume
Hormones that increase blood volume will increase preload and increase strength of contraction (more blood = more contraction) (aldosterone, ADH)
Hormones that decrease blood volume will decrease preload and decrease cardiac output (less blood = less contraction) (ANP)
- Electrolyte level in ECF to maintain concentration gradient for action potentials
- Body temperature (SA nodes fire faster at higher body temperature)
- Age (young children & elderly have higher resting heart rate) (trained athletes have lower resting heart rate)
- Physical fitness
42
velocity of blood flow
Velocity of blood flow is determined by the cross sectional area of the blood vessel
Velocity is inversely proportional to cross sectional area (cross sectional area increases → velocity decreases)
Velocity is lowest in branched capillaries (because they have a large total area due to all the branching) and fastest in the aorta
43
3 main factors that influence blood pressure
- peripheral resistance
- cardiac output
- blood volume and vessel compliance
44
factors that effect resistance
- blood vessel radius
- blood viscosity
- blood vessel length
- obstructions
45
Sympathetic and Parasympathetic Effects on Blood Pressure
- Axons release norepinephrine and epinephrine onto cardiac muscle cells and the smooth muscle cells of blood vessels, to produce two immediate changes
- An increase in heart rate and contractility (which increases cardiac output)
- Vasoconstriction of all types of vessels, but especially arterioles, which increases peripheral resistance
- Both changes increase blood pressure
- parasympathetic = Axons release acetylcholine
- This slows heart rate and has a mild effect on contractility (decreases cardiac output and blood pressure)
- An increase in parasympathetic activity allow vasodilation (inhibits sympathetic ns from causing vasoconstriction) and a decrease in peripheral resistance
46
baroreceptor reflex
- The baroreceptor reflex is a negative feedback loop, that responds to an increase in blood pressure:
Stimulus: blood pressure increases above normal range
Receptor: baroreceptors in the carotid sinus (and aortic sinus) detect the increased pressure and fire action potentials at a faster rate
Control center: the impulses travel to the medulla of the brainstem for integration
Effector/response: autonomic centers in the medulla inhibit sympathetic activity, causing vasodilation and decreased heart rate, lowering cardiac output
Homeostatic range and negative feedback: blood pressure decreases and negative feedback decreases response from the medulla
47
thyroid hormone and the cardiovascular system
causes cardiac muscle cells to produce more receptors for epinephrine and norepinephrine, which allows those chemicals to have a great effect (more sensitive to them)
48
Long Term Maintenance of Blood Pressure
- These systems control blood pressure by increasing or decreasing the amount of body water lost as urine, which affects blood volume
- Endocrine system regulates blood volume through the release of hormones: ANP, angiotensin-II, ADH, aldosterone, renin
- When blood pressure increase:
Atrial cells secrete ANP → kidneys excrete more water and sodium ions → decreases blood volume → decreases blood pressure
- When blood pressure decreases:
Posterior pituitary secretes more ADH → ADH triggers thirst → increases the amount of water retained by the kidneys → raises blood volume → raises blood pressure
49
capillary exchange via 3 mechanisms
- diffusion and osmosis through gaps and fenestrations
- diffusion through the membranes of endothelial cells
- transcytosis
50
types of capillaries
- continuous
- fenestrated
- sinusoidal
51
myogenic mechanism
- The myogenic mechanism counters a change in blood flow by altering arteriolar resistance
- Slows blood flow by increasing resistance when arteriolar pressure rises
- Speed up blood flow by decreasing resistance when arteriolar pressure lowers
- Both changes maintain local tissue perfusion at a constant level
- Based on inverse relationship between velocity and resistance to maintain constant perfusion
- Increase arteriolar pressure → increase arteriolar resistance = decreased velocity
52
metabolic controls (tissue perfusion)
- The interstitial fluid of a metabolically active cell will contain a low concentration of oxygen and a high concentration of carbon dioxide and hydrogen ions (because they are by products of cellular respiration generating ATP)
- All three of these conditions cause the smooth muscle cells of local arterioles to relax, dilating the arterioles → increase perfusion
53
hydrostatic pressure
- The force that a fluid exerts on the wall of its container (bp=hydrostatic pressure)
- causes filtration
- pressure gradient that drives water out of the capillary (from higher pressure in the capillary to lower pressure in the interstitial fluid)
- Pushes water out
54
osmotic pressure
- the movement of a solvent from a solution with a lower solute concentration to one with a higher solute concentration
- Osmotic concentration (osmolarity) - determined by the number of solute particles in the solution
- Osmotic pressure - the force we must apply to a solution to prevent water from moving into it by osmosis
- osmotic pressure gradient moves water into the capillary (absorption)
- pulls water in
55
net filtration pressure (NFP)
- at the arteriole end the hydrostatic pressure gradient is larger and “wins” and water is forced out
- at the venular end colloid osmotic pressure “wins” and water is absorbed into the capillary
- overall more water is being driven out of the capillary, into the interstitial fluid, than taken in (filtration>absorption)
56
components of blood
- plasma
- erythrocytes
- leukocytes
- thrombocytes
57
functions of blood
```
Exchanging gasses
Distributing solutes
Performing immune functions
Maintaining body temperature
Sealing damaged vessels by forming blood clots
Preserving acid-base homeostasis
Stabilizing blood pressure
```
58
plasma proteins
- albumin
- globulin
- fibrinogens
- clotting proteins
59
hematopoiesis
process that produces the formed elements in blood (occurs in red bone marrow which which houses the cells from which all formed elements arise: hematopoietic stem cells (HSC’s))
60
erythropoiesis
Hematopoietic stem cells (HSC’s) → erythrocyte CFU’s (committed to becoming an erythrocyte) → proerythroblasts → erythroblasts (hemoglobin is synthesized, pushes out nucleus and organelles) → reticulocytes (immature red blood cell) → erythrocytes
61
causes of anemia
- Decreased hemoglobin (iron deficiency)
- Decreased hematocrit (decreased number of RBS’s)
- Abnormal hemoglobin (sickle cell)
62
pernicious anemia
results from vitamin B12 deficiency, which interferes with DNA synthesis
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aplastic anemia
red bone marrow stops producing erythrocytes
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hemolytic anemia
RBC’s are destroyed faster than they are made
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granulocytes
- neutrophils
- eosinophils
- basophils
66
Agranulocytes
- lymphocytes
| - monocytes
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myeloid cell line
Produces most of the formed elements, including erythrocytes and platelets
68
lymphoid cell line
Form lymphocytes (T and B lymphocytes)
B lymphocytes remain in the bone marrow
T lymphocytes migrate to the thymus gland to complete their maturation
69
steps of hemostasis
- Vascular spasm
- Platelet plug formation
- Coagulation
- Clot retraction
- Thrombolysis
70
types of clotting disorders
```
Bleeding disorders (blood is unable to clot)
- clotting protein deficiencies
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Hypercoagulable conditions (clots form at improper times and locations)
- pulmonary embolism
- deep vein thrombosis
71
3 basic functions of lymphatic system
- Regulation of interstitial fluid volume
- Absorption of dietary fats
- Immune functions
72
Right lymphatic duct
drain the upper right side of the body
73
Thoracic duct (left)
cisterna chyli and trunks from the left side and lower body of the body drain here (largest lymphatic duct)
74
Tissue of the lymphatic system
loose connective tissue called reticular tissue which contains reticular fibers
75
MALT
- tonsils
- Peters patches
- appendix
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lymph nodes
- Axillary lymph nodes
- Cervical lymph nodes
- Inguinal lymph nodes (groin)
- Mesenteric lymph nodes (abdominal cavity)
77
lymph node cortex
B cell rich lymphoid follicles
Trabeculae
Base of the cortex has lots of T cells
78
lymph node medulla
Rows of macrophages and mature B cells (medullary cords)
79
spleen
Red pulp - contains macrophages that destroy old erythrocytes
White pulp - filters pathogens from the blood and contains leukocytes
80
thymus
Main function: generating a population of functional T cells capable of protecting the body from pathogens (site of T cell maturation)
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Cortex
- Densely packed T cells
Medulla
- Contains fewer cells
- Destruction of certain populations of T cells that could react to the body's own cells
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81
3 lines of defence against pathogens
1st - surface barriers (skin, mucus membranes)
2nd - innate immunity
3rd - adaptive immunity
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cells of innate immunity
- Phagocytic cells (macrophages, neutrophils, eosinophils, dendritic cells)
- Nonphagocytic cells (NK cells and basophils)
83
mast cells
Inflammation helpers located in mucous membranes (allergic reactions)
84
Complement system
- 30 plasma proteins that are produced by the liver
- Circulate in their inactive form and must be activated by a complex cascade of events mediated by enzymes
- Activated complement proteins lead to the following main effects:
cell lysis
enhanced inflammation
neutralized viruses
enhanced phagocytosis
clearance of immune complexes
85
cytokines
- Produced by several types of immune cells that enhance the immune response
- They induce flu like symptoms (fever, chills, aches) so it is actually not the pathogens that cause those symptoms but our own immune system response
- tumor necrosis factor, interferons, interleukins
86
Tumor necrosis factor (TNF)
Secreted by activated macrophages in response to certain bacteria and pathogens
Induce flu like symptoms, which attract phagocytes to the area of infection
87
Interferons (IFN)
Produced in response to infection with intracellular agents such as viruses or bacteria (interfere with the pathogens ability to infect other cells)
Inhibit viral replication inside host cells
Activate components of innate and adaptive immunity
88
Interleukins (IL)
Produced by leukocytes
| Stimulate production of neutrophils and interferons, activate T cells and NK cells
89
inflammatory response: Part 1
- Damaged cells and nearby mast cells release inflammatory mediators (histamine, serotonin, cytokines, bradykinin, prostaglandins, leukotrines)
- Inflammatory mediators trigger:
vasodilation of arterioles (redness)
increased capillary permeability (edema)
pain
chemotaxis (recruitment of other cells)
90
inflammatory response: Part 2
- Local macrophages are activated
- Neutrophils migrate by chemotaxis to the damaged tissue and phagocytize bacteria and cellular debris
- Monocytes migrate to the tissue by chemotaxis and become macrophages, which phagocytize pathogens and cellular debris
- The bone marrow increases production of leukocytes, leading to leukocytosis
91
Pyrogens
chemicals released from damaged cells or bacteria, that initiate a fever
Pyrogens act on the hypothalamus, and cause it to rest at a higher range
92
role of Th cells
No phagocyte or exocytic abilities
Activated by APC’s display portion of antigen on CLass 2 MHC (healthy cell)
Th cells exert their affect through the secretion of cytokines that then activate and enhance various components of the immune response
Main functions:
Innate immunity: stimulation of macrophages
Adaptive cell mediated immunity: activation of Tc cells
Adaptive antibody mediated immunity: stimulation of B cells
93
role of Tc cells
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Activated by diseased cell with antigen on Class 1 MHC molecule, lyses target cell
They kill other cells, specifically those with foreign antigens bound to class 1 MHC molecules
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Antibody-mediated immune response, three phases:
- B cell clone recognizes its specific antigen, which triggers it to undergo changes and start secreting antibodies
- Antibody level in the blood rises dramatically
- Persistence of memory B cells, that react much more rapidly and efficiently if the antigen is encountered again
95
IgG
Most prevalent → higher in secondary immune response
| Able to cross from the blood of a pregnant women to her fetus through the placenta
96
IgA
Present in secretions from the skin, mucous membranes, and exocrine glands (tears, saliva, sweat)
97
IgM
First antibody secreted by plasma cells when the body is invaded by a pathogen (first antibody produced in response to an antigen)
98
IgE
Binds to antigens associated with parasites and tapeworms and environmental antigens (allergens)
99
IgD
Located on the surface of B cells, where it acts as an antigen receptor that helps activate activate B cells
100
functions of secreted antibodies
- agglutination and precipitation
- opsonization
- neutralization
- complement activation
- stimulation of inflammation
101
active immunity
The bodies cells actively respond to an antigen, results in the production of memory cells and large numbers of antibodies
Long lasting
Acquired through exposure via infection or vaccine
102
passive immunity
performed antibodies are passed from one organism to another
Only lasts as long as the antibodies stay in the bloodstream (3 months)
Mother → fetus, in breast milk, injection of antibodies
