Exam 3 Flashcards
6 functions of Urinary system
- Excretes (nitrogenous) waste products
(Urea, uric acid, creatine)
-Regulates composition of blood
-Produces renin
-Produces erythropoietin
-Activates vitamin D
-Gluconeogenesis- converts noncarbohydrate into glucose
what is the layer for the kidney
retroperitoneal
3 layers of kidney supportive tissue
- renal fascia
- adipose capsule
- renal capsule
main 3 regions of the kidneys
Renal cortex- outermost, dense CT, light red/brown
Renal medulla- middle, fat tissue, Dark red/ brown (renal pyramids)
Renal pelvis- inner region, hallow cavity that contains urine
are the structural and functional units of the kidneys
nephrons
how many nephrons per kidney
over 1 million
- filtration takes place here
- consists of Bowmans’s capsule
renal corpuscle
-filtrate is processes to form urine
-consists of the PCT, Loop of Henle and the DCT
Renal tubules
85% of all nephrons
-most in the nephron located in cortex
-have short loops of henle
Cortical nephrons
15% of all nephrons
Most of nephron located near the border between the cortex and medulla
Have long loops of Henle
juxtamedullary nephrons
what are the 2 capillary beds and what do they exchange with
- Glomerulus (1st capillary bed) - exchanged with Bowman’s capsule (filtration)
- Peritubular capillaries (2nd capillary bed) - exchange with the renal tubules (reabsorption and secretion)
are peritubular capillaries that exchange with the long loops of Henle
vasa recta
path of blood flow through renal blood vessels
- Afferent arteriole ->
- glomerulus (capillaries)->
- efferent arteriole ->
- peritubular capillaries or vasa recta
Flow of filtrate through the kidneys
Filtrate forms in Bowman’s capsule_>PCT-> Descending limb of loop of Henle-> ascending limb of loop of Henle-> DCT-> Collecting ducts
fluid that fills the Bowman’s capsule and flows through the renal tubules
filtrate
is plasma without the large sized proteins
filtrate
fluid in the renal pelvis
urine
blood flow through kidneys
1,200 ml/min
GFR- glomerular filtration rate (rate of filtrate formation
120 ml/min
rate of urine formation
1.2 ml/min
three steps in urine formation
- Glomerular filtration —> makes filtrate
- Tubular reabsorption–>adjusts the chemical composition of the filtrate
- Tubular secretion–> adjusts the chemical composition of the filtrate
Passive, nonselective process
Hydrostatic pressures force fluid across filtration membrane
Fluids move out of the glomerulus and into the Bowman’s capsule
Glomerular filtration
Very thin- 0.1 micrometers
Very permeable- consists of
Fenestrated capillaries
Basal lamina
Podocytes (inner wall of the Bowman’s capsule)
the filtration membrane
If NFP is positive
filtration occurs
if NFP is negative
reabsorption occurs
how does the myogenic mechanism regulate glomerular filtration
automatic adjustment of the afferent arteriole diameter
how does the macula densa cells provide regulation of glomerular filtration
chemoreceptors in ascending limb
how does juxtaglomerular cells regulate glomerular filtration
secrete renin (enzyme)
If pressures are too low, juxtaglomerular cells correct the problem by making renin
Renin is secreted by juxtaglomerular cells due to low pressure in glomerulus
angiotensinogen–(renin)–> angiotensin 1–(ACE)–> angiotensin 2
Reabsorption= return to blood
99% of water and many solutes in the filtrate return to the blood
The chemical composition of the filtrate is adjusted
tubular reabsorption
what part renal tubule- selective reabsorption
PCT
in what part of renal tubule does tubular reabsorption generates osmotic gradients in medulla
Long loops of Henle
in what part of renal tubule does tubular reabsorption is mainly regulated by hormones
DCT and Collecting Duct
what is the PCT Tubular Reabsorption for this mechanism:
Primary active transport-> sodium potassium pump (Na+K+ pump)
Na+ (only some of the Na+ gets reabsorbed)
what is the PCT Tubular Reabsorption for this mechanism:
Secondary Active transport
Glucose, amino acids, vitamins
(100% reabsorbed)
what is the PCT Tubular Reabsorption for this mechanism:
Osmosis- passive, obligatory water reabsorption
Water
(some is reabsorbed)
what is the PCT Tubular Reabsorption for this mechanism:
Passive, paracellular (between cells)
Some ions
(some reabsorbed)
what is the PCT Tubular Reabsorption for this mechanism:
Passive
Urea, uric acid, lipids (lipid- soluble substances)
(some reabsorbed)
what is the PCT Tubular Reabsorption for this mechanism:
Tubule cells use endocytosis and break down proteins into amino acids
proteins (some reabsorbed)
what is never reabsorbed in PCT tubular reabsorption
Creatinine
in the plasma is a measure of the glomerular filtration rate and therefore kidney function.
creatinine concentration
solute particles/ 1 liter of water (in medulla)
osmolarity
isotonic solution
300 milliosmolar
very hypertonic
1200 milliosmolar
what is reabsorbed in descending limb
water
what is reabsorbed in ascending limb
solutes
Permeable to water
Impermeable to solutes
Descending limb
Permeable to solutes
Impermeable to water
ascending limb
what hormone does water need in DCT and Collecting Ducts Tubular Reabsorption
Osmosis by facultative water reabsorption needs ADH (antidiuretic hormone)
what hormone does Na+ need in DCT and Collecting Ducts Tubular Reabsorption
Active transport of Na+ needs aldosterone
what hormone does urea need in DCT and Collecting Ducts Tubular Reabsorption
none- Passive, urea leaks out in deep parts of medulla
Substances in the blood in the peritubular capillaries enter the filtrate in the renal tubules and collecting ducts
Helps to get rid of waste products
Helps maintain blood pH
tubular secretion
what is the function of tubular secretion of certain drugs (penicillin)
Rids body of drugs that are poorly filtered
what is the function of tubular secretion of urea and uric acid
Rids the body of some urea, uric acid, that were partially reabsorbed
what is the function of tubular secretion of H+ or bicarbonate ions
Maintains the pH of the blood (7.4)
what is the function of tubular secretion of K+ ions
Regulates the K+ ions in body (removes excess K+ ions from body)
is a measure of a solution’s ability to cause osmosis (water movements)
Osmolarity
Body fluids are maintained at ___ mOsm
300
300 miliosmolar
istonic
1000 miliosmolar
hypertonic
formation of dilute urine
ADH release is inhibited
No facultative water reabsorption
Large volume of dilute urine excreted
Diuretic- substances that increase urine output
Caffeine
Alcohol
Formation of Concentrated Urine needs:
Medullary osmotic gradient (300->1200 mOsm)
Antidiuretic hormone (ADH)
Osmotic gradients in the medulla are mainly due to the
countercurrent mechanism
Countercurrent Mechanism consists of
- Countercurrent multiplier- long loop of Henle which generate the gradient
- Countercurrent exchanger- vasa recta which maintain the gradient
Formation of Concentrated Urine:
ADH is released
Facultative water reabsorption occurs
Small volume of concentrated urine excreted
name the hormone and site of secretion for every effect:
Causes vasoconstriction which increases blood pressure
Hormone: renin->angiotensin
Site of secretion: Juxtaglomerular cells
name the hormone and site of secretion for every effect:
Increase in Na+ reabsorption and increases water reabsorption = increase in blood volume= increases blood pressure
Hormone: aldosterone (triggered by angiotensin II)
Site of secretion: adrenal cortex
Increase in Na+ reabsorption and increases water reabsorption =
Increases facultative water reabsorption- increases blood volume- increases blood pressure= small volume of concentrated urine made
Hormone: ADH (triggered by dehydration)
Site of secretion:
hypothalamus/ posterior pituitary gland
normal urine components
95 % water (solvent)
Urea (solute)
Most abundant solute in urine
Uric acid (solute)
Creatinine (solute)
Ions: Na+, K+. Phosphate, sulfate, Ca+, Mg+2, bicarbonate (solutes)
what abnormal urine component can have this possible cause: diabetes mellitus
glucose
what abnormal urine component can have this possible cause: renal disease, hypertension
proteins
what abnormal urine component can have this possible cause: bleeding (trauma), tumor, kidney stones
RBC
what abnormal urine component can have this possible cause: infection
WBC
what abnormal urine component can have this possible cause: liver disease
bilirubin
what abnormal urine component can have this possible cause: diabetes mellitus, extreme dieting, starvation
Ketone bodies- result of fatty acid metabolism
Membrane Transport Process:
Passive processes do not need ATP
Active processes need ATP
move substances from High- > low concentration
passive processes
small nonpolar molecules can diffuse across the plasma membrane
simple diffusion
needs either a protein carrier or protein channel
facilitated diffusion
diffusion of water across a selectively permeable membrane, needs aquaporins (water channels)
osmosis
usually move substances from low -> high concentration
active processes
directly uses ATP to move particles from low to high concentration
Examples: Na+K+ pump
primary active transport
links the movement of one article to a second particle
secondary active transport
uses vesicles to move substances
vesicular transport
uses membrane sacs (vesicles) to move substances across the membrane
vesicular transport
substances enter cell using vesicles
endocytosis
substances exit cell using vesicles
exocytosis
water and dissolved solutes in the body
body fluids
The body regulates the volume and composition of the body fluids to maintain
homeostasis
fluid inside cells, about 2/3 total body fluid
Intracellular Fluid (ICF)
fluid outside cells, about 1/3 total body fluids
Extracellular Fluid (ECF)
2 ECF compartments
Plasma and Interstitial fluid (IF)
fluid component of blood
plasma
fluid in spaces between cells, includes lymph, CSF, serous fluid, synovial fluid, digestive tract secretions
interstitial fluid (IF)
Components of body fluids (60 %of body)
water, solutes, electrolytes, nonelectrolytes
components that dissociate, and release charged particles in solutions
Examples: salts, acids +bases, most proteins
electrolytes
compounds that do not dissociate in solution
Examples: glucose, lipids, urea, and creatinine
nonelectrolytes
Because ___ dissociate and release more particles in solution, they have a greater effect on fluid movements than ___
electrolytes, nonelectrolytes
Plasma: High
IF: High
ICF: low
Na+
Plasma: low
IF: low
ICF: high
K+
Plasma: medium
IF: low
ICF: high
Protein
continuous intermixing of body fluids in different compartments
fluid movements
Regulation of Water Balance
About 2.5 liters of water gained per day
About 2.5 liters of water lost per day
gain most water into body by
drinking
loose most water through
urinary system
most body fluids are
isotonic
Less then 300 mOsmolar
higher than 300 mOsmolar
hypotonic
hypertonic
if water loss> water gain
dehydration occurs (osmolarity increases)
If water gain>water loss
excess water in body (osmolarity decreases)
The Thirst center is located in the ___ which contains osmoreceptors (sensors that detect osmolarity)
hypothalamus
Thirst center responses that correct for dehydration:
- induces thirst
- Releases ADH- higher facultative water reabsorption -
Produce small volume of concentrated urine
Thirst center responses that correct for excess of water:
- inhibits thirst- stop drinking
- inhibits ADH release - no facultative water reabsorption- no water goes back into the blood-
Kidneys produce a large volume of dilute urine
Na+ is regulated by
tubular reabsorption
(too much Na+) High BP, high blood volume triggers
ANP (produced by overstretched artia) release -> decreases Na+ reabsorption.
Results in lower BP and blood volume
(too little Na+) Low BP, low blood volume triggers
Aldosterone release -> increases Na+
reabsorption.
Results in higher BP and blood volume
K+ is regulated by
tubular secretion
High blood K+ triggers an increase in
secretion of K+ into urine
Results in lowering blood K+
Low blood K+ inhibits secretion
of K+ into urine
Resulting in conserving K+ in blood
Without action potentials
nervous system and muscles will suffer
substances leave blood and enters filtrate/urine
secretion
a measure of the H+ ion concentration in solution
pH
more acid means
more H+
more basic means
less H+
what is the pH of Arterial plasma
7.4
what is the pH of Venous plasma and IF
7.35
what is the pH of ICF
7.0
PH>7.45
Plasma is too basic= too few H+ ion
Alkalosis
PH<7.35
Plasma is too acidic (too many H+ ions)
For body to function
Physiological Acidosis
3 mechanisms to regulate acid- base balance of the blood
- buffers
- respiratory compensation- breathing changes to correct pH imbalance
- renal compensation- kidneys correct for pH imbalance
weak acids or weak bases which minimize changes in pH
buffers
substances that release H+ ions in solution
acids
substances that remove H+ ions from solution
bases
When removing a H+ from a weak acid you get a
weak base
When adding a H+ from a weak base you get a
weak acid
What is the buffer, weak acid, and weak base for ECF- plasma and IF
Buffer: Carbonic acid- bicarbonate buffer
Acid: Carbonic acid: H2CO3
Base: Bicarbonate: HCO3-1
What is the buffer, weak acid, and weak base for Urine and ICF
Buffer: Phosphate buffer
Acid: Dihydrogen Phosphate H2PO4-1
Base: Monohydrogen phosphate: HPO4-2
What is the buffer, weak acid, and weak base for ICF
Buffer: Protein buffer
Acid: Acidic amino acids: aspartic acid and glutamic acid
Base: Basic amino acids: lysine, arginine and histidine
Imbalance: (too many H+) If pH is too low,
Corrected by: the weak base removes H+ from solution-> results in raising the pH
Imbalance: (too little H+) If pH is too high,
Corrected by: the weak acid releases H+ into solution-> results in lowering the pH
corrects blood pH imbalances by changing breathing
Respiratory Compensation-
If blood pH <7.35,(physiological acidosis) respiratory compensation by
hyperventilation -> results in raising pH of blood
If blood pH >7.45 (alkalosis), respiratory compensation by
slow, shallow breathing -> results in lowering the pH of blood
kidneys correct for pH imbalances long- term
Renal compensation
If imbalance is acidosis, then the kidneys compensate by
reabsorbing more bicarbonate-> results in raising blood pH
If imbalance is alkalosis, then the kidneys compensate by
reabsorbing more H+ ions-> results in lowering the pH of blood
8 functions of the respiratory system
Brings in O2
Removes CO2
Regulates blood pH
Smell receptors
Filters inspired air
Produces sounds
Removes excess water and heat
Respiratory pump
What are the functional divisions of the respiratory system
- conducting zone structures (no gas exchange)
- Respiratory cone structures (gas exchange occurs
what functional division have: nasal passages, pharynx, larynx, trachea, bronchi, bronchioles, terminal bronchioles
Conducting zone structures
what functional division has: respiratory bronchioles, alveolar ducts, alveoli, alveolar sacs
respiratory zone structures
Structure of the respiratory membrane
- Alveolar walls made of: simple squamous epithelial
Type I cells- most abundant cell in alveolar wall, makes ACE
Type II cells- makes surfactant (chemical that reduces surface tension)
- Basement membrane
- Capillary walls- tunica interna, simple squamous epithelial (endothelial cells)
Air-blood barrier
Very thin (0.5-1 micrometers)
Has a large surface area- approximately750 square feet
the respiratory membrane
to supply body with O2 and dispose of CO2
respiration
4 processes of respiration
Pulmonary ventilation- breathing (inhalation, exhalation)
External respiration- exchange of O2 and CO2 between air in alveoli and blood
Transport of respiratory gases O2 and CO2 (cardiovascular system)
Internal respiration- exchange of O2 and CO2 between blood and tissues
Inhalation or inspiration- intake of air
Exhalation or expiration- outflow of air
pulmonary ventilation- breathing
Pressure of the air surrounding the body
Atmospheric pressure: 760 mm Hg
Pressure of the air inside the lungs or alveoli
Alveolar pressure: changes with breathing
Pressure in the pleural cavities
Intrapleural pressure: about 4 mm Hg below alveolar pressure
the pressure of a gas varies inversely with its volume
Boyle’s Law
Boyle’s law equation
P1V1=P2V2
When atmospheric pressure > alveolar pressure
Air moves into lungs (inhalation
When alveolar pressure > atmospheric pressure:
air leaves lungs (exhalation)
occurs during resting conditions
quiet breathing
Quiet inhalation is an active process:
The diaphragm and external intercostals contract
Quiet exhalation is a passive process:
The diaphragm and external intercostals relax
occurs during exertion or controlled breathing
forced breathing
Forced inhalation is an active process:
These muscles contract:
- diaphragm
- external intercostals
- scalenes
- sternocleidomastoid
- pectoralis minor
Forced exhalation is both passive and active
These muscles relax:
These muscles contract:
Relax: diaphragm and external intercostals
Contract: internal intercostals and abdominal muscles
Factors affecting pulmonary ventilation
- Alveolar surface tension (low)
Surfactant decreases surface tension
- Lung compliance (high)
- Airway resistance (low)
ability of lungs to be stretched
lung compliance
opposition to air flow- Blockage by phlegm- bronchi/bronchioles constrict (asthma)
airway resistance
exchange of O2 and CO2 between air in lungs and blood
external respiration
external respiration occurs across the
respirator membrane
pressure exerted by each gas o a mixture of gases
partial pressure
Factors affecting the rate of external respirating:
Structure of the respiratory membrane
Partial pressure gradients for O2 and CO2
Gas solubilities for O2 and CO2
partial pressure of a gas is directly proportional to the percentage of that gas in the mixture
Dalton’s law of partial pressures
Which gas in the atmosphere has the highest partial pressure?
Nitrogen
what is the partial pressure of oxygen in the alveoli
105 mm Hg
what is the partial pressure of carbon dioxide in alveoli
40 mm Hg
Each gas in a mixture of gases moves down its own
partial pressure gradient
what is the Po2 and Pco2 in the Alveoli or Arterial blood (o2 rich)
Po2: 105 mm Hg or 100 mm Hg
Pco2: 40 mm Hg
what is the Po2 and Pco2 in Tissues, venous blood or pulmonary capillaries (o2 poor)
Po2: 40 mm Hg
Pco2: 45 mm Hg
O2 diffuses out of alveoli into blood: 105-> 40 mm Hg
Co2 diffuses out of blood into alveoli: 45-> 40 mm Hg
External Respiration
when a mixture of gases is in contact with a liquid, each gas will dissolve in proportion to its partial pressure and solubility
Henrey’s law
Gas solubilities
N2- insoluble in water
O2- slightly soluble
CO2- very soluble
of CO2 and O2 are exchanged across the respiratory membrane due to partial pressure gradients and solubilities.
equal amounts
exchange of O2 and CO2 between blood and tissues
internal respiration
O2 diffuses out of blood into tissues: 100-> 40 mm Hg
CO2 diffuses out of tissues into blood: 45-> 40 mm Hg
internal respiration
Transport of O2 by the blood
98.5 % of O2 attached to hemoglobin in RBCs
1.5 % of O2dissolved in plasma
Hemoglobin is 100% saturated when
all 4 binding sites have O2 (Oxyhemoglobin)
Hemoglobin is partially saturated when
1,2, or3 O2 bound to it
Hemoglobin is 0% saturated when
no O2 bound to it (deoxyhemoglobin)
Binding of O2 to hemoglobin is
reversible and cooperative
arterial blood is ___saturated
100%
Venous blood is ___ saturated during rest
75%
large oxygen reserve exists in
blood
5 Factors affecting rate of O2 binding to hemoglobin:
increase in Po2 = increase in binding of O2 to hemoglobin
increase in H+ ion concentration (Bohr Effect)
increase in Pco2- release of O2 from hemoglobin
increase in Temperature - release O2
increase in BPG- release of O2 from hemoglobin
Transport of CO2 by the blood
7% CO2 dissolved in plasma
23% CO2 bound to amino acids of hemoglobin (carbaminohemoglobin)
70 % CO2 transported as bicarbonate ion in plasma
deoxyhemoglobin has a greater affinity for CO2
Haldane effect
when the pH decreases, more oxygen will be unloaded from
hemoglobin
Bohr effect
Respiratory Centers:
Medullary rhythmicity area
Pons has:
- Pneumotaxic area
- Apneustic area
Pulmonary ventilation also affected by:
Higher brain centers (conscious mind)
Chemicals
- increase in Pco2=(hyperventilation)
- large drops in Po2=(hyperventilation)
- drop in Arterial pH= hyperventilation
Hering-Breuer reflex
has the greatest effect on breathing
Pco2
when lungs are overstretched, lungs receive signal from the medulla to end inspiration
Hering- Breuer reflex
what respiratory center sets the normal rate and rhythm of breathing
medullary rhythmicity (in medulla oblongata)
what respiratory center - moderate breathing
the areas in the Pons
what area of the pons shortens the inhalation period- faster breathing
pneumotaxic area
what area of the pons lengthens the inhalation period- slow and deep inhalation period
Apneustic area
