75 terms

Davis: Urinary System Continued...

Movement of water across the membranes of cells, role of water in the body, chemical reactions within the body to maintain homeostasis
Role of water in the body
all water is used as a medium to carry solutes, like electrolytes and metabolites, throughout the body
Males contain how much water by weight?
Women contain how much water by weight?
How is water distributed throughout the body?
2/3 - intracellular compartments - inside cells
1/3 - extracellular compartments - outside cells
Examples of Extracellular compartments (ECF)
1. interstitial spaces
2. plasma
3. lymph
4. fluid in the eyes
5. synovial fluid in joint capsules
6. cerebrospinal fluid
7. serous fluids in cavities
8. lumens
9. glandular secretions - medium that carries hormones
Intracellular Fluids (ICF) contain what types of substances?
1. K⁺
2. Mg²⁺
3. PO₄³⁻
4. SO₂⁴⁻
5. Proteins
Extracellular Fluids (ECF) contain what types of substances?
1. Na⁺
2. Cl⁻
3. Ca²⁺
4. CO₂³⁻
Ions move by
1. diffusion
2. active transport
3. through protein channels or protein transporters
How does water shift with solute?
1. movement of solutes will shift water by osmosis
2. solvent drag - fluid will shift solutes
Daily water input
1500/3000mL/ day
Where do we get all that water from?
10% from metabolic reactions like aerobic respiration
90% from oral consumption
Thirst Reflex
- maintained by the Hypothalamus within Thirst Center that alerts the body for the need of water
Regulation of Thirst Reflex
1. Osmoreceptors - cells that monitor the osmolarity of bodily fluids
2. Baroreceptors - cells that monitor BP (↓BP will trigger thirst reflex to add more volume to blood)
How is thirst reflex suppressed?
stretching the stomach and moistening of oral mucosa will suppress thirst reflex immediately.
Increased H₂O Toxicity?
1. ↑ BP
2. bodily fluids dilute
3. ↓ in solute concentration
1. insufficient amounts of water either by lack of consumption, elevated temperatures, or high activity
2. ↓BP
3. body will compensate by removing H₂O out of ICF and into ECF
Water Output
1. 61% in urine
2. 4% in poop
3. 35% by respiratory tract (exhalation) and skin (sweat)
1. sweat glands, sudoriferous glands throughout our skin that excrete fluid by exocrine action.
2. excretory mechanism
3. shedds - NH₄, Urea, K⁺, and Na⁺ - forming acid mantle
Insensible Perspiration
1. tiny amounts of sweat shedding at all times
2. not noticeable
3. important for heat regulation
4. lowers body temperature
5. each day .5L of water is shed this way
Sensible Perspiration
1. ↑ temp will ↑ sweat by 100-150mL
2. Diaphoresis
3. associated withe exercise and hot environments
4. an increase in activity can increase visible sweat by 8-10L/day
visible sweat
Causes of body to ↑ Temp?
1. sexual arousal
2. emotional states
3. physical condition
Osmolarity of ECF
285 mOsm/ kg of tissue
Effect of ↑ Osmolarity
1. thirst reflex will trigger
2. ↑ ADH - acts on kidneys to retain water
Effect of ↓ Osmolarity
1. inhibits thirst reflex
2. ↓ ADH - water will be excreted in urine
Affects of BP on Osmolarity
1. ↑ BP will ↑ Glomerular Pressure to ↑ filtration, and pass out more water in urine which will lead to ↓ BP
2. ↓ BP which ↓ Glomerular which will ↓ filtration which will ↓ urine flow. A result is to trigger thirst reflex to ↑ BP.
1. ions or molecules with electrical charges
ie) Na⁺, K⁺, Ca²⁺, Cl⁻, PO₄³⁻
2. electrolytes concentrations will change during weight changes and growing stages
How are electrolytes secreted?
by the kidneys, skin, and lungs
Where are electrolytes stored?
1. skeleton
2. mainly Ca²⁺ and PO₄³⁻
3. downfall is that bone can also store Pb, As, and Hg
1. Cation in ECF
2. involved in sodium-potassium pump
3. vital for glucose absorption
4. essential for muscular contraction
5. Neurotransmitter
6. maintains pH balance with Cl⁻
Body's daily sodium requirement
1. <.5g/ day
how much do we actually consume?
1. 15-20g/ day
2. excess is removed via kidneys and sweat
3. regulated by ANH and Aldosterone
How does salt affect osmolarity?
↑ in salt requires an ↑ in water to balance osmolarity
1. Na⁺ deficiency
Causes of Hyponatremia
- poor diet
- severe burns
- vomiting
- diarrhea
- insufficient Aldosterone secretion
- excessive urination
- Hyperglycemia- ↑ blood sugar
Hyponatremia leads to
- lethargy
- disorientation
- nervous agitation
- seizures
- coma
elevated Na⁺ levels
Causes of Hyernatremia
- dietary
- hypersecretion of Aldosterone
- significant water loss
Hypernatremia leads to
- thirst
- dry mucous membranes
- ↑ body temperature
- hypertension
- bounding pulse
- tendencies toward edema
- convulsions
- death at extremely high Na⁺ levels
1. pH balancer in the body
2. Cl⁻ compounds activate digestive enzymes made of gastric juices
3. can be exhaled, excreted by the kidneys and skin
Chlorine Deficiency
1. causes - impaired digestion, vomiting, diarrhea
2. Leads to Blood Alkalosis
1. Part of sodium -potassium pump
2. Neurotransmitter
3. Essential for muscular contraction
4. Dehydration, circulatory shock, and tissue damage can cause K+ to move out of cells and into ECF as a safeguard mechanism
Regulation of Potassium
1. Regulated by aldosterone - ↑ of aldosterone, ↑ kidney secretion of K+
2. Passes easily through filtration membrane - Primary Convoluted Tubule will reabsorb a lot of K+
insufficient Potassium
Causes of Hypokalemia
i. Diet (not enough fruits and vegetables with potassium)
ii. Renal failure
iii. Insulin administration
Hypokalemia leads to...
i. Poor skeletal health
ii. Bradycardia
iii. Heart blocks
iv. Decreased muscle tone
elevated K⁺ levels
Causes of Hyperkalemia
1. Decreased renal excretion
2. Tissue trauma
Hyperkalemia leads to...
1. Restlessness
2. Irritability
3. Intestinal cramps
4. Diarrhea
5. Muscular weakness
6. Muscular paralysis - extremely elevated levels
1. Managed by kidneys, intestines, skin (vitamin D Production), and skeleton
2. 99%of Ca2+ is stored in the skeleton
3. Vitamin D stimulates organs to absorb Ca2+
4. Essential for teeth and bones
5. Acid/base balancer
6. Essential for muscular regeneration
Parathyroid Hormones
1. Increases Ca2+ in ECF, stimulates kidneys to reabsorb Ca2+ from filtrate
1. Antagonist to PTH
2. Hormone that decreases Ca2+ in the body by slowing down its release from bone
Regulation of Calcium
1. Parathyroid Hormone
2. Calcitonin
insufficient Calcium
Causes of Hypocalcemia
i. Diet
ii. Low vitamin D levels
iii. Underactive Parathyroid
Hypocalcemia leads to
i. Disorientation
ii. Muscle spasms
iii. Frequent cramps
iv. Muscular weakness
v. Convulsions
vi. Tetani
vii. Osteoporosis
viii. Death
elevated Calcium levels
Causes of Hypercalcemia
i. Overconsumption of Ca
ii. Excessive parathyroid activity - due to parathyroid cancers
Hypercalcemia leads to...
i. Fatigue
ii. Muscular weakness and response
iii. constipation
iv. coma
v. kidney stones
vi. death
pH of Bodily Fluids
a. acid base balance in the body is crucial to maintaining homeostasis
b. most human bodily fluids are between 6<pH<8
compounds that regulate pH
Buffering Systems
i. Intercellular systems use proteins to buffer pH
ii.. Cations attract to OH-
iii. Anions attract to H+
1. primary buffering system for ECF
2. Bicarbonate can absorb a H+ from fluid to form Carbonic Acid to stabilize pH
3. Carbonic acid can lose a H+ to form bicarbonate to stabilize pH
Phosphate Buffering System
a. H₂PO₄/HPO₄⁻
Ammonia Buffering System
- high pH levels - blood is more basic
Causes of Alkalosis
a. Overconsumption of Alkaline products - alcohol
b. Low atmospheric pressure of O2
c. Insufficient CO2 - Hypocapnia
d. Severe vomiting
e. Poisoning
Alkalosis leads to..
a. Hyper-excitability of NS
b. Muscular spasms
c. Convulsions
d. Tetani
e. Death
- low pH level - blood is too acidic
Causes of Acidosis
a. Toxin or drug ingestion
b. Decreased O2 perfusion
c. Increased CO2 levels
d. Problems in Diabetes - Increases glucose level
e. Accumulation of fatty acids
f. Bacterial infections - bacterial waste products
Acidosis leads to...
a. Depresses CNS
b. Disorientation
c. Slow responses
d. Blurred vision
e. Unconsciousness
f. Coma
g. death
Most common complications with electrolytes?
1. Hypernatremia
2. Hypokalemia
3. Hypocalcemia
pH of Blood
pH of Hydochloric Acid in the stomach
Buffering systems that work in the Kidneys to regulate fitrate
1. Phosphate Buffering System
2. Ammonia Buffering System