Download KNPE 125 Unit 3: Renal System, Respiratory System, and Cardiovascular Health and more Exams Health sciences in PDF only on Docsity!
KNPE 125 UNIT 3 QUESTIONS AND VERIFIED
DETAILED ANSWERS!!
What are the 3 main functions of the renal system?
- regulate water [ ], ion composition, and acid/base balance
- regulate plasma volume and blood pressure
- excrete foreign chemicals and waste
What are the two types of nephrons? Cortical nephrons and juxtamedullary nephrons
What are cortical nephrons? Found in the renal cortex, have a short loop of henle, make up to 80-85% of nephrons
What are juxtamedullary nephrons? Extends further into renal medulla, much longer loop of henle
What are nephrons made up of? Bowman's capsule, proximal tubule, loop of henle, distal tubule, collecting ducts.
What does the pathway of blood look like when it starts at the renal corpuscle and IS filtered? Blood filtered into Bowman's capuscle, filtered fluid becomes filterate, into proximal convoluted tubule, proximal straight tubule, loop of henle, distal convoluted tubule, collecting ducts, minor calyx, ureter, bladder.
What does the pathway of blood look like when it starts at the renal corpuscle and is
NOT filtered? Non-filtered blood flows through efferent arteriole, and is sent back to venus system to recirculate.
What are the 3 renal processes?
- Glomerular filtration
- Tubular reabsorption
- Tubular secretion
What does glomerular filtration do? High pressure in glomemrulus (PHI), drives contents from blood to Bowman's Capsule (PLO)
What are the 2 major components of renal structure/function and what do they do?
- Glomerulus - filters 20% of plasma volume, unfiltered blood leaves via efferent arteriole
- Bowman's Capsule - filtrate acceptor
What does the reabsorption pathway look like for diffuson and active transport?
- Afferent Arteriole
- Glomerulus
- Bowman's Capsule
- Efferent Arteriole
- Proximal Convoluted Tubule
- Peritubular Capillaries
- Decending Loop of Henle
What are the 2 primary roles of the lungs?
- Allow O2 to diffuse into the blood
- Allow CO2 to diffues out of the blood
What are the two distinct zones in pulmonary anatomy?
- the conducting zone
- the respiratory zone
What is the conducting zone? It carries air form the nose/mouth to the lungs
Where is the 'dead air' space located (where no gas exchange occurs)? In the conducting zone.
What is the respiratory zone? Where gas exchange takes place in the alveoli (over 300 million in the lungs)
What is the chest wall? It is an airtight space that protects the lungs.
What is the pleura?
An intrapleural space that maintains negative pressue.
Flow =? Flow = Patm - Palv / R
Aatmospheric pressure? (Patm) Remains relatively constant.
Alveolar pressure? (Palv) Change in pressure here affects gradient for flow.
Resistance? (R) Depends on airway radius.
What occurs during inspiration? Palv decreases, delta P drives air into lungs, alveolar volume increases.
What occurs during expiration? Palv increases, delta P drives air out of lungs, alveolar volume decreases.
What is the diffusion of gas determined by? Pressure gradients
Why is O2 transported in the blood? Because of low O2 solubility in the blood.
How is O2 transported in the blood? Hemoglobin accepts O2 as it binds to it.
What factors affect diffusive conductance?
- Thickness of barrier (single cell seperating)
- Surface area
- Ability of gas to diffuse (O2 + CO2 is fat soluble, therefore easily diffusable)
How are blood gas levels regulated (2 ways)? Peripheral chemoreceptors and central chemoreceptors
What are peripheral chemoreceptors? Found in carotid bodies, direct contact with blood, afferent feedback sent to medullary respiratory control centre.
What are central chemoreceptors? Found in medulla oblongata, not in direct contact with blood, respond to changes in pH of CSF. H+ does not cross blood brain barrier, CO2 does but does not stimulate chemoreceptors - therefore bicarbonate buffering
What is bicarbonate buffering? CO2 is converted into H+ ions in the CSF, in order to stimulate chemoreceptors.
What does increasing ventilation do? Increases alveolar PO
How do chemoreceptors regulate blood gasses? The rate of ventilation has a large effect on PO2 and PCO2 which are important in determining the pressure between the alveoli and the blood.
What makes up cardiovascular health?
- Mean arterial pressure regulation
- Heart function
- Vascular function
What are two ways to decrease cardiovascular health? Aging and inactivity
Total peripheral resistance (TPR)
What is compliance? A measurement of the increase in pressure that accompanies an increase in volume
Vascular compliance =? increase in volume / increase in pressure (eg balloon and glass)
What is conservation of mass? The amount of blood in the arterial system determines the MAP
What happens when compliance changes?
- High pressure in arteries
- Low pressure in veins
- Pressure from arteries to veins maintains flow
- High pressure in arteries allows rapid redistribution of blood flow
What are the two types of blood pressure? Systolic blood pressure, disystolic blood pressure
What is systolic blood pressure?
Pressure during contraction of the left ventricle
What is disystolic blood pressure? Pressure between contractions of the left ventricle
What is cardiac output (CO)? Blood pumped by the heart
What is total peripheral resistance (TPR)? Conductance of the arteriol system
What is hypertension? Higher than normal blood pressure
What are complications of hypertension?
- Excess work of heart leads to heart failure and heart attack
- High pressure damages major blood vessels - can cause stroke
- Causes damage in kidneys, which leads to renal failure
What is syncope? When the cerebral blood flow falls below a critical level, consciousness is lost, and if
- Depolarizing event from gap junction causes Na+ channels to open
- Na+ channels close
- Slow Na+ channels close while K+ channels start to open
- K+ channels open
- K+ channels close
- Recovery period
What is diastole? When ventricles are relaxed
What is systole? When ventricles are contracted
What is end diastolic volume? Volume of blood in ventricle at end of diastole
What is end systolic volume? Volume of blood in ventricle at end of systole
What is edjection fraction? The percent of end diastolic volume pumped each heart beat
How is excitation spread throughout the heart?
- Action potentials in SA node excite cardiac muscle
- Action potentials spread from cell to cell via intercalated disks and gap junctions
Where do excitations go once they reach the gap junctions?
- Left and right atria
- Purkinje fibres via AC node
- Left and right ventricles
What is venous return? The amount of blood returning to the heart
How is venous retun increased? The volume of blood in the right atria increases when more blood is waiting to pump ***
How is venous return decreased? Standing up allows gravity to pull blood to the periphery, and due to veins compliance the pressure is not high enough to overcome gravity
What can happen when venous return fails? SU and CO will fall, MAP will then fall, causing syncope
What are the physical properties of capillaries? Walls are a single cell thick, very high conductance, allows easy diffusion of nutrients and waste into/out of blood
What is the order of the arterial tree? Arteries, arterioles, capillaries
How is blood flow determined? Blood flow to different areas of the body is not equal, determined by need
More metabolism = More blood flow
How do arteriols and TPR control blood flow? TPR is resistance/conductance of arteriols which keeps MAP high
Where is the main site for control of local blood flow? Arteriols
How do arteriols control local blood flow? They constrict and dilate after conductance
How is flow through arterioles determined? Pressure and conductance
What happens when demand for blood flow increases in an organ? Arterioles leading to the organ dilate
What does increased arteriole size mean? Decreased resistance, increased flow to specific organ
What is the vasodilator theory? As metabolism increases so do bi-products of metabolism
What do the bi-products of metabolism do? Smooth muscle (arterioles) to relax (dilate)
What happens when the muscle contracts? Metabolism increases
What do arterial baroreceptors do? Increase sympathetic nerve activity (increases HR), and decrease vagal outflow (parasympathetic activity) (decreases HR)
What do baroreceptors do? Provide feedback to maintain blood pressure
What are pathogens? Any organism that has potential to cause disease (virus, bacteria, parasite)
What is immunity? The capacity for protecting individuals from disease by recognizing and eliminating potential pathogenic agents
What are the two immune responses? Non-specific (innate) and specific (adaptive)
What is an immune response? A complex series of physiological events that end in destruction and elimination of substances
What is a non-specific (innate) response? The first line of defense against pathogens
What is a specific (adaptive) response? Strong defense against a specific pathogen(s)
What is an inappropriate response? Allergies, autoimmune diseases, multiple sclerosis
What are lysosomes? Membrane bound cell organelles that contain digestive enzymes that break down excess cell parts and destroy invading viruses and bacteria
What do phagocytes do? Engulf foreign particles and microorganisms, removing them from blood and tissue
What are the two components of epithelium? Skin and mucous membranes
What are the two layers of skin?
