1
Expert solutions
BIO 2301 Lecture Exam 3 Questions and
Answers (100% Correct Answers) Already
Graded A+
How do conduction, convection, radiation and evaporation regulate body
temperature? Which are involved in heat gain and which with heat loss?
✓✓ *Conduction*: The loss or gain of heat by transfer of thermal energy during
collisions between adjacent molecules. Happens with direct contact with cooler or
warmer substances. Involved with heat loss/gain
**Radiation: The process by which the surfaces of all objects constantly emit heat
in the form of electromagnetic waves. Involved with heat loss/gain
*Convection*: The process whereby conductive heat loss or gain is aided by
movement of air or water NEXT to the body. Involved with heat loss/gain.
*Evaporation*: Occurs when water vaporizes from the skin and membranes
lining the respiratory tract. ONLY INVOLVED WITH HEAT LOSS.
Understand moderate and profound hypothermia and heat
exhaustion/stroke. How do they differ?
✓✓ With moderate hypothermia/heat exhaustion the hypothalamus is still
working. With profound hypothermia/heat stroke the hypothalamus is no longer
working. The key sign is for hypothermia there will be an absence of shivering
and in heat stroke there will be an absence of sweating.
What is BMI (body mass index) and what are the recommended ranges and
what health consequences result from an increased BMI. Why is BMI
sometimes misleading?
✓✓ BMI is a measure of body fat based on height and weight. It can be
misleading because it doesn't take into account different body types/muscle
mass/etc. The recommended ranges are: 18.5-24.9. A higher BMI can lead to
heart disease, stroke, diabetes, joint problems, etc.
What is the nephron? Know the difference between the parts of the renal
corpuscle and renal tubule?
, 2
Expert solutions
✓✓ The nephron is the functional unit of the kidney
The renal corpuscle is the initial blood-filtering component of a nephron. It
consists of two structures: a glomerulus and a Bowman's capsule.
The renal tubule helps with reabsorption and secretion. It consists of the
proximal/distal convoluted tubule and the loop of henle (descending/ascending).
What are glomerular filtration, tubular secretion and tubular reabsorption?
Where does each occur?
✓✓ *Glomerular filtration*: urine formation begins with the filtration of plasma
from the glomerular capillaries into the bowman's space.
*Tubular re-absorption*: when a substance moves from the tubule back into the
peritubular capillaries.
*Tubular secretion*: when substance moves from peritubular capillaries to the
tubule.
How often does the kidney filter the blood? What is the average GFR?
✓✓ The kidney filters the blood approximately 60 times per day
The avg GFR=125mL/min
What can increase/decrease GFR (think afferent arterioles)?
✓✓ In a sympathetic episode, the afferent arterioles vasoconstricts, which helps
to shunt or divert blood to heart and muscles. --> Urine formation decreases. This
increases GFR due to high bp/osmolarity
During parasympathetic regulation, the afferent arterioles will vasodilate which
will reroute blood back to the rest of the body, which will increase urine
formation. This decreases GFR due to low BP/osmolarity.
Water, Sodium, Glucose and Urea... which do we reabsorb in large
amounts and which do we excrete...
✓✓ Glucose is reabsorbed 100%
Water is reabsorbed 99% after filtration
Sodium is reabsorbed approx 99.5%
Urea is mostly excreted- approx 44% reabsorbed
What does low/high tubular osmolarity mean... low/high plasma
osmolarity?
Expert solutions
BIO 2301 Lecture Exam 3 Questions and
Answers (100% Correct Answers) Already
Graded A+
How do conduction, convection, radiation and evaporation regulate body
temperature? Which are involved in heat gain and which with heat loss?
✓✓ *Conduction*: The loss or gain of heat by transfer of thermal energy during
collisions between adjacent molecules. Happens with direct contact with cooler or
warmer substances. Involved with heat loss/gain
**Radiation: The process by which the surfaces of all objects constantly emit heat
in the form of electromagnetic waves. Involved with heat loss/gain
*Convection*: The process whereby conductive heat loss or gain is aided by
movement of air or water NEXT to the body. Involved with heat loss/gain.
*Evaporation*: Occurs when water vaporizes from the skin and membranes
lining the respiratory tract. ONLY INVOLVED WITH HEAT LOSS.
Understand moderate and profound hypothermia and heat
exhaustion/stroke. How do they differ?
✓✓ With moderate hypothermia/heat exhaustion the hypothalamus is still
working. With profound hypothermia/heat stroke the hypothalamus is no longer
working. The key sign is for hypothermia there will be an absence of shivering
and in heat stroke there will be an absence of sweating.
What is BMI (body mass index) and what are the recommended ranges and
what health consequences result from an increased BMI. Why is BMI
sometimes misleading?
✓✓ BMI is a measure of body fat based on height and weight. It can be
misleading because it doesn't take into account different body types/muscle
mass/etc. The recommended ranges are: 18.5-24.9. A higher BMI can lead to
heart disease, stroke, diabetes, joint problems, etc.
What is the nephron? Know the difference between the parts of the renal
corpuscle and renal tubule?
, 2
Expert solutions
✓✓ The nephron is the functional unit of the kidney
The renal corpuscle is the initial blood-filtering component of a nephron. It
consists of two structures: a glomerulus and a Bowman's capsule.
The renal tubule helps with reabsorption and secretion. It consists of the
proximal/distal convoluted tubule and the loop of henle (descending/ascending).
What are glomerular filtration, tubular secretion and tubular reabsorption?
Where does each occur?
✓✓ *Glomerular filtration*: urine formation begins with the filtration of plasma
from the glomerular capillaries into the bowman's space.
*Tubular re-absorption*: when a substance moves from the tubule back into the
peritubular capillaries.
*Tubular secretion*: when substance moves from peritubular capillaries to the
tubule.
How often does the kidney filter the blood? What is the average GFR?
✓✓ The kidney filters the blood approximately 60 times per day
The avg GFR=125mL/min
What can increase/decrease GFR (think afferent arterioles)?
✓✓ In a sympathetic episode, the afferent arterioles vasoconstricts, which helps
to shunt or divert blood to heart and muscles. --> Urine formation decreases. This
increases GFR due to high bp/osmolarity
During parasympathetic regulation, the afferent arterioles will vasodilate which
will reroute blood back to the rest of the body, which will increase urine
formation. This decreases GFR due to low BP/osmolarity.
Water, Sodium, Glucose and Urea... which do we reabsorb in large
amounts and which do we excrete...
✓✓ Glucose is reabsorbed 100%
Water is reabsorbed 99% after filtration
Sodium is reabsorbed approx 99.5%
Urea is mostly excreted- approx 44% reabsorbed
What does low/high tubular osmolarity mean... low/high plasma
osmolarity?
