Previous Exam Material 1
Which type of signaling is this?
A notch receptor on one cell directly interacts with a ligand on an adjacent cell's surface. This interaction does not involve releasing signaling molecules into the extracellular space but rather requires direct cell-to-cell contact.
juxtacrine
How does exercise reduce chronic inflammation in obesity?
Muscle tissue (inc IL-6 and anti-inflammatory cytokines, dec pro-inflammatory cytokines)
Adipose tissue (dec hypoxia and macrophage infiltration)
Endothelial cells (inc cell regeneration and dec vascular wall inflammation)
Immune cells (dec PAMPs and inflammatory monocytes, inc Treg)
What is the PO2 at the lung? At the tissues?
It is high, so this is where we form oxyhemoglobin
It is low, so this is where O2 is unloaded from hemoglobin
What are the different transports LDL and HDL, and which is considered "good vs bad"
HDL: good, taking lipid from the tissue to the liver
LDL: bad, taking lipid from the liver to the tissue
What are some cardiovascular changes with pregnancy?
Increased heart rate, stroke volume, cadiac output.
What is the best predictor of physical performance?
VO2 at lactate threshold
What are the three main energy systems?
Phosphagen: interchangeable with ATP/phosphocreatine (quick, seconds long)
Glycolysis: catalyzes glucose into two pyruvate (last 2 minutes)
Oxidative phosphorylation: (anything past 2 minutes)
If your RER is .7 you are metabolizing what percent of fats and what percent of CHO?
100% fats, 0% CHO
What are the four factors that help with extrinsic lymph flow?
Muscle contraction, ROM, arterial pulsations, external compression
What is the enteric nervous system for peristalsis?
ACh and substance P stimulate smooth muscle contraction above the bolus.
NO, VIP, and ATP stimulate smooth muscle relaxation below the bolus.
How does hypoxia affect lactate production?
More Anaerobic Metabolism: When there's not enough oxygen, cells rely more on anaerobic processes to get energy quickly.
Pyruvate to Lactate: Instead of using pyruvate in aerobic processes, cells convert it to lactate to keep energy production.
Higher Lactate Levels: This increases lactate in the muscles and bloodstream.
Energy vs. Fatigue: While producing lactate helps generate energy when oxygen is low, too much lactate can cause fatigue and acidity.
What is renal threshold vs transport maximum?
Renal threshold: the plasma glucose concentration at which transport maximum is exceeded in SOME nephrons. Glucose begins to be excreted.
Transport maximum: filtered glucose will not be reabsorbed and is excreted. Transport maximum is reached for ALL nephrons
What is the process of bone modeling with circumferential growth?
Osteoblasts create bone on the OUTER surface by osteoid secretion, then deposition of calcium phosphate (hydroxyapatite). Stronger but heavy
Osteoclasts: break down bone on the INNER surface by secreting acid and enzymes. Bone thickness is the same initially, but stronger to increase the diameter
What is the importance of the first pass effect?
The metabolism of drugs before its able to go into general circulation.
What does gastrin stimulate?
Parietal cells to secrete HCL, chief cells to secrete pepsinogen --> increase pepsin.
What are some of the adaptations of muscle fibers during endurance exercise that help maintain homeostasis?
Shift in m. fiber type (fast to slow) and increased number of capillaries
Increased mitochondrial volume
Training-induced change in fuel utilization
Increased antioxidant capacity
Improved acid-base regulation
How do Beta-adrenergic blocking drugs (beta blockers) work?
They block epinephrine and norepinephrine from binding to B1 receptors on the heart, which reduces HR and contractility. This lowers the work of the heart and the myocardial oxygen demand.
What is the difference between steroid hormones and peptide hormones?
Steroid hormones are more cholesterol lipids. Peptides are more amino acids and play a role in homeostasis and metabolism. Peptides cannot pass through the cell membrane. Steroid hormones are used more for information and immune function.
What are the major functions of the liver?
Filtration and storage of blood
Metabolism of CHOs, proteins, fats
Metabolism of hormones and foregin chemicals (drugs)
Formation of bile
Storage of vitamins and iron
Formation of coagulation factors
In males on the HPG axis, what are the functions of the Sertoli and Leydig cells?
Sertoli cells maintain contact with germ cells to stimulate spermatogenesis.
Leydig cells secrete testosterone into the bloodstream.
What are the two ways you can increase your lactate threshold?
constant load training: RPE 14-15
interval training: RPE 17-80, reps 6-10, working 2-3 min, rest 3 min
How does cytokine secretion enhance the immune response?
T helper release IL-2
IL-2 proliferates cytotoxic T cells to destroy infected cells
What are the 6 main roles of the Kidneys?
1) Regulation of ECF volume and BP
2) Regulation of osmolarity
3) Maintenance of ion balance
4) Regulation of acid-base balance
5) Excretion of metabolic waste products and foreign chemicals
6) Secretion, metabolism, and excretion of hormones
What is the lyphatic pathway from distal tissue to the venous system
lymphatic capillary --> vessel --> node --> vessel --> trunk --> collecting duct --> subclavian vein
At what age do androgen-producing cells stop being quiescent>
About age 6.