Nervous system and heart electricity
The __________ system slows heartrate, while the __________ system speeds it up during stress.
parasympathetic, sympathetic
Describe and provide an example of negative feedback in the endocrine system.
Blood glucose increase (after eating).. pancreas detects this and secretes insulin. Once glucose is WNL, the pancreas stops releasing insulin.
Blood glucose decreases (during exercise or fasting).... pancreas secretes glucagon. Once glucose is WNL, the pancreas stops releasing glucagon.
What hormone helps regulate water balance by acting on the kidneys?
Antidiuretic Hormone (ADH)
What is cardiac output?
What is stroke volume?
total volume of blood the heart pumps per minute.
amount of blood pumped by heart per beat.
What is VO2 max?
The maximum amount of oxygen the body can use during exercise.
Indicates aerobic fitness level.
Higher VO2 max = athlete can perform at a high intensity for longer periods.
Which section of the nervous system controls involuntary functions like heart rate?
Autonomic Nervous System (ANS)
Which hormone converts glucose from the blood into cells, regulating blood sugar?
Insulin
What condition is caused by excessive loss of sodium and water through sweating?
Hyponatremia
How do you calculate cardiac output?
Stroke volume X heart rate = Cardiac output
What is the difference between acclimatization and acclimation?
acclimation refers to laboratory or controlled settings
acclimatization refers to natural environment (temp and altitude)
How do the nervous system and heart work together to adjust the heart rate during exercise?
Sympathetic nervous system increases heartrate to get increased oxygen and nutrients to muscles. The parasympathetic nervous system decreases heartrate during rest.
What endocrine gland secretes melatonin?
Pineal Gland
What is cardiovascular drift?
The progressive increase in heart rate that occurs during prolonged, steady-state exercise, despite constant intensity.
What is tidal volume (respiratory system)?
What is respiration rate?
Volume of air inhaled or exhaled in a "normal" breath.
The number of breaths taken per minute.
What physical adaptations happen in the body during acclimatization to high altitudes? (2)
Increased breathing rate
What term in the heart acts as a "natural pacemaker" initiating heart contractions?
SA node (sinoatrial node)
What gland is often referred to as the "master gland" because it controls many other endocrine glands?
Pituitary gland
What are the signs and symptoms of hyponatremia?
headache, nausea, confusion, muscle cramps (severe cases = seizures/coma)
During exercise, ______ ______ increases to ensure muscles receive adequate oxygen and nutrients.
Stroke Volume
How does VO2 Max respond in high altitudes? Why?
VO2 Max decreases in high altitudes because there is less oxygen available and lower atmospheric pressure. This reduces aerobic performance making physical activity feel much more strenuous.
What term in the heart refer to the network of fibers that carry electrical impulses to ventricles for contraction?
Purkinje fibers
Describe the relationship between the hypothalamus and the pituitary gland.
Hypothalamus is the link between the nervous and endocrine systems.
They work together as a negative feedback loop to maintain homeostasis.
Pituitary gland receives signals from the hypothalamus about internal conditions (temperature, hunger, thirst, stress), then the pituitary gland controls the other endocrine glands (getting them to release or stop release of hormones)
How does the hypothalamus help maintain hydration during exercise?
Hypothalamus triggers thirst. It also signals the release of ADH (antidiuretic hormone) to conserve water by reducing urine output.
Why do trained athletes typically have a lower resting heart rate compared to untrained individuals?
Trained athletes often have an increased stroke volume (heart can pump more blood per beat).
Because they have an increased SV, each beat delivers more oxygenated blood, the heart doesn't need to beat as frequently to meet the body's needs.
How does the body's cardiac and respiratory system respond to low oxygen levels?
Heart rate and breathing increase to enhance oxygen uptake and distribution. Also... increase in RBC production (to help carry oxygen)