Lesson 4: Cardiovascular, Respiratory, Lymphatic and Endocrine Systems Flashcards
The cardiovascular, circulatory system is a closed-circuit system composed of?
the heart, blood vessels and blood
Blood continuously travels a circular route, what is this route?
it flows through the heart into the arteries, then to the capillaries into the veins and back round to the heart.
What are arteries?
the blood vessels that deliver oxygen-rich blood from the heart to the tissues of the body.
What are capillaries?
They are very tiny blood vessels that help to connect your arteries and veins in addition to facilitating the exchange of certain elements between your blood and tissues.
They are so small a single red blood cell barely fits through them
What are veins?
blood vessels that carry blood towards the heart.
Veins usually carry deoxygenated blood back to the heart, what 2 veins are the exceptions?
Umbilical and pulmonary that carry oxygenated blood
What is the liquid component of blood called and what does is carry?
Plasma carries hormones, plasma proteins, food materials, ions and gases throughout the body.
What are 4 components of blood?
- plasma
- red blood cells
- white blood cells
- platelets
The primary function of blood is __________.
transportation
Which system plays an important role in temp regulation and acid-base balance?
the cardiovascular system
What do each of the following carry/do: arteries/arterioles, veins/venules and capillaries?
- Arteries - carry oxygen rich blood away from the heart
- Veins return oxygen poor blood to the heart
- Capillaries provide sites for gas, nutrient and waste exchange between the blood and tissues
What is arteriosclerosis?
Hardening of the arteries and narrowing of the arteries due to plaque accumulation
What contributes to arterial rigidity and decreases the arteries’ ability to expand (most common in older adults)?
arteriosclerosis
As arteries lead away from the heart, they branch off into smaller, microscopic vessels called?
arterioles
What do arterioles develop into when carrying blood?
beds of much smaller structures called capillaries
Where do capillaries allow the exchange of materials between?
Between the blood and interstitial fluid between cells
Where does blood pass to after capillaries?
To small venous vessels called venules
As venules lead (blood) back to the heart, what do they develop into?
They increase in size and become veins
Are the walls of veins thinner and less elastic than arterial walls?
yes
What is commonly found inside the veins of lower limbs?
Valves that allow blood to flow only toward the heart
What are the 2 major veins in the body?
inferior and superior vena cava
Where does blood leaving the inferior/superior vena cava veins empty directly into?
It directly empties into the heart where it is transported to the lungs to pick up a fresh supply of oxygen.
Where is the heart located and what does it act as?
It is located between the lungs and lies just left of center, behind the sternum. It acts as a pump that pushes blood throughout the body.
The heart is divided into 4 chambers, what are they each responsible for?
the 2 right chambers are responsible for pulmonary circulation whilst the 2 left chambers are responsible for systemic circulation
The chambers of the heart consist of X2 Atria and X2 ventricles, what is the difference between atria and ventricles?
Atria receive blood returning to the heart from the body and ventricles pump blood from the heart to the body.
What is the muscular wall that separates the right and left sides of the heart? What does it do?
The Interventricular septum prevents the mixing of blood from either side of the heart.
What are the propulsion chambers and receiving chambers of the heart?
Propulsion = ventricles Receiving = atria
How does blood move within the heart?
from the atria to the ventricles and then to the arteries
How is backflow of blood from the arteries into the ventricles prevented?
By the pulmonary semilunar valve and aortic semilunar valve.
What do the left/right atrioventricular valves do?
They connect the atria with the right and left ventricles respectively and prevent backward movement of blood.
How does the pulmonary circuit work?
It transports deoxygenated and CO2 elevated blood to the right side of the heart where it is pushed to the lungs to absorb oxygen and release carbon dioxide.
The oxygenated blood then flows back to the heart.
How does the systemic circuit work?
It transports newly oxygenated blood from the lungs to the left side of the heart and pumps it to various tissues of the body.
Where does all blood from the venous system first enter?
right atrium
What is the journey of venous blood?
It flows first to the right atrium, enters the right ventricle which pumps it through the pulmonary arteries to the lungs to be reoxygenated and relieved of CO2. It then flows through the pulmonary veins to the left atrium, through the left ventricle and then pumped via the aorta to the rest of the body.
What is the cardiac cycle?
The period from the beginning of one heartbeat to the beginning of the next
True or false, the right and left sides of the heart perform their pumping actions simultaneously?
True
When the heart beats, do both atria contract together to empty blood into the ventricles?
yes
When both atria contract, what circuits is the blood delivered to?
the pulmonary and systemic circuits
What does systole and diastole refer to?
These are the repeating phases of contraction and relaxation of the heart.
Systole is the contraction phase of the cardiac cycle in which blood leaves the ventricles.
Diastole is the relaxation phase in which blood fills the ventricles.
The respiratory system makes it possible for the body to?
- exchange gases between the external environment and tissues
- replace oxygen and remove CO2 from the blood
- vocalization
- regulate acid-base balance during exercise
What is the respiratory system made up of? (7)
nose nasal cavity pharynx larynx trachea bronchi lungs
Where does gas exchange occur in the lungs?
Within microscopic air sacs called alveoli
How much air do humans approx breath per minute through the nose at rest vs the mouth during exercise?
5-6 litres vs 20-30 litres per minute
What is the journey of air entering the respiratory system?
- Warmed and passes through the pharynx and larynx
- Travels through trachea to right and left primary bronchi
- The primary bronchi divide into secondary bronchi which divides into tertiary bronchi that results into bronchioles
- The bronchioles further divide into alveoli where gas exchange occurs
Where does the trachea (windpipe) extend to?
5th and 6th thoracic vertebrae where it divides into 2 smaller branches: right and left bronchi
How many alveoli do the lungs contain?
approx 300 million
What is the estimated surface area available for diffusion in the human lung?
approx the size of a tennis court
What are the lungs encased and separated by?
They are encased within the rib cage and separated by the mediastinum
The mediastinum separates the two lungs but what does it contain?
heart, aorta, esophagus and part of the trachea
What is the most important muscle of inspiration and the only skeletal muscle considered essential for life?
the diaphragm
What happens when the diaphragm contracts?
It forces the abdominal contents downwards and forwards whilst the external intercostals lift the ribs outwards.
This reduces pressure surrounding the lungs and causes them to expand which allows airflow into the lungs.
What are the external intercostals?
a group of muscles that run between the ribs
At rest, the diaphragm and external intercostals perform most of the inspiration work - what accessory muscles are recruited during exercise? How do they help?
pectoralis minor
scalenes
sternocleidomastoid
They assist the diaphragm and external intercostals to further increase the volume of the thorax and aid in inspiration
True or false, expiration occurs passively during normal, quiet breathing and requires no muscle action?
true
Does expiration remain inactive or become active during exercise? Why?
becomes active because important muscles of expiration (rectus abdominis, internal obliques, serratus posterior, internal intercostals) activate to help pull the rib cage downward and force air from the lungs by squeezing the abdominal organs upward against the diaphragm
What are important muscles of expiration? (4)
rectus abdominis, internal obliques, serratus posterior, internal intercostals
What does the locomotor skeletal system refer to?
the musculoskeletal system
What effect does regular endurance exercise have on the respiratory muscles?
it increase the oxidative capacity of the respiratory muscles which improves the endurance of the respiratory muscles
What is the lymphatic system composed of?
an extensive network of capillaries, collecting vessels, lymph nodes and lymphoid organs
What does the lymphatic system do?
Serves to return excess fluid from between the cells (interstitial fluid) back to the bloodstream, thereby preventing swelling of the intercellular spaces (edema.)
What is edema?
Swelling of the intercellular spaces
How is lymph fluid different from blood?
it does not contain any red blood cells or platelets as these cannot escape through the blood-vessel walls
How does lymph enter the blood?
through specialized vessels called lymphatic capillaries
What happens once lymph enters the blood via lymphatic capillaries?
it circulates through the arteries, blood capillaries and veins.
What are the 4 important functions of the lymphatic system?
- destruction of bacteria and other foreign substances that are present in the lymph nodes
- specific immune responses that aid in manufacturing antibodies to destroy bacteria and foreign substances
- the return of interstitial fluid to the bloodstream
- prevention of excessive accumulation of tissue fluid and filtered proteins by drainage into highly permeable lymphatic capillaries in the connective tissues
What is cardiorespiratory endurance defined as?
the capacity of the heart and lungs to deliver blood and oxygen to working muscles during exercise
What does a person’s aerobic exercise capacity depend on?
the interaction of the cardiovascular and respiratory systems as they provide oxygen to the active cells via blood so that carbs and fatty acids can be converted to ATP for muscular contraction.
What 2 systems are important for the removal of metabolic waste products (e.g CO2, lactate) and for the dissipation of heat produced by metabolic processes?
cardiovascular and respiratory systems
What 3 basic processes must interact to provide adequate blood and nutrients to tissues? What is each one a function of?
- getting oxygen into the blood - a function of pulmonary ventilation coupled with oxygen carrying capacity of the blood
- delivering oxygen to active tissues - a function of cardiac output
- extracting oxygen from the blood to complete ATP production - a function of localizing delivery of the cardiac output to active muscles and the oxidative enzymes located within active cells
What is the oxygen carrying capacity of blood determined by?
- ability to adequately ventilate the alveoli in the lungs
2. the hemoglobin concentration of the blood
What is pulmonary ventilation a function of?
both the rate and depth (tidal volume) of breathing
an increase in ventilation brings more oxygen into the lungs, why is it important to maintain an adequate tidal volume during even heavy exercise?
so that the gas concentrations in the alveoli can be effectively exchanged and gases can move in the desired direction.
(from alveoli to pulmonary capillaries or vice versa)
What conditions prevent individuals from moving enough air through their lungs to adequately aerate the alveoli and oxygenate the blood?
emphysema - degradation of alveoli
asthma - constriction of breathing passages
Why do those with emphysema and asthma experience limited exercise capacities?
because they cannot move enough air through their lungs to adequately aerate the alveoli and oxygenate the blood. This means blood leaving the lungs is not sufficiently loaded with oxygen which diminishes their exercise capacity.
The brain is sensitive to the CO2 concentration in blood, what will failure to adequately ventilate the lungs result in?
it will result in elevated co2 blood concentration which will cause the exerciser to suddenly feel the need to stop exercising.
What is hemoglobin?
it is a protein in red blood cells that is specifically adapted to bond with oxygen molecules
What happens when oxygen enters the lungs?
it diffuses through the pulmonary membranes into the bloodstream where it binds to hemoglobin
Once oxygen binds with hemoglobin, what does it then do?
it is then carried within the bloodstream throughout the body
How little hemoglobin is defined as being anaemic?
less than 12 g of HB per 100mL of blood
What does hemoglobin do in the warmer, more acidic and lower o2 environments of exercising muscles?
it reverses its tendency to bind with O2 and releases it to the tissues instead
What is cardiac output?
the product of HR and Stroke Volume
What does cardiac output average at rest vs during max exercise? What can it increase to in highly trained individuals?
5L at rest per minute
20 - 25L during max exercise per min
It can increase to 30-40L in highly trained individuals
How do both HR and SV increase?
HR increases in a linear fashion wheread SV increases up to 40/50% of a person’s max before it plateaus
What is an increase in stroke volume caused by?
an increase in both venous return and in the contractile force of the heart
What % is ejection fraction usually at during rest and during exercise?
rest = 50-60% exercise = 60-80%
why might someone’s ejection fraction be reduced if they have cardiovascular disease?
due to loss of heart muscle tissue following a myocardial infarction
What is ischemia?
inadequate blood flow to the heart because of narrowed coronary arteries
Why is it common for those with ischemia to experience a normal ejection fraction at rest and a decreased one during exercise?
because ischemic tissue which is tissue receiving too little blood flow to restore ATP aerobically loses much of its contractility.
Which type of fibers are specifically adapted for oxygen extraction and utilization due to their high levels of oxidative enzymes?
slow-twitch
where does aerobic production of ATP take place?
in the mitocondria of cells
What does active vasoconstriction in the viscera/inactive muscles and active vasodilation in active muscles result in?
an efficient use of cardiac output during exercise that results in increased cardiac output delivered to exercising muscles and decreased blood flow to the viscera.
What are the principal endocrine glands?
pituitary thyroid parathyroids adrenals pancreas gonads
What is the endocrine system responsible for?
Regulating bodily activities through the production of hormones
Where does the cells of the endocrine system release hormones?
directly into the bloodstream where they are delivered to target organs
Where is the pituitary gland located?
beneath the brain, it is divided into anterior and posterior lobes
What hormones does the posterior pituitary lobe release? What do these hormones act on?
- Vasopressin acts on the kidneys and is considered an antidiuretic
- Oxytocin stimulates the smooth muscles of the reproductive organs and intestines
What hormones does the anterior portion of the pituitary gland release? (6)
- follicle stimulating hormone
- luteinizing hormone
- thyroid stimulating hormone
- adrenocorticotropin hormone
- growth hormone
- prolactin
Follicule-Stimulating + Luteinizing hormones are Gonadotropins because of their effects on the gonads, what do these substances control?
They control the secretion of estrogen and progesterone in the ovaries and the production of testosterone in the testicles.
what does TSH stimulate the synthesis and release of? What does this do?
Thyroid stimulating hormones releases thyroxine from the thyroid gland which helps control the rate at which all cells utilize oxygen.
What does Adrenoctricotropin Hormone (ACTH) control?
- the secretion in the adrenal gland of hormones that influence the metabolism of carbs, sodium and potassium.
- it also controls the rate at which substances are exchanged between the blood and tissues
What does Growth Hormone stimulate?
- stimulates the growth of the skeletal system and general growth
- promotes the entrance of amino acids into the body’s cells for their incorporation into protein
- releases fatty acids into the blood for use as energy
- promotes formation of glucose and release into the blood
Where is the thyroid gland located?
anterior to the upper part of the trachea
What 3 hormones does the thyroid gland release?
Thyroxine
Triiodothyronine
Calcitonin
What 2 hormones released by the thyroid gland are iodine-containing hormones that regulate the metabolism of carbs, proteins and lipids?
thyroxine
triiodothyronine
What does calcitonin do?
lowers blood calcium and phosphate levels by accelerating the absorption of calcium by the bones
Where are the parathyroid glands located?
these are 4 structures located on the posterior surface of the thyroid gland
What is the parathyroid hormone responsible for?
primarily controlling the levels of calcium and phosphorus in the blood through its actions on the kidneys and skeleton
What vitamin does the parathyroid hormones work with and to do what?
it works with Vitamin D to maintain the body’s calcium levels
Where are the adrenal glands located?
These appear as 2 pyramid shaped organs located close to the superior border of each kidney
What are the 2 distinct parts of an adrenal gland?
the medulla (inner portion) and the cortex (outer portion)
What does the adrenal medulla produce?
epinephrine (adrenaline) and norepinephrine (noradrenaline)
The adrenal cortex secretes mineralocorticoids associated with ______ and _______ metabolism, glucocorticoids that in the utilization of glucose and mobilization of fatty acids and gonadocorticoids.
sodium and potassium
Where does the pancreas lie?
just below the stomach
The pancreas secretes insulin, what does this hormone do?
it facilitates the uptake and utilization of glucose by cells and prevents the breakdown of glycogen in the liver and muscle
Why is insulin a hypoglycemic agent?
because it decreases the blood sugar levels
How does insulin play a role in lipid and protein metabolism?
it favors lipid formation and storage and facilitates the movement of amino acids into cells
The pancreas secrete glucagon, what does this hormone do?
It generally oppose the actions of insulin in that it decreases glucose oxidation and increase the blood sugar level.
Its main action is to stimulate the breakdown of glycogen in the liver for release into the bloodstream.
Which of the 4 components of blood carries hormones, food materials, ions and gases throughout the body?
plasma
When blood is flowing through the heart, where does it go after passing through the tricuspid valve?
Blood passes through the tricuspid valve on its way from the right atrium to the right ventricle.
Christopher is an endurance athlete. He often gets low blood sugar during his long workouts. Once the liver recognizes the release of glucagon from the pancreas, _______________ is released to help increase his blood sugar levels.
glucose
During an endurance race, cortisol helps maintain blood glucose levels by promoting the breakdown of _______________ and _______________.
protein and triglycerides
True or false, hormones only have actions on specific receptors on specific tissues?
true
what does the female athlete triad compose of?
osteoporosis, disordered eating and amenorrhea
what is the general hormone response to a given exercise load? why?
the hormonal response to a given exercise load declines with regular endurance training, the increased efficiency may result from improved target tissue sensitivity and/or responsiveness to a given amount of hormone.
What are the 2 most prevalent training adaptations that prove evidence of decreased catecholamine levels?
a lowered RHR and a smaller rise in BP during submaximal exercise
Why does circulating cortisol levels generally increase slightly as a result of exercise training?
to aid the body in becoming more efficient at preserving glucose
Individuals that participate in regular aerobic-endurance exercise maintain blood levels of _____ and ______ during exercise that are closer to resting values. Why is this important?
insulin and glucagon
this is important because the trained state requires less insulin at any specific point from rest through submaximal-intensity exercise
what forms of exercise might individuals with blood glucose regulation problems benefit from including?
incorporating both aerobic and resistance exercises
Why do endurance-trained individuals show less rise in circulating blood growth hormone levels at a given exercise intensity compared to untrained individuals?
due to a reduction in stress that arises as a result of the exercise stimulus as their training progresses and fitness improves
why does resistance training increase growth hormone?
via increases in testosterone
what effect does resistance training have on growth hormone release?
it increases growth hormone release and interacts with nervous system function to increase muscle force production (especially in men)
What resistance training leads to an increase in testosterone?
heavy resistance exercises at 85-95% of 1RM OR moderate-high volume with multiple sets and less than 1 min rest intervals
What level of SBP + DBP will suggest prehypertension?
Individuals are classified as prehypertensive when systolic blood pressure is 120-139 mmHg or diastolic blood pressure is 80-89 mmHg.
