Lesson I: Functional Organization of the Human Body and Control of the "Internal Environment"

Question 1

goal of physiology

Answer 1

to explain the physical and chemical factors that are responsible for the origin, development, and progression of life

Question 2

Example of complex control system

Answer 2

✓ hunger makes us seek food
✓ fear makes us seek refuge
✓ Sensations of cold make us look
for warmth.

Question 3

basic living unit of the body

Answer 3

cell

Question 4

numbering 25 trillion in each human being, transport oxygen from the lungs to the tissues

Answer 4

red blood cells

Question 5

the most abundant of any single type of cell in the body

Answer 5

red cells

Question 6

_____________ being transported from the cells to the __________ to be excreted,
plus other cellular waste products that are being transported to the _______£ for excretion

Answer 6

oxygen
lungs
kidneys

Question 7

The intracellular fluid differs significantly from the extracellular fluid; for example, it contains large amounts
of;

Answer 7

potassium, magnesium, and phosphate ions

Question 8

Special mechanisms for transporting ions through the cell membranes maintain the _________________.

Answer 8

ion concentration

Question 9

maintenance of nearly constant conditions in the internal
environment

Answer 9

homeostasis

Question 10

__________reacts with ___________, ____, and _________ to release the energy required for cell function.

Answer 10

oxygen
carbohydrate
fat
protein

Question 11

deliver endproducts of their chemical reactions into the surrounding
fluids

Answer 11

cells

Question 12

also have the ability to reproduce
additional cells of their own kind

Answer 12

cells

Question 13

how many percent of the adult human body is fluid, mainly a water solution of ions and other substances

Answer 13

60%

Question 14

constant motion throughout the body. It is transportedrapidly in the circulating blood and then mixed between the blood and the tissue fluids by diffusion through thecapillary walls

Answer 14

extracellular fluid

Question 15

are the ions and nutrients needed by the cells to maintain cell life

Answer 15

extracellular fluid

Question 16

_________ capable of living, growing, and performing their special functions as long as the proper concentrations of ________, _______, ________ , ________, ____________, and
other constituents are available in this internal
environment

Answer 16

cells
oxygen, glucose, different ions, amino acids, fatty substances

Question 17

The extracellular fluid contains
large amounts of _________, _________, and __________ plus nutrients for the cells, such as _________, ________, ________, and ___________. It also contains carbon dioxide that is

Answer 17

sodium, chloride, bicarbonate ions

oxygen, glucose, fatty acids, amino acids

Question 18

transported through all parts
of thebody in two stages

Answer 18

extracellular fluid

Question 19

2 stages in extracellular fluid

Answer 19

✓ movement of blood through the body in the blood vessels
✓ movement of fluid between the blood capillaries and the
intercellular spaces between the tissue cells

Question 20

A large portion of the bloodpumped by the heart also passes through
the walls

Answer 20

gastrointestinal tract

Question 21

each time the blood passes through the body, it also flows throughthe lungs. The blood picks up oxygen in the alveoli, thusacquiring the oxygen needed by the cells.

Answer 21

respiratory system

Question 22

different dissolved nutrients including;

Answer 22

carbohydrates, fatty acids, and amino acids

Question 23

are
absorbed from the ingested food into the extracellularfluid of the blood.

Answer 23

carbohydrates, fatty acids, and amino acids

Question 24

How does the musculo -
skeletal system contribute to homeostasis?

Answer 24

✓ the body could not move to the
appropriate place at the appropriate time to obtain the foods required for nutrition
✓ The musculoskeletal system also provides motility for protection against adverse surroundings,
without which the entire body, along with its
homeostatic mechanisms, could be destroyed
instantaneous

Question 25

Removal of Carbon Dioxide by the Lungs

Answer 25

At the sametime that blood picks up oxygen in the lungs, carbon dioxide is released from the blood into the lung alveoli; therespiratory movement of air into and out of the lungs carries the carbon dioxide to the atmosphere

Question 26

the most abundant of all the end products of metabolism

Answer 26

carbon dioxide

Question 27

kidney

Answer 27

Passage of the blood through the kidneysremoves from the plasma most of the other substances besides carbon dioxide that are not needed by the cells.

Question 28

These substances include different end products of cellular metabolism, such as

Answer 28

urea and uric acid

Question 29

filtering large quantities of plasma through the glomeruli into thetubules and then reabsorbing into the blood those sub stances needed by the body, such as glucose, amino acids,appropriate amounts of water, and many of the ions

Answer 29

kidneys

Question 30

detoxification or removal of many drugs and chemicals that areingested

Answer 30

liver

Question 31

secretes many of these wastes into thebile to be eventually eliminated in the feces

Answer 31

liver

Question 32

nervous system is composed of three major parts:

Answer 32

✓ sensory input portion ✓ central nervous system ✓ motor output portion

Question 33

detect the state of the bodyor the state of the surroundings

Answer 33

sensory receptors

Question 34

can store information, generate thoughts, create ambition, and determine reactions that the body performs in response to the sen sations

Answer 34

brain

Question 35

An important segment of the nervous system

Answer 35

autonomic system

Question 36

It operates at a subconscious leveland controls many functions of the internal organs, includ ing the level of pumping activity by the heart, movementsof the gastrointestinal tract, and secretion by many of the body’sglands

Answer 36

autonomic system

Question 37

are transported in the extra cellular fluid to all parts of the body to help regulate cellular function

Answer 37

hormones

Question 38

increases the rates of most chemical reactions in all cells, thus help ing to set the tempo of bodily activity

Answer 38

thyroid hormone

Question 39

controls glucose metabolism

Answer 39

insulin

Question 40

control sodium ion, potassium ion, and protein metabolism

Answer 40

adrenocortical hormone

Question 41

controls bone calcium and phosphate

Answer 41

parathyroid hormone

Question 42

provide a system for regulation that complements the nervous system

Answer 42

hormones

Question 43

regulates many muscular and secretory activities of the body, whereas the hormonal system regulatesmany metabolic functions

Answer 43

nervous system

Question 44

consists of the white blood cells, tissue cells derived from white blood cells, the thymus, lymph nodes, and lymph vessels that protect the body from pathogens such as bacteria, viruses, parasites, and fungi

Answer 44

immune system

Question 45

The immune system provides a mechanism for the body to;

Answer 45

(1) distinguish its own cells fromforeign cells and substances (2) destroy the invaderby phagocytosis or by producing sensitized lymphocytes orspecialized proteins (e.g., antibodies) that either destroyor neutralize the invader.

Question 46

The skin and its various appendages, including the hair, nails, glands, and other structures, cover, cushion, and protect the deeper tissuesand organs of the body and generally provide a bound ary between the body’s internal environment and the outside world.

Answer 46

integumentary system

Question 47

integumentary system

Answer 47

important for temperature regulation and excretion of wastes and it provides a sensory interface between the body and the external environment. The skin generally comprises about 12 to 15 percent of body weight.

Question 48

not considered a homeostatic function

Answer 48

reproduction

Question 49

help maintain homeo stasis by generating new beings to take the place of those that are dying

Answer 49

reproduction

Question 50

that operate in all cells to help control intracellular func tion and extracellular functions

Answer 50

genetic control system

Question 51

regulates the concentration of carbon dioxide in the extracellular fluid

Answer 51

nervous system

Question 52

regulatethe concentration of glucose in the extracellular fluid

Answer 52

liver and pancreas

Question 53

regulate concentrations of hydrogen,sodium, potassium, phosphate, and other ions in the extracellular fluid.

Answer 53

kidney

Question 54

one of the major substances required forchemical reactions in the cells

Answer 54

oxygen

Question 55

present in all red blood cells

Answer 55

hemoglobin

Question 56

Hemoglobin combines with oxygen as the blood passes through the lungs. Then, as the blood passes through the tissue capillaries, hemoglobin, because of its own strong chemical affinity for oxygen, does not release oxygen into the tissue fluid if too much oxygen is already there. But if the oxygen concentration in the tissue fluid is too low, sufficientoxygen is released to re-establish an adequate concentration. Thus, regulation of oxygen concentration in the tissues is vested principally in the chemical characteristics of hemoglobin itself. This regulation is called?

Answer 56

oxygen-buffering function of hemoglobin

Question 57

is a major end product of the oxidative reactions in cells

Answer 57

carbon dioxide

Question 58

is a simple and excellent example of a rapidly acting control mechanism

Answer 58

baroreceptor system

Question 59

which are stimulated by stretch of the arterial wall

Answer 59

baroreceptors

Question 60

which in turn decreases the number of impulses transmitted from the vasomotor center through the sym pathetic nervous system to the heart and blood vessels

Answer 60

vasomotor center

Question 61

a decrease in arterial pressure below normal relaxes the stretch receptors, allowing the vasomotor center to become more active than usual, thereby causing?

Answer 61

vasoconstriction and increased heart pumping

Question 62

Values outside these ranges are usually caused by

Answer 62

illness

Question 63

another important factor is the ___________ because whenever it decreases to less than one-third normal, a person is likely to be paralyzed as a result of the nerves’ inability to carry signals

Answer 63

potassium ion concentration

Question 64

if the potassium ion concentration increases to two or more times normal, the heart muscle is likely to be

Answer 64

severely depressed

Question 65

when the calcium ion concentration falls below about one-half normal, a person is likely to experience tetanic contraction of muscles throughout the body because of the spontaneous generation of excess nerve impulses in the peripheral nerves

Question 66

When the glucose concentration falls below one half normal, a person frequently develops extreme mental irritability and sometimes even convulsions

Question 67

a high concentration of carbon dioxide in the extracellular fluidincreases

Answer 67

pulmonary ventilation

Question 68

the high concentration of carbon dioxide initiates events that decrease the concentration toward normal, which is ___________ to theinitiating stimulus

Answer 68

negative

Question 69

if the carbon dioxide concentration falls too low, this causes feedback to

Answer 69

increase the concentration

Question 70

ahigh pressure causes a series of reactions that promotea lowered pressure, or a low pressure causes a series ofreactions that promote an elevated pressure

Question 71

if some factor becomes excessive or deficient, a control system initiates

Answer 71

negative feedback

Question 72

which consists of a series of changes that returnthe factor toward a certain mean value, thus maintaininghomeostasis

Answer 72

negative feedback

Question 73

The degree of effectiveness with which a control system maintains constant con ditions is determined by the

Answer 73

gain of the negative feedback

Question 74

Positive Feedback Can Sometimes Cause

Answer 74

Vicious Cycles and death

Question 75

is caused by positive feedback when 2 liters of blood are removed.

Answer 75

death

Question 76

the initiating stimulus causes more of the same

Answer 76

positive feedback

Question 77

is better known as a “vicious cycle

Answer 77

positive feedback

Question 78

is an example of a valuable use of positive feedback

Answer 78

blood clotting

Question 79

When a blood vessel is ruptured anda clot begins to form, multiple enzymes called?

Answer 79

clotting factors

Question 80

are activated within the clot itself

Answer 80

clotting factors

Question 81

is another instance in which positive feed back plays a valuable role

Answer 81

childbirth

Question 82

positive feedback "childbirth"

Answer 82

When uterine contractions become strong enough for the baby’s head to begin push ing through the cervix, stretch of the cervix sends signal through the uterine muscle back to the body of the uterus, causing even more powerful contractions. Thus, the uterine contractions stretch the cervix and the cervical stretch causes stronger contractions. When this process becomespowerful enough, the baby is born. If it is not powerfulenough, the contractions usually die out and a few dayspass before they begin again.

Question 83

Another important use of positive feedback is for thegeneration of nerve signals

Answer 83

That is, when the membrane of a nerve fiber is stimulated, this causes slight leakage of sodium ions through sodium channels in the nerve membrane to the fiber’s interior. The sodium ions entering the fiber then change the membrane potential, which in turn causes more opening of channels, more change of potential, still more opening of channels, and so forth.Thus, aslight leak becomes an explosion of sodium entering the interior of the lnerve fiber, which creates the nerve action potential. This action potential in turn causes electrical current to flow along both the outside and the inside of the fiber and initiates additional action potentials. This process continues again and again until the nerve signalgoes all the way to the end of the fiber.

Question 84

the positive feedback itself is part of an overall negative feed back process. For example;

Answer 84

✓ in the case of blood clotting,the positive feedback clotting process is a negative feed back process for maintenance of normal blood volume. ✓ Also, the positive feedback that causes nerve signals allows the nerves to participate in thousands of negative feedback nervous control systems.

Question 85

simple feed- functional structure contributes its share to the maintenance of homeostatic conditions in the extracellular fluid,which is called?

Answer 85

internal environment

Question 86

in a sense, is delayed negative feedback.

Answer 86

adaptive control