Module 2

Question 1

Natural selection has acted over thousands of years to …

Answer 1

select/shape or mold a particular organ or system to best fit with its intended function for the body.

Question 2

homeostasis

Answer 2

Our ability to maintain a relatively constant internal environment despite fluctuations in our external environment (temperature changes, what you have to eat and drink, etc.)

Question 3

negative feedback loop**

Answer 3

In a negative feedback loop, the brain (or some other sensor in our bodies) detects a change in the body’s internal environment and triggers an effector to reduce or oppose the change. (((EX))) The classic example used is the explanation of how the thermostat in your house works. Let’s say it is set at 70 degrees. When the temperature drops below 70, the heat pump or furnace cuts on, raising the temperature in the house. Once the temperature gets back up to 70, what happens? That’s right, the heat pump cuts off. That is a negative feedback loop.

Question 4

positive feedback loop**

Answer 4

in a few situations, the body uses a positive feedback loop to detect and promote (not reduce, as in a negative feedback loop) changes within, such as when blood clots (((EX))) Once the blood has clotted and the bleeding has stopped, conditions within the body return to normal (i.e. the positive feedback loop gets turned off).

Question 5

important parts of homeostasis

Answer 5

((1)) involves the regulation of our internal body temperature, which on average is 98.6 degrees Fahrenheit. Our bodies thermoregulate (sweat, shiver, etc.) to maintain that internal temperature despite our activity level and changes in the outdoor temperature. ((2)) the regulation of the amount of water in our internal environment. our bodies have to keep in balance the amount of water and solutes (things dissolved in water such as salt, wastes, etc.) in our cells, in the fluid surrounding our cells, and in our blood.

Question 6

hyperthermia

Answer 6

Too hot

Question 7

hypothermia

Answer 7

Too cold

Question 8

A mild- to- moderate fever does what?

Answer 8

A mild- to- moderate fever (102 degrees F or less) will help kill the infectious bacteria, stimulate the immune system and speed the healing process, so a person (adult) actually should NOT take medications to reduce a mild fever, contrary to what you may hear on TV. A fever in an adult over 105 should be controlled asap since it can begin to degrade your body’s proteins.

Question 9

osmoregulation**

Answer 9

active regulation of the osmotic pressure of an organism’s fluids to maintain the homeostasis of the organism’s water content; that is, it keeps the organism’s fluids from becoming too diluted or too concentrated

Question 10

Your kidneys filter nearly ___quarts of blood every day, and since you only have about __pints (__ quarts) of blood, all of your blood makes at least ___ trips through your kidneys each day!

Answer 10

2000, 10, 5, 400

Question 11

where are your kidneys are located in the body

Answer 11

they are nestled in fatty tissue against your back at waist level.

Question 12

Humans have ___ kidneys

Answer 12

2

Question 13

nephrons

Answer 13

each kidney contains about one million of tiny filtering units called nephrons consisting of complicated tubules intertwined with capillaries (tiny blood vessels). The nephrons separate out the excess salt, drugs, wastes, etc. in the blood and concentrate them in a small amount of water, forming urine.

Question 14

ureter

Answer 14

he tube that carries the urine from each kidney to the bladder for storage. When you need to urinate (the technical word is excretion, as in excretory system), the urine travels out the body through the urethra. Meanwhile, the tubules in the nephrons have saved the ions, vitamins, minerals and water from the blood; these goodies get reclaimed or reabsorbed into the bloodstream via the capillaries.

Question 15

dialysis**

Answer 15

Dialysis is the process of separating smaller molecules from larger molecules in a solution by means of diffusion through a selectively permeable membrane. A machine (artificial kidney) basically cleanses the blood of metabolic wastes and excess ions and adjusts (regulates) the ionic composition of the blood in place of the poorly-functioning kidneys. If this is not done, toxic wastes and fluid build up in the blood, and the person may not survive.

Question 16

Four Main Tissue Types in the human body**

Answer 16

((1)) epithelial ((2)) connective ((3)) muscle ((4)) nervous

Question 17

epithelial tissue**

Answer 17

this tissue covers outer and inner surfaces of the body, forms glands, and lines organs. It provides protection (like your stomach lining), enables transport of nutrients (like in your small intestine), and functions in secretion of sweat, saliva, hormones, etc. (((Examples))) include the epithelial cheek cells (the cells inside your mouth; “epithelials” as they are called on CSI shows), and the outer layer of your skin (epidermis).

Question 18

connective tissue**

Answer 18

((1))these tissues bind and support other tissues and consist of cells embedded in a non-living matrix (background material) (((Examples))) include blood (red blood cells, etc. are in a matrix of plasma which is primarily water), bone (yes, bone is a living tissue!), cartilage, tendons, ligaments and fat ((2)) usually the most abundant type of tissue in an animal. Most activities rely heavily on connective tissue, often in conjunction with muscle tissue. Playing tennis, for example, relies on blood to deliver oxygen to muscle, tendons that connect muscles to bones, and cartilage that cushions the joints ((3)) sometimes called “cellular glue,” because it holds cells together and, as bone and cartilage, for example, gives shape, structure, and support to other tissues, structures, and organs throughout the body.

Question 19

difference between tendons and ligaments

Answer 19

tendons join muscle to bone while ligaments connect bone to bone (like the ligaments around your knee). Here’s one way to remember the difference between tendons and ligaments: Tendons “Tie” muscle to bone and Ligaments “Link” bones together. (connective tissue)

Question 20

collagen

Answer 20

The cells in ligaments, tendons, bone and cartilage secrete the most abundant protein found in animals. (connective tissue)

Question 21

Muscle tissue**

Answer 21

this is a special kind of tissue that contracts to do work/ provide movement for the body.

Question 22

Three Types of muscle tissue

Answer 22

((a)) skeletal – when you “make a muscle” or eat chicken, steak, or any meat, that is skeletal muscle. Examples include your biceps (the muscle you see when you “make a muscle” with your arm), triceps, quads, etc. Humans have over 500 skeletal muscles.
((b)) smooth – this type of muscle lines hollow organs including your GI (gastrointestinal) tract, reproductive tract and blood vessels. Smooth muscle contractions of your esophagus, etc. help to propel food through your GI tract. When a woman is giving birth, smooth muscle contractions of the uterus help to push the baby out. Smooth muscle lining your arteries helps to propel blood through these vessels and contributes to blood pressure.

((c))cardiac – found only in your heart, it looks very similar to skeletal muscle except that it has tiny gaps to allow for transmission of the electrical signals that tell your heart to beat

Question 23

Nervous Tissue**

Answer 23

this tissue type processes sensory input (information such as when you get stung by a bee or hear or see something) using sensory neurons (nerve cells), then processes that information using the brain, and finally sends out a response to your muscles, etc. via the spinal cord and peripheral motor neurons

Question 24

Benefits of multicellularity

Answer 24

((1)))multicellularity makes it possible for animals to attain much larger sizes and much greater physiological complexity than single-celled organisms. Increased size and complexity bring many benefits, including fewer potential predators, more potential prey, and, more generally, some protection from the influence of the external environment. ((2))the transition from a single-celled to a multicellular body is one of the most important evolutionary transitions.((3)) chief benefit of multicellularity is that it makes possible a division of labor and specialization at the cellular level. It is unnecessary for each cell to carry out every single process (such as generating movement, detoxifying harmful chemicals, digesting macromolecules, and sensing and responding to environmental changes). Instead, cells can be organized into groups, and groups organized into larger groups, to carry out specific life-sustaining functions such as exchanging gases between the organism and its environment, thinking and feeling, and fighting pathogens

Question 25

thermoregulate**

Answer 25

Our bodies thermoregulate (sweat, shiver, etc.) to maintain that internal temperature despite our activity level and changes in the outdoor temperature.

Question 26

How does Kidney work? **

Answer 26

1. Filtration. As blood passes through the kidneys, it is filtered. During this process, water, ions, and other dissolved substances are removed from the blood as a filtrate, leaving behind just cells and large proteins.
   
   2. Reabsorption. The filtrate is then processed and modified, as water, nutrients (including glucose and amino acids), and some ions are reabsorbed into the blood, concentrating the filtrate.
   3. Secretion. Following concentration of the filtrate, the substances not needed by the body are excreted in the urine.

Question 27

circulatory (cardiovascular) system consists of

Answer 27

) a liquid tissue (blood), 2) vessels that enclose the blood, and 3) a pump (the heart) that helps to circulate the blood. The circulatory system provides for transport of nutrients, wastes, hormones, blood gases, etc., body temperature regulation, and protection via immune system cells

Question 28

pharynx

Answer 28

back of throat

Question 29

trachea

Answer 29

windpipe

Question 30

larnyx

Answer 30

voicebox

Question 31

How respiratory system works

Answer 31

The air passes through your pharynx (back of your throat), over your larynx (aka voicebox) and into the trachea (aka windpipe). Notice that the trachea is reinforced by rings of cartilage, sort of like a vacuum cleaner hose. Why is that? (So that it stays open so gas exchange can occur easily). The trachea splits into two bronchi; if they get inflamed from an infection, smoking, etc. it is called bronchitis. Inside the lungs, the bronchi branch into tiny tubes called bronchioles which dead-end in grape-like clusters called alveoli. The alveoli are surrounded by capillaries and are the sites of gas exchange between the respiratory and circulatory systems.

Question 32

solar plexus

Answer 32

the main nerve that tells the diaphragm to contract.

Question 33

When you hold your breath, what causes you to start breathing again?

Answer 33

when breathing control centers in the brain detect high levels of carbon dioxide, this gets interpreted to mean that the muscles are very active and, therefore, releasing lots of waste product (carbon dioxide) from aerobic respiration, so oxygen is needed to fuel those muscles and so the person needs to start breathing again

Question 34

3 main factors that limit oxygen diffusion (availability).

Answer 34

Warmer air and water hold less oxygen than cooler air and water – that’s why you hear about fish die-offs in the summer (if the rivers, lakes, etc. heat up too much, the fish suffocate). Water is “thicker” than air and, therefore, holds less oxygen in general. Lastly, the higher you go up in altitude, the less oxygen is in the air. That’s why people who climb Mt. Everest carry pressurized cans of oxygen, and that’s why you’ll need oxygen if an airplane’s cabin becomes de-pressurized in flight (a happy thought indeed!).

Question 35

The common cold

Answer 35

we may never have a vaccine for the common cold (or at least not one for all types) for two reasons: 1) nearly 200 different types of viruses can cause a cold, and 2) it is usually not a potentially fatal or debilitating disease, though it can be darn inconvenient! See Fig. 26-19. Contrary to popular belief, colds usually are not transmitted through the air via sneezing or coughing (though they certainly can be), but rather a person usually picks up a cold virus by touching a contaminated doorknob, keyboard, telephone, etc. or shaking hands with an infected person and then touching your mouth or rubbing your eyes, thereby inoculating yourself with the cold virus.

Question 36

how can you tell if you have a cold or the flu?

Answer 36

With a cold you usually have no fever, little to no headache or muscle aches, little fatigue, but quite a sore throat (at least initially), then a runny nose and a cough. You can usually go to work or at least function fairly well with a cold. With the flu, you are in bed for several days, down for the count! Your fever will be at least 102, you may experience alternate bouts of fever and chills, and you will have a headache and pronounced muscle aches and will be VERY tired. There usually is very little sore throat or coughing symptoms with the flu. If you are too tired to get out of bed, then it is probably the flu. Remember that antibiotics do NOT work against viral infections (remember why?), so please do NOT go to the doctor and ask for a prescription for an antibiotic. This practice perpetuates antibiotic resistant bacteria in the environment!

Question 37

Influenza (the flu)

Answer 37

The genome (genetic material) of the influenza virus consists of 8 different pieces of RNA that code for the two main types of protein spikes on the surface of the virus: H spikes and N spikes (called “surface glycoproteins” in the book). There are 10 different kinds of N spikes and 17 different kinds of H spikes that may occur on the surface of the flu virus.Birds (mostly waterfowl) infected with various strains of the flu virus (i.e. their RNA genes can code for lots of different H and N spikes) migrating from the north encounter other birds, geese, ducks and pigs, often on farms in Asia. They transmit the different strains of flu virus to each other; pigs in particular are sensitive, and their lungs end up serving as “mixing tanks” for the various strains of the virus

Question 38

The strain of the flu virus that killed all of those people in 1918

Answer 38

was H5N1, meaning that it had H spike kind #5 and N spike kind #1 (Fig. 13-26). In 2003 this strain reappeared in migrating birds and spread through some poultry and pigeon flocks in Asian and European countries. Millions of birds and a few people in Asian countries have died from this so-called avian (bird) flu. This version of the virus is particularly lethal to all birds such as ducks, chickens and turkeys; humans who have died from this bird flu primarily have been farmers, slaughterhouse workers, etc. who come in direct contact with poultry every day.

Question 39

The strain of influenza that appeared in our country in April, 2009

Answer 39

was H1N1 – now you understand what those numbers and letters mean. From April, 2009 until February, 2010, there was an epidemic of H1N1 in this country, meaning that it occurred in unusually high numbers of people in a community at the same time. The Centers for Disease Control (CDC) estimates that approximately 12,000 people in the U.S. died from H1N1 influenza during that time period. There was also a pandemic of H1N1 influenza during that time, meaning that the virus affected a large number of people in a wide geographic region (i.e. many other countries besides the U.S. had epidemics of H1N1).

Question 40

Asthma

Answer 40

occurs when the bronchi and bronchioles spasm due to allergies, pollutants, smoking, etc. There has been a noticeable increase in asthma cases over the last several years, most likely because of air pollution from coal-fired power plants and other sources. This has become a serious national concern, and I was very pleased when in Dec., 2011 the Environmental Protection Agency (EPA) mandated that coal- and oil-fired power plants must limit their emissions of mercury and other toxic air pollutants – this is a victory for all of us, not only asthma-sufferers

Question 41

Smoking-related disorders

Answer 41

Nearly 450,000 people die each year in the U.S. because of diseases directly linked to smoking!! (It costs our country nearly $200 billion each year in medical costs and lost productivity). Smoke immobilizes the cilia on the epithelial cells lining your upper respiratory system. These cilia beat the mucus in your system (it traps pollutants, pollen, etc.) in an upward direction; many times a day you swallow this mucus and do not even realize it. When these cilia are paralyzed the mucus cannot move upward, so the person develops a “smoker’s cough” to physically hack up the mucus, since the epithelial cells cannot do it anymore. When a person stops smoking the ciliated cells will regenerate. Smoking also constricts blood vessels (which jacks up the blood pressure and can lead to strokes and heart attacks!) and impairs white blood cells crucial to your immune system. Cigarette smoke contains pollutants called tars (which turn the lungs brown or black) and a whole host of nasty substances such as cyanide, formaldehyde, carbon monoxide, sulfur & nitrogen oxides, and the addictive drug nicotine

Question 42

COPD

Answer 42

Chronic Obstructive Pulmonary Disease
This refers to a combination of lung diseases that leads to a buildup of mucus or loss of elasticity in the lungs, resulting in restricted/blocked airflow that makes breathing more difficult over time. COPD commonly includes one or both of the following:
· Chronic bronchitis: occurs when the breathing tubes become inflamed and narrowed (thickened), resulting in a shortness of breath.
· Emphysema: sulfur & nitrogen oxides (usually from heavy cigarette smoking) cause the lungs to lose elasticity over time, resulting in inefficient breathing and a shortness of breath; this cannot be reversed. Emphysema is the most common cause of death from respiratory disease in the U.S. (excluding lung cancer).

Question 43

circulatory (cardiovascular) system

Answer 43

consists of 1) a liquid tissue (blood), 2) vessels that enclose the blood, and 3) a pump (the heart) that helps to circulate the blood. The circulatory system provides for transport of nutrients, wastes, hormones, blood gases, etc., body temperature regulation, and protection via immune system cells

Question 44

Vessels

Answer 44

your body contains nearly 60,000 miles of blood vessels, most of which are capillaries. Arteries take blood away from the heart (you can memorize this by saying that both “artery” and “away” begin with an “a”) while veins take blood toward the heart.

Question 45

the basic path of blood flow through vessels

Answer 45

heart-> arteries-> arterioles (small arteries)-> capillaries-> venules (small veins)-> veins-> heart.

Question 46

Capillaries

Answer 46

have walls that are only one-cell thick, so nutrient and gas exchange takes place in tiny capillaries embedded in all of our tissues. Capillaries on the arterial side of the capillary bed deliver oxygen and nutrients to the tissues, while capillaries on the venous side pick up the wastes, carbon dioxide, etc.

Question 47

systolic

Answer 47

pressure when the heart is working or contracting

Question 48

diastolic

Answer 48

pressure when the heart is relaxing

Question 49

Blood pressure

Answer 49

systolic/diastolic Normally blood pressure is taken in the main artery in your left arm (this blood has just come from the heart). The numbers refer to millimeters of mercury (in the old days the blood pressure cuff was attached to a tube containing mercury). Healthy blood pressure is a reading of around 120/70.

Question 50

Hypertension

Answer 50

considered to be consistent readings of 140/90 or greater; consistently high readings can lead to heart attacks and strokes. You can feel when your heart beats (contracts during systole) as the pulse in the brachial artery in your arm (at your wrist just under your thumb) or carotid artery in your neck; normal is around 60-70 beats per minute

Question 51

heart murmur

Answer 51

indicates that a valve is a bit sloppy or leaky, allowing some blood to flow backwards. If a person needs a new heart valve, they frequently get one from a pig

Question 52

The heart has its own pacemaker

Answer 52

Your brain regulates the rate of your heartbeat but it does NOT tell your heart to beata cluster of neurons that generate electrical impulses, on the wall of the right atrium. These electrical signals coordinate the beating of the heart muscle cells, keeping them all in sync

Question 53

electrocardiogram (aka EKG)

Answer 53

provide a display of a person’s cardiac cycle. If a person’s heartbeat is too slow or erratic because these neurons are not functioning properly, he made need an artificial pacemaker.

Question 54

BLOOD

Answer 54

consists of roughly half plasma and half cellular elements (Fig. 21-12). You have approximately 10 pints of blood in your body. Plasma is primarily water that contains clotting proteins, nutrients (monomers from the foods you have eaten), salts, wastes, hormones and dissolved gases.

Question 55

There are 3 kinds of cellular elements in blood

Answer 55

1. red blood cells (RBCs or erythrocytes; erythro = red, cyte = cell): you have trillions of these cells, and each contains millions of hemoglobin (protein) molecules that contain iron. The oxygen you breathe in binds to the iron in the hemoglobin molecules. That is why people with low iron in their blood (a disorder called anemia; p. 815) may feel tired frequently – they do not have enough of the stuff (iron) that the oxygen needs to bind to in order to be transported throughout the body. Because RBCs are basically “trucks” for transporting oxygen and some carbon dioxide to and from your cells, they do not need (or have the room for) a nucleus and other organelles. Because they lack a nucleus and, therefore, chromosomes, RBCs cannot divide, which is why you can donate blood only about once every two months – your body needs the time to replenish the cells from stem cells in the bone marrow. So, when DNA is isolated from a person’s blood, is it isolated from the RBCs? No, because no nucleus means no chromosomes means no DNA in these cells. So, the blood gets centrifuged and the DNA gets extracted from the next cell type, the white blood cells.
   2. white blood cells (WBCs or leukocytes; leuko = white): these fight infections and cancer; we will learn about them in the immune system chapter.
   3. platelets (thrombocytes; thrombo = clot): these cell fragments are responsible for initiating the blood clotting process. If you need to have surgery, the doctor will ask you to refrain from taking aspirin, ibuprofen, etc. a week or two before the surgery because these drugs inhibit platelet aggregation, meaning that they prevent the platelets from easily sticking to the lining of a blood vessel to begin the clotting process. Older people may take an aspirin a day to “thin” the blood so clots do not form inappropriately (a risk factor for stroke), but you do not want thinned blood before surgery or else you may bleed quite a bit during the procedure.

Question 56

Atherosclerosis

Answer 56

(which leads to cardiovascular disease) involves the build-up of fatty plaque (trans fats, saturated fats, cholesterol, etc.) in any artery of the body. Remember LDL cholesterol from Ch. 2? This bad cholesterol along with other types of fats can participate in an inflammatory reaction inside your vessels, leading to cardiovascular disease.

Question 57

The four stages of food processing

Answer 57

ingestion, digestion, absorption and elimination

Question 58

gastrointestinal or GI tract

Answer 58

The food that we ingest (eat) is in too big a form to enter our cells, so we have a 25-30 ft. tube (gastrointestinal or GI tract) that mechanically and chemically (enzymatically) breaks down the polymers (starch, protein, lipids, etc. – remember those from Ch. 2?) into their monomers (which are small enough to enter our cells).