APK2105 Ch1

About ____ of the ECF comprises the water portion of the blood (blood plasma). The largest portion of the ECF (80%) bathes most of the cells in the body and is called _____ ______.

20% ; the interstitial fluid (ISF)

The cell types blood, bone, fat, and lymph would be categorized into what major cell class?

Connective tissue cells

______ ___ _____is a category of cell that is not defined as precisely as the other cell types. Connective tissue cells generally act to provide physical support and anchoring to other structures. Common examples include ligaments around joints, tendons on muscles, and cartilage in the nose, ears, and joints.

Connective tissue cells

_____ glands produce and secrete products into ducts leading to the exterior of the body, such as sweat glands and salivary glands.

Exocrine

Extracellular fluid is composed of plasma only. True/ False

False: Plasma AND interstitial fluid

Here is how this control system works: Our body temperature can vary within a _____ range without serious disruption to homeostasis. However, regulated variables (such as temperature) have a set point that the body tries to maintain. The set point for body temperature is 98.6o F (37o C).

"normal"

Some organs serve more than one _______. For example, the pancreas produces a hormone, insulin, which helps to maintain nutrients in the blood for distribution to the cells.

"system".

____ ____ ____serve special control functions such as blood vessel dilation and constriction among many other tasks central to maintaining homeostasis.

Smooth muscle fibers

The fluid compartment with a high protein and potassium conc. is called (besides plasma)

Intracellular fluid

_____ muscle fibers are found in the heart (cardiac muscle) and in other organs (smooth muscle).

Involuntary

____ _______ is the process whereby a change in some regulated variable (such as body temperature) is sensed by receptors that elicit changes to one or more systems, causing the regulated variable to return to "normal" levels.

Negative feedback

_____ is a common term used for nerve cells that are anatomically and chemically specialized to transmit impulses from one area of the body to another.

Neuron

______ are structures containing two or more tissues with a particular function, usually helping to support cell homeostasis. For example, the lungs are made up of all tissue types (epithelial tissue, smooth muscle tissue, nerve tissue and connective tissue) working together to promote breathing to maintain the proper balance of Ó and CÓ between the lungs and the blood.

Organs

Most of the TBW is inside the cells. True or false

True

Organs of the body are defined as a combination of two or more tissues that make up a structure which performs a specific function. True/ False

True

For this reason, two or more cell types are grouped to form ______ with specific functions in physiological control. The tissues are also grouped by combining 2 or more tissue types to form organs. Organs typically have specific jobs in physiological function and are often combined with other organs to form systems. These systems are in control of various functional aspects of our body and maintain normalcy throughout our lives.

tissues

Specifically, _____ are composed of two or more cell types performing similar functions. The term "tissue" loosely refers to the materials of which the body is composed. The same term describing cells are often used to describe tissues: nerve tissue, muscle tissue, epithelial tissue, and connective tissue. For example, a muscle is composed of mostly muscle cells and is, therefore, referred to as muscle tissue. However, it also contains nerve, epithelial, and connective cells.

tissues

The purpose of cardiopulmonary resuscitation (CPR) or a hospital life support system is to maintain air exchange in the lungs and keep blood_______ during times when these organs are not working properly. In this way the life threatening disruption of homeostasis is averted.

circulating

Let's use a change in body temperature as an example. We are ______; meaning our body temperature must remain within a relatively narrow limit. If we get too hot or cold, the disruption in homeostasis can result in cell death. If a significant numbers of cells die, this can lead to life-threatening, major organ failure. Therefore, negative feedback mechanisms take control to increase or decrease the regulated variable.

homeotherms

Organs have one or more specific jobs. An example of an organ is the pancreas, which produces _____ and ______. A combination of organs (such as heart and lungs) forms a system with the overall job of providing support to the cells; in essence, maintaining homeostasis.

hormones and enzymes

Scientist can remove cells from the body and place them into "physiological solutions" (i.e., solutions formulated to mimic the intercellular fluids) in an attempt to keep them "alive" for study. For these experimental purposes, cells can be kept in a homeostatic state for _____, however, no one has discovered a way to keep them alive for long periods of time.

hours

Epithelial cells are also found lining hollow organs such as the stomach, intestines, and blood vessels. This interior cavity of organs and vessels is referred to as the ____

lumen

The solutes (inorganic ions, sugars, amino acids, and large proteins) serve critical functions, but without the fluid medium provided by water, they are irrelevant. One of the key aspects to the study of physiology is how water and solutes ___ _____ cell membranes and epithelial barriers. These barriers permit certain types of molecules through more easily than others and exclude some molecules completely.

move across

Muscle cells are also called _____ _____ and consist of many overlapping proteins working together to cause muscle fiber contraction, or shortening.

muscle fibers

What tissue is specialized for generating electrical signals?

nervous

We often refer to the cell membranes and epithelial tissues as being ______ _______

semipermeable membranes.

The 200 different kinds of cells are classified into 4 functional categories:

1) neurons (2) muscle cells (3) epithelial cells (4) connective tissue cells.

____ are the basic functional unit of the body. Indeed, the purpose of homeostasis is to maintain "life" in these cells. However, the maintenance of homeostasis requires support systems to help maintain this normalcy of the cell's internal environment.

Cells

_____ glands secrete their product referred to as hormones, into the bloodstream. Hormones are chemicals released to the blood for circulation to other tissues throughout the body with the purpose of controlling the function of those cells.

Endocrine

What tissue is specialized for separating fluids?

Epithelial

_____ cells are assembled in a sheet-like array on top of a basement membrane and serve as a foundation for the cells. They may also be assembled in multiple layers and forms. Typically, these cells form a barrier to prevent molecules and fluids on one side, from mixing with those on the opposite side.

Epithelial cells

Many other regulated variables, such as _____ _____, breathing rate, and blood levels of various chemicals such as potassium, sodium, calcium, etc. are controlled by negative feedback.

blood pressure,

With an increase in the ambient temperature, skin temperature gradually rises and, within minutes, the core temperature of the body also begins to increase. At this point, receptors in the _____(central receptors) and in the skin (peripheral receptors) sense this increase in temperature and relay signals through sensory nerves to the brain (referred to as the integrating center).

brain

When two or more organs work together to help maintain homeostasis, they are collectively referred to as an organ system. For example, the heart and the lungs are referred to as the ________ system. In this organ system, the lungs are responsible for keeping the Ó and CÓ balanced in the blood. Then, the heart pumps the blood throughout the body so the balance of Ó and CÓ is maintained in the cells. In essence, the overall goal of the cardiorespiratory system is to transport Ó from the atmosphere to the cells, and, to transport CÓ produced in the cells out to the atmosphere thereby maintaining the homeostatic levels of Ó and CÓ in the cells.

cardiorespiratory

The ICF and ECF are distinct compartments separated by ____ _______ with very different compositions. INSIDE the cells there are many proteins and a relatively high concentration of potassium; whereas OUTSIDE the cells there are few proteins and more sodium. This difference in composition is important in understanding the functioning of cells.

cell membranes

Physiology is the study of how the body functions to maintain a ______ internal environment so it can survive.

constant

In addition, the pancreas also assists the digestive system by producing fluid and _____ ______ capable of breaking down nutrients. In this way, the pancreas is part of both the digestive system and the endocrine system.

digestive enzymes

We typically divide the body into compartments. The internal environment of the body is separated from the external environment by the _______ barrier provided by the skin on the outside, and by the linings of the lungs, gastrointestinal tract, and kidney tubules on the inside.

epithelial

When gases or particulate matter enters the lungs, it is still considered _____ to the body until it crosses the epithelial linings of the lung and enters the blood.

external

The _____ balance between compartments is essential to maintaining homeostasis in the body. Water is the most abundant substance in the body (~60% of body weight or 42 L of water for a 70 kg person) and acts like a solvent for the large number of solutes found in the body fluids.

fluid

The same is true in the gastrointestinal tract. In fact, the gastrointestinal tract is often likened to a tube "running through" the body. Nutrients are absorbed across the epithelial lining of the gastrointestinal tract as ____ passing through is processed.

food

The gastrointestinal tract lining is specially constructed to prevent "non-nutrients" and toxins from moving into the internal environment and disrupting ________. Typically, these "non-nutrients" and toxins will pass through the gastrointestinal tract and be excreted. The kidneys act as another filtering mechanism helping prevent a disruption of homeostasis.

homeostasis

This internal constancy is called _______ and is the theme of the processes we study. Maintenance of homeostasis is the overall mission of the physiological systems of the body.

homeostasis

As mentioned earlier, the focus of the physiological systems in the body is to maintain _______. If the heart or lungs stop working, the supply of oxygen needed to maintain homeostasis will also stop and death to all cells will occur in a matter of minutes.

homeostasis.

The volume of water contained in all of the body's compartments is defined as total body water (TBW). In other words, TBW includes all the water enclosed by the external epithelial layer we refer to as the skin. It includes all the water _____ the cells (intracellular fluid [ICF]) and the water _____ the cells (extracellular fluid [ECF]).

inside; outside

Some neurons, called _____ neurons, transmit impulses out from the brain and spinal cord to tissues throughout the body. In contrast, some neurons, called ____ neurons, are specialized to receive impulses from our environment such as light, smell, or touch, and relay them to the spinal cord and brain.

motor ; sensory

The fluid compartment with a high sodium and protein conc. is called_____

plasma

Other neural cells are support cells and act to_____ and _____ brain and spinal neurons.

protect and nourish

The blood plasma and the ISF are similar in composition because a main objective of the circulating blood is to replenish the ECF fluid bathing and nourishing the cells. The blood retains most of the large _____ such as those responsible for transport of Ó2 and CÓ2

proteins

These cells are usually embedded in a mass of noncellular material called the extracellular matrix. The extracellular matrix is a dense meshwork of ______ (such as elastin for elasticity and collagen for strength) and other large molecules. However, this category also includes a diverse array of cells such as blood cells, bone cells, fat cells, and others not fitting the above categories. These cells don't seem to serve the "connecting" role of other types of connective tissue but are categorized here because of their diverse functions and because they connect the body in some way.

proteins

The ___ and the lining of the ____ are good examples of how epithelial cells are used to form a barrier. They may also release chemicals important in controlling the internal environment.

skin; lungs

Epithelial cells also form glands, which are organs ........? Glands are categorized into two types: exocrine glands and endocrine glands.

specialized to Synthesize and Secrete products.

The cells, being clustered internally, are _____ to obtain the nutrients and Oxygen they need to maintain life of the cell from the blood that circulates around them. Thus, our complex structure requires support systems such as lungs, heart, blood vessels, digestive systems, etc. to "take care of" these cells.

unable

In some of our life activities we may encounter extreme conditions of temperature, muscle stress, and nutritional deprivation. If the physiological systems are_______ to these changes, normal cellular conditions are disrupted and death will quickly follow.

unresponsive

Our cells have a remarkable ability to withstand large _______ in the composition, temperature and volume of the extracellular fluid caused by such changes. How the body senses these changes and responds with feedback control to maintain homeostasis is a major focus in the study of physiology.

variations

Muscle fibers under ______ control permit us to move about (skeletal muscle).

voluntary