Physiology Exam 1

Anatomy is the structure of everything, so then ____ is how those structures function together or how they function overall.

Physiology

List the two big ideas (or themes) of Physiology

1.) Structure dictates function

2.) The body will always try to maintain homeostasis

What term refers to your body attempting to maintain a certain set of values so that it can function correctly?

Homeostasis

True/False: As cells develop they start to differentiate

True

What are the four main muscle cell types?

Epithelial, Connective, Nervous, Muscle

What type of cell is specialized to generate mechanical force?

Muscle cell

List the 3 types of muscle cells in the human body

Cardiac, Skeletal, and Smooth

Cardiac and smooth muscle is _____ (voluntary/involuntary)

Involuntary

skeletal muscle control is ____ (voluntary/involuntary)

Voluntary

A ____ is a cell of the nervous system specialized to initiate, integrate, and conduct electrical signals (action potentials) to other cells, sometimes over long distances.

Neuron

A collection of neurons forms _____ tissue (brain or spinal cord).

Nervous

Cellular extensions from many neurons are packaged together along with connective tissue to form a _____

Nerve

Epithelial cells are specialized for what?

selective secretion and absorption of ions and organic molecules, and for protection

Epithelial cells are characterized and named according to their unique shapes, name a few

Cuboidal (cube-shaped), columnar (elongated), squamous (flattened), and ciliated

True/False: Epithelial tissue (known as an epithelium) may form from any type of epithelial cell.

True

Epithelia may be arranged in single-cell-thick tissue, called a _____ epithelium, or a thicker tissue consisting of numerous layers of cells, called a _____ epithelium.

Simple, stratified

True/False: The type of epithelium that forms in a given region of the body reflects the function of that particular epithelium.

True

Where are epithelia located in the body?

At the surfaces that cover the body or individual organs and line the inner surfaces of tubular and hollow structures within the body

What is the extracellular protein layer that epithelial cells rest on?

The basement membrane

What is the side of an epithelial cell anchored to the basement membrane called? (faces the blood vessels)

The basolateral side.

What is the side of an epithelial cell that typically faces the interior (the luman) called?

The apical side

True/False: The two sides of all the epithelial cells in the tissue may perform different physiological functions.

True

What holds epithelial cells together along their lateral surfaces?

Extracellular barriers called tight junctions.

What is the function of tight junctions in epithelial cells?

Enable epithelia to form boundaries between body compartments and function as selective barriers regulating the exchange of molecules.

What would be move likely to have tighter junctions the blood brain barrier or the liver.

The blood brain barrier

_____ tissue cells connect, anchor, and support the structures of the body (allows for communication)

Connective tissue cells

What are the 6 types of connective tissue?

1. Loose Connective Tissue, 2. Adipose, 3. Dense Connective Tissue, 4. Cartilage 5. Bone 6. Blood

The environment that surrounds cells is referred to as _____

Extracellular matrix

What are the primary components of the extracellular matrix (ECM)?

Proteins, polysaccharides, Ions/minerals

What are the two general functions of the ECM?

1.) Provides a scaffold

2.) Allows for information to be transmitted from cell to cell.

What types of fibers are found in the proteins ECM?

Rope-like collagen fibers and rubber band-like elastin fibers. (others are a mixture of nonfibrous proteins that contain carbohydrate.)

What is an organ made of?

A collection of different cell types, different tissue types (at least two).

What is a collection or organs referred to as?

An organ system

What is the general definition of body fluid?

A watery solution of dissolved substances (oxygen, nutrients, and wastes) present in the body

The fluid in the blood and in spaces surrounding the cells is called ____ (essentially all fluid outside of cells)

Extracellular fluid

Of the Extracellular fluid, most of it consists around and between the cells and is referred to as _____ fluid, whereas the remaining is referred to as ____

Interstitial fluid, plasma

The space containing interstitial fluid is called the _____

Interstitium

The total volume of extracellular fluid is the sum of what two fluids?

Plasma and interstitial fluid volumes

The fluid that is located INSIDE the cells and makes up for 67% of all the fluid in the body.

Intracellular fluid

True/False: The composition of the extracellular fluid is similar to that of the intracellular fluid.

False. The composition of extracellular fluid is very different from that of intracellular fluid.

What is Homeostasis?

Physiological variables in a state of dynamic constancy; it is not a static process.

What do we refer to when homeostasis is maintained?

Physiology

What term is used when homeostasis is not maintained?

Pathophysiology

Is homeostasis a static or dynamic process?

Dynamic process

Blood glucose levels increase after eating, and then levels return to their set point via homeostasis. This is an example of _____ constancy

Dynamic

Which feedback system enhances the production of the product or accelerates a process?

Positive feedback system

Which feedback system brings about responses that move a variable opposite to the direction of its original change?

Negative feedback system

Give some examples of positive feedback systems

Child birth, blood clotting, the nervous system action potential.

Give some examples of negative feedback systems

Endocrine system (hormones), glycolysis, body temp, (there are alot of examples)

What is a reflex?

A specific, involuntary, unpremeditated, "built-in" response to a particular stimulus. (Example: pulling your hand away from a hot object or shutting your eyes as an object rapidly approaches your face.)

Describe pathway of the reflex arch in order

1. Stimulus: External environmental change

2. Receptor: Receptors detect envermental change and generate a signal.

3. Afferent Pathway: The sensory neurons carry the signal from the receptor to the integrating center. This pathway “carries to” the central nervous system (CNS).

4. Integrating Center: :Processes signal. It integrates information from various receptors and determines an appropriate response.

5. Efferent Pathway: The motor neurons “carry away” the command from the integrating center to the effectors.

6. Effector: The effector, which is typically a muscle executes the action.

7. Response: The overall response

True or False: Almost all body cells can act as effectors in homeostatic reflexes.

True

What are the two major effectors of biological control systems?

Muscles and glands

What dual roles can glands perform in biological control systems?

Glands can act as both receptors and integrating centers.

What is a hormone?

A type of chemical messenger secreted into the blood by cells of the endocrine system.

Why can hormones act on many different cells simultaneously?

Because they circulate throughout the body.

Where are hormones produced and secreted from?

Endocrine glands or scattered cells distributed throughout another organ.

How do hormones reach their target cells?

They travel through the blood.

What are neurotransmitters?

Chemical messengers released from the endings of neurons onto other neurons, muscle cells, or gland cells.

True or False: A neuron, an endocrine gland cell, and other cell types can all secrete the same chemical messenger.

True

In what ways can a particular chemical messenger function?

As a neurotransmitter, a hormone, or a paracrine or autocrine substance.

A chemical messenger that functions both as a neurotransmitter in the brain and as a hormone produced by cells of the adrenal glands.

Norepinephrine

True/False: A given chemical messenger can belong to more than one category.

True

What are two types of chemical communication between cells that do not require secretion of a chemical messenger?

Gap junctions and juxtacrine signaling

What are gap junctions?

Physical linkages connecting the cytosol between two cells, allowing molecules to move directly from one cell to an adjacent cell without entering the extracellular fluid.

What is juxtacrine signaling?

A type of signaling where the chemical messenger is not released from the cell but is located in the plasma membrane, and communication occurs when the cell contacts another cell capable of responding to the message.

In juxtacrine signaling, where is the chemical messenger located?

In the plasma membrane of the cell producing it.

How do cells communicate in gap junctions?

By directly connecting their cytosol, allowing molecules to pass between adjacent cells. (without entering the extracellular fluid)

What does the term adaptation refer to?

A characteristic that favors survival in specific environments.

What is acclimatization?

The improved functioning of an already existing homeostatic system, often due to prolonged exposure to an environmental change.

What are biological rhythms?

Regular, rhythmical changes associated with many body functions.

What is the most common type of biological rhythm?

The circadian rhythm

How do biological rhythms relate to homeostatic control systems?

They add an anticipatory component to homeostatic control, functioning as a feedforward system without detectors.

What is the purpose of negative feedback homeostatic responses?

They are corrective responses initiated after the steady state of the individual has been perturbed.

How do biological rhythms enhance homeostasis?

By enabling homeostatic mechanisms to activate automatically and immediately at times when a challenge is likely to occur, even before it happens.

What is the primary role of homeostatic systems in the body?

They regulate the balance between addition and removal of a chemical substance from the body.

What does total-body balance depend on during any period of time?

The relative rates of net gain and net loss to the body.

What two factors determine the pool concentration of a substance in the body?

1. The total amount of the substance in the body.

2. The exchanges of the substance within the body.

What are the three possible states of total-body balance? Explain what happens in each.

1. Negative balance = Loss of the substance is greater than gain.

2. Positive balance = gain of the substance is greater than loss.

3. Stable balance = Gain equals loss.

START OF CHAPTER 2

What is an atom?

The smallest unit of matter that forms all chemical substances.

What are the three subatomic particles in an atom?

Protons, neutrons, electrons

Protons and neutrons are located in the _____.

Atomic nucleus

Electrons orbit the nucleus in regions called _____.

Orbitals

The atomic number of an element equals the number of _____.

Protons (or electrons in a neutral atom).

An atom that loses an electron (now positive) becomes a _____ (cation/anion).

Cation

An atom that gains an electron (now positive) becomes a _____ (cation/anion).

Anion

Because of their charge, ions are able to conduct electricity when dissolved in water; consequently, the ionic forms of mineral elements are collectively referred to as ____

Eelectrolights

Ionic Forms of Elements:

Two or more atoms bonded together make up a ____

molecule

What are the four chemical bonds

Polar covalent bonds

Nonpolar covalent bonds

Ionic bonds

Hydrogen bonds

What is electronegativity?

The measure of an atom's ability to attract electrons in a covalent bond

The more electronegative atom acquires a slight negative charge, while the other atom, having partly lost an electron, becomes slightly positive. Such bonds are known as _____ covalent bonds because atoms at each end of the bond have an opposite electrical charge.

Polar

One example of a polar covalent bound is between the hydrogen and oxygen in a hydroxyl group (--OH) explain why this is an example of a polar covalent bound.

The oxygen is slightly negative and the hydrogen slightly positive.

Since water is polar other molecules that contain _____ (nonpolar/polar) bonds tend to be more soluble in water than molecules arranged in nonpolar covalent bonds.

Polar

In contrast to polar covalent bonds, bonds between atoms with similar electronegativities are said to be ________ (nonpolar/polar) covalent bonds. In such bonds, the electrons are equally or nearly equally shared by the two atoms.

Nonpolar

Molecules that contain high proportions of nonpolar covalent bonds are called _____ (nonpolar/polar) molecules; they tend to be less soluble in water than those with polar covalent bonds.

Nonpolar

Table 2.3 Examples of Polar and Nonpolar Covalent Bonds

What is an ionic bond?

A strong attraction between two oppositely charged ions

What causes ionic compounds like NaCl to dissolve in water?

The ion is attractive to the partial charges of water molecules.