BIOL 191: Chapter 32
When is a positive feedback loop an appropriate response? Name an example. Positive feedback mechanisms are often integrated within what?
- Is an appropriate response when a potentially dangerous or stressful process must be completed quickly -E.g., blood clotting, uterine contractions during birth in mammals -Positive feedback mechanisms are often integrated within broader negative feedback mechanisms
What is an organ composed of? How do tissues interact with each other in an organ? What is an organ system?
-An organ is composed of two or more tissues arranged in particular proportions/patterns (sheets, tubes, layers, bundles, strips) -Different tissues in an organ interact with each other through direct contact and secretions -In an organ system, different organs function together to perform an overall function
What are connective tissues? What do many connective tissues contain? What are some examples?
-Connective tissues are a diverse group that connect, surround, anchor, and support the structures of an animal's body -Many contain a few cells dispersed in a prominent non-cellular matrix -adipose tissue, bone, cartilage, loose or dense connective tissue, blood
Match each term with the correct definition. Radiation Evaporation Convection Conduction
-Emission of electromagnetic waves from the surface of an object -Transformation of water from the liquid to the gaseous state -Transfer of heat by the movement of air or water next to the body -Transfer of heat through direct contact between two substances
What do epithelial tissues? Epithelial are specialized for what functions? What kind of surfaces do they have?
-Epithelial tissues are sheets of densely packed cells that cover body surfaces, enclose organs, or line the walls of body cavities -Epithelial cells are specialized for protection and transport; they are asymmetrical (have distinct basal and apical surfaces)
Match each organ system with its function. Respiratory system Circulatory system Urinary system Digestive system Immune and lymphatic systems
-Exchange of gases with the environment -Transport of nutrients, gases, and waste -Regulation of the concentration of body fluids -Breaking complex foods into smaller units -Defense against pathogens
What does feedforward regulation prepare the body for? Often occurs in what? Describe an example
-Feedforward regulation prepares the body for a possible challenge to homeostasis before it occurs -Often occurs in animals with well-developed nervous systems -E.g., an increase in heart rate or respiratory rate prior to an increase inactivity -E.g., an increase indigestive gland activity prior to eating28Often occurs in animals with well-developed nervous systems
Distinguish among body fluids by matching the names with the descriptions below. Intracellular fluid Extracellular fluid Interstitial fluid Plasma
-Fluid within cells -Composed of interstitial fluid and plasma -Fluid in the spaces between cells -Fluid portion of blood
What do muscle tissues contain? What do they produce? What do they decrease? What do they exert pressure on? What are the three types of muscle?
-Muscle tissue contain specialized cells that contract(shorten), generating mechanical forces that may -produce body movements, decrease the diameter of a tube, exert pressure on a fluid-filled cavity -skeletal, smooth, and cardiac muscle
What do nervous tissues do? An electrical signal may stimulate what? (3 things)
-Nervous tissues are complex networks of neurons, cells that communicate by initiating and conducting electrical signals (action potentials) from one part of the body to another An electrical signal may: -stimulate or inhibit another neuron -stimulate muscle cells to contract - stimulate glandular cells to secrete their products (e.g.: swea tglands, digestive glands
How are surface area and volume important properities of cells? What allows increased surface area?
-Surface area and volume are important properties of cells ;they increase at different rates as cells become larger -Many structural modification (adaptations) allow increased surface area to facilitate processes of exchange
Homeostasis is a dynamic process. Variables maintained within a normal range include
-concentration of nutrients, wastes, and ions in the blood -concentration of O2 and CO2 in body fluids -pH of body fluids - blood pressure and blood volume
Place these events in order. Start with the earliest at the top.
1. A sugary snack is consumed 2. Blood glucose level increases 3. Endocrine and nervous systems respond to deviation from normal 4. Homeostatic mechanism lower glucose levels
Order the following events in a homeostatic response to temperature variation from first to last. Start at top with a change in temperature in response to the environment.
1. Decrease in body temperature occurs in response to ambient temperatures 2. Temperature sensitive neurons sense the change in body temperature 3. The brain compares input from the sensor to the set point 4. Skeletal muscle responds to the homeostatic challenge by shivering
What results in a magnification of a change in a physiological variable?
A positive feedback loop
What is a tissue? What are the tissue types? What functions do they perform?
A tissue is an association of many cells having a similar structure and function. They can be classified as muscle tissue, nervous tissue, epithelial tissue, connective tissue. Each contains subtypes that perform variations of the main function
Why is homeostasis important?
Animals typically live in variable environments -E.g., fluctuations in air temperature, water temperature, nutrient availability, water availability, pH, and oxygen availability -These changes can be harmful/fatal if an organism is unable to respond appropriately
How do endotherms respond to cold temperatures?
By shivering By reducing blood flow to the skin
Which of the following are connective tissues?
Cartilage Bone Blood Adipose tissue
How are cells organized in animal bodies?
Cells are organized into progressively more complex structures ,including tissues, organs, and organ systems
Which of the following processes result in obligatory exchanges of salt and water with the environment?
Consumption and metabolism of food Elimination of nitrogenous wastes Regulation of body temperature Exchange of oxygen and carbon dioxide with the environment
Which of the following are mechanisms used by animals to exchange heat with the environment?
Evaporation Conduction Radiation Convection
The environmental conditions in which organisms live are generally constant.
False
Someone whose pulse rate increases before starting a running race is exhibiting what type of homeostatic control system?
Feedforward regulation
What do ectotherms use to warm their bodies?
Heat from external sources
How is homeostasis maintained?
Homeostasis is maintained through the actions of homeostatic control systems; consisting of: -a set point -a sensor - an integrator -an effector
What is homeostasis?
Homeostasis is the process of maintaining a relatively stable internal environment, despite changes in the external surroundings
Mutations in specific _______ led to abnormal or lack of development of organs such as the thymus, thyroid, lungs, and kidneys
Hox genes
Recent experiments have demonstrated that _____ also play a role in the development and spatial patterning of organs
Hox genes
What happens in a negative feedback loop? Name an example. What does it maintain and prevent?
In a negative feedback loop, a change in the variable being regulated brings about a response that moves the variable in the opposite direction -E.g., body temperature decreases ;the response is to increase body temperature -Negative feedback maintains a variable within a normal range; -Negative feedback prevents homeostatic responses from overcompensating
What is neuroglia?
In addition to neurons, nervous tissues also contain neuroglia, a collection of diverse types of cells that surround, support, and protect the neurons
What is an example of feedforward control?
Increase in salivation rate upon smelling food
Homeostasis does not imply that a given physiological variable is rigidly constant. Instead what?
Instead, a variable may fluctuate within a certain normal range; if a disturbance drives that variable out of range, compensatory mechanisms restore the variable toward normal
Which of the following describes an animal that is a homeotherm?
It maintains its body temperature within a narrow range.
Which of the following describes a negative feedback loop?
It moves the level of the physiological variable opposite that of a recent change.
What are the ranges that mammals survive in? A body temp of 41 C (106 F) and 43-43 C (107-109) causes what in humans?
Mammals survive in a relatively narrow range of body temperatures -Resting body temperature is ~35-38°C (95-100°F) In humans, a body temperatures of: -41°C (106°F) ⇒ organ damage -42-43°C (107-109°F) ⇒ is fatal
Do organ systems work together?
Multiple organ systems frequently work together.
Which of the following represent types of tissues found in animals?
Nervous Connective Epithelial Muscle
Which of the following vital processes can potentially disrupt the salt and water balance?
Nitrogenous waste elimination Consuming and metabolizing food CO2 elimination
Organ development in animals is controlled by what? How does organ development happen?
Organ development in animals is controlled by a highly conserved family of body-plan genes (Hox genes) with homologs in all animals -Different Hox genes are expressed indifferent regions along the anteroposterior axis (runs from head toward abdomen)
What happens in a positive feedback loop? What happens to the normal range?
Positive feedback loops accelerate a process; a change in a variable leads to events that amplify that change -The normal range is lost
Match the muscle type with its appropriate characteristic. Instructions Skeletal Cardiac Smooth
Provides the force for locomotion Provides the force to circulate blood through the body Surrounds hollow tubes and cavities inside the body
What aspects of cellular structure and function are affected by temperature?
Rates of chemical reactions Plasma membrane structure Protein folding and function
Which of the following are functions of epithelial cells?
Secretion and/or absorption of ions and organic molecules Protection of underlying structures
Which of the following are components of a homeostatic control system?
Set point Integrator Sensor Effector
Epithelial tissues may be_______
Simple, stratified, pseudostratified, transitional
Which of the following best demonstrates the relationship between form and function in the animal body?
Sites of gas exchange within tissues are typically one cell thick.
What are conformers? What is an example of a conformer? What are some benefits that conformers have? Cons?
Some animals are conformers; features of the internal environment match the external environment -E.g., body fluids in a marine crab have about the same solute concentration as the surrounding seawater; body temperature of many fishes matches the surrounding water temperature -Energetically, conforming is an inexpensive strategy -Conformers are often restricted to stable environments
What are regulators? What is an example? What are some benefits that regulators have? cons?
Some animals are regulators; features of the internal environment differ from the external environment E.g., human body temperature regulation -Energetically, regulating the internal environment is an expensive strategy -Regulators can inhabit a wider ange of environments, including more variable environments
Which of the following are functions of connective tissues?
Surround structures Support structures Anchor structures
What is an example of an organ and why?
The stomach is an example of an organ ;it contains all four types of tissues. It is also part of the digestive system
What is countercurrent heat exchange?
The transfer of heat from warm blood to cold blood that is being returned to the body's core
Which of the following are reasons why animals must maintain normal water levels?
There are many vital processes which have the potential to disrupt the water balance. Proper water levels are critical for survival.
Which of the following describes physiological variables?
They fluctuate around a mean within a certain, typically very narrow, range
The _______metabolic rate is the most common measure used to compare the metabolic rates of organisms.
basal
The most common measure used to compare the metabolic rates of different species is the_____
basal metabolic rate
Intracellular and interstitial fluids are separated by Blank______; interstitial fluid and plasma are separated by Blank______. Multiple choice question.
cell membranes; blood vessel walls
An animal can be both a ______ and______ with respect to different variables
conformer and a regulator
The tissues that function to anchor, surround, and support the structures of an animal's body are called______ tissues.
connective
The tissues in a typical animal's body can be classified into four main types:
connective tissue, epithelial tissue, muscle tissue, and nervous tissue
Adipose tissue and cartilage are examples of:
connective tissue.
Endotherms tightly regulate Blank______. Multiple choice question.
core body temperature only
The Blank______ body temperature of an endotherm is regulated, but the temperature of the Blank______ of the body varies.
core; surface
The process in which heat from warm blood is transferred by conduction to cold blood that is being returned to an animal's core is called _______heat exchange.
countercurrent
The first response of an endotherm when placed into a cold environment is to Blank______ the flow of blood to surfaces that conduct heat away from the body. The second response is to Blank______ skeletal muscle contraction. Multiple choice question.
decrease; increase
A key principle of biology is that structure
determines function
Cells _________ during development; they become specialized to perform a particular function
differentiate
The components of a homeostatic control system are the sensor, integrator, and , _______which work together to maintain a variable near its________ point.
effector, set
The components of a homeostatic control system are the sensor, integrator,and________ , which work together to maintain a variable near its_______ point.
effector, set
Animals that generate their own internal heat through their metabolism are called
endotherms
Conformers save energy by adapting some aspect of their internal body composition to match that of their:
environment.
Functions of_______ tissues include protecting structures and secreting materials.
epithelial
All animals share what similarities?
exchange materials with their surroundings, obtain energy from organic nutrients, synthesize complex molecules• detect and respond to signals in their environment, reproduce themselves
Ectotherms use_______ heat sources to warm their bodies.
external
Structures in animals involved with the absorption of nutrients all have large surface areas. They have this similar structure because they share the same_____
function
Endotherms warm their bodies using
heat from their own metabolic reactions
The body temperature of a(n) Blank______ varies with the environment, while a(n) Blank______ maintains its body temperature within a narrow range.
heterotherm; homeotherm
After a student ate breakfast, his glucose levels rose from just below 100 mg/dL to around 170 mg/dL. The reason that the level of glucose did not rise higher is:
homeostatic mechanisms are in place to control the levels.
Maintaining homeostasis via conforming is energetically:
inexpensive.
In osmosis, water moves from an area of Blank______ solute concentration to one of Blank______ solute concentration.
lower; higher
The immune and ______systems defend the body against disease.
lymphatic
Regulating homeostasis requires Blank______ energy expenditure compared to conforming homeostasis.
more
A positive feedback loop, when presented with a change in a physiological variable, results in responses that:
move the variable further in the direction of the change.
Nerve signals from the stretch receptors in the urinary bladder wall relay information to the brain cells, signaling that the bladder is full and needs to be emptied, which is an example of:
multiple organ systems working together.
A feedback loop in which a change in the physiological variable being regulated brings about responses that move that variable in the opposite direction is a(n) ______feedback loop.
negative
The type of tissue that initiates and conducts electrical signals from one part of an animal's body to another part is______ tissue.
nervous
Tissues that receive and transmit electrical signals throughout the animal's body are Blank______ tissues.
nervous
The part of an organism that is composed of different kinds of tissues is called a(n)
organ
The mechanism by which water moves from a body compartment of lower solute concentration to one of higher solute concentration is known as:
osmosis.
In a homeostatic control system, a component called a(n)_______ must first detect a change for a particular variable. The last step of the system involves a(n) _______which produces a response that compensates for the change.
sensor, effector
Three types of muscle tissue may be found in animals: 1. _____muscles provide the force needed for locomotion; 2._____ muscles control the movement of the contents of internal body organs; and 3.______ muscle provides the force needed for a heartbeat.
skeletal, smooth, cardiac
One of the reasons why animals must maintain normal water levels is that water is the_______ that permits dissolved solutes in cells to participate in chemical reactions.
solvent
Epithelial cells vary in shape; they can be_______
squamous, cuboidal ,or columnar
The rates of chemical reactions, the structure and function of proteins, and the structure of the plasma membrane are all influenced by Blank______. Multiple choice question.
temperature
An organ is made up of two or more different types of
tissues
A high surface area/volume(SA/V) ratio is ideal to
transport, absorption, or detection of environmental stimuli1
Habitat Blank______ imposes fluctuations in availability of basic needs such as food and water upon organisms.
variability
A high surface area/ _______ratio is ideal for the exchange of heat, solutes, and water.
volume
A structure that has a high surface area to volume ratio is suited for the exchange of:
water. solutes. heat.
Maintenance of homeostasis within an organism means that the physiological variables such as glucose levels and blood pH are maintained Blank______.
within a narrow range
