bio Chapter 40
homeostasis
"steady state" referring to the maintenance of internal balance
3 types of connective tissue fibers
1. collagenous fibers 2. reticular fibers 3. elastic fibers
4 types of animal tissue
1. epithelial 2. connective 3. muscle 4. nervous
3 types of muscle tissue`
1. skeletal 2. smooth 3. cardiac
Most land-dwelling invertebrates and all of the amphibians _____. A) are ectothermic organisms with variable body temperatures B) alter their metabolic rates to maintain a constant body temperature of 37°C C) are endotherms but become thermoconformers when they are in water D) become more active when environmental temperatures drop below 15°C
A) are ectothermic organisms with variable body temperatures
You discover a new species of bacteria that grows in aquatic environments with high salt levels. While studying these bacteria, you note that their internal environment is similar to the salt concentrations in their surroundings. You also discover that the internal salt concentrations of the bacteria change as the salt concentration in their environment changes. The new species can tolerate small changes in this way, but dies from large changes because it has no mechanism for altering its own internal salt levels. What type of homeostatic mechanism is this species using to regulate its internal salt levels? A) conformation B) regulation C) integration D) assimilation
A) conformation
A woman standing and watching the stars on a cool, calm night will lose most of her body heat by _____. A) radiation B) convection C) conduction D) evaporation
A) radiation
An example of an ectothermic organism that has few or no behavioral options when it comes to its ability to adjust its body temperature is a _____. A) sea star living deep in the ocean B) bass living in a farm pond C) hummingbird flying through a prairie D) honeybee in a hive on a rural farm
A) sea star living deep in the ocean
) Examine the figure above. Near a goose's abdomen, the countercurrent arrangement of the arterial and venous blood vessels causes the _____. A) temperature difference between the contents of the two sets of vessels to be minimized B) venous blood to be as cold near the abdomen as it is near the feet C) blood in the feet to be as warm as the blood in the abdomen D) loss of the maximum possible amount of heat to the environment
A) temperature difference between the contents of the two sets of vessels to be minimized
What is an example of negative feedback?
After you eat, insulin stimulates the lowering of blood sugar levels.
The temperature-regulating center of vertebrate animals is located in the _____. A) thyroid gland B) hypothalamus C) subcutaneous layer of the skin D) liver
B) hypothalamus
An example of a properly functioning homeostatic control system is seen when _____. A) the core body temperature of a runner rises gradually from 37°C to 45°C B) the kidneys excrete salt into the urine when dietary salt levels rise C) a blood cell shrinks when placed in a solution of salt and water D) the blood pressure increases in response to an increase in blood volume
B) the kidneys excrete salt into the urine when dietary salt levels rise
Positive feedback differs from negative feedback in that _____. A) positive feedback benefits the organism, whereas negative feedback is detrimental B) the positive feedback's effector responses are in the same direction as the initiating stimulus rather than opposite of it C) the effector's response increases some parameter (such as body temperature), whereas in negative feedback it can only decrease the parameter D) positive feedback systems have only effectors, whereas negative feedback systems have only receptors
B) the positive feedback's effector responses are in the same direction as the initiating stimulus rather than opposite of it
Which principle of heat exchange is the most important explanation for why birds look larger in colder weather because they fluff their feathers? A) Fluffing feathers results in less cooling by radiation because feathers emit less infrared radiation than other tissues do. B) Fluffing decreases the amount of heat lost by conduction when the bird makes contact with cold objects in its environment. C) Fluffing creates a pocket of air near the bird that acts as insulation. D) Fluffing decreases the surface-area-to-volume ratio, thus decreasing the amount of heat lost to the environment.
C) Fluffing creates a pocket of air near the bird that acts as insulation.
You are studying a large tropical reptile that has a high and relatively stable body temperature. How would you determine whether this animal is an endotherm or an ectotherm? A) You know from its high and stable body temperature that it must be an endotherm. B) You know that it is an ectotherm because it is not a bird or mammal. C) You subject this reptile to various temperatures in the lab and find that its body temperature and metabolic rate change with the ambient temperature. You conclude that it is an ectotherm. D) You note that its environment has a high and stable temperature. Because its body temperature matches the environmental temperature, you conclude that it is an ectotherm
C) You subject this reptile to various temperatures in the lab and find that its body temperature and metabolic rate change with the ambient temperature. You conclude that it is an ectotherm.
Chum salmon (Oncorhynchus keta) are born in freshwater environments and then migrate to the sea. Near the end of their lives, they return to the freshwater stream where they were born to spawn. In freshwater, water constantly diffuses into the body and ions are lost from the body. In salt water, body water diffuses out of the body and excess ions are gained from the water. A salmon's gills have special cells to pump salt in or out of the body to maintain homeostasis. In response to the salmon's moves between freshwater and salt water, some cells in the gills are produced and others are destroyed. These changes made in the cells of the gills during the lifetime of an individual salmon are an example of which of the following? A) evolution B) trade-off C) acclimatization D) adaptation
C) acclimatization
The body's automatic tendency to maintain a constant and optimal internal environment is termed _____. A) balanced equilibrium B) physiological chance C) homeostasis D) static equilibrium
C) homeostasis
In a cool environment, an ectotherm is more likely to survive an extended period of food deprivation than would an equally sized endotherm because the ectotherm _____. A) maintains a higher basal metabolic rate B) expends more energy per kilogram of body mass than does the endotherm C) invests little energy in temperature regulation D) has greater insulation on its body surface
C) invests little energy in temperature regulation
The metabolic breakdown of specialized brown fat depots in certain animals is substantially increased during _____. A) acclimatization B) torpor C) nonshivering thermogenesis D) shivering thermogenesis
C) nonshivering thermogenesis
To prepare flight muscles for use on a cool morning, hawkmoths _____. A) relax the muscles completely until after they launch themselves into the air B) decrease their standard metabolic rate C) rapidly contract and relax these muscles to generate metabolic warmth D) reduce the metabolic rate of the muscles to rest them before flight
C) rapidly contract and relax these muscles to generate metabolic warmth
The thin horizontal arrows in the figure above show that the _____. A) warmer arterial blood can bypass the legs as needed, when the legs are too cold to function well B) warmer venous blood transfers heat to the cooler arterial blood C) warmer arterial blood transfers heat to the cooler venous blood D) arterial blood is always cooler in the abdomen, compared to the temperature of the venous blood in the feet of the goose
C) warmer arterial blood transfers heat to the cooler venous blood
Which of the following would increase the rate of heat exchange between an animal and its environment? A) feathers or fur B) vasoconstriction C) wind blowing across the body surface D) blubber or fat layer
C) wind blowing across the body surface
How does connective tissue differ from the other three major tissue types?
Connective tissue often consists of relatively few cells embedded in an extracellular matrix.
Which of the following is an example of negative feedback? A) During birthing contractions, oxytocin (a hormone) is released and acts to stimulate further contractions. B) When a baby is nursing, suckling leads to the production of more milk and a subsequent increase in the secretion of prolactin (a hormone that stimulates lactation). C) After a blood vessel is damaged, signals are released by the damaged tissues that activate platelets in the blood. These activated platelets release chemicals that activate more platelets. D) When the level of glucose in the blood increases, the pancreas produces and releases the hormone insulin. Insulin acts to decrease blood glucose. As blood glucose decreases, the rate of production and release of insulin decreases as blood glucose decreases.
D) When the level of glucose in the blood increases, the pancreas produces and releases the hormone insulin. Insulin acts to decrease blood glucose. As blood glucose decreases, the rate of production and release of insulin decreases as blood glucose decreases.
There are advantages and disadvantages to adaptations. Animals that are endothermic are likely to be at the greatest disadvantage in _____. A) very cold environments B) very hot environments C) environments with a constant food source D) environments with variable and limited food sources
D) environments with variable and limited food sources
Sweating allows a person to lose heat through the process of _____. A) conduction B) convection C) radiation D) evaporation
D) evaporation
The panting responses that are observed in overheated birds and mammals dissipate excess heat by _____. A) countercurrent exchange B) acclimation C) vasoconstriction D) evaporation
D) evaporation
Snake behavior in Wisconsin changes throughout the year. For example, a snake is _____. A) less active in winter because the food supply is decreased B) less active in winter because it does not need to avoid predators C) more active in summer because that is the period for mating D) more active in summer because it can gain body heat by conduction
D) more active in summer because it can gain body heat by conduction
A moth preparing for flight on a cold morning may warm its flight muscles via _____. A) acclimatization B) torpor C) evaporative cooling D) shivering thermogenesis
D) shivering thermogenesis
Which component of a homeostatic system sends instructions based on sensory information?
Integrator
What describes loose connective tissue?
It is a loose weave of fibers that functions as a packing material.
positive feedback
a control mechanism that amplifies the stimulus
negative feedback
a control mechanism that reduces the stimulus
vasoconstriction
a decrease in the diameter of superficial vessels that reduces blood flow and heat transfer
hibernation
a long term torpor that is an adaptation to winter cold and food scarcity
bone
a mineralized connective tissue
torpor
a physiological state of decreased activity and metabolism. an adaptation that enables animals to save energy while avoiding difficult and dangerous conditions
cardiac rhythm
a set of physiological changes that occur every 24 hours
adipose tissue
a specialized loose connective tissue that stores fat in adipose cells
muscle tissue
a tissue that is responsible for all types of body movement
vasodilation
a widening of superficial blood vessels
conformer
allows its internal condition to change in accordance with external changes in the variable
poikilotherm
an animal who's body temp varies with its environment
homeotherm
animals that have a constant body temperature
Cartilage is found _____.
at the end of each bone
tendon
attached muscle to bones
skeletal muscle
attached to bones by tendons is responsible for voluntary movements also called striated muscle
anatomy
biological form
physiology
biological function
_____ is the connective tissue specialized for transport.
blood
Cardiac muscle is the only muscle composed of _____ fibers.
branched
fibroblasts
cells within the matrix that secrete fiber proteins
ligament
connects bones at joints
cartilage
contains collagenous fibers embedded in a matrix
hypothalmus
contains the sensors for thermoregulation and also the circadian clock
epithelial tissue
cover the outside of the body and line organs and cavities within the body. closely packed cells
A neuron consists of _____.
dendrites, a cell body, and axons
bioenergetics
determines nutritional needs and is related to the animals size, activity, and environment
cuboidal epithelium
dice shaped cells specialized for secretion
organs
different types of tissue that are organized into functional units
macrophages
engulf foreign particles and nay cell debris by phagocytosis
interstitial fluid
fluid that fills the space between cells
cardiac muscle
forms the contractile wall of the heart
nervous tissue
functions in the receipt, processing, and transmission of information
tissue
groups of cells with similar appearances and a common function
organ system
groups of organs that work together and provide an additional level of organization
blood
has a liquid extracellular matrix called plasma
glia cells
help nourish, insulate, and replenish neurons
connective tissue
holds many tissues and organs together and in place
endothermic
humans and other mammals (birds too) that are warmed mostly by heat generated by their metabolism
reticular fibers
join connective tissue to adjacent tissue
smooth muscle
lacks striation and is found in the walls of the digestive tract, urinary bladder, arteries, and other internal organs.
simple columnar epithelium
large brick shaped cells found where secretion or active absorption is important
elastic fibers
make tissue elastic
stratified squamous epithelium
multilayered and regenerate rapidly, commonly found on surfaces like skin
nervous system
neurons transmit signals along dedicated routes connecting specific locations in the body
ectothermic
nonvertebrates and reptiles that gain most of their heat from external sources
collagenous fibers
provides strength and flexibility
Which component of a homeostatic system perceives changes in some parameter of the environment?
sensor
Which action acts to warm a homeothermic body?
shivering
endocrine system
signaling molecules released into the blood stream by endocrine cells are carried to all locations in the body
hormones
signaling molecules that broadcast throughout the body by the endocrine system
What type of epithelial tissue, found in the intestines, absorbs nutrients?
simple columnar epithelium
What type of epithelial tissue lines kidney tubules?
simple cuboidal cells
What tissue, found in the lungs, permits gas exchange by diffusion?
simple squamous epithelium
pseudo stratified columnar epithelium
single layer of cells varying in height and the position of their nuclei
simple squamous epithelium
single layer of platelike cells that function in the exchange of material by diffusion
_____ muscle is attached to bones.
skeletal
What type of muscle is responsible for contractions of the digestive tract and arteries?
smooth muscle
What type of epithelium would you expect to find covering a surface subject to physical forces?
stratified epithelium
acclimatization
the gradual process by which an animal adjusts to changes in its external environment
standard metabolic rate (SMR)
the metabolic rate of a fasting non stressed ectotherm at rest at particular temperature
basal metabolic rate (BMR)
the minimum metabolic rate of a non growing endotherm that is at rest, has an empty stomach, and is not experiencing stress
integumentary system
the other covering of the body, consisting of the skin, hair, and nails
thermoregulation
the process by which animals maintain their body temperature within a normal range
metabolic rate
the sum of all energy an animal uses in a given time interval
contercurrent exchange
the transfer of heat or solutes between fluids that are flowing in opposite directions
Nervous tissue functions _____.
to sense stimuli
neurons
transmit nerve impulses as wells as support glial cells
regulator
uses internal mechanisms to control internal changes in the face of external fluctuation