Chapter 40 - Basic Principles of Animal Form and Function Flashcards
thermoregulation
The maintenance of internal body temperature within a tolerable range.
endothermic
Referring to organisms that are warmed by heat generated by their own metabolism. This heat usually maintains a relatively stable body temperature higher than that of the external environment.
ectothermic
Referring to organisms for which external sources provide most of the heat for temperature regulation.
integumentary system
The outer covering of a mammal’s body, including skin, hair, and nails, claws, or hooves.
countercurrent exchange
The exchange of a substance or heat between two fluids flowing in opposite directions. For example, blood in a fish gill flows in the opposite direction of water passing over the gill, maximizing diffusion of oxygen into and carbon dioxide out of the blood.
hypothalamus
The ventral part of the vertebrate forebrain; functions in maintaining homeostasis, especially in coordinating the endocrine and nervous systems; secretes hormones of the posterior pituitary and releasing factors that regulate the anterior pituitary.
bioenergetics
(1) The overall flow and transformation of energy in an organism. (2) The study of how energy flows through organisms.
metabolic rate
The total amount of energy an animal uses in a unit of time.
basal metabolic rate (BMR)
The metabolic rate of a resting, fasting, and nonstressed endotherm at a comfortable temperature.
standard metabolic rate (SMR)
Metabolic rate of a resting, fasting, and nonstressed ectotherm at a particular temperature
torpor
A physiological state in which activity is low and metabolism decreases.
hibernation
A long-term physiological state in which metabolism decreases, the heart and respiratory system slow down, and body temperature is maintained at a lower level than normal.
anatomy
The structure of an organism
physiology
The process and functions of an organism.
interstitial fluid
The fluid filling the spaces between cells in most animals.
tissue
An integrated group of cells with a common structure, function, or both.
organ
A specialized center of body function composed of several different types of tissues.
organ system
A group of organs that work together in performing vital body functions.
epithelial tissue
Sheets of tightly packed cells that line organs and body cavities as well as external surfaces.
connective tissue
Animal tissue that functions mainly to bind and support other tissues, having a sparse population of cells scattered through an extracellular matrix.
fibroblast
A type of cell in loose connective tissue that secretes the protein ingredients of the extracellular fibers.
macrophage
A phagocytic cell present in many tissues that functions in innate immunity by destroying microbes and in acquired immunity as an antigen-presenting cell.
tendon
A fibrous connective tissue that attaches muscle to bone.
ligament
A fibrous connective tissue that joins bones together at joints.
bone
A connective tissue consisting of living cells held in a rigid matrix of collagen fibers embedded in calcium salts.
adipose tissue
A connective tissue that insulates the body and serves as a fuel reserve; contains fat-storing cells called adipose cells.
cartilage
A flexible connective tissue with an abundance of collagenous fibers embedded in chondroitin sulfate.
blood
A connective tissue with a fluid matrix called plasma in which red blood cells, white blood cells, and cell fragments called platelets are suspended.
epithelium
An epithelial tissue.
muscle tissue
Tissue consisting of long muscle cells that can contract, either on its own or when stimulated by nerve impulses.
skeletal muscle
A type of striated muscle that is generally responsible for the voluntary movement of the body.
smooth muscle
A type of muscle lacking the striations of skeletal and cardiac muscle because of the uniform distribution of myosin filaments in the cells; responsible for involuntary body activities.
cardiac muscle
A type of striated muscle that forms the contractile wall of the heart. Its cells are joined by intercalated disks that relay the electrical signals underlying each heartbeat.
nervous tissue
Tissue made up of neurons and supportive cells.
neuron
A nerve cell; the fundamental unit of the nervous system, having structure and properties that allow it to conduct signals by taking advantage of the electrical charge across its plasma membrane.
glia (glial cells)
Cells of the nervous system that support, regulate, and augment the functions of neurons.
hormone
In multicellular organisms, one of many types of secreted chemicals that are formed in specialized cells, travel in body fluids, and act on specific target cells in other parts of the body, changing target cells’ functioning. Hormones are thus important in long-distance signaling.
regulator
An animal for which mechanisms of homeostasis moderate internal changes in a particular variable in the face of external fluctuation of that variable.
conformer
An animal for which an internal condition conforms to (changes in accordance with) changes in an environmental variable.
homeostasis
The steady-state physiological condition of the body.
set point
In homeostasis in animals, a value maintained for a particular variable, such as body temperature or solute concentration.
stimulus
In feedback regulation, a fluctuation in a variable that triggers a response.
sensor
In homeostasis, a receptor that detects a stimulus.
response
(1) In cellular communication, the change in a specific cellular activity brought about by a transduced signal from outside the cell. (2) In feedback regulation, a physiological activity triggered by a change in a variable.
negative feedback
A form of regulation in which accumulation of an end product of a process slows the process; in physiology, a primary mechanism of homeostasis, whereby a change in a variable triggers a response that counteracts the initial change.
positive feedback
A form of regulation in which an end product of a process speeds up that process; in physiology, a control mechanism in which a change in a variable triggers a response that reinforces or amplifies the change.
circadian rhythm
A physiological cycle of about 24 hours that persists even in the absence of external cues.
acclimatization
Physiological adjustment to a change in an environmental factor.
