chapter 40: basic principles of animal form and function Flashcards
What is physiology?
study of biological functions an organism performs
What are the characteristics of direct exchange between cells and their environment?
rate of change is proportional to a cells surface area
amount of exchange material is proportional to cells volume.
What is interstitial fluid and where is it found?
found in vertebrates, its the space between cells that allows the movement in and out of cells.
What are the four categories that tissues are classified into?
- epithelial
- connective
- muscle
- nervous
What is the purpose of epithelial tissue and what is its shape?
- covers the outside of the body and lines organs and cavities within body.
- it can be shaped cuboidal, columnar or squamous
What is the purpose of connective tissues?
binds and supports other tissues, it has packed cells scattered throughout matrix.
What are the three types of connective tissue fibers?
- collagenous fibers: strength and flexibility
- elastic fibers: stretch and snap back to original length
- resticular fibers: join connective tissues to adjacent tissues
What are two main cells seen in connective tissues?
- fibroblasts: secretes protein of extracelullar fibers
- macrophages: involved in the immune system
What are the six major types of connective tissues?
- loose connective tissue
- fibrous connective tissue
- bone
- adipose tissue
- cartilage
- blood
What is muscle cells consists of what?
consists of filaments of the proteins actin and myosin which together enable muscle to contract in response to nerve signals
What are the three types of muscle tissues?
- skeletal muscle
- smooth muscle
- cardiac muscle /
What do nervous tissue contain?
- neurons, nerve cells that transmit nerve impulses
- glial cells or glia that help nourish, insulate and replenish neurons
What does control and contribution within a body depend on?
endocrine system and nervous system
What is the endocrine responsible for?
- transmits chemical signals called hormones to receptive cells throughout body via blood.
- a hormone can affect one or more regions throughout the body
- hormones relatively slow acting however can have long-lasting effects
What is the nervous system responsible for?
- it transmits information between specific locations
- information conveyed depends on a signal pathway not the type of signal
- nerve signal transmission is very fast
What are regulators?
use internal control mechanisms to moderate internal change in the face of external, environmental fluctuation
What are conformers?
allow their internal condition to vary with certin external changes
What is the mechanism of homeostasis?
for a given variable, fluctuations above or below a set point serve as a stimulus, these are detected by a sensor and trigger a response.
What is negative feedback?
returns a variable to a normal range
What is positive feedback?
amplifies a stimulus and does not usually contribute to homeostasis in animals
What is acclimation?
adjustment to a single environmental factor
What is acclimatization?
adjustment to multiple factors.
What is thermoregulation?
the process by which animals maintain an internal temperature within a tolerable range
What are the characteristics of endothermic animals?
- they generate heat by metabolism (birds and mammals)
- they can maintain a stable body temperature even in the face of large fluctuations in environmental temperature
What are the characteristics of ectothermic animals?
- they gain heat from external sources (invertebrates, fish, amphibians)
- it is more energetically expensive than ectothermy.
What are the four physical processes used by organisms to exchange heat?
- radiation
- evaporation
- convection
- conduction
What does heat regulation in mammals involve?
the integumentary system (skin, hair, nails)
What are five adaptations that help animals thermoregulate?
- insulation
- circulatory adaptations
- cooling by evaporative heat loss
- behavioural responses
- adjusting metabolic heat production
What is circulatory adaptations?
- regulation of blood flow near the body surface significantly affects thermoregulation
- can alter amount of blood flowing between the body core and skin
- countercurrent exchange: transfer heat between fluids in opposite directions and thereby produces heat loss.
What is the mechanism of cooling by evaporative heat loss?
- sweating and bathing helps moisten the skin, helping to cool animals down, panting increases cooling effect
What is the mechanism for behavioural responses?
- some terrestrial invertebrates have postures that minimize or maximize absorption of solar heat
What is the mechanism for adjusting metabolic heat production?
- thermogenesis
- production of brown fat (BAT) and thermogenin
What is thermogenesis?
- the adjustment of metabolic heat production to maintain body temperature
- it is increased by muscle activity sich as moving and shivering
What does hypothalamus do?
region in the brain that controls thermoregulation
What is bioenergetics?
- overall flow and transformation of energy in an animal
- determines how much food an animal needs, relates to an animals size, activity and environment
What are autotrophs?
harness light to build energy-rich molecules
What are heterotrophs?
harvest chemical energy from food
What is the mechanism of energy allocation?
- energy containing molecules from food are usually used to make ATP, which powers cellular work
- remaining food molecules can be used in biosynthesis
What does biosynthesis include?
body growth, repair, synthesis of storage material like fat, production of gametes
What is the metabolic rate and how can it be determined?
- it is the amount of energy an animal used in a unit of time
- it is determined by an animal heat loss, amount of oxygen consumed or carbon dioxide produced nd measuring energy content of food consumed and energy lost in waste products
What is basal metabolic rate?
it is the metabolic rate of an endotherm at rest at a comfortable temperature
What is standard metabolic rate?
it is the metabolic rate of an ectotherm at rest at a specific temperature
What is torpor?
- a physiological state in which activity is low and metabolism decrease
- it enables to save energy while avoiding difficult and dangerous conditions
What is hibernation?
is long-term torpor that is an adaption to winter cold and food scarcity
