Topic 1: General Principles of Physiology Flashcards
What is anatomy?
the biological form of an organism
What is physiology?
the biological functions an organism performs
What is proportional to a cell’s surface area?
rate of exchange
How do small molecules move between cells and their surroundings?
diffusion
Why is diffusion only efficient over small distances?
the time it takes to diffuse is proportional to the square of the distance (t = x(squared) / 2D), where t is time (s), x is distance (cm), D is the diffusion coefficient
What is the diffusion of glucose?
D = 5 x 10(power to the -8) cm(square)/sec
If x is 10 microemters (0.001 cm), t is 100 msec.
If x is 1 cm, t is 27 hours
Single-celled organisms are not _
“diffusionally challenged”
How do single-celled organisms exchange?
a single-celled organism living in water has sufficient surface area to carry out all necessary exchange
How do multicellular organisms exchange?
multicellular organisms with a saclike body plan have body walls that are only two cells thick, facilitating diffusion of materials
What is cell contact in flat animals?
such as tapeworms, direct contact with their environment
What enables sufficient exchange with the environment?
evolutionary adaptations such as specialized, extensively branched or folded structures
What are more complex organisms composed of?
compact masses of cells with complex internal organization
What is the organization of body plans?
most animals are composed of cells organized into tissues that have different functions; tissues make up organs, which together make up organ systems
What are the main components of the digestive system?
mouth, pharynx, esophagus, stomach, intestines, liver, pancreas, and anus
What are the main components of the circulatory system?
heart, blood vessels, and blood
What are the main components of the respiratory system?
lungs, trachea, other breathing tubes
What are the main components of the immune and lymphatic system?
bone marrow, lymph nodes, thymus, spleen, and lymph vessels
What are the main components of the excretory system?
kidneys, ureters, urinary bladder, and urethra
What are the main components of the endocrine system?
pituitary, thyroid, pancreas, adrenal, and other hormone-secreting glands
What are the main components of the reproductive system?
ovaries or testes and associated organs
What are the main components of the nervous system?
brain, spinal cord, nerves, and sensory organs
What are the main components of the integumentary system?
skin and its derivatives (such as hair, claws, sweat glands)
What are the main components of the skeletal system?
skeleton (bones, tendons, ligaments, caritlage)
What are the main components of the muscular system?
skeletal muscles
What is the main function of the digestive system?
food processing (ingestion, digestion, absorption, elimination)
What is the main function of the circulatory system?
internal distribution of materials
What is the main function of the respiratory system?
gas exchange (uptake of oxygen; disposal of carbon dioxide)
What is the main function of the immune and lymphatic system?
body defense (fighting infections and virally induced cancers)
What is the main function of the excretory system?
disposal of metabolic wastes; regulation of osmotic balance of blood
What is the main function of the endocrine system?
coordination of body activities (such as digestion and metabolism)
What is the main function of the reproductive system?
gamete production; promotion of fertilization; support of developing embryo
What is the main function of the nervous system?
coordination of body activities; detection of stimuli and formulation of responses to them
What is the main function of the integumentary system?
protection against mechanical injury, infection, dehydration; thermoregulation
What is the main function of the skeletal system?
body support, protection of internal organs, movement
What is the main function of the muscular system?
locomotion and other movement
What are the four main types of animal tissues?
- epithelial
- connective
- muscle
- nervous
What are the eight basic types of epithelial tissue?
- single columnar (digestive organs)
- simple cuboidal (kidneys)
- simple squamous (lungs)
- stratified squamous (skin)
- stratified columnar (mammary ducts, epididymus)
- stratified cuboidal (salivary gland duct)
- pseudostratified columnar (trachea)
- transitional (bladder)
What is the function of the single columnar tissue?
single layer of columnar cells: absorption
What is the function of simple cuboidal tissue?
single layer of plump cell diffusion
What is the function of simple squamous tissue?
single layer of cells (look like fried eggs): rapid exchange
What is the function of stratified squamous tissue?
multiple layers of flattened cells: protection
What is the function of stratified columnar tissue?
multiple layers of plump cells: secretion
What is the function of stratified cuboidal tissue?
multiple layers of plump cells: secretion
What is the function of pseudostratified columnar tissue?
appearance of multiple layers (but really only one): ciliated, mucous producing (protection)
What is the function of transitional tissue?
changes from one layer (bladder full and stretched) to multiple layers (bladder empty)
What are the five types of connective tissue?
- loose connective tissue
- fibrous connective tissue
- bone
- adipose tissue
- cartilage
What is the function of connective tissue?
mainly binds and supports other tissues
What is the function of fibrous connective tissue?
dense, tough tendons, ligaments
What is the function of bone?
mineralized matrix of calcium, magnesium, and phosphate
What is the function of adipose tissue?
padding, insulation, energy source
What is the function of cartilage?
rubbery flexible, sometimes converted to bone at maturity
What are the three types of muscle tissue?
- skeletal muscle
- smooth muscle
- cardiac muscle
What are the two types of nervous tissue?
- neurons
- glia
What is the function of epithelial tissue?
covers the outside of the body and lines the organs and cavities within the body
What is the function of muscle tissue?
responsible for nearly all types of body movement
What is the function of nervous tissue?
the receipt, processing, and transmission of information
What system does control and coordination within a body depend on?
the endocrine and the nervous system
What does the endocrine system release?
hormones
What are hormones?
- signaling molecules
- may affect one or more regions throughout the body
- low acting, but can have long-lasting effects
What does the nervous system transmit?
- information between specific locations
- the information conveyed depends on a signal’s pathway, not the type of signal
- very fast
What two systems often work in close coordination?
the endocrine and nervous system
What maintains the internal environment in many animals?
feedback control
What is a regulator?
uses internal control mechanisms to control internal change in the face of external fluctuation
What is a conformer?
allows its internal condition to vary with certain external changes
What is the body temperature of a poikilotherm?
varies with its environment
What is the body temperature of a homeotherm?
relatively constant
What is homeostasis?
maintains a “steady state” or internal balance regardless of external environment (body temperature, blood pH, and glucose concentration)
Fluctuations above or below a _ serve as a _; these are detected by a _. A sensory generates output that triggers a _. The response returns the variable to the set point
set point; stimulus; sensor; response
What is a negative feedback?
helps to return a variable to a normal range
What is a positive feedback?
amplifies a stimulus and does not usually contribute to homeostasis in animals
What are the four physical processes to exchange heat?
- radiation
- evaporation
- convection
- conduction
What is radiation?
emission of electromagnetic waves (sun)
What is evaporation?
loss of heat by losing molecules as gas
What is convection?
transfer of heat by air movement past a surface
What is conduction?
direct heat transfer between objects
What is insulation?
a major thermoregulatory adaptation in mammals and birds
What are examples of insulators?
skin, feathers, fur, and blubber reduce heat flow between an animal and its environment
What affects thermoregulation?
regulation of blood flow near the body surface
What is an example of a circulatory adaptation?
many endotherms and some ectotherms can alter the amount of blood flowing between the body core and the skin
What happens in vasodilation?
blood flow in the skin increases, facilitating heat loss
What happens in vasoconstriction?
blood flow in the skin decreases, lowering heat loss
What does the arrangement of blood vessels in marine mammals and birds allow for?
countercurrent exchange
What is countercurrent exchange?
transfers heat between fluids flowing in opposite directions and thereby reduce heat loss
What are autotrophs?
harness light energy to build energy-rich molecules
What are heterotrophs?
harvest chemical energy from food
Where do food molecules go?
- used to make ATP which powers cellular work
- remaining can be used in biosynthesis
What is biosynthesis
includes growth and repair, synthesis of storage material, and production of gametes
