Animal Form and Function Flashcards
Evolutionary convergence
Different species independently adapt to a similar environmental challenge
Exchange with the environment
Occurs as substances dissolved in an aqueous medium
Substances diffuse and are transported across the cells’ plasma membranes
Organisms with more complex body plans
Highly folded internal surfaces specialized for exchanging materials
Specialized cells and tissues
Digestive system
Mouth, pharynx, esophagus, stomach, intestines, liver, pancreas, anus
Food processing
Circulatory system
Heart, blood vessels, blood
Internal distribution of materials
Respiratory system
Lungs, trachea, other breathing tubes
Gas exchange
Immune and lymphatic systems
Bone marrow, lymph nodes, thymus, spleen, lymph vessels, white blood cells
Body defense against infection
Excretory system
Kidneys, ureters, urinary bladder, urethra
Disposal of metabolic wastes, regulation of osmotic balance of blood
Endocrine system
Pituitary, thyroid, pancreas, adrenal and other hormone secreting glands
Coordinations of body activities
Reproductive system
Ovaries or testes and associated organs
Reproduction
Nervous system
Brain, spinal cord, nerves, sensory organs
Coordinations of body activities, detection of stimuli and formulation of responses to them
Integumentary system
Skin and its derivatives (hair, claws, skin glands, etc.)
Protection against injury, infection, or dehydration; thermoregulation
Skeletal system
Skeleton (bones, tendons, ligaments, cartilage)
Body support, protection of internal organs, movement
Muscular system
Skeletal muscles
Locomotion and other movement
4 tissue types
Epithelial
Connective
Muscle
Nervous
Epithelial tissue
Covers outside of body and lines organs and cavities within the body
Contains cells that are closely joined in sheets
Columnar: column-like cells
Cuboidal: square-shaped cells
Squamous: “squashed” cells
Connective tissue
Binds and supports other tissues
Sparsely packed cells scattered throughout an extracellular matrix of fibers
Collagenous fibers and elastic fibers (thinner)
Examples of connective tissue
Loose connective tissue (holds organs in place)
Fibrous connective tissue (found in tendons and ligaments)
Adipose (fat)
Cartilage
Bone
Blood
Fibroblasts
Connective tissue matrix: secrete fiber proteins
Macrophages
Connective tissue matrix: engulf foreign particles and debris by endocytosis
Muscle tissue
Composed of long cells (muscle fibers) capable of contracting in response to nerve signals
3 types of muscle tissue
Skeletal (striated-horizontal stripes, voluntary control)
Cardiac (striated, involuntary)
Smooth (non-striated, involuntary)
Nervous tissue
Senses stimuli and transmits signals throughout the animal
Made up of neurons and glial cells
Parts of neuron
Cell body (soma)
Axon: transmits signal from one cell to another
Dendrites: receives signal
Glial cells
Support and nourishment of long lines of axons
Homeostasis
Balance between external changes and the animal’s internal control mechanisms that oppose the changes
Regulator
Uses internal control mechanisms to moderate internal change in the face of external, environmental fluctuation
Fluctuations above or below a set point serve as a stimulus that is detected by a sensor and triggers a response
Response returns the variable to the set point
Conformer
Allows internal condition to vary with certain external changes
Negative feedback
Returns variable to normal range
Most homeostatic control systems function by using this
Buildup of end product shuts system off
Positive feedback
Amplifies a stimulus
Example: baby’s head pushing against uterus increases contractions until baby is born
Doesn’t usually contribute to homeostasis
Thermoregulation
Process by which animals maintain an internal temperature within a tolerable range
Insulation (feathers, fur, fat)
Circulatory adaptations (vasodilation, vasoconstriction, etc.)
Evaporative heat loss (sweating, panting)
Behavioral (basking, hibernation, shivering)
Endothermic
Generate heat by metabolism
Mammals and birds
Can bask in sun- lowers energy output
Ectothermic
Gain heat from external surfaces
Reptiles, bugs, fish, amphibians, etc.
4 ways to exchange heat
Radiation
Evaporation
Convection
Conduction
Radiation
Transfer of heat between objects that aren’t in direct contact
Evaporation
Removal of heat from the surface of a liquid that is losing its molecules as gas
Convection
Transfer of heat by movement of air or liquid past a surface
Conduction
Direct transfer of heat between of molecules of objects in direct contact with each other
Vasodilation
Blood vessels enlarge, releasing heat
Vasoconstriction
Blood vessels constrict, keeping heat in body
Countercurrent heat exchange
Warm blood in arteries transfers heat to cold blood in veins
Takes place in extremities
Hypothalamus
Specific part of human brain that controls thermoregulation
Nerve cells function as a thermostat
Bioenergetics
Flow of energy through an animal
Basal metabolic rate
Metabolic rate of an endotherm at rest
Standard metabolic rate
Metabolic rate of an ectotherm at rest
Measured at standard temperature- different for each animal
Metabolic rate
Inversely proportional to body size among similar animals
Small animals have higher: hearts beat faster and they breathe more times per minute
