Animal Structure and Function Flashcards
Why do structures evolve the way they do?
Adaptation through natural selection allows organisms to evolve certain structures as a result of functional outcomes.
Difference between anatomy and physiology?
Anatomy: features evolved to allow for survival
Physiology: biological processes taking place through the anatomy
What does a large membrane surface area allow for? Give 3 examples of this.
Greater rate of exchange of nutrients, waste products, gases. (e.g. Villi in small intestine allow for maximal absorption of nutrients, porous lung tissue allows for maximal absorption of oxygen, Kidney tubules allows for maximal reabsorption of nutrients.
What does evolutionary convergence reflect?
Adaptations to a similar environmental challenge coupled with the constraints of physical laws resulting in similar structures (size and shape).
How does exchange of metabolites occur?
Substances dissolved in aqueous medium diffuse and are transported across the plasma membrane of cells.
What is an element of multicellular organization that is required for it to function?
Equal access to suitable aqueous environment to allow for equal distribution of nutrients.
What is interstitial fluid?
fluid outside of the body’s cells and outside of the blood vessels that allows for movement of material into and out of cells.
What is a pro and on of complexity in a multicellular organism?
Pro: allows for maintenance of relatively stable internal environment in a variable external environment
Con: Energy expensive and relies on coordination.
What is the hierarchal organization of cells and what does each do?
- Cells: smallest unit of life.
- Tissues: group of specialized cells with specific functions
- Organs: part of an organism made of multiple tissues functioning as one unit.
- Organ system: a collection of organs that perform a vital function
What are the four main categories of tissues and their functions?
- epithelial tissue: closely joined cells that cover the outside of the body and line the organs/cavities within the body
- connective tissue: sparsely packed cells throughout an extracellular matrix that binds and supports other tissues.
- muscle tissue: long fibrous cells that contract in response to nerve signals.
- nervous tissue: senses stimuli and signals throughout the animal.
What are the 7 types of epithelial tissue?
Simple cuboidal, simple squamous, simple columnar, stratified cuboidal, stratified squamous, stratified cuboidal, pseudo-stratified columnar, transitional.
What is located in the connective tissue’s extracellular matrix? What state is the substance of the matrix?
fibroblasts: secrete fibre proteins
macrophages: engulf foreign particles and cell debris
Matrix consists of liquid, jellylike or solid fibers.
What are 6 types of connective tissue and their functions?
- Loose connective tissue: collagenous and elastic fibres for strength and flexibility
- Fibrous connective tissue: attach muscles to bones and connect bones to joints
- Bone tissue: mineralized connective tissue (osteo- cells) that forms the skeleton
- Cartilage: a strong and flexible support material made of chondrocytes
- Adipose tissue: stores fat for insulation and fuel
- Blood: composed of erythrocytes, leukocytes, and cell fragments in blood plasma.
What are the two types of muscle fibres?
Skeletal muscle: aka striated muscle, attached to bones and responsible for voluntary movement
Smooth muscle: many lines internal organs and is responsible for involuntary body activities
What is the nervous tissue composed of?
Neurons: nerve cells that transmit nerve impulses
Glial cells/glia: help nourish, insulate and replenish neurons
Control and coordination within a body depend on which systems? What’s the difference?
endocrine system: transmits hormones to receptive cells throughout the body via blood.
nervous system: transmits information between specific locations
What is a hormone?
Regulatory substances made by one tissue to stimulate action in another tissue. Can be either fast or slow acting, but can have long-lasting effects.
What does nervous signalling and endocrine signalling depend on?
Nervous signalling: pathway of signal
Endocrine signalling: type of signal
What are two ways animals manage their internal environment and how do they differ?
Regulator: uses energy to fuel internal control mechanisms to moderate internal change in the face of external environmental fluctuation
Conformer: allows internal condition to vary with external environment.
Homeostasis
a self-regulating process by which a living organism can maintain internal stability while adjusting to changing external conditions
How does a negative feedback loop work?
- variable fluctuates above/below a set point and serves as stimulus
- Stimulus is detected by a sensor and triggers a response
- Response returns the variable to set point. (e.g. thermoregulation)
How does a positive feedback loop work?
- variable fluctuates above/below a set point and serves as stimulus
- stimulus is detected by a sensor and triggers a response
- response intensifies a response until an endpoint is reached (e.g. childbirth/blood clotting)
What is the difference between acclimation and acclimatization?
Acclimation: adjusting to a single environmental factor
Aclimatization: adjusting to complex changes in external environment
What is thermoregulation?
Process by which animals maintain and internal temperature within a tolerable range.
What is the difference between an endothermic and an ectothermic individual?
Endothermic: generate heat via metabolism (e.g. birds, mammals)
Ectothermic: gain heat from external sources (e.g. reptiles, amphibians, fish, invertebrates)
what’s the difference between a poikilotherm, a homeotherm, and a heterotherm?
Poikilotherm: body temp varies with environment
Homeotherm: body temp is relatively constant
Heterotherm: maintains different temperatures in specific regions of the body
What are the 4 physical process by which organisms exchange heat?
conduction, convection, radiation and evaporation.
What is the integumentary system?
Mammalian method of regulating heat: includes skin, hair and nails
What are the five general adaptations that help animals thermoregulate?
- Insulation
- Circulatory adaptations
- Cooling by evaporative heat loss
- behavioural responses
- adjusting metabolic heat production
How does insulation regulate heat?
Insulation, present in mammals and birds, use skin, feathers, fur and blubber to reduce heat flow between an animal and its environment.
How do circulatory adaptations regulate heat?
Vasoconstriction/dilation: increase/reduce blood flow in the skin increases/reduces heat exchange with the environment
Countercurrent heat exchange: arrangement of blood vessels in marine mammals and birds allows heat transfer between fluids flowing in opposite directions
How does cooling by evaporative heat loss regulate heat?
Sweating or bathing moistens the skin, cooling an animal down as the heat from the skin surface is absorbed by the water to evaporate.
How do behavioural responses regulate heat?
Some terrestrial invertebrates have postures that minimize or maximize absorption of solar heat.
How does adjusting metabolic heat production regulate heat?
Muscle activity produces heat and adipose tissue have thermogenin proteins that causes the mitochondria to produce heat.
What’s osmoregulation?
regulation of solute concentration in body fluids through the osmotic gain and loss of water. It is based largely on controlled movement of solutes between internal fluids and the external environment.
What is osmolarity? What are the three levels of osmolarity?
Osmolarity is the solute concentration of a solution (osmoles of solute per litre of soution). Can be isosmotic, hyposmotic, and hypersmotic.
What is the difference between osmoconformers and osmoregulators? Marine examples.
Osmoconformers: isosmotic with their surroundings and do not regulate osmolarity (e.g. marine invertebrates)
Osmoregulators: use energy to control water uptake in a hyposmotic environment and water loss in a hyperosmotic environment (marine vertebrates and invertebrates)
What is the difference between a stenohaline animal and a euryhaline animal?
Stenohaline: cannot tolerate substantial changes in external osmolarity
Euryhaline: survive large fluctuations in external osmolarity
What is the relationship between osmotic strategy (regulator/conformer) and osmotic tolerance (stenohaline/euryhaline)
There is no relationship or correlation between osmotic strategy and osmotic tolerance.
How do saltwater osteichthyes and freshwater osteichthyes regulate their osmolarity in seawater?
Saltwater: By drinking seawater and excreting salt ions in scanty urine, they maintain their hyposmolarity to saltwater.
Freshwater: By taking in salts through the gills and excreting large amounts of water in dilute urine, they maintain their hyperosmolarity to freshwater.
What is smoltification?
Complex series of physiological changes where young salmonid fish adapt from living in fresh water to living in seawater
What is transport epithelia?
Specialized cells that regulate solute movement and are essential components of osmotic regulation and metabolic waste disposal. They are arranged in complex tubular networks.
