Exam II Flashcards
Class Sarcopterygii
Lobe-finned fishes; Old lineage, fins shifting to legs, gills to lungs
What are derived characters of tetrapods?
Four limbs and feet with digits, ears for detecting airborne sounds
Amphibians are represented by about _____ species of organisms in 3 orders.
6,150
“Amphibian” translates to _____.
Both ways of life
Fertilization occurs externally in _____.
Amphibians
What are the 3 amphibian orders?
orders Caudata, Anura, and Apoda
Order Caudata
with tails; salamanders
Order Anura
Lacking tails; frogs and toads
Order Apoda
Legless, resembling words; Caecilians
What are the causes of the decline in amphibian populations?
Chrytid fungus, habitat loss, climate change, trematodes (cause deformities), pollution and chemicals
A derived character of tetrapods is
four limbs
Amniotes
A group of tetrapods whose living members are the reptiles, including birds, and mammals
Derived characters of amniotes?
Amniotic egg, relatively impermeable skin, ability to use the rib cage to ventilate the lungs
What are the extra-embryonic membranes in an amniotic egg?
Amnion, chorion, yolk sac, and allantois
The reptile clade includes:
Tuataras, lizards, snakes, turtles, crocodilians, birds, and the extinct dinosaurs
Derived characters of reptiles?
Reptiles have scales that create a waterproof barrier, they lay shelled eggs on land
Ectothermic
Cold blooded. When an animal’s body temperature changes with the temperature of its surroundings
Endothermic
Warm blooded. Keeps a constant body temp. Temperature is regulated internally
Most reptiles are ___
Ectothermic
Birds are ___
Endothermic
Squamata
Lizards and snakes
Rhynchocephalia
Tautaras
Archosaur
A member of the reptilian group that includes crocodiles, alligators, and dinosaurs, including birds
Pterosaurs
Winged reptiles that lived during the time of dinosaurs
All turtles have a boxlike shell made of upper and lower shields that are fused to the _____, _____, and _____.
Vertebrae, clavicles, ribs
Crocodilians belong to the _____ lineage and dates back to the late _____.
Archosaur, Triassic
What are derived characters of birds?
Wings with Keratin feathers, lack of urinary bladder, four chambered heart, endothermy, females with only one ovary, small gonads, loss of teeth
A marsupial embryo develops within a _____ in the mother’s uterus.
Placenta
Mammals are represented by more than _____ species.
5,300
Eutherians
Placental mammal; mammal whose young complete their embryonic development within the uterus, joined to the mother by the placenta.
What are derived characters of mammals?
Mammary glands, which produce milk, hair, a larger brain than other vertebrates of equivalent size, differentiated teeth
What were the three lineages of mammals that emerged by the Cretaceous?
Monotremes, marsupials, eutherians
Monotremes
Egg laying mammals
Placenta
A structure that allows an embryo to be nourished with the mother’s blood supply
Primates
An animal order including lemurs and tarsiers and monkeys and apes and human beings
What are derived characteristics of primates?
Grasping hand with 1st opposable digit Flat fingernails instead of claws Reduced sense of smell Stereoscopic, color vision Small litters Reduction to two mammary glands Relatively long gestation Relatively large brain size Teeth evolved for omnivorous diet
Paleoanthropology
The study of the history of human evolution through the fossil record
Hominids
Humans and other creatures that walk upright
Hominids originated in Africa about _____ million years ago.
6 1/2
Derived characteristics of humans?
Upright posture and bipedal locomotion, larger brains capable of language, symbolic thought, artistic expression, the manufacture and use of complex tools, reduced jawbones and jaw muscles, shorter digestive tract
Anatomy
The study of body structure
Gross Anatomy
Large structures, easily observable
Physiology
Study of function
Amphibians
Vertebrates that live in water and on land, smooth skin covers body, lay eggs, cold blooded
Interstitial fluid
Fluid between cells
Tissues make up _____.
organs
How many body cavities do Vertebrates have?
2
Dorsal body cavity
Contains the cranial cavity and spinal column
Ventral body cavity
Thoracic and abdominopelvic cavities
Thoracic cavity
Cavity housing lungs and heart
Abdominopelvic cavity
Contains both the abdominal and pelvic cavities
Pericardial cavity
Contains the heart
Pleural Cavity
Contains the lungs
Peritoneal cavity
Space between the parietal and visceral peritoneum
What are the four main categories of tissues?
Epithelial, connective, muscle, nervous
Epithelial tissue
A body tissue that covers the surfaces of the body, inside and out
Cube shaped
Cuboidal
Columnar
Column shaped
Squamous
Flat, like floor tiles
The shape of epithelial cells can be one of three:
Cuboidal, squamous, columnar
Pseudostratified
This type of epithelial tissue appears to have multiple layers but all cells are in contact with the basement membrane; single layer of uneven thickness
The arrangement of epithelial cells may be _____, ______, or _____.
Simple (single cell layer), stratified (multiple tiers of cells), or pseudostratified (single uneven layer of thickness)
Connective tissue
A body tissue that provides support for the body and connects all of its parts
Special connective tissue
Cartilage, bone, blood
Fibroblasts
In connective tissue, cells that secrete the proteins of the fibers.
Loose connective tissue
Surrounds various organs and supports both nerve cells and blood vessels, binds epithelia to underlying tissues and holds organs in place
Collagen
Structural protein found in the skin and connective tissue
Elastin
Protein base similar to collagen that forms elastic tissue
Reticulin
Helps support the network of collagen
Macrophages
Found within the lymph nodes, they are phagocytes that destroy bacteria, cancer cells, and other foreign matter in the lymphatic stream.
Cartilage
A connective tissue that is more flexible than bone and that protects the ends of bones and keeps them from rubbing together.
Fibrous connective tissue
Dense tissue, large number of collagen fibers organized into parallel bundles. Includes ligaments and tendons.
Tendons
Connect muscle to bone
Ligaments
Connect bone to bone at joints
Adipose tissue
Tissue that stores fat.
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.
Bone
A connective tissue with a fluid matrix called plasma in which red blood cells, white blood cells, and cell fragments called platelets are suspended.
Blood
Collagen and the mineral hydroxyapatite, forms skeleton
Muscle tissue
A body tissue that contracts or shortens, making body parts move.
Skeletal muscle
A muscle that is attached to the bones of the skeleton and provides the force that moves the bones, also known as striated muscle
Smooth muscle
Involuntary muscle found inside many internal organs of the body
Cardiac muscle
Muscle of the heart
Matrix
Abundant extracellular material
Nervous tissue
A body tissue that carries electrical messages back and forth between the brain and every other part of the body.
Neurons
A body tissue that carries electrical messages back and forth between the brain and every other part of the body.
Nervous tissue
A nerve cell; the basic building block of the nervous system
Cell body
Contains nucleus
Dendrites
Branchlike parts of a neuron that are specialized to receive information.
Axon
The extension of a neuron, ending in branching terminal fibers, through which messages pass to other neurons or to muscles or glands
Neuroglial cells
Provide physical support, insulation, and nutrients for neurons
Central nervous system
Brain and spinal cord; integration and interpretation of input
Peripheral nervous system
Nerves and ganglia; Communication of signal to and from the CNS to the rest of the body
Endocrine system
The body’s “slow” chemical communication system; a set of glands that secrete hormones into the bloodstream
Hormones
Chemical signals
Regulator
An animal that uses internal control mechanisms to moderate internal change in the face of external fluctuation.
Conformer
An animal that allows its internal condition to vary with certain external changes.
Homeostasis
A tendency to maintain a balanced or constant internal state; the regulation of any aspect of body chemistry, such as blood glucose, around a particular level
Set point
The point at which an individual’s “weight thermostat” is supposedly set. When the body falls below this weight, an increase in hunger and a lowered metabolic rate may act to restore the lost weight.
Negative feedback
A primary mechanism of homeostasis, whereby a change in a physiological variable that is being monitored triggers a response that counteracts the initial fluctuation.
Positive feedback
A type of regulation that responds to a change in conditions by initiating responses that will amplify the change. Takes organism away from a steady state.
Most homeostatic control systems function by _____ _____.
Negative feedback
_____ _____ does not generally contribute to homeostasis.
Positive feedback
Antagonistic Effectors
Homeostasis is often maintained by opposing effectors that move conditions in opposite directions
Hypothalamus
A neural structure lying below the thalamus; it directs several maintenance activities (eating, drinking, body temperature), helps govern the endocrine system via the pituitary gland, and is linked to emotion and reward.
Thalamus
The brain’s sensory switchboard, located on top of the brainstem; it directs messages to the sensory receiving areas in the cortex and transmits replies to the cerebellum and medulla
If the hypothalamus detects high temperature, it _____.
Promotes heat dissipation via sweating and dilation of blood vessels in skin
If the hypothalamus detects low temperature, it _____.
Promotes heat conservation via shivering and constriction of blood vessels in skin
Examples of positive feedback?
Blood clotting, contractions during childbirth
Thermoregulation
Process of maintaining an internal temperature within a tolerable range.
Ectotherms can tolerate greater ranges of _____ temperature.
Internal
Endotherms can tolerate greater ranges of _____ temperature.
External
What are the four physical processes of heat exchange
Conduction, convection, radiation, evaporation
Conduction
The direct transfer of heat from one substance to another substance that it is touching.
Convection
The transfer of heat by the movement of a fluid, consistent flow of heat over top of organism
heat Radiation
Direct transfer of heat from a radiation energy source of higher temperature to one of cooler temperature. directly absorbed without the need for a medium.
Evaporation
Loss of heat
What are the five ways organisms thermoregulate?
Insulation, circulatory adaptions, cooling by evaporative heat loss, behavioral responses, adjusting metabolic heat production
Insulation
A major thermoregulatory adaptation in mammals and birds; skin, feathers, fur, and blubber reduce heat flow between an animal and its environment
Circulatory Adaptations
Altering the amount of blood flowing between the body core and the skin
Vasodilation
Blood flow in the skin increases, facilitating heat loss
Vasoconstriction
Blood flow in the skin decreases, lowering heat loss
Alcohol is a _____.
Vasodilator
The arrangement of blood vessels in many marine mammals and birds allows for _____ _____.
Countercurrent exchange
Countercurrent exchange
The exchange of a substance or heat between two fluids flowing in opposite directions
Evaporative loss
Sweating, panting, bathing
Behavioral responses to heat
Assume posture that minimizes or maximizes absorption of solar heat
Migration
Cyclic movement often timed with the seasons
Antifreeze
A substance which slows the process of freezing by changing the freezing point of water
As an endotherm, would it be easier to be small or big?
Big
The hypothalamus is involved in what?
Mammalian thermoregulation
Thermogenesis
Generation of heat
Epinephrine
Adrenaline
Environmental stimuli
Change in an organism’s external surroundings like a change in light or temperature
Sensory receptors
Specialized cells unique to each sense organ that respond to a particular form of sensory stimulation.
Motor effectors
Respond to stimulus
The nervous system links _____ _____ and _____ _____.
Sensory receptors, motor effectors
Peripheral nervous system
The sensory and motor neurons that connect the central nervous system to the rest of the body.
Where is the central nervous system found?
The dorsal axis
Somatic nervous system
The division of the peripheral nervous system that controls the body’s skeletal muscles
Autonomic nervous system
The part of the peripheral nervous system that controls the glands and the muscles of the internal organs (such as the heart). Its sympathetic division arouses; its parasympathetic division calms.
Sympathetic nervous system
The division of the autonomic nervous system that arouses the body, mobilizing its energy in stressful situations
Parasympathetic nervous system
The division of the autonomic nervous system that calms the body, conserving its energy
Sensory neurons
(Afferent neurons) Carry impulses to central nervous system
Motor neurons
(Efferent neurons) Carry impulses from CNS to effectors (muscles and glands)
Interneurons
(Association neurons) Provide more complex reflexes and associative functions (learning and memory)
Neuroglia
Cells that support and protect neurons
Schwann cells
Supporting cells of the peripheral nervous system responsible for the formation of myelin.
Oligodendrocytes
Type of glial cell in the central nervous system that wrap axons in a myelin sheath.
Myelin sheaths
Little bodies that speed up the time it takes for the impulse to pass through the neurons
Schwann cells and oligodendrocytes both produce _____ _____.
Myelin sheaths
In the CNS, myelinated axons form _____ _____.
White matter
In the PNS, myelinated axons are bundled to form _____.
Nerves
Negative Pole
Cytoplasmic side
Positive pole
Extracellular fluid side
What are the three types of neurons?
Sensory, motor, interneurons
What is the average resting potential of an unstimulated neuron?
-70 mV
The inside of the cell is more _____ charged than the outside.
Negatively
Sodium-potassium pump
A carrier protein that uses ATP to actively transport sodium ions out of a cell and potassium ions into the cell
Ion leakage channels
Allow more K+ to diffuse out than Na+ to diffuse in
Concentration of K+ is _____ in the cell.
Higher
Neuron membranes are not permeable to _____.
Negative ions
Equilibrium potential
The magnitude of the membrane voltage at equilibrium for a particular ion
Action potential
A neural impulse; a brief electrical charge that travels down an axon
_____ bring the neuron closer to the threshold potential (-55mV).
Depolarizations
_____ moves the neuron further from the threshold potential (-55mV).
Hyperpolarizations
Action potential is caused by _____ _____ _____ _____.
Voltage-gated ion channels
What are the three phases of action potential?
Depolarization, repolarization, hyperpolarization
Action potentials are always _____.
Separate, all-or-none events with same amplitude
Intensity of a stimulus is coded by the _____, not amplitude, of action potentials
Frequency
Each action potential, in its rising phase, reflects a reversal in _____ _____.
membrane polarity
Positive charges are due to an influx of _____.
NA+
What is the process of an action potential?
Positive charges can depolarize the adjacent region to threshold, the next region produces its own action potential, and the previous region depolarizes back to the resting membrane potential
What are two ways to increase velocity of conduction?
Axon has a large diameter, axon is myelinated
Axons with _____ _____ are found primarily in invertebrates.
Large diameters
When an axon is myelinated, action potential is only produced at nodes of _____.
Ranvier
When an axon is myelinated, impulse jumps from _____ to _____.
Node to node
Saltatory conduction
Rapid transmission of a nerve impulse along an axon, resulting from the action potential jumping from one node of Ranvier to another, skipping the myelin-sheathed regions of membrane.
_____ cell transmits action potential.
Presynaptic
____ cell receives action potential.
Postsynaptic
What are the two basic types of synapses?
Electrical and chemical
Electrical synapse
A type of synapse in which the cells are connected by gap junctions, allowing ions (and therefore the action potential) to spread easily from cell to cell
_____ synapses are rare in vertebrates.
Electrical
Chemical synapses have a _____ _____ between the two cells.
Synaptic cleft
Action potential triggers an influx of _____.
Ca^2+
_____ _____ fuse with the cell membrane.
Synaptic vesicles
Neurotransmitter is released by _____.
Exocytosis
_____ action is terminated by enzymatic digestion or cellular uptake.
Neurotransmitter
Diffuses to other side of cleft and binds to chemical-or ligand-gated receptor proteins
Neurotransmitter
Acetylcholine (ACh)
A neurotransmitter that enables learning and memory and also triggers muscle contraction
_____ binds to receptor in the postsynaptic membrane.
Acetylcholine
Acetylcholine causes _____-gated ion channels to open.
Ligand
Acetylcholine produces a depolarization called an _____ _____ _____.
Excitatory postsynaptic potential (EPSP)
What degrades acetylcholine?
Acetylcholinesterase
Acetylcholinesterase causes _____ _____.
Muscle relaxation
Glutamate
A major excitatory neurotransmitter; involved in memory
Glycine and GABA are _____ neurotransmitters.
Inhibitory
Glycine and GABA produce a hyperpolarization called an _____ _____ _____.
Inhibitory postsynaptic potential (IPSP)
Dopamine
Influences movement, learning, attention, and emotion
Serotonin
Affects mood, hunger, sleep, and arousal
Dopamine also acts outside the nervous system as a _____ messenger and _____.
Paracrine, vasodilator
Neuropeptides
Brain chemicals, such as enkephalins and endorphins, that regulate the activity of neurons
Intensity of pain perception depends on _____ and _____.
Enkephalins and endorphins
Nitric oxide
A gas released by the endothelial cells to promote blood flow
What are the two ways that the membrane can reach the threshold voltage?
Spatial summation, temporal summation
Spatial summation
Many different dendrites produce EPSPs
Temporal summation
One dendrite produces repeated EPSPs
What chemicals interfere with hormone signals?
Exogenous chemicals
Endocrine disruptors
Chemicals that interfere with the normal functioning of hormones in an animal’s body
What are examples of endocrine disruptors?
Insecticides, herbicides, dyes, plastics, detergents
Chemical signals bind to _____ _____ on target cells.
Receptor proteins
Only _____ _____ respond to chemical signals.
Target cells
Exocrine glands
Secrete chemical substances into ducts that lead either to other organs or out of the body
Examples of exocrine glands?
Tear ducts, sweat glands, salivary glands, liver, pancreas, mammary glands, stomach
Local regulators
Chemical signals that travel over short distances by diffusion; help regulate blood pressure, nervous system function, reproduction
What are the two types of local regulators?
Paracrine and autocrine
Paracrine system
Signals act on cells near the secreting cell
Autocrine system
Signals acting on the secreting cell itself
Synaptic signaling
A nerve cell releases neurotransmitter molecules into a synapse, stimulating the target cell
Neuroendocrine signaling
Neurohormones diffuse into the bloodstream and trigger responses in target cells anywhere in the body
Target cells
Cells that have receptors for a particular hormone
Pheromones
Chemical signals released by an animal that communicate information and affect the behavior of other animals of the same species.
What are functions of pheromones?
Marking trails leading to food, defining territories, warning of predators, and attracting potential mates
What are the three major classes of hormones?
Polypeptides, steroids, amines
Polypeptides
Proteins and peptides
Amines
Derived from amino acids
The solubility of a hormone correlates with the location of _____ inside or on the surface of _____ cells.
Receptors, target
Hydrophilic hormones
Secreted by exocytosis, travel freely in the bloodstream, bund to cell-surface receptors. Cannot penetrate the target cell, must stimulate physiology indirectly
Lipophilic hormones
Diffuse across cell membranes, travel in the bloodstream bound to transport proteins, and diffuse through the membrane of target cells. Steroid hormones
Signal transduction
A series of molecular changes that converts a signal on a target cell’s surface to a specific response inside the cell.
Binding of a hormone to a receptor initiates a _____ _____.
Signal transduction
Signal transductions lead to what reactions?
Reactions in the cytoplasm, enzyme activation, or a change in gene expression
Response to lipid-soluble hormone?
Change in gene expression (typically bypasses most steps to get to receptor)
Steroids, thyroid hormones, and the hormonal form of vitamin D enter target cells and bind to protein receptors in the _____ or _____.
Cytoplasm or nucleus
_____-_____ complexes act as transcription factors in the nucleus for lipophilic hormones, regulating transcription of specific genes.
Protein-receptor
Vitamin D is formed on the skin of _____.
Vertebrates
Vitamin D is transported to the _____.
Liver
Vitamin D regulates what?
Calcium and phosphate in the blood, cell proliferation and apoptosis, and neuromuscular function
Gland hyposecretion
Not producing enough secretion
Gland hypersecretion
Gland overproducing secretion
What is caused by either an overabundance or a limitation of a hormone?
Gland hyposecretion, gland hypersecretion, tumors (benign or malignant)
Negative feedback loop
A feedback loop that causes a system to change in the opposite direction from which it is moving
What regulates many hormonal pathways involved in homeostasis?
Negative feedback
Antagonistic hormones
Two hormones that have opposite effects.
What are examples of antagonistic hormones?
Insulin and glucagon
What do the antagonistic hormones insulin and glucagon do?
Maintain glucose homeostasis
Pancreas
Regulates the level of sugar in the blood
The pancreas has clusters of endocrine cells called _____ _____.
Pancreatic islets
What is the older term for pancreatic islets?
Islets of Langerhans
Pancreatic islets have _____ cells that produce glucagon and _____ cells that produce insulin.
Alpha, beta
Insulin
A protein hormone synthesized in the pancreas that regulates blood sugar levels by facilitating the uptake of glucose into tissues
Glucagon
A protein hormone secreted by pancreatic endocrine cells that raises blood glucose levels; an antagonistic hormone to insulin.
How does insulin reduce blood glucose levels?
Promoting the cellular uptake of glucose, slowing glycogen breakdown in the liver, promoting fat storage
How does glucagon increase blood glucose levels?
Stimulating conversion of glycogen to glucose in the liver, stimulating breakdown of fat and protein into glucose
Type I Diabetes Mellitus
Insulin dependent, caused by autoimmune destruction of the beta cells of the pancreas leading to little or no production of insulin, require regular injections of insulin to permit entry of glucose into cells
Type II Diabetes Mellitus
Non-insulin dependent, caused by receptor level resistance to insulin, partially inherited and partially due to environmental factors like obesity, meds can help body more effectively use the insulin it produces
Peripheral neuropathy
Disorder of the peripheral nerves that carry information to and from the brain and spinal cord
Nephropathy
Disease of the kidney
