The various organ systems in animals are reviewed in this chapter.
There will be questions about the respiratory, circulatory, excretory, digestive, muscular, and reproductive organ systems.
The exam will use multiple-choice questions to evaluate your understanding of lab processes and your ability to demonstrate scientific inquiry and reasoning.
You will be able to demonstrate your understanding of a general concept and use your knowledge of these systems as illustrative examples in free-response questions.
You may be able to choose one from several different systems to use as an example.
Animals are complex systems of cells working in a coordinated fashion to monitor changing external conditions while maintaining a constant internal environment.
To accomplish these tasks, animal cells are organized into specialized systems.
The structure of these various systems is the focus of this chapter.
There are two examples of muscle and nervous tissue.
The heart has four different kinds of tissues that work together to pump blood through the body.
The mouth, stomach, small and large intestines, pancreas, and liver are all involved in the digestion system.
If the need for that activity has been satisfied, a feedback mechanism assesses the product of that activity.
In living things, these activities are regulated by enzymes and need energy.
The process is terminated when the condition returns to its previous state.
This kind of regulation is used by every organ system.
Humans respond to hot temperatures by sweating.
The water cools the body.
The body stops sweating when it returns to the set point temperature.
The body is adequately warm.
Sensitivity and stimulation increase until an orgasm is reached.
Energy is required to stay alive.
Larger organisms need more energy than smaller organisms.
As the size of the animal increases, the amount of energy required per unit weight decreases.
An elephant uses less energy than a mouse.
One explanation is that thermoregulation is more expensive for smaller animals because their surface area to volume ratio is larger than for larger animals.
It is possible that there is efficiency in numbers.
As the number of cells to service increases, the cost of servicing a single cell may decrease.
A nerve impulse begins at the tips of the dendrite branches and ends at the axon.
The eye's sensory cells are stimulated by light while the hand's sensory cells are stimulated by touch.
For example, motor neurons can be used to create a movement to maintain balance or to avoid pain, for example, or cells in the stomach can be used to make gastrin in response to the smell of food.
The excess of Na+) on the outside and the excess of K+) on the inside creates polarization.
A certain amount of Na+ and K+ is always leaking, but Na+/K+ active-transport pumps restore the ion to the appropriate side.
Large, negatively charged proteins and nucleic acids are found inside the cell.
There are graded potentials and resting potentials.
The resting potential shows the state of a neuron.
A gated ion channel can be opened or closed by a stimulated neuron.
A graded potential is a local event, with the magnitude of the stimuli decaying as they pass along the neuron.
When action potential is attained, the Na+ channels become inactivated, but neighboring Na+ channels are activated.
The action potential travels down the length of the neuron when Na+ gates are opened.
The nerve impulse can only travel in the forward direction when Na+ channels are activated.
When the stimulus fails to produce a depolarization that exceeds the threshold value, no action potential results, but when the threshold potential is exceeded, complete depolarization occurs.
The Na+ ion is on the inside and the K+ ion is on the outside.
By the time the K+ voltage-gated channels close, more K+ ion have left the cell than are necessary to establish the original potential.
With the passage of the action potential, the Na+ voltage-gated ion channels remain inactivated, and the neuron can't respond to new stimuli.
Some of the Na+ and K+ ion are on the wrong side of the cell membranes.
The Na+ and K+ are returned to their resting potential location by Na+/K+ active-transport pumps.
The Na+ voltage-gate ion channels don't respond to a stimuli again until after the resting potential is reestablished.
The gates of calcium are open.
When an action potential reaches the end of an axon, the depolarization of the membrane causes voltage-gated channels to open and allow Ca2+ to enter the cell.
The neurotransmitter is released by synaptic vesicles.
The transmitter binding with the postsynaptic receptors.
The neurotransmitter diffuses across the synaptic cleft.
Different neurotransmitters are affected by different proteins.
The postsynaptic membrane is active.
There are two possible outcomes for the postsynaptic membrane, depending on the kind of neurotransmitter and the kind of membrane receptors.
An action potential is generated if the threshold potential is exceeded.
As a result, it becomes more difficult to generate an action potential.
The neurotransmitter is recycled.
The neurotransmitter is broken down by the synaptic cleft.
The presynaptic cell recyclesgraded neurotransmitters.
At other junctions, it may produce an effect on the brain.
There are two or three neurons, a sensory and motor neuron and an interneuron.
The brain does not integrate sensory and motor activities despite the fact that neurons transmit information to the brain.
The brain is three bulges early in development.
The adult brain is made up of various parts.
Speech, evaluation of stimuli, conscious thinking, abstract thought, and control of muscle movement are some of the functions of the cerebrum.
The left cerebral hemisphere is associated with the right side of the body.
The right side is associated with non-verbal thinking and image recognition, while the left side is associated with language, math, and logic skills.
Emotions are associated with a network of neurons.
The cerebrum is connected to the brainstem.
The cerebellum is used to coordinate body movements with sensory stimuli.
Eyehand coordination is established by the cerebellum.
The internal environment of animals provides attractive conditions for the growth of organisms.
Some of these organisms can live with animals, but they can cause damage to cells or produce toxic chemicals.
Humans have three levels of defense to protect against foreign invaders.
A nonspecific defense isn't specialized for a particular invader.
It is a general defense against all kinds of pathogens.
phagocytes help attract foreign cells and destroy foreign cells by promoting cell lysis.
An increase in temperature, redness, and swelling are caused by this additional blood.
White blood cells may be stimulated by the increase in temperature, making the environment inhospitable to pathogens.
Any molecule that can be identified as foreign is an idiosyncrasy.
It could be a toxin that is injected into the blood by the sting of an insect, or a molecule that is unique to foreign cells.
The MHC is a collection of glycoproteins that are found in all body cells.
Each of the 20 genes that make up a single individual's proteins has at least 50 alleles.
It is very unlikely that two people will have the same set of cells.
Antibodies have certain properties.
There is a specific Antibody.
The class is associated with an activity.
Constant regions and variable regions are part of the basic Y-shaped protein that makes up each class of antibodies.
The variable regions are the parts of the immune system that are different from one another.
Antibodies binding to antigens.
Macrophage phagocytosis is followed by inactivation.
By binding to the surface of nonself cells, the antibodies cause the lysis of pathogens.
After the first occurrence of a disease, this mechanism provides immunity.
T cells have the same function as B cells.
The MHC markers on the cells distinguish between self and nonself cells.
The body cell displays a combination of self and nonself markers when it is invaded.
T cells see the display of markers as nonself.
T cells recognize cancer cells and other cells that display markers as nonself cells.
When a nonself cell binding to a T cell causes the B cell to divide, there are copies of the parent cell in each daughter cell.
There is a proliferation of B cells and T cells that will engage a specific invader.
T cells are capable of producing cytotoxic T cells.
Nonself cells are destroyed by these cells.
T cells bind to macrophages.
The macrophages that have engulfed the pathogens have abnormal markers on them.
T cells identify marker combinations and bind to them.
The proliferation of T cells is caused by a sequence of positive-feedback events that start with the interleukins.
B cells produce cells.
The plasma cells release the antibodies that bind with the pathogens.
B cells make memory cells.
Future immunity is provided by memory cells.
B cell production is stimulated by macrophage and T cells.
The proliferation of B cells will not be stimulated by the antigen.
The pathogen must be engulfed by a macrophage first.
In a cell-mediated response, T cells bind to the macrophage.
The production of B cells is stimulated by interleukins.
Humans have learned how to defend themselves.
Vaccines are the use of inactivated viruses or fragments of viruses.
The introduction of live microorganism will cause the immune system to respond quickly to any disease that can be established.
Newborn infants are protected by passive immunity through the transfer of antibodies across the placenta and breast milk.
A hormone is a long-distance chemical messenger produced in one part of the body that affects another part of the body.
There are hormones in the blood.
Target cells can be influenced by minute amounts of hormones.
Steroids, peptides, or modified amino acids are hormones.
The external environment and internal conditions of the body are monitored by the brain and hypothalamus.
As the master of information, the brain may determine that some kind of action is necessary to maintain homeostasis or that conditions are appropriate to change.
hormone-secretory cells are similar to neurons, but instead of secreting neurotransmitters into synaptic connections, they excrete hormones into the blood.
There are two parts to the brain.
The hormones produced in the hypothalamus are stored in the anterior pituitary.
Tropic hormones are hormones that can be found in other parts of the body.
They regulate the production of hormones.
The AP exam requires several hormones and actions.
The cells are distributed among the cells of the pancreas.
Most body cells absorb glucose from the blood.
The cells that convert the sugar to fat are the lysosomes and the cells that convert the sugar to glycogen are the muscle cells.
The production ofinsulin stops when bloodglucose reaches normal concentrations.
Glucagon stimulates the body's metabolism.
The breakdown of glycogen leads to the conversion of amino acids, lactic acid, and glycerol into sugars in the body.
The production of glucagon stops when blood sugar is normal.
The cause of this is an autoimmune response.
The inability of body cells to respond toinsulin is the second most common cause.
Excess body weight and a lack of exercise are associated with this condition.
If left undetected, diabetes can lead to death.
Humans and other animals respond to life threatening situations.
The hormones stimulated the liver and muscle cells to break down glycogen.
There is a source of energy for fighting or taking flight.
The fight-or-flight response is promoted by the increased blood pressure, breathing rate, and cellular metabolism of the two drugs.
When danger passes, the fight-or-flight response ends and the hormones are no longer produced.
The metabolism of cells in the body is regulated by throxin.
TRH production slows and homeostasis is established as a result of the stimulation of the TSH.
The negative feedback mechanism can be interfered with by the environment or disease.
The production of thyroxin declines when there is a deficiency of iodine.
The hypothalamus is trying to boost production of thyroxin.
There is no effect on the production of thyroxin because of the deficiency of iodine.
Efforts to boost production result in an enlargement of the neck.
The symptoms are reversed by a return of Iodide to the diet.
Antibodies produced by the immune system mistakenly bind to the TSH and cause the thyroid to produceThyroxin.
Even though there is no TSH, the production of thyroxin continues.
Hyperthyroidism causes high metabolism, which can cause problems such as insomnia, weight loss, and excessive sweating.
The growth factors in the blood stimulated bone and cartilage development.
gigantism and dwarfism can be caused by excess and underproduction of human growth hormone.
The examples include animals and fish.
Many of these animals are called "cold-blooded" because they feel cold to the touch, but other land-dwelling animals can exceed ambient temperatures by basking in the sun.
They are referred to as "warm-blooded" because their temperature is relatively warm compared to other mammals.
Birds and mammals are endotherms.
The temperature is cooling by evaporation.
Many animals sweat.
Body heat is removed when water is evaporated.
The respiratory tract is used to cool animals when they pant.
Warming by metabolism.
There are two ways in which heat is generated.
When animals shiver, heat is generated.
Some animals have fat deposits called brown fat.
When the permeability of the inner mitochondria to H+ is increased, the electron transport chain is decoupled.
As a result of this, heat is generated.
The surface area should be adjusted to regulate the temperature.
The arms, hands, feet, and ears add a lot of surface area to the body.
By increasing or decreasing the diameter of blood vessels, heat can be lost.
huddling into a group, curling up into a ball, or withdrawing the head or feet into feathers reduce exposed surface area and conserve heat.
The heat from the warm blood goes to the internal parts of the body.
This happens in the legs of wading birds.
The ability to survive in a particular environment is one of the things that all animals have.
Some animals have hair, while others have feathers.
Some animals move from sun to shade, while others restrict their activity during the day.
O2 is required for aerobic respiration.
Gas exchange to internal cells is needed if cells are not exposed to the outside environment.
Some animals are small enough to allow gas exchange.
Many of these animals, such as the Platyhelminthes (flatworms), have large surface areas, and every cell is exposed to the outside environment or is close enough that gases are available by diffusion through adjacent cells.
Gas exchange through the skin is augmented by a distribution system just inside the skin in larger animals such as the Annelida.
The gills have a circulatory system that removes oxygen and delivers waste CO2.
The voice box contains the vocal cords.
The alveves are surrounded by blood vessels.
Oxygen diffuses through the alveolar wall, through the blood capillary wall, and into the red blood cells.
In the opposite direction, carbon dioxide diffuses.
The body's circulatory system transports O2 from one part of the body to another.
Red blood cells have iron in them.
The body has blood vessels.
Oxygen diffuses out of the red blood cells, across the blood capillary walls, into the fluids surrounding the cells.
In the opposite direction, carbon dioxide diffuses.
The CO2 is dissolved in the blood's liquid portion.
HCO - 3 ion diffuses back into the plasma after their formation in the red blood cells.
2 does not become HCO3 because it mixes directly with the plasma or with the hemoglobin in red blood cells.
Changing the volume of the lungs moves air into and out of them.
The air in the lungs has a higher pressure than the air outside the body.
When the intercostal muscles relax, the volume of the lungs decreases, causing the air to rush out.
The pH of the blood and the fluids surrounding the brain and spinal cord are monitored by the Carotenoids.
CO2 production increases when a body is active.
The pH drops when CO2 is converted to HCO - 3 and H+.
Nerve impulses are sent to the intercostal muscles to increase respiratory rate.
Blood CO2 is returned to normal by a faster turnover in gas exchange.
The regulation of the respiratory rate is an example of how negative feedback can maintain homeostasis.
Large organisms need a transport system to move their resources around and to remove waste and CO2 from their cells.