BIOLOGY 1040, Exam 2
SPRING 2017 Bill Surver
CHAPTER 24 – The Immune System
Compare and contrast innate and adaptive (acquired) immunity. The adaptive immune system:
Found only in vertebrates
Reacts to specific pathogens (antigens)
“Remembers” an invader
Lymphocytes are responsible for adaptive immunity
Originate from stem cells in the bone marrow:
B lymphocytes (B cell) continue to develop in the bone marrow
T lymphocytes (T cells) develop further in the thymus
The B cells and T cells of the adaptive immune response provide a twopronged defense; combat pathogens both in the body fluids and inside body cells. The innate immune system: a series of defenses that
Act immediately upon infection
Are the same whether the pathogen has been encountered before Invertebrates rely solely on innate immunity which may consist of: Exoskeleton
Enzymes – lysozyme
Immune cells capable of phagocytosis, cellular ingestion and digestion of foreign substances
Vertebrates have innate and adaptive immunity If you want to learn more check out Out of 1,094 feature films made during the nazi era, how many were genre films?
What are the components of innate immunity?
Innate immunity in vertebrates includes:
Skin and mucus membranes
Neutrophils – phagocytic cells
Natural killer cells that attack cancer cells and virusinfected cells Macrophages
What is Interferon and how does it function?
Interferons proteins produced by virusinfected cells that help to limit the celltocell spread of viruses
They function in 5 steps:
1. the virus infects a cell, which causes, 2. Interferons genes in the cell’s nucleus to be turned on.
3. the cell synthesizes the interferon; the infected cell then dies, but 4. Its interferon proteins may diffuse to neighboring healthy cells, and 5. Stimulating them to produce other proteins that inhibit viral reproduction.
Describe the inflammatory response.
Inflammatory response a major component of our innate immunity; any damage to tissue causes this response Don't forget about the age old question of What is the meaning of slavs?
its main function is to disinfect and clean injured tissues
This has 3 steps:
1. signaling molecules released> affect capillary cells
2. capillaries widen and become leaky> go to the infected area Don't forget about the age old question of What gave the east india tea company a monopoly on tea imported into the colonies?
3. neutrophils digest bacteria> tissue begins to heal
What is self and nonself?
Nonself Antigens are nonself molecules that protrude from pathogens or other particles such as viruses, bacteria, mold, spores, pollen, house dust or cell surfaces of transplanted organs
self antigens are markers on cells and tissues which may have entered the organism eg. transplant, virus, bacteria, and which the body's immune system recognises as foreign and as a result will initiate an immune response.
Self self antigens are marker molecules on the surface of individual cells in a multicellular organism such as mammals which indicate that cell to be a part of the organism.
What is an antigen, an antibody?
Any molecule that elicits an adaptive immune response
**When the immune system detects an antigen, it responds with an increase in the number of cells that either attack the invader directly or produce immune proteins called antibodies
What is the lymphatic system. Read assigned section of text
Lymphatic system involved in both innate and adaptive immunity consists of branching network of vessels, numerous lymph nodes (little, round organs packed with macrophages and lymphocytes), bone marrow, and several organs. this system carries a fluid called lymph, which is similar to the interstitial fluid that surrounds body cells but contains less oxygen and fewer nutrients. We also discuss several other topics like How do we learn new words?
What are B and T lymphocytes? If you want to learn more check out What is the meaning of merton’s theory of anomie?
The B cells and T cells of the adaptive immune response provide a twopronged defense; combat pathogens both in the body fluids and inside body cells B cells:
1. Participate in the humoral immune response
2. Defend against bacteria and viruses present in body fluids If you want to learn more check out According to piaget, schemes are mental structures that infants use to understand the world. they use these to group similar things and with experience, these schemes change. the changes are called what?
3. Secrete antibodies into the blood and lymph
1. Participate in the cellmediated immune response
2. Defend against infections inside body cells
3. Attack cells infected with bacteria or viruses
4. Promote phagocytosis by other white blood cells and by stimulating B cells to produce antibodies
**Some T cells play a part in both the cellmediated and humoral immune responses **B cells bind antigens directly and T cells require an additional step for recognition
What are the humeral and cellular/cellmediated response?
Humoral response defends primarily against bacteria and viruses present in body fluid
produced by B cells
Cellmediated Response defends against infections inside body cells produced by T cells
How does humoral immunity occur?
This response involves the secretion of freefloating antibodies by B cells into the blood and lymph
humoral immunity can be passively transferred by injecting antibodycontaining blood plasma form an immune individual into a nonimmune individual.
How does cellular immunity occur?
This defensive system results from the action of defensive T cells
the action of free floating defensive antibody proteins produced by B cells of the humoral response
defensive T cells destroy body cells infected with bacteria or viruses
What are the steps of clonal selection?
1) A hematopoietic stem cell undergoes differentiation and genetic rearrangement to produce 2) immature lymphocytes with many different antigen receptors. Those that bind to 3) antigens from the body's own tissues are destroyed, while the rest mature into 4) inactive lymphocytes. Most of these will never encounter a matching 5) foreign antigen, but those that do are activated and produce 6) many clones of themselves.
What is primary immunity? Secondary immunity?
Primary Immunity occurs upon the first exposure to an antigen and is slower than the secondary response
Secondary Immunity occurs upon a second exposure to an antigen and is faster stronger than the primary immune response
the secondary response like the primary, activates both effector cells and memory cells
How do antibodies function?
Secreted into the blood and lymph by effector B cells:
Yshaped and have two antigenbinding sites specific to the antigenic determinants that elicit its secretion
Antibodies promote antigen elimination through several mechanisms Neutralizationbinding to surface proteins on a virus or bacterium and blocking its ability to infect a host
Agglutinationusing both binding sites of an antibody to join invading cells together into a clump
Precipation similar to agglutination except that the molecules link dissolved antigen molecules together
**Activation of the complement system
CHAPTER 26 – Hormones and Endocrine Systems
Understand the relationship between a chemical messenger and its target tissue. Chemical messengers are signaling molecules with target tissues: Hormones – endocrine glands and some neurons
Neurotransmitters – ends of axon
Local signaling molecules – released by a variety of cells
Pheromones – secretions of exocrine glands
What are the chemical messengers?
Signaling molecules that exert their effects on specific cells called target cells; along with the nervous system coordinate and integrate activities.
What is reception, transduction and response?
Reception receptor protein on/in the target cell
Transduction converts signal
Response change in the cells behavior
How do watersoluble and lipid soluble hormones differ in their function? Both hormones
Watersoluble includes proteins, short polypeptides and some modified amino acids most hormones
cannot pass through the phospholipid bilayer of the plasma membrane can bring about cellular changes without enter their target cells
Lipidsoluble includes the steroid hormones, small molecules made from cholesterol pass through the phospholipid bilayer and bind to receptors inside the cell
Understand the interaction(s) between the hypothalamus and posterior and anterior pituitary
Hypothalamus: blurs distinction between endocrine and nervous systems receives input from the nerves about internal conditions of the body and external environment
responds by sending out appropriate nervous and endocrine signals uses the pituitary gland to exert master control over the endocrine system Pituitary gland consists of two parts:
1. Posterior pituitary:
Composed of nervous tissue
Is an extension of the hypothalamus
Stores and secretes oxytocin and ADH which are made in the hypothalamus
2. Anterior pituitary:
Synthesizes and secretes hormones that controls other glands
Is controlled by two types of hormones released from the hypothalamus **Releasing hormones stimulate the anterior pituitary
**Inhibiting hormone inhibits the anterior pituitary
Using thyroxine and glucose metabolism as examples of negative feedback. The levels of glucose in the blood are regulated by the hormones insulin and glucagon from the pancreas, and T3 and T4 from the thyroid.
When blood glucose levels rise, insulin is secreted by the pancreas, lowering blood glucose by increasing its uptake in cells and stimulating the liver to convert glucose to glycogen, in which form it can be stored.
If insulin secretion is impaired, it can result in diabetes mellitus: a disease in which blood glucose levels remain high, leading to excess glucose in the urine, increased urine output, and dehydration, among other symptoms.
When blood glucose levels fall, glucagon is secreted by the pancreas, which increases blood glucose levels by stimulating the breakdown of glycogen into glucose and the creation of glucose from amino acids.
The basal metabolic rate of the body is controlled by the hormones T3 and T4, produced by the thyroid gland in response to the thyroid stimulating hormone (TSH), produced by the anterior pituitary.
T3 and T4 bind to receptors on the mitochondria, causing an increase in the production of ATP, as well as increase in the transcription of genes that help utilize glucose and produce ATP, resulting in higher metabolism of the cell.
Recognize examples of positive feedback
the effector of a process bolsters the stimulus, which increases the production of the product.
example: of a positive feedback system in living things is blood clotting and the positive feedback process of labor, in which oxytocin stimulates uterine contractions
CHAPTER 27 – Reproduction and Development
Distinguish between asexual and sexual reproduction.
Asexual: creation of genetically identical offspring by one parent Very rapid form of reproduction
Can occur via:
Sexual reproduction: sex
Joining of gametes
Eggs and sperm
**Some animals have both modes
Name animals that use external fertilization and internal fertilization. occurs in most bony fish, many reptiles, some cartilaginous fish, most amphibians, two mammals, and all birds
Name the components and the activity of hormones of both the male and female reproductive systems.
Some animals exhibit hermaphroditism: an individual has both male and female reproductive systems
Makes it easier to find a mate
May exchange gametes with other individuals
May fertilize their own eggs
Modes of Reproduction
Sexual reproduction results in the generation of unique offspring.
1. External fertilization:
When eggs and sperm are discharged near each other
Many fish and amphibian species
2. Internal fertilization:
Sperm is deposited in or near the female reproductive tract
Some fish and amphibians and most terrestrial species
Both sexes have:
1. A set of gonads gamete producing structure
2. Ducts for gamete transport
3. Structures for copulation
Testes produce sperm and male hormones.
Epididymis stores sperm as they develop further
Several glands contribute to semen:
1. Seminal vesicles
2. Prostate gland
2. Bulbourethral glands
1. Sperm is expelled from the penis
2. Seminal vesicles, prostate, and bulbourethral glands secrete into the urethra 3. Semen is formed and expelled
Is regulated by a negative feedback system of hormones
Involves the hypothalamus
Hormones synchronize cyclic changes in the ovary and uterus.
About every 28 days
The hypothalamus signals the anterior pituitary to secret FSH and LH Trigger the growth of a follicle and ovulation
After ovulation, the ovarian follicle becomes the corpus luteum. The corpus luteum secretes estrogen and progesterone which… 1. Stimulate the endometrium to thicken
2. Prepare the uterus for implantation
3. Inhibit the hypothalamus, reducing FSH and LH
If the egg is fertilized:
The embryo releases hormones that maintain the uterine lining and menstruation does not occur
If the egg is NOT fertilized:
The drop in LH shuts down the corpus luteum and its hormones Menstruation is triggered and the hypothalamus and pituitary stimulate development of a new follicle
CHAPTER 28 – Nervous Systems
Know the structure and the function of the various parts of a neuron
Neurons: cells specialized for carrying signals and are the functional units of the nervous system
A neuron consists of:
1. Cell body
2. Two types of extensions (fibers) that conduct signals:
3.Myelin sheath – Schwann cells
5.Form a cellular insulation
6.Speed up signal transmission
What is the function of sensory, inter, and motor neurons?
Nervous systems have two main anatomical divisions:
The central nervous system (CNS) consists of the brain and spinal cord (vertebrates)
The peripheral nervous system (PNS) is located outside the CNS and consists of nerves (bundles of neurons wrapped in connective tissue) and ganglia clusters of cell bodies
The nervous system:
1. Obtains sensory information, sensory input
2. Processes sensory information, integration
3. Sends commands to effector cells (muscles and glands) that carry out appropriate responses, motor output
Sensory neurons: convey signals from sensory receptors to the CNS Interneurons: located entirely in the CNS and they integrate information and send it to the motor neurons
Motor neurons: convey signals to effector cells
What are the components of a simple reflex arc?
Demonstrates the relationship between neurons and nervous system structure and function.
Explain the various components of an action potential. (include resting potential, depolarization, hyperpolarization, and reestablishment of the resting potential) Resting potential:
Negatively charged proteins
Action potential: A stimulus is any factor that causes a nerve signal to be generated A stimulus:
1. Alters the permeability of a portion of the neuron membrane
2. Allows ions to pass through
3. Changes the membrane’s voltage
A nerve signal, action potential, is a change in the membrane voltage from the resting potential to a maximum level, and back to the resting potential. 1. Threshold
What is propagation and synapse?
Propagation: Action potentials are selfpropagated in a oneway chain along a neuron Allornone events
Threshold versus nonthreshold
Frequency of action potentials, but not their strength changes with the strength of the stimulus
Synapses: are relay points between a synaptic terminal of a sending neuron and a receiving cell
The receiving cell can be:
1. Another neuron
2. An effector cell such as a muscle cell or endocrine cell
Chemical synapses: the ending (presynaptic) cell secretes a chemical signal, a neurotransmitter
The neurotransmitter crosses the synaptic cleft
The neurotransmitter binds to a specific receptor on the surface of the receiving (postsynaptic) cell
Explain an EPSP and an IPSP
1. Excite a receiving cell (E.P.S.P)
2. Inhibit a receiving cell (I.P.S.P.)
A receiving neuron’s membrane may receive excitatory and inhibitory signals from different sending neurons
The summation of excitation and inhibition determines if a neuron will transmit a nerve signal
The nervous systems of invertebrates are not as complex as that those of vertebrates; however they are still able to respond to stimuli and carryout some complex behavior Trends to look for:
1. Whole body response to more local response
2. Cephalization – the formation of a head
3. Specialized functions of sensory, integrating, and responding
Radial symmetrical animals have a nervous system arranged in a weblike system of neurons called a nerve net
Cephalization and Centralization
Most bilaterally symmetrical animals evolved:
Cephalization – the concentration of the nervous system at the head end Centralization – the presence of a central nervous system distinct from a peripheral nervous system
**Presence of ganglia
Name the components of the human nervous system and their function The PNS can be divided into two functional components
1. Motor system – mostly voluntary
2. Autonomic nervous system – mostly involuntary
The motor nervous system:
1. Carries signals to and from skeletal muscles
2. Mainly respond to external stimuli
The autonomic nervous system:
1. Regulates the internal environment
2. Controls smooth and cardiac muscle and organs and glands of the digestive, cardiovascular, excretory, and endocrine systems