Biology Exam 2

The Nervous System

Brain and spinal cord are part of the Central Nervous System (CNS)

Peripheral Nerves are part of the Peripheral Nervous System (PNS)

• Somatic

• Autonomic-Sympathetic (fight or flight) and Parasympathetic (rest and digest)

1. be able to label and list the function of the following: cerebrum, cerebellum, brain stem, medulla oblongata, cerebral cortex, corpus callosum, frontal lobes

Corpus callosum: left and right hemisphere communication

Cerebellum: balance and coordination of movement

Frontal Lobe: cognitive thinking skills, voluntary movement

Occipital lobe: visual processing area

Cerebral cortex: occipital, temporal, frontal, and parietal lobes

Cerebrum: Muscle function and temperature regulation

Parietal lobe: sensory perception of the 5 senses

Temporal lobe: auditory stimuli, memory, emotion

*Brain stem: animal brain and primitive (Midbrain, Pons, Medulla)

Midbrain: reflexes and fight or flight response

Pons: regulates sleep and breathing

Medulla oblongata: controls heart rate, breathing, and blood pressure

*Brain lobes- know where they are Frontal, Parietal, Temporal, Occipital

*CSF- fluid protecting brain stored in ventricles

2. list function of neuron and its parts (dendrites, cell body, axon, nucleus). Label parts of neurons on a diagram. 

Dendrites: receive signals

Cell body: central part containing nucleus

Axon: conducts electrical impulses away from cell body

Nucleus: contains genetic material

3. define synapse, neurotransmitter, afferent, efferent, vesicles, receptor, and label on diagram 

Synapse: neurons are connected by synapses

Neurotransmitter: chemical messages across synapse

Afferent: Sensory- from body to spinal cord or brain (Quick reflexes and less time)

Efferent: Motor- from brain or spinal cord to the muscle (More time to think)

Vesicles: store and release neurotransmitters

Receptor: structure at the end of a sensory neuron that receives information from internal/external environment

4. list steps in order of nerve impulse and synaptic transmission 

   1. Dendrite receptors receive neurotransmitters

   2. Signal travels down neuron

   3. To axon

   4. Signal crosses synapse

   5. Neurotransmitters broken down by reuptake

5. List the major neurotransmitters of the brain and what they do

Dopamine: pleasure and reward center of brain

Serotonin: overall mood and well-being, sleep and memory (depression=low serotonin)

Epinephrine: Adrenaline, fight or flight response, raises heart rate, shuts down systems

Acetylcholine: muscle contraction, affected by tobacco

Melatonin: sleep cycles (pineal gland)

• Depressants: blocked neurotransmitters

• Stimulants: more dopamine produced

6. Contrast the various nervous systems (sympathetic, parasympathetic, somatic, etc..)

Autonomic = internal organs and glands

Sympathetic: fight or flight

Parasympathetic: rest and digest

Somatic = muscular system

Sensory: Afferent

Motor: Efferent

7. Differentiate between the different parts of the limbic system

Thalamus: processes sensory information

Hypothalamus: homeostasis

Amygdala: fears and emotion

8. Differentiate between the different parts of the brain stem

Brain stem: animal brain and very primitive

Pons: sleep and breathing

Midbrain: reflexes and fight or flight response

Medulla: controls heart rate, breathing, and blood pressure

9. Multiple Sclerosis:  symptoms, causes, diagnosis, treatment, experimental therapies  

Symptoms: difficulty walking, fatigue, numbness/tingling, muscle spasms, weakness, vision problems

Causes: Immune system attacks the CNS -Mylien sheath

*Diagnosis:

1. Damage in 2 separate areas of CNS

2. Problems at least 2 different times 

3. Rule out everything else

*Treatment- Rehab: PT, OT, Speech/visions, Cognitive therapy. No known cure but strategies.

1. Limit entry of T cells into CNS

2. Interfere with T cell activation

3. Limiting immune system activity (Inflammatory response)

Note: Rheumatoid arthritis, lupus, and Crohn's disease

Immune System- 20 questions 

Infectious is something easily caught

Pathogen, something can cause harm in body

10. list different types of infectious agents (pathogens) and give examples of each 

Viruses= create colds and influenza Bacteria= living and can reproduce Fungus= real bad

Colds are rhinoviruses

11. explain how each type of pathogen causes disease and examples of diseases caused by each (ie. virus vs. bacteria)

Virus: non-living and contain genetic material, they hijack cells to reproduce. Can’t be killed with antibiotics (Rhinovirus and influenza virus) need host and only survive by immune system

Bacteria: living, have a metabolism, DNA, and can reproduce on their own. Can be killed with antibiotics because they target specific processes like production of the cell wall. (E. coli and streptococcus)

12. define pathogen, immune system, infectious disease 

Pathogen: viruses, bacteria, fungus

Immune System: A complex network of cells, tissues, organs, and the substances they make that helps the body fight infections and other diseases. (Recognizes, then mounts defense)

Infectious Disease: disorders that are caused by organisms, usually microscopic, such as bacteria, viruses, fungi, or parasites that are passed, directly or indirectly, from one person to another.

13. list some immune system components (blood, red bone marrow, lymphatic system, and specific organs). 

14. describe the external innate defenses (barriers) that defend you against disease, where they are found, how they work, whether they are innate or adaptive immune responses 

Innate: Non-specific, born with it

• Skin Mucus membranes, inflammatory response, and white blood cells (Most on exterior)

Adaptive/Acquired: You must learn the pathogen first

• Begins after birth, B and T cells, accumulate by being alive (why vaccines work)

15. list the components of the internal innate immune system 

Innate: First line of defense

• External: skin, mucus, cilia

• Internal: Fever, Inflammation, WBC’s=Phagocytes-Neutrophils, macrophages, NK cells, Dendritic cells

• Non-specific defenses are designed to prevent infections by viruses and bacteria, including…

1. Intact skin: acidic and oily -kills things

2. Mucus and cilia

3. Phagocytes (WBC’s) -Inside=certain white blood cells -Neutrophils and macrophages

16. explain how fever, mucus, cilia defend the body

Fever: Warmer temps are bad for pathogens, a defense mechanism that can destroy many microbes, helps fight viral infections by increasing interferon production. (Can be dangerous)

Mucus: contains lysosomes, enzymes that destroy cell walls (split things apart using water + enzymes)

Cilia: in the respiratory tract, move mucus out of the lungs to keep bacteria and viruses out

17. Explain how the internal innate immune system works:  specifically phagocytes  

Role of WBC’s: all are phagocytes that engulf and destroy pathogen

• Neutrophils: most basic defender, fight all

• Macrophages: blood ⇾ tissue

• Natural killer cells: early cancer cells

• Dendritic cells: antigen presenting cells.

Phagocytes are attracted by an inflammatory response of damages cells

18. describe adaptive immunity (memory or not, response time, broad or specific) 

Acquired/Adaptive immune system: specific defenses are those that give us immunity to certain diseases. The immune system forms a chemical “memory” of invading microbe. If the microbe is encountered again, the body reacts so quickly, few or no symptoms are felt.

19. Describe differences between cell mediated and humoral response 

Humoral Response: Pathogens, lymphatic system

• B cells=Antibodies

1. Clump

2. Block receptor sites

3. Signal phagocytes

• helper T cells in charge, fights extracellular pathogens

Cell mediated: All T cells. Helper T cells activate and direct other T cells and phagocytic cells

• Helper T -direct immune response, Memory -remember past illness, Regulatory -tells cells to stop and shut down (part of autoimmune disease), Cytotoxic -they kill bad things with enzymes

• Memory cells, regulatory cells, travels through blood, infected cells and cancer

20. Contrast antigen, antibody, antibiotic

Antibiotic: various chemicals produced by certain soil microbes that are toxic to mayn bacteria. Some we use as medicines.

Antibody: a protein produced by the human immune system to tag and destroy invasive microbes. (B-cells) -Don’t directly kill pathogen

Antigen: any protein that our immune system uses to recognize “self” vs. “not self” (Name tag) all cells have unique antigens

• Antigens are lock and antibody is key

21. describe how B cells and T cells fight pathogens 

Antigen recognition: cells of the immune system are trained to recognize self vs. not self proteins. If not self protein is encountered by a macrophage, it will bring the protein to a helper T cell for identification. If it is not self, then T cell will launch an immune response.

Role of Antibodies: What B-cells make but don’t directly kill pathogens

1. Signal macrophages to come and destroy

2. Clump pathogens together

3. Block receptor sites on pathogen

22. explain how the response of B and T cells is different the second time you are exposed to the exact same virus or bacterium 

B cells: in general produce antibodies, Memory cells and plasma cells (kill)

T cells: Helper T’s stimulate B cell division, Killer T’s seek and destroy any antigen in the system

23. List the various types of T cells and their role

Helper T’s stimulate B cell division, key cell to signal an immune response

Killer T’s seek and destroy any antigen in the system and tagged microbes by antibodies

• Cytokines: chemical messages and some Cytotoxic T cells can recognize and destroy cancer cells (NK cells- Natural killer)

24. describe how antibiotics, antivirals, and vaccines work 

Antibiotics work: help destroy bacteria only (kill bacteria)

1. Weaken cell wall

2. Slowing bacteria reproduction

Vaccines work: created from killed bacteria or viruses (killed or weakened) -immune system recognizes the mounts defense (work because of humoral immunity system)

Antivirals work: aren’t many out there

25. explain whether or not antibiotics and antivirals can eliminate a pathogen when you have a disease 

No they help our immune system by weakening the bacteria

26. explain which immune system cells are involved in causing an allergic response and why a first exposure to an allergen differs from the second exposure 

Evolution-20 Questions 

Different gene versions is allele

Density in a population is allele frequency

Variation in traits different hair color and such

Horizontal gene transfer- antibiotic resistance happens quickly

27. List Darwin's observations and inferences about evolution

Observations of Nature

1. Genetic Variation: within a species, no two individuals are exactly alike. Some of this variation is heritable.

2. Limited Resources: Every habitat contains limited supplies of the resources required for survival.

3. Overproduction of Offspring: More individuals are born than survive to reproduce

Inferences from Observations

1. Struggle for existence: individuals compete for the limited resources that enable them to survive. (Competition)

2. Unequal Reproductive success (natural selection): the inherited characteristics of some individuals make them more likely to obtain resources, survive, and reproduce.

• Struggle, heredity, variation in traits

3. Descent with modification: over many generations, a population’s characteristics, can change by natural selection, even giving rise to new species. (Vertical evolution with mutations)

• 3 reasons for natural selection: Variation in traits, heredity, and difficulty surviving

28. define and give examples of evolution, species, population, gene, mutation, allele, allele frequency 

Evolution: genetic change over time gene distribution changing

Species: Micro -slowly changing one gene vs. Macro -one species to a new species

Population: evolution occurs here because allele frequencies change from one generation to the next over time (Scandinavian vs. Asian)

Gene: code for different traits (Genes on chromosomes)

Mutation: change in DNA sequence causing evolution to occur -creates genetic diversity

Allele: version of a gene

Allele Frequency: vary between populations (isolated populations are high -Black hair in Asia)

29. define and give examples of variation in traits, heredity (heritable traits), struggle, unequal reproductive success 

Variation in traits: within a species, no two individuals are exactly alike (attached/detached earlobes)

Heredity: 

Struggle: struggle for existence and competition to survive

Unequal reproductive success: natural selection and the best genes survive and reproduce

30. explain the process of natural selection 

Natural selection requires genetic variation- since more individuals are born than resources available, there is a struggle to survive. Some individuals in a population are better at surviving and reproducing

31. define and give examples of microevolution, natural selection, macroevolution, speciation, descent with modification, theory of common descent

Microevolution: change in allele frequency in a population of species overtime

Macroevolution: a new species evolves overtime

Natural selection: 3 reasons for natural selection

1. Variation in traits

2. Heredity

3. Difficulty surviving

Speciation: formation of a new and distinct species through evolution (Gradual or punctuated)

Descent with modification: 

Theory of common descent:

32. list types of evidence for evolution, define them, give an example of each (fossils, molecular data, comparative anatomy, embryological development)

Evidence of Evolution

1. Fossils -older is lower (Law of Superposition)

2. *Anatomical Comparisons -Homologous and Analogous

3. Molecular Data -Cytochrome C

4. Embryology

33. describe the evidence for evolution expected for organisms that are closely related to one another

34. define and give examples of homologous and analogous structures 

Homologous- common ancestor similar body parts but different species

Analogous- survive similar situation and look similar but separate (cactus)

Convergent- species got slowly more similar

Divergent- species dived by geography and slowly get further apart with different environments