Biology - Test 2

CNS (Central Nervous System)

Brain and spinal cord

PNS (Peripheral Nervous System)

Peripheral Nerves

Dendrites

Receive signals from other neurons

Myelin Sheath

Lipid/fat coat that protects the neuron and speeds up signals

Axon Terminal

Where the signal is sent

Synpase

Space between neurons where chemical signals travel

Afferent Neurons

Sensory neurons, from body to spinal cord or brain

Efferent Neurons

Motor neurons, from spinal cord or brain to muscles

How does the synapse carry the signal?

1. Electrical current travels down the axon
2. Vesicles with chemicals move toward the membrane
3. Chemicals are released and diffuse toward the next cell's plasma membrane
4. The chemicals open up the transport proteins and allow the signal to pass to the next cell

Stimulant

A substance that raises the amount of neurotransmitters in the synapse

Depressant

A substance that blocks and creates less neurotransmitters in the synapse

Dopamine

The pleasure and reward center of the brain

Serotonin

Overall mood and well-being (depression), sleep and memory

Epinephrine and Norepinephrine (Adrenaline)

Fight or flight response, raises heart rate, shuts down digestive and immune system

Acetylcholine

Muscle contraction, affected by tobacco

Melatonin

Sleep cycles (pineal gland)

Somatic Nervous System

Muscular system, afferent and efferent systems (motor and sensory)

Autonomic Nervous System

Sympathetic (fight or flight) and parasympathetic (rest and digest system)

Dura

Durable coat around brain, protection

Arachnoid

Web like coat around brain, blood vessels

Pia

Thinnest layer around brain, capillaries, blood exchange

Cerebrospinal Fluid

Keeps pressure around brain and allows for the brain to move

Frontal Lobe

Higher executive functions, thinking, planning, good vs bad

Temporal Lobe

Language, speech, hearing, memories, emotion

Parietal Lobe

Sensory relay, all senses, left vs right

Occipital Lobe

Sight, color, depth

Cerebellum

Fine motor movement, coordination, balance, posture

Midbrain

Reflexes

Pons

Sleep, breathing

Medulla

Heart rate, blood pressure, involuntary functions

Hippocampus

Converts memories to long term

Hypothalamus

Homeostasis, regulates pituitary gland, metabolism

Thalamus

Processes and relays to cerebrum

Amygdala

Fear, emotions, motivation

Mammillary Bodies

Recalls smells to memories

Basal Nuclei

Motor behaviors and habit learning, dopamine

Multiple Sclerosis - What is it?

Immune system attackes the CNS, believed to be an autoimmune disease

Multiple Sclerosis - Symptoms

Difficulty walking, fatigue, numbness/tingling, muscle spasms, weakness, vision problems

Multiple Sclerosis - Diagnosis

Must show damage in 2 areas of CNS, show problmes at least 2 times, rule out everything else

Multiple Sclerosis - How the immune system affects MS?

1. T cells enter CNS
2. T cells release inflammators
3. Myelin is damamged - hurts neurontransmission

T cells cause inflimmation in CNS and stop immune responses, regular T cellsdon't work properly in MS patients, cytotoxic (killer) T cells attack CNS, B cells (antibodies) become active

Multiple Scelorsis - Treatment

No known cure - Strategies:
1. Limit entry of T cells into the CNS
2. Interfere with activation of T cells
3. Limit immune system acitivity (limit inflammation)

Rhinoviruses

Common cold - over 100

True or False: Both flu and cold are viruses

True

Virus vs Bacteria

Viruses are non-living particles that contain genetic material and hijack your cells to reproduce (chicken pox, flu, COVID-19, pneumonia, measles)

Bacteria are living organisms that can reproduce on their own and can be killed by antibiotics (tetnis, salmonella, ecoli, strep, staff)

Innate vs Acquired

Innate: non-specific (tries to fight everything), naturally born with, mostly exterior (skin, mucus membranes, inflammatory response, and white blood cells)

Acquired: adaptive, learned through pathogens (virus, bacteria fungus), after birth, B cells and T cells (why vaccines work)

What is the role of skin?

Dead skin cells are constantly sloughed off making it hard for bacteria to colonize, sweat and oils contain anti-microbial chemicals including some antibiotics

What is the role of mucus and cilia?

Mucus contains lysosomes and enzymes that destroy bacterial cell walls (use acid and water to split things apart), the normal flow of mucus washes bacteria and viruses away, cilia in the respiratory tract move mucus out of the lungs to keep bacteria and viruses out

What is the role of white blood cells?

All WMC's are phagocytes (except B and T cells) that destroy pathogens

Neutrophils

Most basic WBC defenders, fight everything

Macrophages

WBC's that go from blood to tissue

Natural Killer Cells

WBC's that kill early cancer cells

Dendritic Cells

WBC's that are antigen presenting

What is the role of inflammation?

Signaled by mast cells (first on scene of problem) which release a histamine, which cause fluids to collect around the injury and cause swelling, temperature may rise which can kill temperature-sensitive microbes

What is the role of a fever?

Defense mechanism that can destroy microbes, also help fight viral infections by increasing interferon production

Antibody

A protein produced by the human immune system to tag and destroy invasive microbes, don't directly kill pathogens, made in the body by B cells

Antibiotic

Various chemicals produced by certain soil microbes that are toxic to many bacteria, some we use as medicines

Antigen

Any protein that our immune system uses to recognize "self" vs "not self", it's the marker

How does antigen recognition work?

Cells of the immune system are trained to recognize proteins and if an antigen protein is encountered by a macrophage it will bring the protein to a helper T-cell for identification, if the helper T-cell recognizes the protein as foreign it will launch an immune response

What is the role of antibodies? (3 ways)

Antibodies don't directly kill pathogens, but there are 3 ways they can help detect and tag pathogens
1. Signal macrophages to come and destroy
2. Clump pathogens together
3. Block receptor sites on pathogens

What are the 2 types of lymphocytes?

B and T cells

Helper T Cells

Direct and regulate the immune system, recognize antigens, release cytokines (chemical messages) to stimulate B cell division

Memory T Cells

Remember antigens and their tags for next response time

Cytotoxic T Cells

Killer T cells, recognize and destroy foreign cells, release enzymes, some killer T cells can recognize and destory cancer cells

Phagocytes

Destroy things - macrophages, dendritic

B Cells

Produce antibodies

Humoral Response

Mostly B cells, helper T cells are in charge, fights extracellular pathogens
1. B cells find pathogens
2. B cells attach to pathogens and start cloning itself
3. Antibodies mark pathogens and await phagocytes

Cell Mediated Response

Helper T cells are in charge, memory cells, regulatory cells, travels in blood, fights infected cells and cancer
1. Binds to presented antigens of pathogens
2. Begins to multiply into more T cells
3. Release cytokines to activate killer T cells and phagocytes
4. Memory T cells are made for future immunity
5. Regulatory T cells are made to stop immune response

How do antibiotics work?

Help destroy bacteria (but not viruses), weaken cell wall of bacteria, slow reproduction of bacteria

Variolatioin

The act of inhaling dried secretions or rubbing broken skin from people with secretions of smallpox sores

Who created vaccines? And how?

Edward Jenner, invented when he knew that dairy maids how had contracted cowpox never got smallpox, he exposed a boy with secretions from cowpox sores and showed the boy was immune to smallpox

How do vaccines work?

They work because of the humoral system, made from killed bacteria or viruses or fragments of proteins from these microbes

Autoimmune Disorder

Occur when the immune system fails to recognize a protein and launches an attack

What is evolution?

When gene distribution changes over time

Allele Frequencies

The changes from one generation to the next over time

Chromosome

A structure found inside the nucleus of a cell, made up of proteins and DNA

Gene

A segment of DNA on a chromosome that codes for a specific trait

Allele

Different versions of the sme gene

Law or Principal of Super Position

The newer fossils and evidences of evolution are on top

3 Reasons for Natural Selection

1. Variation in traits
2. Heredity
3. Difficulty surviving

True or False: Natural selection is vertical evolution

True!

Mutations turn into...

DNA sequences

True or False: The evolutionary theory is horizontal evolution

True

Fitness

The ability of organisms to change and improve a feature of themselves to survive and reproduce

Mutations create...

Genetic diversity and are passed onto the next generations

Macroevolution

All new species that evolve over time (horizontal evolution)

Microevolution

Change in an allele frequency in a population of the same species overtime (vertical evolution)

Homologous Structure

Involve closely related species with common ancestor

Analogous Structures

Two things that have nothing to do with each other and are separate but look alike and have similar features (related to convergent evolution)

Convergent Evolution

Two species who converge to be like on another (related to analogous structures)

Divergent Evolution

When a population with common ancestors separates

4 Types of Evidence of Evolution

1. Fossils
2. Anatomical comparisons (analogous, homologous)
3. Molecular data (cytochrome C)
4. Embryology

Cytochrome C

A protein in all eukaryotic cells, the less differences in cytochrome c the closer the organisms are related (genetics, DNA, RNA, protein)

Cell Body

Contains nucleus in a neuron

Cerebrum/Cerebral Cortex

Area of the brain responsible for all voluntary activities of the body, contains the 4 lobes

Brain Stem

Keeps you alive (medulla, pods, midbrain)

Corpus Callosum

Allows left and right hemisphere to communicate

Neurotransmitter

Chemical messenger of the nervous system that trigger responses

Vesicles

Store neurotransmitters that are released at synapse

Receptor

Structure at the end of a sensory neuron that receives information from the internal or external environment

Limbic System

Neural system (including the hippocampus, amygdala, and hypothalamus