College Bio Unit 2

What makes up the Central Nervous System?

Brain, Spinal cord

What makes up the Peripheral Nervous System?

Peripheral Nerves

Neurons

Cells in our nervous system that “sandbag”

Dendrite

Receiving end of a neuron

Myelin Sheath

Functions in multiple sclerosis, protective layer that wraps around the nerve fibers

What connects neurons?

Synapses

Synapse

Where chemical signal transfers, the space between two neurons

Sensory/Affarent Neurons

From the body to the spinal cord or brain, would be the neuron that registers someone’s voice

Motor/Efferent Neurons

From the brain/spinal cord to the muscle, would be the response to someone’s voice

Interneuron

In the spinal cord, instant quick reactions

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

What are the neurotransmitters that affect how we feel?

Dopamine, serotonin, epinephrine/norepinephrine, acetylcholine, melatonin

Dopamine

Pleasure and reward centers in brain, “feel-good drug,” functions in motor movement

Serotonin

Overall mood and well-being, sleep and memory, functions in depression

Epinephrine/Norepinephrine

Fight or flight response, raises heart rate, shuts down digestive and immune systems (adrenal gland)

Acetylcholine

Muscle contraction, affected by tobacco

Melatonin

Sleep cycles (pineal gland)

Symatic Nervous System

Muscles

Autonomic nervous system

We don’t think about it. It includes sympathetic/parasympathetic

Sympathetic Division

Fight or flight

Parasympathetic

Rest and digest

What systems stop working when you’re in fight/flight?

Digestive, immune, reproductive

Dura meninges

Outermost meninges layer, strong/thick, protects brain

Arachnoid

Spider-web, middle meninges layer

Pia

Cappilaries, super thin meninges layer

Meningitis

Inflammation of the meninges

Cerebrospinal fluid

Carries cells including stem cells, circulates in the ventricles/dura, very hard to access except through spinal cord. Spinal taps, chemotherapy, and epidurals all involve CSF.

How many ventricles are there in the brain?

4

What do the ventricles do?

Store/circulate cerebrospinal fluid

Frontal lobe

Decision making, higher executive function, planning, develops as you age, good vs. bad

Temporal lobe

Language, memories, emotion, speech, hearing

Parietal Lobe

Sensory relay, spatial navigation, touch, taste, reading, left vs. right, hearing interpretation

Occipital Lobe

Sight, depth perception, movement

Cerebellum

Balance, fine motor movement, coordination

Symatic nervous system

Motor, sensory, inter neurons

Where do neurotransmitters travel?

Synapse

Midbrain

Reflex center for quick sensory actions, fight/flight

Pons

Breathing/sleep paralysis

Medulla

Heart rate, blood pressure, swallowing, vomiting, sneezing (basic functions)

Hippocampus

Converts memories to long term storage

Hypothalamus

Homeostasis, regulates pituitary gland and metabolism

Thalamus

Sensory relay to parietal lobe

Amygdala

Fear, emotions, motivation

Mammillary bodies

Recolective smell memories

Basal Nuclei

Motor behavior and habit learning, involved in dopamine

Multiple Sclerosis

Autoimmune disease that attacks the CNS. Symptoms include difficulty walking, fatigue, numbness, muscle spasms, etc. Diagnosis is difficult, because there has to be a problem in 2 different areas of the CNS at 2 different times, and you have to rule out all other diagnosis. Immune system attacks myelin and nerve fibers.

T cells

Organize the immune response

B cells

Make antibodies

How does the immune system affect MS?

T Cells cause inflammation in CNS, regulatory T cells don’t work properly, cytotoxic T cells attack CNS cells, B cells become active

How does MS happen?

1. T cells enter CNS crossing the blood/brain barrier

2. T cells release inflammatores

3. Damage to myelin and what makes myelin

Cytotoxic T cells

Killer T (kill things)

Regulatory T cells

Stop immune response

How do you treat MS since there is no known cure?

Limit T cell entry into CNS, inactivate T cells/limit activation within CNS, reduce immune inflammatory response

What kind of virus is the cold?

Rhinovirus

Why don’t we become immune to the cold?

Over 100 rhinoviruses have been identified

What is a cold?

Infection of the mucus membranes of the respiratory tract by rhinovirus

Virus

Colds and influenza, non-living, hijack your cells to reproduce. Viruses cannot be killed with antibiotics, your immune system fixes it yourself.

Bacteria

Living, can be killed with antibiotics because they target the bacteria’s cell wall, includes strep throat, staph, etc. 

Innate Immune System

Non-specific defenses designed to prevent infections, including skin, mucus/cilia, phagocytes

Acquired/Adaptive Immune System

Must learn the pathogen first

Role of skin

Skin is acidic and constantly dying off, making it hard for bacteria to colonize

Role of mucus

Contains lysozymes that destroy bacterial cell walls

Lysozymes

Break things apart w/ water

Role of Cilia

Move mucus out of the lungs to keep bacteria and viruses out

Role of WBC

All are phagocytes that engulf and destroy pathogens

Neutrophils

Fight basic infections

Macrophage

Can travel to/from blood and tissue

Natural killer cells

Fight cancer cells

Dendritic Cells

Antigen presenting cells

Mast cells

Phagocytes are attracted by an inflammatory response of damaged cells

Inflammation

Signaled by mast cells, which release histamine

Histamine

Causes fluids to collect around an injury to dilute toxins, causes swelling

Why does tissue temp sometimes rise if it is inflamed?

Can kill temp-sensitive microbes

Fever

Defense mechanism that can destroy many kinds of microbes, can help fight viral infections

Vaso dilate

Bigger

Vaso constrict

Smaller

Acquired immune system

Specific defenses that give us immunity to certain diseases. 2nd response to a pathogen is much stronger!

Why do you keep getting the flu?

Flu antigens mutate every year

Do antibodies directly kill?

No

Antibody

Protein produced by the human immune system to tag and destroy invasive microbes

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”

Who is on the scene first when antigens are recognized?

Neutraphils

Antigen recognition

Cells of the immune system are “trained” to recognize self proteins vs. not self proteins. If an antigen "(“not self”) is encountered by a macrophage, it will bring the protein to a helper-T cell for identification

What cell coordinates everything?

Helper-T. If it recognizes a protein as “not self,” it will launch an immune response.

What do antibodies (B-cells) do instead of directly killing the pathogen?

1. Send signal to macrophage to come and kill

2. B cells multiple like Gremlins so the pathogen can’t move

3. Block receptor sites

Antibodies may do what to microbes?

Cause them to agglutinate

Are phagocytes in the acquired or innate immune system?

Both

How do Helper T cells recognize antigens?

Receptors, if they are presented with an antigen they release cytokines to stimulate B-cell division.

Cytokines

Chemical Messenger

What disease are Helper T cells disabled?

AIDS

Kinds of T Cells

Cytotoxic, Macrophage, Dendritic, Natural Killer

B Cells can differentiate into what kinds of cells

Memory B or Plasma

Humoral Response

Within body fluids (blood, stream, lymph)

B cells are which branch of acquired immune?

Humoral

Intra/Extracellular pathogens (bacteria, fungus, toxins) are which branch of acquired immune?

Humoral

What are examples of the bacteria, toxins, and fungus in the acquired immune system?

E-coli, salmonella, strep, staph, chlamydia

Which branch of acquired immune works first?

Humoral

T cells work in which branch of the acquired immune?

Cell Mediator

Helper T cells work in which branch of acquired immune?

Both