question

List the 12 organ systems

answer

1. Nervous system 2. Endocrine system 3. Circulatory system 4. Lymphatic system 5. Immune system 6. Digestive system 7. Urinary system 8. Skeletal system 9. Muscular system 10. Respiratory system 11. Intergumentary system (skin) 12. Reproductive system

question

List the tissue types

answer

- Muscle - Nervous - Epithelial - Connective

question

List the 3 characteristics of muscle tissue

answer

contraction, extensibility, elasticity

question

What is the nervous tissue made of?

answer

neurons and glial cells

question

What are neuroglial cells?

answer

they are support cells that surround neurons and provide nutrients, immune support, and appropriate external environment

question

Where is the epithelial tissue located?

answer

surrounds the exterior of the body and lines the walls of body openings, body cavities, glands, organs.

question

Which are the 2 types of epithelial tissue?

answer

membraneous: lines external/internal surfaces glandular: form secretory glands

question

List the 5 characteristics of epithelial tissue

answer

1. High rate of regeneration 2. Cellularity 3. Avascularity 4. Polarity 5. Basement membrane

question

Describe the cellularity of epithelial cells

answer

cells are in close contact with each other through tight junctions, desmosomes, adherents junctions

question

Describe the polarity of epithelial cells

answer

cells have apical surface and basal surface. Tight junctions prevent migration of membrane proteins between apical and basal surfaces, thus maintaining polarity

question

Describe the basement membrane of epithelial cells

answer

membranous epithelial tissue is connected to underlying connective tissue by a basement membrane, which is an acellular matrix of glycoproteins and collagen fibers

question

Which body layers can connective tissue be found in?

answer

bones, tendons, ligaments, blood, fat, the underlying layers of the skin, and the interstitial matrix

question

Which germ later can epithelia be derived from?

answer

all three (endoderm, mesoderm, ectoderm)

question

Which germ layer is connective tissue derived from?

answer

Mesoderm (specifically the mesenchyme)

question

Which proteins is the extracellular matrix made of?

answer

Collagen or elastin

question

What is the ECM made of?

answer

Ground substance with fibers of collagen or elastin. There are also fibronectin proteins and cellular adhesion molecules (e.g. integrins)

question

What is the ground substance made of in the ECM?

answer

proteins, polysaccharides, and glycoproteins (including proteoglycans)

question

Which are the 3 types of fibers that occur in the ECM? State them and describe their properties.

answer

1. White fibers - made of collagen - tough but flexible 2. Yellow fibers - made of elastin - elasticity and flexibility - found in lungs, blood vessels, dermis of skin... 3. Reticular fibers - composed of thin collagen fibers

question

Which types of tissues does the connective tissue differentiate into from the mesenchyme?

answer

- Connective tissue proper (loose + dense) - cartilage - blood - bone

question

What cells make the connective tissue proper?

answer

fibroblasts

question

List the function and location of common connective tissue cells

answer

Fibroblasts (connective tissue proper) Adipocytes (fat tissue) Chondrocytes (cartilage) Osteocytes (bone) White blood cells and macrophages (immune, ECM) Mast cells (Histamine release, inflammatory response)

question

How are endocrine hormones secreted into the circulatory system?

answer

by exocytosis or by diffusion into capillaries

question

Which are the two type of glands that secrete signaling molecules?

answer

Endocrine (ductless) glands: secrete products into circulatory system Exocrine (ducted) glands: secrete products directly into another organ

question

Which are the 3 main components of the endocrine system?

answer

Endocrine glands, hormones, and receptors on target cells

question

How can hormones be classified as?

answer

1. Amino acid based hormones - water soluble - derivatives of individual amino acids, or polypeptides, or proteins 2. Steroid hormones - insoluble - derived from cholesterol

question

Mention 6 amino acid based hormones.

answer

Serotonin, Melatonin, Histamine, Epinephrine (adrenaline), Norepinephrine (noradrenaline), Thyroxine

question

Mention 3 peptide hormones

answer

Calcitonin, Insulin, Glucagon

question

State the role of Calcitonin

answer

lowers blood Calcium levels

question

State the role of Insulin

answer

Decreases blood glucose levels

question

State the role of Glucagon

answer

Increases blood glucose levels

question

Give 2 examples of steroid hormones and their role

answer

Sex hormones - made by the gonads - estrogen, progesterone, testosterone Adrenocorticoids - secreted by adrenal glands - mineralocorticoids (maintain Na+/K+ levels) - Glucocorticoids (regulate blood glucose levels)

question

Define prostaglandin and its role

answer

Prostaglandins are lipid-soluble messenger molecules derived from fatty acids (e.g. Arachidonic acid). They generate the inflammation response and are involved in vasodilation

question

What are growth factors and what do they do?

answer

- either proteins or steroid hormones - stimulate the growth and development of tissues or cells

question

What is EPO and what does it do?

answer

Erythropoietin is a growth factor that increases erythrocytes in the blood

question

What is VEGF and what does it do?

answer

The Vascular Endothelial Growth Factor is a growth factor that promotes growth of new vasculature to supply a tumor.

question

Define cytokines

answer

Certain substances (including hormones) secreted by the immune system. They can also trigger apoptosis or inhibit cell division.

question

Define pheromones

answer

chemical signaling molecules that act outside the body to trigger a physiological response in another individual (e.g. sweat)

question

How do water soluble polar hormones act differently from steroid hormones?

answer

- Water soluble polar molecules can't cross the plasma membrane. So they bind to receptors on surface and activate intracellular second messengers. - Steroid hormones cross the membrane and bind with receptors in the cell. The complex then travels to nucleus and binds to DNA. (Steroid hormones have to travel through blood with a carrier protein)

question

Give an example of negative feedback

answer

If blood glucose becomes elevated, the pancreas secretes insulin. Insulin allows glucose to enter cells, lowering blood sugar. (The hormone insulin acts to reduce further effects by inhibiting hormone production)

question

Give an example of positive feedback

answer

During labor, the child presses on and distends muscle of the cervix, triggering the release of oxytocin, which causes muscles in the uterus to contract, leading to more dilation of the cervix, which triggers more release of oxytocin

question

Define effector

answer

muscles and glans that carry out a response

question

Which part of a neuron receives information?

answer

Dendrites

question

What's the part between the cell body and the axon? Role?

answer

Axon hillock. Acts as a threshold for nerve signals. If the threshold is strong enough, the signal conducts through the axon

question

What's the role of the Myelin Sheath?

answer

insulation to prevent current loss during propagation of the electrochemical signal and speeds up rate of transmission

question

What are glial cells? Function?

answer

- support cells - non excitable - nourish, support, protect neurons

question

List the different types of glial cells and their function

answer

Astrocytes -support neurons in brain and spinal chord (CNS) Microglia -CNS -defensive phagocytes Ependymal cells -line fluid filled brain cavities Oligodendrocytes -secrete myelin Satellite cells and Schwann cells -peripheral nerves and ganglia

question

How are electrochemical signals initiated in neurons or muscle cells?

answer

membrane ion channels (ligand or voltage gated) open and ions rush in/out of cell, resulting in a rapid and reversible change in membrane potential

question

Which are the 3 components off the propagation of a nerve impulse?

answer

1. resting potential 2. graded potential 3. action potential

question

Define resting potential

answer

difference in electrical charge between the inside and outside of cell when the neuron is not conducting a nerve impulse. Inside of cell is negative compared to outside.

question

Which pump is involved in maintaining resting potentials?

answer

Sodium potassium pump

question

How does the Na+/K+ pump work to establish the resting potential?

answer

For every two K+ ions pumped in, three Na+ ions are expelled. (Relative negative charge inside the cell)

question

Define graded potential

answer

The change in potential in a localized area of the cell. its magnitude depends on the strength of the stimulus

question

How is a signal carried out through the nervous system?

answer

information reaches receptive region of cell and binds with a ligand gated ion channel. Channel opens and ions enter the cell and alter resting potential

question

How could a graded potential occur?

answer

Excitatory 1. From the opening of gated sodium channels Inhibitory 2. opening of K+ channels 3. Opening of Cl- channels - So either the loss of positive ions or a gain of negative ions

question

Define depolarization

answer

increase in membrane potential

question

Explain how an action potential occurs

answer

one or more graded potentials results in a net depolarization of the axon hillock to threshold and initiates an action potential in the axon of the neuron. If a graded potential raises membrane potential in the vicinity of the axon hillock to threshold, voltage gated Na+ channels open, allowing influx of Na+

question

The opening of which transport molecule leads to depolarization?

answer

voltage-gated sodium channels

question

The opening of which transport molecule leads to repolarization?

answer

voltage gated potassium channels

question

Why is an action potential a positive feedback system

answer

Because an action potential is self reinforcing and self propagating. each Na channel is triggered to open by the opening of adjacent Na+ channels

question

How do depolarization and hyper polarization occur one after another?

answer

- Voltage gated Na+ channel opens and lets Na+ come in (depolarization) - Channel closes - Voltage gated K+ channel opens and K+ leaves cell (repolarization)

question

Define refractory period

answer

the time delay between the opening of Na+ channels and the restoration of resting potential

question

Action potentials always have the same magnitude regardless of the strength of the stimulus. What happens if you change the strength of the stimulus?

answer

frequency of nerve impulses changes. e.g. if you drop a brick instead of a pen on your foot, more nerve impulses are conducted

question

Why do myelinated axons exhibit saltatory conduction?

answer

Because voltage gated sodium channels are concentrated in nodes of Ranvier, the action potential jumps through cytoplasm from one node to the next.

question

Why does an action potential travel faster through myelinated axons?

answer

fewer sodium channels over a smaller membrane surface area

question

What does a chemical synapse consist of?

answer

- Axon terminal (presynaptic neuron) which has synaptic knobs that contain vesicles with neurotransmitters - fluid filled synaptic cleft - postsynaptic cell

question

What happens when an action potential arrives at the synaptic knob?

answer

voltage gated calcium channels open triggering vesicles to release neurotransmitter

question

What happens when neurotransmitter binds to postsynaptic membrane receptors?

answer

ion channels open and create a graded potential in the postsynaptic cell

question

How does the binding of neurotransmitter to postsynaptic cell change membrane potential?

answer

either depolarizes or hyperpolarizes

question

Define summation

answer

the process whereby a single cell responds to multiple nerve impulses. summation can be spatial, temporal, or both

question

Define spatial summation

answer

stimulation of the same postsynaptic cell by more than one axon terminal at the same time

question

Define temporal summation

answer

rapid stimulation of the same postsynaptic cell by several nerve impulses in succession

question

What happens if both excitatory and inhibitory stimuli are received?

answer

inhibitory stimuli subtracts from the effect of the excitatory stimuli, and the cell will be less likely to depolarize sufficiently to reach threshold

question

What happens to a neurotransmitter once it's released into the synaptic cleft?

answer

- degraded - diffuses out of the cleft - taken up by active transport

question

Define synaptic delay

answer

the slight delay in signal transmission that occurs at a synapse

question

Define synapse fatigue

answer

vesicles at the end of the axon run out of neurotransmitters

question

Describe electrical synapses and their characteristics

answer

- Nerve impulse is transmitted through protein channels (connections) located at gap junctions - bidirectional signal is possible - no synaptic delay - signal can't be amplified

question

Where do electrical synapses occur?

answer

- embryonic tissues to coordinate development - protective reflex arcs and in the retina and cerebral cortex

question

List the important neurotransmitters

answer

- Acetylcholine - Dopamine - Norepinephrine - Serotonin - Glutamate - GABA - Endorphine - Adenosine/ATP - Nitric oxide

question

What types of molecules can neurotransmitters be?

answer

peptides, amino acids, purines, lipids, dissolved gases

question

Acetylcholine 1- What type of molecule is it? 2- What degrades it? 3- What does it degrade into? 4- What happens if neurotoxins inhibit its activity? 5- What does it bind to? 6- What does it stimulate?

answer

1- neurotransmitter 2- acetylcholinesterase 3- acetate and choline 4- causes tetanus and muscle spasms, or even Alzheimer's 5- excitatory receptors 6- Muscle contraction

question

Dopamine and Norepinephrine 1- What type of molecule are they? 2- What functions are they involved in? 3- What happens with low dopamine levels? 4- What happens with high dopamine levels? 5- Which drugs increase dopamine and norepinephrine levels?

answer

1- monoamine neurotransmitters derived from Tyrosine 2- memory, reward, motivation, voluntary movement, arousal (norepinephrine), fight or flight response 3- Attention deficit disorder 4- Schizophrenia 5- amphetamines, cocaine, antidepressants

question

Serotonin 1- What type of molecule is it? 2- What does it bind to? 3- What is it involved in? 4- Which drug increase serotonin?

answer

1- monoamine neurotransmitter derived from tryptophan 2- inhibitory receptors 3- peristalsis, blood clotting, vasoconstriction 4- antidepressants, and selective serotonin reuptake inhibitors, cocaine, amphetamines

question

Glutamate 1- What type of molecule is it? 2- What is its function?

answer

1- neurotransmitter derived from glutamic acid 2- primary excitatory neurotransmitter in the brain

question

GABA (Gamma-Aminobutyric Acid) 1- What is it? 2- What does it bind to?

answer

1- neurotransmitter derived from glutamate 2- binds to inhibitory receptors

question

Endorphins 1- What are they? 2- What is their function? 3- Which drugs bind to the same receptors?

answer

1- peptide neurotransmitters 2- natural opiates. inhibit release of GABA, increase the production of dopamine, and decrease pain sensitivity

question

What's the difference between excitatory and inhibitory neurotransmitters?

answer

excitatory neurotransmitters stimulate the brain whereas inhibitory neurotransmitters balance the excessive simulations without stimulating the brain.

question

Adenosine and ATP 1- What are they? 2- What's the role of Adenosine? 3- What's the role of ATP? 4- How does caffeine acts as an adenosine antagonist?

answer

1- purine molecules that function as neurotransmitters 2- binds to inhibitory receptors in the brain, facilitating sleep 3- released by sensory neurons in response to injury, initiating a pain response 4- blocks adenosine receptors in the brain and acts as a stimulant by reducing the inhibitory effects of adenosine

question

Nitric Oxide 1- What is it? 2- What is its role?

answer

1- disclosed gas 2- produces second messengers to aid learning and memory. also induces muscle relaxation

question

What makes up the CNS?

answer

brain + spinal chord

question

What makes up the PNS?

answer

peripheral nerves + ganglia

question

What are afferent (sensory) neurons?

answer

neurons that transmit sensory information towards the brain and spinal chord

question

What are efferent (motor) neurons?

answer

neurons that send responses from the CNS to muscle and glands

question

What happens differently in the gray matter and the white matter?

answer

Gray matter (nuclei): here processing of information occurs in CNS. there are unmyelinated cell bodies and synapses White matter (tracts): consists of myelinated axons that function in the transmission of info between brain regions and between the CNS and the PNS.

question

What is a nerve made of?

answer

bundles of multiple neurons wrapped by connective tissue

question

What are mixed nerves?

answer

nerves with afferent/efferent/myelinated/unmyelinated axons

question

What are ganglia?

answer

synapses and collections of cell bodies of the PNS

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