ls7c final

this class is basically an english class ngl

1. Identify critical cells involved in auditory and visual sensory transmission to the brain. 

1. auditory: hair cells

2. visual: rods, cones, bipolar cells, ganglion cells

1. Describe how hair cells function to transduce mechanical signals to the brain.

1. mechanical stimulus disturbs kinocilium

2. K+ channels open and K+ enters the cell 

3. VG Ca2+ channels open and interact with vesicles

4. vesicles release neurotransmitters into synapse

5. neurotransmitters bind to ligand-gated channels on afferent neuron

Describe parts of a simple reflex circuit

1. afferent neurons: receive sensory signals and transmit them to spinal cord

2. interneurons: relay info in spinal cord from afferent to efferent neurons

3. efferent neurons: relay signal to muscles

4. muscles: contract

Predict how photoreceptors change in response to light exposure

1. in presence of light, rhodopsin dissociates from G-protein, which binds to the effector to turn cGMP into GMP

Predict the effect of toxins or genetic mutations on the function of skeletal muscles

1. botox prevents muscle contraction

2. Clostridium tetani causes prolonged muscle contraction

Evaluate the physiological consequences of altering the structure/function of skeletal muscle components (e.g., SR, myosin, troponin)

1. SR

   1. if SR were always open, Ca2+ presence in the cell would be toxic

   2. if SR were always closed, no muscle contraction could occur

2. myosin

   1. if myosin could not bind actin or ATP cannot be hydrolyzed, muscle contraction cannot occur

   2. if there is no ATP, muscles stay in rigor

3. troponin

   1. if troponin cannot bind Ca2+, muscle contraction cannot occur

   2. if troponin gains function, prolonged muscle contraction will occur

Explain how sensory information is encoded in action potentials

intensity of stimulus is proportional to rate of action potentials

Explain how the processes of vision and hearing occur

1. vision

   1. light hits rod or cone, causing rod or cone to hyperpolarize and stop sending neurotransmitters

   2. without neurotransmitter, mGluR channels on bipolar cells close, causing their VG channels to open and depolarization to occur

   3. in turn, the ganglion cells are depolarized

   4. signals are sent from the optic nerve to the brain for processing

2. hearing

   1. sound waves travel through endolymph of the cochlea, causing vibrations of the basilar membrane and a mechanical stimulus against the hair cell’s stereocilia to kinocilium

   2. hair cell releases neurotransmitter and signal is processed

Describe the structure and function of a neuromuscular junction

1. junction between motor neuron and muscle cell

2. motor neuron releases Ach, binds to channels on muscle cell and allows depolarization of muscle cell

1. Identify cellular, molecular, and protein components involved in muscle contraction and explain their role

1. action potential: allows motor neuron’s Ca2+ channels to open, which allows Ach to be released

2. Ca2+: in the motor neuron, allows Ach release; in muscle cell, binds to troponin to move tropomyosin and expose actin binding sites

3. Sarcoplasmic Reticulum: stores Ca2+ when muscle is not contracting because Ca2+ is toxic to the cell

4. voltage-gated channels: motor neuron has VG Ca2+ channels to allow Ca2+ in during action potential

5. Troponin: binds to Ca2+ and moves tropomyosin

6. Tropomyosin: covers actin binding sites to prevent muscle contraction in the absence of Ca2+

7. Actin: “thin” filament of muscle which moves when myosin heads bind to it

8. Myosin: “thick” filament of muscle which forms cross-bridges with actin to contract the muscle

9. ATP: binds to myosin after a power stroke, causing it to enter a high-energy state

1. Relate the structure of skeletal muscle to its function in generating a contractile force

1. bundles of muscle fibers are individual cells, and bundles of these cells make up fascicles

2. the large amount of muscle fibers in a muscle allow a high amount of force to be produced during contraction

1. Describe the cross-bridge cycle in a skeletal muscle

1. the myosin head’s ATP is hydrolyzed to ADP and Pi as it binds to the exposed binding site

2. the myosin heads pulls the actin in a power stroke, releasing its ADP and Pi

3. the power stroke ends and the myosin head is in a low energy state

4. ATP binds to the myosin head and causes it to enter a high energy state

1. Compare and contrast the structure and function of slow-twitch versus fast-twitch muscles

1. slow-twitch

   1. prolonged muscle contraction

   2. many mitochondria

   3. oxidative phosphorylation is main source of ATP

   4. have more myoglobin

   5. are red in color

2. fast-twitch

   1. short bursts of powerful muscle contraction

   2. can be oxidative or use glycolysis; exercise converts glycolytic cells into oxidative cells

   3. have less myoglobin

   4. have a pale to white color

1. Explain the relationship between surface area-to-volume ratio and gas exchange efficiency

better surface area-to-volume ratio means more places for gas exchange to occur so gas exchange efficiency is higher

Describe the changes in muscle contraction, volume, and pressure that occur during ventilation

the diaphragm contracts, the volume increases and the pressure in the thoracic cavity decreases causing inhalation; the diaphragm then relaxes, decreasing volume and increasing pressure, leading to exhalation

Relate partial pressure and Boyle’s Law to ventilation and gas exchange

1. partial pressure is inversely related to volume, driving ventilation

2. gases flow from high partial pressure to low partial pressure, driving gas exchange

Explain how the nervous system regulates breathing and how this relates to homeostasis

chemoreceptors in the medulla sense pH: if it is too low, breathing rate increases to bring more oxygen to the blood until it rises to normal

Describe how hemoglobin binds oxygen and how this relates to gas exchange

hemoglobin binds 4 oxygen molecules to carry them throughout the blood

Predict how changes in elevation or external pressure will affect ventilation and gas exchange

higher elevation/lower external pressure shifts curve to the right

Describe the properties of blood and blood vessels

1. blood is 55% plasma, which has water, ions and proteins; 45% cells and platelets

2. blood vessels allow blood to flow from high to low pressure gradients; they have three layers: adventitia, tunica media, and tunica intima

Discuss the various functions of the cells, proteins, and other components found in human blood

1. cells

   1. red blood cells

      1. carry oxygen

   2. white blood cells

      1. fight infections

2. proteins

   1. albumins

      1. create and maintain osmotic pressure

   2. globulins

      1. immune function

   3. fibrinogen

      1. blood coagulation

   4. regulatory proteins

      1. regulate gene expression

   5. clotting factors

      1. convert fibrinogen into fibrin

3. plasma

   1. transportation, immune function, and contribution to blood volume

4. platelets

   1. clotting

Trace the flow of blood through the human circulatory system

left ventricle → aorta → arteries → arterioles → capillaries → veins → venae cavae → right atrium → right ventricle → pulmonary artery → lungs → pulmonary vein → left atrium → left ventricle

Describe the changes in blood pressure and muscle contraction that occur during the cardiac cycle

1. pressure rises during contraction

2. pressure drops during relaxation

Relate changes in ion movement to the cardiac action potential

1. phase 0: cardiac cells send Na+ ions through gap junctions to trigger depolarization and action potentials

2. phase 2: Ca2+ binds to ryanodine receptors on SR, opening SR and causing contraction; K+ flows out, Cl- flows in, 

3. phase 3: K+ pumps remain open to kick out K+ and repolarize cell

4. phase 4: cardiac cells have only pumps like Na+/K+ pumps working to maintain potential, but cardiac pacemaker cells have slow Na+ influx

Explain heart muscle contraction in response to an action potential

1. SA node fires

2. atria contract

3. AV node

4. bundle of His

5. Purkinje fibers

6. ventricular contraction

Relate the events during the cardiac cycle to those represented on an ECG

1. SA node contracts = beginning of P wave

2. atrial contraction = P wave to beginning of Q wave

3. AV node = end of P wave

4. atria relax = beginning of Q wave

5. ventricles contract = beginning of Q wave to beginning of T wave

6. ventricles relax = beginning of T wave to beginning of Q wave

Discuss how a signal can lead to both short- and long-term responses.

1. short: most pathways, stuff that relies on phosphorylation

2. long: anything that activates a transcription factor to alter gene expression

1. Describe the mechanism of action for a receptor tyrosine kinase pathway.

1. signal molecule dimerizes RTK

2. RTK becomes phosphorylated

3. more proteins are activated, leading to a signaling cascade

1. Define the role of kinases and phosphatases in cell signaling pathways.

1. kinases add phosphates

2. phosphatases take phosphates away

1. Distinguish the potential for differentiation of totipotent, pluripotent, and multipotent stem cells.

1. totipotent: can become any cell in the organism

2. pluripotent: can become any somatic cell

3. multipotent: can become any cell of a specific tissue type

Explain why diffusion and surface area limit cell size and its implications for large, multicellular organisms.

1. cells that are too big will have relatively small surface areas

2. this makes diffusion inefficient

3. large, multicellular organisms must have lots of cells

Determine if certain proteins in a signaling pathway function as phosphatases, kinases, or neither.

1. takes a phosphate away from something when active: phosphatase

2. adds a phosphate to something when active: kinase

3. does neither: neither

1. Explain how a signal transduction pathway can be turned off.

1. ligand dissociates from receptor

Predict the effect of altering part of a signaling transduction pathway.

1. different product formed

2. product formed when it isn’t supposed to be

3. no product formed when it is supposed to be

Interpret data related to different types of cell signaling pathways.

1. dimers: RTK

2. squiggly thing with G protein: G protein receptor coupled

Predict cell fate based on cell activation of signaling pathways.

1. follow the diagram

1. Describe the different types of cell-cell junctions.

1. tight junction: seals off layer of cells, divides cells into apical and basal portions, not attached to cytoskeleton

2. adherens junction: connects cells to epithelial layer and each other, belt-like structure, connected to cytoskeleton, uses cadherins

3. desmosome: connects cells to each other through button-like points, connected to cytoskeleton, uses cadherins

4. hemidesmosome: connects cells to basal lamina for anchorage, connected to cytoskeleton, involves integrins and intermediate filaments

5. gap junction: allows direct cell communication, not attached to cytoskeleton, made of connexins

Define microtubule, microfilament, and intermediate filament.

1. microtubule: made of tubulin dimers; supports structure, function, and cell division

2. microfilament: made of actin monomers, supports structure and function

3. intermediate filament: made of many subunits, provides cell shape and structure

Explain how motor proteins actively move material around the cell.

1. kinesin: conformational changes, with ATP, to move along microtubules, goes “out” toward + end

2. dynein: goes “in” toward - end

Explain how cell-cell junctions and the ECM contribute to the cell’s abilities to form tissues and organs.

1. they connect cells and tissues together

1. Evaluate how changing components of the cytoskeleton would change cell structure (shape) and/or function (i.e., motility).

1. cells might not be able to connect to each other

2. cells might not be anchored

3. cells might lose communication pathways

Evaluate the effect of modifying cell-cell junctions or ECM components on tissue structure and function.

1. no tight junctions: movement of stuff through cells is lost

1. Describe the general structure of a neuron.

1. cell body connected to many dendrites, also to axon hillock, then to axon covered in myelin sheath which is broken up by nodes of Ranvier, then to axon terminal

Relate the structural features of a neuron (dendrites, axons, etc.) to their functions

1. dendrites are many = can receive many signals

2. axon is long = can send signals long distances

3. myelin sheath = faster signaling

4. nodes of Ranvier = faster signaling

Explain membrane potential and how it arises in both neuronal and non-neuronal cells.

1. electrochemical gradient produced by active transport

2. in neurons, Na+/K+ pump

Explain the process by which an action potential is generated and propagated.

1. enough EPSPs are generated to reach threshold, -55 mV

2. voltage-gated Na+ channels open

3. mass influx of Na+ channels open down the axon; depolarization

Compare and contrast ligand-gated and voltage-gated ion channels with respect to their role in signal transduction in a neuron.

1. ligand-gated are at dendrites and receive neurotransmitters from other neurons

2. voltage-gated are on the neuron and control action potentials

Explain the process by which two neurons communicate at a synapse.

1. presynaptic neuron releases neurotransmitters

2. neurotransmitters bind to ligand-gated receptors on dendrites of postsynaptic neuron

3. EPSP or IPSP is generated in postsynaptic neuron

Discuss how EPSPs and IPSPs are received and integrated by a postsynaptic neuron.

1. temporal: many signals at once cause significant effect

2. spatial: many of the same type at the same time on different dendrites cause effect

3. they can cancel each other out

Evaluate how multiple signals will be integrated by a postsynaptic neuron that has formed synapses with two or more presynaptic neurons.

1. see temporal and spatial summation

Predict how a charged molecule will move across a semipermeable membrane in the presence of an electrochemical gradient.

1. it will attempt to move through a channel with its gradient

Predict how the addition of drugs or the introduction of mutated proteins will alter membrane potential, excitability, and/or signal transmission.

1. proteins can change resting potential

2. drugs can act on receptors as agonists or antagonists

Describe the global organization of the human nervous system.

1. central (brain and spinal cord)

2. peripheral (everything else)

   1. somatic (voluntary)

   2. autonomic (involuntary)

      1. sympathetic (fight or flight)

      2. parasympathetic (rest and digest)

Relate the major regions of the brain, including the hypothalamus, thalamus, and sensory cortex to their respective functions.

1. hypothalamus: effects responses in body regulation from brain

2. thalamus: processes sensory info except smell

3. sensory cortex: analyzes sensation

Compare and contrast the sympathetic and parasympathetic divisions of the autonomic nervous system.

1. both are in autonomic divisions

2. sympathetic: danger mode, increased heart rate, adrenaline

3. parasympathetic: no danger, decreased heart rate, digestion

Explain how the brain receives, processes, and sends information.

1. receives: sensory organs, signals from PNS

2. processes: neuron signaling

3. sends: more neuron signaling to rest of body; hormones

Evaluate which region of the brain has been damaged in a patient based on a set of symptoms.

1. Broca’s area: unable to speak well

2. Wernicke’s area: unable to understand

3. cerebellum: coordination problems

4. frontal lobe: personality changes

5. occipital lobe: vision changes

Predict which branch, sympathetic or parasympathetic, will respond to different stimuli.

1. dangerous stuff: sympathetic

2. calming stuff: parasympathetic 

Identify the components of a homeostatic negative feedback system.

1. stimulus, sensor, effector, response

Explain how each component of a homeostatic negative feedback system contributes to maintaining physiological stability.

1. sensor senses a stimulus

2. sensor triggers effector

3. effector creates response

4. response stops stimulus

Differentiate between negative feedback and positive feedback, providing examples of each.

1. negative: response stops stimulus (calcium, blood glucose)

2. positive: response increases stimulus (childbirth, blood clotting)

Predict how components of a homeostatic system will change when part of the system is perturbed.

1. sensor may not sense stimulus

2. effector may not create response or create wrong response

Apply the concept of negative feedback to the process of thermoregulation.

1. too hot: brain tells blood vessels to dilate and skin to sweat, causing cooldown

2. too cold: brain tells blood vessels to constrict and muscles to shiver, causing warming up

Relate changes in environmental conditions to changes in physiological or behavioral responses to temperature regulation.

1. environment affects what temperature brain perceives

2. causes appropriate response to environment

1. Relate endocrine function to homeostatic regulation.

1. endocrine system is used to send signals from brain to body (effector)

Explain when and why hormones are released.

1. hormones are released in response to signals

2. hormones cause changes throughout the body

Define the different types of hormones.

1. peptides are made of chains of amino acids

2. amines are derived from aromatic amino acids

3. steroids are derived from cholesterol

Discuss the role that hormones play in the maintenance of homeostasis.

hormones cause changes as effectors

Explain the relationship between the hypothalamus and pituitary.

hypothalamus hormones cause pituitary to release hormones

Determine whether a particular hormone will interact with a cytosolic or membrane-bound receptor.

1. peptides and amines: membrane-bound

2. steroids: cytosolic

Predict which hormones have been released from the pituitary to elicit a specific tissue response.

1. anterior:

   1. ACTH affects blood sugar

   2. FSH causes sperm production or estrogen production

   3. Growth hormone causes growth

   4. LH causes ovulation or testosterone production

   5. prolactin causes milk production

   6. TSH causes thyroid to produce hormones

2. posterior: 

   1. ADH regulates water balance

   2. oxytocin assists in labor and promotes mother-child bonding

Evaluate the consequences of altering a component of a hormone pathway.

1. too much response produced

2. not enough produced

Describe different vertebrate reproductive strategies.

ovipary: embryo develops in an egg outside the mother’s body

ovivipary: embryo develops in an egg inside the mother’s body

vivipary: embryo develops in the mother’s body

1. Describe the method of action for a G-protein coupled receptor pathway.

1. ligand binds to receptor, activating it

2. G-protein binds to activated receptor

3. G-proteins GDP is replaced with GTP, attached to the alpha-subunit, which detaches

4. alpha-subunit with GTP binds to adenylyl cyclase

5. adenylyl cyclase converts ATP into cAMP

6. cAMP activates PKA, causing response

Identify critical components of the endocrine system involved in regulating the human reproductive system.

1. gonads contain testes/ovary

2. gametes (sperm or egg)

3. hormones: testosterone and estrogen or estrogen and progesterone

4. hormones target Leydig and Sertoli cells or granulosa cells

5. causes gametes to be released

Discuss the similarities and differences in hormonal control of male and female reproductive systems.

1. they use some of the same hormones but in different balances and with different responses

Describe the process of oogenesis and spermatogenesis.

1. oogenesis: 

   1. FSH and LH cause development of secondary follicles around oocyte

   2. after LH surge, secondary oocyte splits off and undergoes meiosis II

   3. ovulation

2. spermatogenesis

   1. spermatogenic cells reach testes

   2. after meiotic division, spermatids are formed

   3. spermatids differentiate into sperm cells

Predict how changes in release of pituitary sex hormones will alter oogenesis and spermatogenesis.

1. no hormones = no production

Provide examples of organisms that rely on different modes of reproduction.

1. yeast: asexual budding

2. some fish: parthenogenesis

Distinguish between second messengers and other components of signal transduction pathways.

second messengers are intracellular and relay receptor cell signals to effector proteins

anatomy of a signaling pathway

anatomy of a signaling pathway

calcitonin and pth

calcitonin and pth

cell junction

cell junction

glucagon

glucagon

G-protein coupled receptor

G-protein coupled receptor

homeostasis

homeostasis

insulin

insulin

membrane potential

membrane potential

motor protein highway

motor protein highway

motor proteins

motor proteins

nervous system organization

nervous system organization

neural pathways

neural pathways

neurotransmitters

neurotransmitters

reproductive cycles

reproductive cycles

sex hormones and feedback loops

sex hormones and feedback loops

signal amplification

signal amplification

T3 and T4

T3 and T4

uterus

uterus

Define and differentiate between the terms microbiome, microbiota, metagenome, and holobiont

1. microbiome: organisms and their genetic material

2. microbiota: community of microbes living in a specific environment

3. metagenome: the sum of all genetic material of microorganisms

4. holobiont: combination of the host and all its microorganisms

Explain how and when the human microbiome is formed

formed at birth from environment of birth (skin microbiome of mother inherited in C-sections, vaginal microbiome of mother inherited in vaginal birth)