A&P Unit 3 exams

Cellular Respiration

ATP required for cellular respiration. ~10 million used per second in humans. It’s required for muscles to relax/contract.

Starts with Glycolysis and breaks down glucose: 2 pyruvate.

Acetyl-coa enters CAC, generates most electron carriers for ETC:makes most ATP for cell matrix (34/38 atp per glucose.)

ATP

Adenosine triphosphate

Proton Pumps

NADH Dehydrogenase complex

Cytochrome C-1 complex

Cytochrome oxidase

Electron carriers

Q or Ubiquinine

Cytochrome C

Mitochondria

CAC(in Matrix) and ETC (in IMS)site

ETC

Series of Oxidation & Reduction reactions.

Molecule oxidized:loses electron, reduced: gains electron

Nicotinomile NADH & Flovindinucleotide FADH2

Reduced form of electron carriers, donate to ETC.

After giving electrons, oxidized to NAD+ and FAD, reduced in CAC

6 steps of ETC

1. NADH donates 2 electrons → 1st proton pump. NADH dehydrogenase complex pumps → 2 protons (H+) matrix → IMS.

2. two electrons carried via Q → Cytochrome b-c pumps 2 more electrons. Matrix→IMS

3. Electrons→3rd pump Cytochrome oxidase by cytochrome C.

4. Cytochrome oxidase needs 4 electrons, other 3 come from NADH →1st pump or FADH2 → 2nd pump cytochrome b-c.

5. Cytochrome oxidase has 4 electrons, 4 protons pumped matrix→IMS.

6. 4 electrons cleared from chain via O2, 4 more added forming 2 H2O.

7. Potential energy:proton gradient between IMS & matrix→ ATP-Synthase(spinning) form of kinetic energy→ ADP + PI: ATP

   ~10 H+ ~ 3 ATP

Classes of Enzyme

Kinase:

ATP + INTERMEDIATE → ADP + INTERMEDIATE

ADP + INTERMEDIATE → ATP + INTERMEDIATE

Isomerase (mutaste): rearranges connectivity of molecule. Nothing added/taken.

Dehydrogenase: facilitate movement of electrons. They’re oxidation reduction enzymes. Often create electron carriers. oxidized→ NADH from NAD+, FADH2 from FAD.

Products:

Glycolysis:

2 NADH

2 ATP

2 PYRUVATE

Pyruvate Oxidation:

2 NADH

2 ACETYL-COA

Citric Acid Cycle:

3 NADH

1 ATP(gtp)

1 FADH(per turn)

Produces 2 ACETYL-COA in PYRUVATE OXIDATION, turns 2x per glucose:

6 NADH, 2 FADH2, 2 ATP(gtp)

Total: 10 NADH, 2 FADH2, 4 ATP

Acetyl-COA: coenzyme of Citrate Synthase made in 3 ways

(1st step facilitates conversion of oxaloacetate → citrate)

1. Pyruvate oxidation

2. conversion of some amino acds

3. Beta oxidation of fatty acids (glycerol used)

Adenosine Triphosphate (3 phosphates)

Molecule the body uses as chemical potential energy

Terminal Phosphate

Broken off ATP → ADP energy released

ATP → Adenosine Diphosphate (ADP)

ADP + Pi → ATP not favorable, +🔺G

Two ways to make ATP from ADP + Pi :

1. Via ATP-Synthase in ETC

2. Via Kinase enzyme

38 ATP made per glucose molecule, 4 via Kinase, 34 via ATP-Synthase

ADP+PI→ATP(+🔺G), not spontaneous, add together to ATP. Instead, Kinetic energy of ATP ATR-Synthase spinning hits 2 molecules together forcing ADP+Pi → ATP

Excessive ATP deactivates 3 enzymes in glycolysis = Phosphofructokinase

Muscles

Muscle cells have Myoglobin (protein) that stores oxygen. Oxygen used for 5-6 seconds for quick activity and supplies ETC with Oxygen.

Glycogen (polymer of glucose)

found in muscle and hepatic(liver) cells , can be used in glycolysis during times of low glucose.

Muscle Contractions

1. Synaptic end bulbs releases Acetylcholine binds → Na+ channels

2. Na+ ions rush inside cell & raise voltage -70mV → +30mV. Voltage gated calcium channels on Sacroplasmic Reticulum open & flood Cytosol with Ca2+.

3. Calcium ions bind Troponin→attached→Tropomyosin which moves Troponin/Tropomyosin complex out of way of Myosin binding sites on actin.

4. ATP per Myosin (1000s) reaches up, binds to Actin and shortens sacromeres moving actins closer to midline.

Muscle Relaxtion

1. Acetylcholinesterase destorys Acetylcholine, closes NA+ channels.

2. ATP driven Na+ pump, pumps out Cytosolice Na+ ions, restore -70 mV Cytosolice voltage.

3. ATP-driven Calcium pumps returns calcium → sarcoplasmic reticulum.

4. ATP per Myosin head used to relax muscle.

Skeletal muscle

Arranged in bundles with Fascia (clear thin connective tissue).

Fascia wraps Epimysium (outer most bundle).

Inside Epimysium is Permysiumbundles (contain Endomysium bundles).

Endomysium bundles have individual skeletal muscle cells. (thin long fivers on repeating sacromeres).

Skeletal muscles have multiple nuclei. During Embryogenesis, myoblast (precursoe muscle cells) fuse together, all nuclei retained. With cardiac and smooth muscle, myoblast don’t fuse together. Skeletal muscle is vountary, controlled by somatic nervous system.

Cardiac Muscle

Uninucleated, different shaped cells than skeletal. Cells are branching, controlled by Autonomic Nervous System.

Smooth muscle

Uninucleated, involuntary, and different shaped cells. Resemble a grain of rice but together create “smooth” muscle. Found in stomach.

Nervous system

Divided into Somatic and Autonomic Nervous systems.

Somatic nervous system

Direct conscious control. Controls skeletal muscles.

Autonomic nervous system

Not direct conscious, controls heartbeat, rate of breathing, various organs and glands

Structures

Brain and Spinal Cord make up Central Nervous System(CNS). All nerves and ganglia branch off Brain and Spinal Cord, and make up Peripheral Nervous System (PNS)

Nervous System

Composed of Neuron cells connecting to each other

Autonomic Nervous System new subdivision

Enteric Nervous System: controls Gastrointestinal tract

Neurons

Number of connection points to cell body indicating Neuron type.

Unipolar

Single connection point to cell body, usually Afferent sensory neurons

Bipolar

Two connection point to cell body, found in spinal cord

Multipolar

Multiple connections points from dendrites, usually Efferent motor neurons

Axoaxonic connections

Connect one neuron to axon of another

Axosomatic connections

Connect one neuron to cell body of another

Axodendritic connections

Connect one neuron to dendrites of another

Diverging Circuits

starts with one or few neurons having Action Potential, passing signals to others, as signal progresses

Converging Circuits

starts with multiple neurons passing Action Potential to smaller number of neurons

Reverberating signals

intital neuron sending signal (looped) and stimulates original neuron again (usually seen with pain)

Parallel circuits

travel side by side, originate from same neuron → split into two Action Potential series

Neurons pass Action Potential signals

inside of neuron -70mV, and with Stimulus/Acetylcholine from previous Action Potential, previous neuron passing Action Potential → calcium channels on Sarcoplasmic Reticulum open. If inside the cell reaches - 55mV (threshold), then Action Potential occurs. If -55mV not reached, nothing happens. (all or nothing).

Rapid depolarization occurs as voltage gated Na+ channels open at trigger zone (base of axon).

Pricking Finger!

Na+ channels open at trigger zone, Na+ rushes into cell and spikes voltage +30mV. Signal → next node of ranvier, and at previous node, Na+ K+ pump exchanges 3 Na+ out of cell for 2 K+ back into cell. Quickly repolarizes membrane, and hyperpolarizes membrane to -90mV. Leaky Na+ channels bring membrane back up -70mV.

Sense of Touch

Afferent sensory neurons when stimulated cause release of calcium → cell body of Unipolar Afferent Neuron. Threshold of -55mV reached due to Smoother ER releasing calcium, voltage gated Na+ channels on trigger zone of axon open, quickly spiking membrane + 30 mV. Action Potential passed → next node of Ranvier, previous node becomes repolarized via Na+/K+ pump kicks out 3 Na+ for every 2K+ brought in cell. Quickly hyperpolarizes membrane -90mV → back to rest -70 mV via leaky Na+ channels. Signal taken up Spinal Cord via Ascending Horn to Brain stem. Structure called Reticular Formation: relay statin shunt signals → appropriate part of brain. Parietal lobe contains sensory cortex → processes signals and passes → motor cortex in frontal lobe → sends signal back down spinal cord, the Efferent motor neurons in arm cause muscle to contract. Acetylcholine released from Synaptic end bulbs → Neuromuscular junction.

Myelin (lipid)

increases speed of Action Potential → -100m/s. Without Myelin, signal only travels 2-3 m/s. Myelin coats the axon, placed in CNS by Oligodendrocytes, and in PNS by Schwann cells. Gaps between Myelin Sheaths called Modes of Ranvier: allow Action Potential signals to hop node to node.

sense of smell

scent molecules in air picked up by receptors → trigger Afferent sensory neurons. Olfactory nerves travel → holes in cribiform plate (Ethmoid)→ Olfactory bulbs, signal here is taken to Parietal Lobe’s sensory association center to identify smell.

*Olfactory receptors work with specific molecular shapes. Different scent molecules will lock into different receptors Many smells are combination of different molecules*

Sense of taste

tongue has taste buds: receptors capable of recognizing sweat, salty, bitter, sour, and umami. Different combinations give all possible flavors. Signal taken → Assocation center (to see possible flavors). Signal → Association center of Parietal lobe of Parietal lobe via Cranial Nerve (CLX) Glossopharyngeal

sense of hearing

sound travels in waves. Every sound wave has a unique frequency and amplitude. sound enters ear canal → tympanic membrane (ear drum) vibrates some frequency and amplitude as sound waves. The vibrations cause 3 inner ear bones (incus, malleus, and stopes) to push on vestibule. Vibrations on Vestibule and Cochlea, have proteins within Corti (small organ) their vibrations, relayed → Afferent Auditory Neurons → lead to → Vestibulocochlear Nerve (CN8) → takes signal→ Temporal Lobe→ where sound is understood → sent→ Assocation Center to look for familiarity. (do we know the sound?) signal → Brocas area (temporal lobe) to respond appropriately.

Sense of Sight

Light travels in Photons (particles of light) that enter eye through Pupil (small opening). Around pupil is Ciliary bodies (smooth muscle) that can constrict (less light), dilate (more light). In front of ciliary bodies is the Iris (eye pigment). Brown eyes (less light), Blue/green/albino eye (all light in). Eye itself filled with Crystalline protein: Vitrious humor: amplifies light for Retine (membrane on back of eye)

Retina has

rods and cones (photoreceptors)

Rods

grey scale (white, grey, black)

cones

colors

Lens are behind

Pupil that mirror image (flipping/reversing) signal from left/right are separate image

optic nerve (cranial nerve 2)

takes signals from eyes → midbrain

optic chiasma

criss-crosses left/right signals → occipital lobe

images in occipital lobe

corrected, flipped, reversed, integrated into one. signals → association center in Parietal Lobe for interpretation

Sympathetic nervous system response

subdivision of Autonomic Nervous System. Amygdala (in temporal lobe): threat assessment center.

Danger sensed Amygdala triggers Pituitary to release Adrenocorticotropic hormone, stimulates Adrenal glands to make Epinephrine, Norepinephrine, and cortisol.

Epinephrine

heart beat with more force

Norepinephrine

stimulates Glycolysis. Gluconeogenesis cortisol helps fat to be stored more efficiently in the liver. Pupils dilate (more light in) to see any other possible dangers. Precapillary sphincter leading to Gastrointestinal Tract closes, allowing blood → redirected → skeletal muscle. Eccrine sweat glands activated during flight/fight.

Parasympathetic nervous system

most people live most of their life in this mode. Adrenal glands mot putting out stress hormones, Pupils not dilated unless low light, Eccrine sweat glands inactive unless it’s not outside. Blood flow prioritized → Gastrointestinal tract.

Lobes of the brain

Frontal, Temporal, Parietal, Occipital,

not lobes: Cerebellum, Reticular Formation, Thalamus, Hypothalamus

frontal lobe

contains motor cortex: responsible for voluntary movement.

Short term memories started here. → transferred → long term memory → temporal

Temporal Lobe

long term memories stored here. Amygdala: threat assessment center.

When in “LOVE“, amygdala turned off until procreation, then resumes normal functionality. Temporal processes all activity for Auditory and Visual signals

Parietal:

contains sensory cortex: interprets Afferent signals → frontal motor cortex. Also Assocation center for auditory and visual signals.

Occipital Lobe

processes sense of sight. Image corrected by flipping, reversing and integrating Afferent Photoreceptor signals from eyes.

Cerebullum

not a lobe, located under occipital, responsible for muscle tone, normal breathing, and heart rate

Reticular Formation

located superior→ brainstem, signal relay station that sends singal from spinal cord → appropriate part of Brain

Thalamus

controls sense of alertness, keeps you awake.

Hypothalamus

controls hunger, thirst, and body temperature

How many Cranial Nerves are there?

12