Cellular Respiration, Neural Physiology, Cranial Nerves, and Spinal Tracts

Flashcards covering cellular respiration, membrane transport, nerve action potentials, cranial nerve testing, and spinal cord ascending/descending tracts.

Glycolysis

A process occurring in the cytoplasm where glucose is converted into $2$ pyruvate, $2$\text{ NADH}, and $4$ (NET $2$) $\text{ATP}$.

Krebs Cycle

A metabolic cycle occurring in mitochandria with an output of $6$\text{ NADH}, $2$\text{ FADH}_2, $6$\text{ ATP}, and $4$\text{ CO}_2.

Electron Transport Chain

Occurs in mitochondria using an input of $\text{NADH}$ and $\text{FADH}_2$ to yield an output of $34$\text{ ATP} and water.

Diffusion

Passive transport moving substances from high concentration to low concentration without requiring energy.

Osmosis

Passive transport of water across a permeable membrane from a low concentration of solute to a high concentration of solute requiring no energy.

Facilitated Diffusion

Passive transport from high to low concentration using transport proteins for non-lipid soluble substances.

Filtration

Movement of water and small solutes across a membrane due to pressure, requiring no $\text{ATP}$.

Active Transport

Movement of solutes from low to high concentration using pump proteins and requiring $\text{ATP}$.

Resting Membrane Potential

State at $-70$\text{ mV} when not sending a signal, where the sodium-potassium pump moves out $3$\text{ Na}^+ and in $2$\text{ K}^+ creating higher $\text{Na}^+$ outside and higher $\text{K}^+$ inside.

Depolarization

Phase triggered when a stimulus opens voltage-gated $\text{Na}^+$ channels at $-55$\text{ mV} (point of no return), causing $\text{Na}^+$ to rush in and reaching $+30$\text{ mV}.

Repolarization

Phase at the peak of an action potential where $\text{Na}^+$ gates close and $\text{K}^+$ gates open, causing $\text{K}^+$ to rush out and the inside to become more negative again.

Hyperpolarization

Brief overshoot of membrane negativity reaching $-80$\text{ mV}.

Enzymatic Degradation

Neurotransmitter degradation method where an enzyme in the synaptic cleft breaks down neurotransmitters into inactive components to stop the signal.

Reuptake

Neurotransmitter degradation method where transport proteins pull neurotransmitters back into the presynaptic neuron to be repackaged or broken down.

Excitatory Neurons

Neurons that release glutamate to bind to postsynaptic receptors, allowing $\text{Na}^+$ to enter the cell and move membrane potential closer to $-55$\text{ mV}.

Inhibitory Neurons

Neurons that reduce the likelihood of postsynaptic firing by releasing neurotransmitters that open ligand-gated channels for negative ions, causing hyperpolarization.

Saltatory Conduction

Conduction mechanism where electrical current travels quickly under the myelin sheath and triggers voltage-gated $\text{Na}^+$ channels located at the Nodes of Ranvier, appearing to jump from node to node.

CN I (Olfactory)

Cranial nerve responsible for smell, tested by having the patient identify a familiar odor.

CN II

Cranial nerve carrying sensory impulses from the eye; evaluated via Shellen Charts for acuity, ishihara plates for color, visual field tests, and fundoscopy.

CN III, IV, and VI (Oculomotor, Trochlear, Abducent)

Cranial nerves tested by drawing two 'H' shapes in front of patient's eyes to follow and checking for double vision.

CN V (Trigeminal)

Cranial nerve tested using cotton ball/blunt point to jaw, cheek, and forehead, touching cornea with cotton, feeling clenched jaw, and testing jaw jerk.

CN VII (Facial Nerve)

Cranial nerve responsible for taste on anterior $\frac{2}{3}$ of tongue and muscles of facial expression (creasing forehead, keeping eyes closed against resistance, puffing cheeks, showing teeth).

CN VIII (Vestibulocochlear)

Cranial nerve evaluated using the Rinne test (mastoid process vs next to ear) and Webster's test (center of forehead).

CN IX (Glossopharyngeal)

Cranial nerve responsible for sensory input on posterior $\frac{1}{3}$ of tongue, gag reflex, and touching arches of pharynx.

CN X (Vagus)

Cranial nerve regulating speech and swallowing, tested by evaluating speech and inspecting for uvula deviation before and after saying 'ahh'.

CN XI (Accessory Nerve)

Cranial nerve testing Sternocleidomastoid and trapezius muscles by having the patient shrug shoulders and turn head against resistance.

CN XII (Hypoglossal)

Cranial nerve tested by inspecting for any tongue deviation when stuck out.

Fasciculus Gracilis

Ascending spinal tract in posterior funiculi carrying discriminative touch, visceral pain, vibration, and proprioception for the lower body; combines at T6 and decussates at medulla oblongata.

Fasciculus Cunneatus

Ascending spinal tract in posterior funiculi carrying discriminative touch, visceral pain, vibration, and proprioception for the upper body; combines at T6 and decussates at medulla oblongata.

Anterior Spinothalamic Tract

Ascending tract located in anterior funiculi carrying pain and light touch information that crosses in the spine at varying levels.

Lateral Spinothalamic Tract

Ascending tract located in lateral funiculi carrying pain and temperature information that crosses in the spine at varying levels.

Spinocerebellar Tracts

Ascending tracts located in anterior funiculi delivering motor control to the cerebellum; anterior crosses at medulla oblongata while posterior does not cross.

Corticospinal Tracts

Descending motor tracts forming the pyramidal system; anterior crosses at varying levels while lateral crosses at medulla oblongata.

Rubrospinal Tract

Descending tract located in the lateral funiculus regulating motor control, posture, and coordination.

Ascending Sensory Motor Pathway

Pathway where sensory receptors convert information, carry it to CNS via afferent pathways, ascend spinal tracts to the thalamus, and route to cerebral cortex.

Descending Sensory Motor Pathway

Pathway beginning in pre-central gyrus (frontal lobe), bypassing thalamus into spinal cord via descending tracts, and exiting via efferent pathways to effectors.

C5 Spinal Root Testing

Assesses shoulder abduction (Deltoid and Bicep), lateral arm sensation below deltoid, and bicep reflex.

C6 Spinal Root Testing

Assesses elbow and wrist flexion (Brachioradialis and ECRL), thumb and radial hand sensation, and brachioradialis reflex.