anat

What does the all-or-nothing principle of action potentials state?

A neuron fires fully or not at all.

Fill in the blank: The steps of an action potential are resting, __, repolarization, and refractory.

depolarization (Na+ in)

What are the two main parts of the nervous system?

CNS (Central Nervous System) and PNS (Peripheral Nervous System).

What does CNS stand for?

Central Nervous System.

What is the structure of a multipolar neuron?

It has dendrites (receive), a cell body, an axon (transmit), and myelin (insulate).

What is an example of a reflex arc?

Knee-jerk.

What is the path of a reflex arc?

Receptor → Sensory neuron → Spinal cord → Motor neuron → Effector.

What are the most acute receptors in the vision process?

Cones located in the fovea.

Fill in the blank: Erythrocytes are responsible for transporting and in the blood.

O₂ and CO₂.

What are leukocytes responsible for?

Immunity.

What is the normal pH range of blood?

7.35–7.45.

What is the function of arteries?

Carry oxygenated blood from the heart.

What is the path blood takes through the heart?

RA → RV → Lungs → LA → LV → Body.

What does the SA node do?

Functions as the pacemaker of the heart.

What are the layers of the heart?

Pericardium, myocardium, endocardium.

What is the process of pulmonary ventilation?

Inspiration and expiration.

What happens during inspiration?

The diaphragm contracts, increasing volume and decreasing pressure.

What is the tidal volume in normal breathing?

Approximately 500 mL.

What regulates blood pH in the respiratory system?

CO₂ through bicarbonate.

Fill in the blank: The path of food in the digestive system is Mouth → Esophagus → Stomach → Small intestine → Large intestine → _.

Anus.

What is the function of the liver in digestion?

Produces bile and detoxifies substances.

What does the pancreas produce?

Enzymes (amylase, lipase) and insulin.

What is bolus in the digestive system?

Chewed food mixed with saliva.

What defines chyme?

Partially digested food from the stomach.