What are the 3 layers of the heart?

What are the 3 layers of the heart?

Epicardium, Myocardium, Endocardium

What does the myocardium do?

Pumps blood; muscular layer of heart

What do arteries do?

Carry blood away from the heart

What do veins do?

Carry blood toward the heart

What happens in capillaries?

Gas and nutrient exchange

What are the AV valves?

Tricuspid (RA→RV) and Mitral/Bicuspid (LA→LV)

What are the semilunar valves?

Pulmonary valve (RV→lungs) and Aortic valve (LV→aorta)

Path of blood flow through the heart?

Body → RA → Tricuspid → RV → Pulmonary valve → Lungs → LA → Mitral → LV → Aortic valve → Body

What vessels return blood from lungs to heart?

Pulmonary veins

Normal blood pressure?

120/80 mmHg

What does the P wave represent?

Atrial depolarization

What does the QRS complex represent?

Ventricular depolarization

What does the T wave represent?

Ventricular repolarization

Where is the heart located?

Mediastinum

What is the function of the coronary arteries?

Supply blood to the myocardium

Basic functional unit of the nervous system?

Neuron

Three parts of a neuron?

Dendrites, Cell body, Axon

What do dendrites do?

Receive impulses

What does the axon do?

Sends impulses

What is a synapse?

Gap between neurons where neurotransmitters act

What is a neurotransmitter?

Chemical messenger across synapse

Myelin is made by what in the PNS?

Schwann cells

Function of myelin?

Speed up nerve conduction

Resting membrane potential value?

–70 mV

Depolarization caused by what ion?

Sodium (Na+) rushing in

Repolarization caused by what ion?

Potassium (K+) rushing out

All-or-none response means what?

Neuron fires fully or not at all

Three functions of the nervous system?

Sensory, Integrative, Motor

CNS includes what?

Brain and spinal cord

PNS includes what?

All nerves leaving CNS

Reflex arc order?

Receptor → Sensory neuron → Interneuron → Motor neuron → Effector

Sympathetic division function?

Fight or flight

Parasympathetic division function?

Rest and digest

What does the cerebellum control?

Balance and coordination

What does the brainstem control?

Vital functions (breathing, heart rate)

Where is CSF found?

Subarachnoid space

Three muscle types?

Skeletal, Cardiac, Smooth

Basic unit of muscle contraction?

Sarcomere

Thick filament protein?

Myosin

Thin filament proteins?

Actin + troponin + tropomyosin

What ion triggers muscle contraction?

Calcium (Ca²⁺)

What neurotransmitter triggers muscle contraction?

Acetylcholine (ACh)

Enzyme that breaks down ACh?

Acetylcholinesterase

Sliding filament model summary?

Myosin pulls actin → muscle shortens

First energy source for contraction?

Stored ATP

Backup energy source?

Creatine phosphate

What causes oxygen debt?

Lactic acid buildup

Fast-twitch fibers are for?

Quick, powerful movements; fatigue fast

Slow-twitch fibers are for?

Endurance; fatigue-resistant

Motor unit definition?

One motor neuron + all muscle fibers it controls

Isotonic contraction definition?

Muscle shortens with same tension

Isometric contraction definition?

Muscle produces tension without shortening

Cardiac muscle unique feature?

Intercalated discs

Smooth muscle found where?

Walls of hollow organs