Sound wave transmission in the ear (LAB)

Order in which vibrations enter the ear to create sound.

1. Auricle

2. Auditory Canal

3. Tympanic Membrane

4. Ossicles

5. Oval Window

6. Cochlea

7. Auditory Nerve

8. Brain

Correct order of how light enters the eye to create an image

1. Cornea

2. Aqueous Humor

3. Pupil

4. Lens

5. Vitreous Humor

6. Retina

7. Optic nerve

8. Brain

A neuron (nerve cell) consists of several key anatomical structures, each with a specific function:

1. Dendrites – Branch-like extensions that receive signals from other neurons.

2. Cell Body (Soma) – Contains the nucleus and organelles; processes incoming signals.

3. Nucleus – Controls the neuron's activities and contains genetic material.

4. Axon – A long fiber that transmits electrical impulses away from the cell body.

5. Myelin Sheath – A fatty layer that insulates the axon to speed up signal transmission.

6. Nodes of Ranvier – Gaps in the myelin sheath where signals "jump" to increase speed.

7. Axon Terminals – End branches of the axon that release neurotransmitters to communicate with other neurons or muscles.

8. Synapse – The junction between neurons where neurotransmitters transmit signals.

The neuromuscular junction is key anatomical structures:

1. Motor Neuron Axon Terminal – The end of the motor neuron where neurotransmitters are released.

2. Synaptic Vesicles – Contain acetylcholine (ACh), the neurotransmitter that signals muscle contraction.

3. Synaptic Cleft – The small gap between the neuron and the muscle fiber where ACh is released.

4. Motor End Plate – The specialized region of the muscle fiber membrane (sarcolemma) that contains ACh receptors.

5. Acetylcholine (ACh) Receptors – Proteins on the motor end plate that bind ACh, leading to muscle activation.

6. Acetylcholinesterase (AChE) – An enzyme that breaks down ACh to stop the signal and allow muscle relaxation.

The heart is a muscular organ with several key anatomical structures:

• Right Atrium – Receives deoxygenated blood from the body via the superior and inferior vena cava.

• Right Ventricle – Pumps deoxygenated blood to the lungs through the pulmonary artery.

• Left Atrium – Receives oxygenated blood from the lungs via the pulmonary veins.

• Left Ventricle – Pumps oxygenated blood to the body through the aorta (strongest chamber).

Valves (Prevent Backflow of Blood):

• Tricuspid Valve – Between the right atrium and right ventricle.

• Pulmonary Valve – Between the right ventricle and pulmonary artery.

• Mitral (Bicuspid) Valve – Between the left atrium and left ventricle.

• Aortic Valve – Between the left ventricle and aorta.

Major Blood Vessels:

• Superior & Inferior Vena Cava – Bring deoxygenated blood from the body to the right atrium.

• Pulmonary Arteries – Carry deoxygenated blood from the right ventricle to the lungs.

• Pulmonary Veins – Bring oxygenated blood from the lungs to the left atrium.

• Aorta – The largest artery, carries oxygenated blood from the left ventricle to the body.

Other Important Structure:

• Septum – Divides the right and left sides of the heart.

• Myocardium – The thick muscular layer of the heart that contracts to pump blood.

• Endocardium – The inner lining of the heart chambers.

• Pericardium – The protective outer membrane surrounding the heart.

Possible Tests in Lab:

• Snellen Eye Chart – Tests visual acuity (sharpness of vision).

• Astigmatism Test – Checks for uneven curvature of the cornea or lens.

• Pupillary Reflex Test – Observes how pupils react to light.

• Blind Spot Test – Determines the location of the optic disk (where no photoreceptors exist).

Key Reflexes to Know

• Patellar Reflex (Knee-Jerk Reflex) – Tests spinal cord and nerve function.

• Pupillary Light Reflex – Constriction of the pupil in response to light.

• Blink Reflex – Protects the eye from foreign objects.

• Achilles Reflex – Tests the function of the S1 spinal nerve.

• Reaction Time Test – Measures the time it takes to respond to a stimulus.

Reflex Arc Pathway (Know These Steps!)

1. Receptor (detects stimulus).

2. Sensory Neuron (sends impulse to spinal cord).

3. Integration Center (spinal cord processes the impulse).

4. Motor Neuron (sends response signal).

5. Effector (muscle or gland reacts).

Blood Pressure:

• Systolic Pressure – The pressure when the heart contracts (higher number).

• Diastolic Pressure – The pressure when the heart relaxes (lower number).

• Normal BP – 120/80 mmHg (can vary slightly).

• Pulse Points – Common locations to check heart rate (radial artery, carotid artery, etc.).

How to Measure Blood Pressure:

1. Place the cuff around the upper arm.

2. Inflate the cuff to restrict blood flow.

3. Slowly release air while listening with a stethoscope.

4. First sound heard = Systolic pressure (top number).

5. Sound disappears = Diastolic pressure (bottom number).

How to Measure Heart Rate (Pulse Check)

• Place fingers on the radial artery (wrist) or carotid artery (neck).

• Count beats for 15 seconds, then multiply by 4 to get BPM (beats per minute).

• Normal resting HR: 60-100 BPM (lower in athletes).