LAB PRACTICAL 1

1. Explain the difference between olfaction, gustation, photoreception, auditory reception and equilibrium. 

Olfaction: 

• Stimulus- chemical molecules in the air

• Organ-  olfactory receptors in the nose 

• function- sense of smell, sending signals of chemicals (smells) to brain

Gustation

• Stimulus- chemical molecules in foods and liquids

• Organ- taste buds on tongue and in mouth 

• Function- The sense of taste allows us to detect flavors; taste receptors on the tongue bind with the chemicals in food which then is processed by brain

Photoreception

• Stimulus- Light waves

• Organ- Photoreceptors in retina of eye 

• Function-  Vision involves detecting light through specialized cells in the retina and then the brain processes this allowing us to see colors, shapes, etc.

Auditory Reception

• Stimulus- sound waves; vibrations in ear drum

• Organ- outer and inner ear

• Function- Hearing detects sound waves through the outer ear, which are funneled to the eardrum. Vibrations are transmitted to the inner ear, where they are converted into electrical signals for the brain to interpret as sounds.

Equilibrium

• Stimulus- changes in head position and motion

• Organ- Inner ear

• Function- The sense of balance helps us detect motion and maintain posture. Specialized cells in the inner ear respond to head movements and gravity, sending signals to the brain to help us maintain balance.

2. Explain the relationship between gustation and olfaction.
It’s role in flavor perception Gustation provides the basic tastes: sweet, salty, sour and bitter. While olfaction contributes the complex aromas and scents that enhance flavor. Gustation gives us basic taste information, while olfaction adds complexity and richness to our overall flavor experience. Without smell, we would miss out on much of the flavor experience, which is why food seems tasteless when you have a stuffy nose.

3. Identify the special sense assessed by the Snellen chart exam, Weber test, Rinne test, Romberg and postural tests, dry solid test.

Snellen: Assess how well a person can see at different distances based on a chart

Weber: a quick test for hearing loss; A tuning fork is placed in the middle of the forehead or the top of the head, and the patient is asked if they hear the sound equally in both ears

Rinne:  compares air conduction and bone conduction of sound. A tuning fork is placed on the mastoid bone (behind the ear), then in front of the ear.

Romberg: assesses a person’s sense of balance and proprioception. The individual is asked to stand with their feet together and eyes closed

Postural: assess a person’s ability to maintain balance in different positions or movements. 

Dry-Solid: assesses taste perception by presenting dry or solid food items that do not have a strong odor, helping evaluate how well the person can perceive taste.

4. Model/explain how each test listed in statement 3 is performed. DONE

5. Describe how homeostatic imbalances may be found when performing the tests listed in statement 3. 

Snellen: Visual impairment

Weber: Hearing loss

Rinne: Hearing loss

Romberg: Balance issues

Postural: Posture instability

Dry-Solid: Taste disorders an imbalance

6. Describe possible abnormal findings when assessing the function of cranial nerves III, IV, VI, V, VIII, and XI. 

3-  Oculomotor: Controls most of the eye's movements, constriction of the pupil, and eyelid elevation.

4- Trochlear: Controls the superior muscle of eye difficulty looking down or moving the eye 

5- Abducens: responsible for outward eye movement;  inability to move the affected eye outward

6- Trigeminal Nerve:  Responsible for sensation in the face and motor control for chewing.

7- Vestibulocochlear Nerve: controls hearing and balance

8- Accessory: responsible for head rotation and shoulder shrugging; Damage to the accessory nerve can cause weakness or inability to raise the shoulder on one side

Endocrine System

1. Identify and explain the response exhibited in the prolactin, FSH, LH, oxytocin, ADH, testosterone, and estrogen. 

Prolactin primarily stimulates milk production in the mammary glands after childbirth. It also plays a role in regulating the immune system and metabolism. (Produced in the anterior pituitary.

FSH plays a crucial role in both male and females reproductive system. Produced in anterior pituitary gland

LH triggers ovulation in females and stimulates testosterone production in males. Produced in anterior pituitary gland

Oxytocin causes uterine contraction during childbirth and milk production. Produced in anterior pituitary gland

ADH helps regulate water balance by promoting water reabsorption in the kidneys. Produced in posterior pituitary gland

Testosterone is the male sex hormone and is responsible for the development of male characteristics like facial hair, deep voice and muscles. Produced by the testes

Estrogen is the female sex hormone, regulating the menstrual cycle, maintaining pregnancy, and promoting the development of female secondary characteristics like breast development and wider hips. Produced in the ovaries.

2. Outline the pathway of release for each of the hormones listed in statement 1 (see pages 16-17 in your lab manual). 

3. Identify all major endocrine structures in the body and the hormone(s) they produce/release. 

The hypothalamus controls the pituitary gland and releases various hormones, such as GnRH, TRH, CRH, and oxytocin (which is also stored in the posterior pituitary).

Pituitary Gland:

Anterior Pituitary: Produces hormones like FSH, LH, GH (growth hormone), ACTH (adrenocorticotropic hormone), prolactin, and TSH (thyroid-stimulating hormone).

Posterior Pituitary: Stores and releases oxytocin and ADH (vasopressin), which are produced by the hypothalamus.

• Thyroid Gland: Produces hormones like T3 (triiodothyronine), T4 (thyroxine), and calcitonin. These regulate metabolism, growth, and calcium balance.

• Parathyroid Glands: Produce parathyroid hormone (PTH), which regulates calcium levels in the blood.

Adrenal Glands:

THE Adrenal Cortex: Produces cortisol, aldosterone, and androgens.

THE Adrenal Medulla: Produces epinephrine and norepinephrine (fight or flight response).

Pancreas: Produces insulin and glucagon, which regulate blood sugar levels.

Ovaries: Produce estrogen and progesterone, which regulate female reproductive functions.

Testes: Produce testosterone, which regulates male reproductive functions.

4. Compare and contrast the messaging style of the endocrine system and the nervous system. 

 Endocrine System uses hormones in the bloodstream and travel to target cells

-The effects are generally slower but more prolonged

-Regulates functions like growth, metabolism, and reproduction.

Nervous System uses electrical signals and chemical neurotransmitters 

-The effects are faster and have short-lived effects

-Communicate quickly between neurons, affecting muscle contractions, sensory perception, and immediate responses to stimuli

Vessels of the Cardiovascular System

1. Compare and contrast histological views of arteries and veins. 

Arteries- carries oxygenated blood away from the heart to body tissues, thicker walls due to higher pressure, and smaller lumen

Veins- carries deoxygenated blood towards heart, thinner walls, bigger lumen, and contain valves to prevent backflow of blood

2. Explain the structure and function of each of the blood vessel tunics (intima, media, externa). 

Tunica intima- innermost layer, composed of epithelial cells that line the lumen of the vessel 

Tunica media- Middle layer, made up of smooth muscle and elastic fibers (the smooth muscle allows the vessel to contract and dilate) ; vasoconstriction (narrowing) and vasodilation (widening) are facilitated by smooth muscle contraction and relaxation.

Tunica externa- Outermost layer, composed of collagen fibers that provide strength and support to the vessel.

3. Locate and name major arteries and veins in the body (see page 20-21 of your manuals). 

Arteries:

• Aorta: The largest artery in the body, it carries oxygenated blood from the heart to the systemic circulation.

• Carotid Arteries: These arteries (left and right) supply blood to the brain, face, and neck.

• Subclavian Arteries: These arteries supply blood to the arms.

• Brachial Arteries: Located in the upper arms, these supply blood to the arms and forearms.

• Femoral Arteries: These arteries supply blood to the legs.

• Popliteal Arteries: Located behind the knee, they supply blood to the knee and lower leg.

Veins:

Superior Vena Cava: Carries deoxygenated blood from the upper body back to the right atrium of the heart.

Inferior Vena Cava: Carries deoxygenated blood from the lower body back to the right atrium.

Jugular Veins: These veins drain deoxygenated blood from the head and neck.

Subclavian Veins: These veins drain blood from the arms and upper extremities.

Femoral Veins: These veins drain blood from the legs and lower extremities.

Popliteal Veins: Located behind the knee, these veins drain blood from the knee and lower leg.

4. Describe the location of each of the 8 pulse points assessed during lab # 3 using ANATOMICAL TERMS. 

Radial Pulse:

• Location: On the lateral side of the wrist, near the base of the thumb.

• Anatomical Term: At the distal end of the radius bone in the forearm.

Brachial Pulse:

• Location: In the antecubital fossa (the bend of the elbow).

• Anatomical Term: In the brachial artery, just medial to the biceps tendon.

Carotid Pulse:

• Location: In the neck, just lateral to the trachea (windpipe).

• Anatomical Term: Along the common carotid artery, at the level of the thyroid cartilage.

Femoral Pulse:

• Location: In the groin area, where the leg meets the torso.

• Anatomical Term: At the femoral artery, just inferior to the inguinal ligament.

Popliteal Pulse:

• Location: Behind the knee.

• Anatomical Term: In the popliteal artery, found in the popliteal fossa.

Dorsalis Pedis Pulse:

• Location: On the top of the foot, between the first and second metatarsal bones.

• Anatomical Term: Over the dorsalis pedis artery, on the dorsum of the foot.

Posterior Tibial Pulse:

• Location: Just behind the medial malleolus (the bony prominence on the inner side of the ankle).

• Anatomical Term: Over the posterior tibial artery, near the ankle joint.

Temporal Pulse:

• Location: On the side of the head, above the ear.

• Anatomical Term: Over the superficial temporal artery, near the temple.

Heart Anatomy

1. Follow the pathway of blood within BOTH the pulmonary and systemic circuits, citing all relevant structures in each pathway.

Pulmonary circuit: SVC/IVC - R.A - Tricuspid valve- R.V - pulmonary trunk - pulmonary vein

Systemic circuit: 

Right Side (Pulmonary Circulation): Pumps deoxygenated blood to the lungs via the pulmonary trunk for oxygenation.

Left Side (Systemic Circulation): Pumps oxygenated blood to the body through the aorta, ensuring that all tissues receive nutrients and oxygen.

2. Use external landmarks to establish ventral and dorsal views of the sheep heart. 

the anterior interventricular sulcus- ventral side

3. Use internal and external landmarks to establish anatomical left and right of the sheep heart. 

4. Describe the locations of the great vessels in the context of the sheep heart (superior and inferior vena cava, aorta, pulmonary trunk (NOT pulmonary veins). 

Aorta: The large artery that arises from the left ventricle and is located posteriorly and superiorly, arching over the heart and branching to deliver oxygenated blood throughout the body.

SVC/IVC: These two large veins are located on the right side of the heart, entering the right atrium.

Pulmonary trunk: originates from the right ventricle and is located just anterior to the aorta. It splits into the left and right pulmonary arteries to carry deoxygenated blood to the lungs

5. Identify and explain the function of ALL the internal structures of the sheep heart; for example the AV and SL valves.

 AV valves: -tricuspid valve=located between RA and RV, prevents back flow in r.atria

-bicuspid valve= located between LA and LV,  prevents back flow in L.atria

S.L

• Pulmonary Semilunar Valve: Located between the right ventricle and the pulmonary trunk, it prevents blood from flowing back into the right ventricle after contraction.

• Aortic Semilunar Valve: Located between the left ventricle and the aorta, it prevents blood from flowing back into the left ventricle after contraction.

~The chordae tendineae are thin, fibrous cords that connect the AV valves (both tricuspid and bicuspid) to the papillary muscles, which contract to prevent the AV valves from inverting during ventricular contraction.

Cardiovascular Physiology

1. Use EKG readings to locate a p wave, QRS complex and T wave. 

2. Match each of the waves listed in statement 1 with the event of the cardiac cycle they represent. 

P-wave:

Qrs complex:

T-wave:

3. Identify the homeostatic imbalance associated with abnormal EKG readings (see page 36 of your manuals). 

arrhythmias, coronary artery disease, heart attack causing damage, or electrolyte imbalances

4. Demonstrate the use of a stethoscope to auscultate heart sounds. 

Auscultation is performed for the purposes of examining the circulatory system and respiratory system (heart sounds and breath sounds)

5. Explain what each of the heart sounds actually represent (lub and dub, as well as the “pause” between heart sounds/beats). 

Lub- The sound of the mitral and tricuspid valves closing after the atria pump blood into the ventricles

Dub- The sound of the aortic and pulmonary valves closing after the ventricles contract to pump blood away from the heart

6. Model the use of a blood pressure cuff (sphygmomanometer) and stethoscope to take a manual blood pressure reading - explanation must be similar to “teaching” this skill to someone else. 

carefully positioning the cuff, inflating it until arterial blood flow is cut off, then slowly releasing pressure while listening for the characteristic sounds with the stethoscope to identify systolic and diastolic pressure

7. Explain what the two values in a blood pressure reading represent (systolic and diastolic values).

systolic pressure (the top number) which measures the pressure in your arteries when your heart beats, AND the diastolic pressure (the bottom number) which measures the pressure in your arteries when your heart rests between beats are critical indicators of cardiovascular health. A normal blood pressure reading is typically around 120/80 mmHg, where the systolic pressure reflects the force exerted against the artery walls during heart contraction, while the diastolic pressure indicates the pressure during the relaxation phase of the heart.