HAPII Lab Final

Base of the heart

The broad superior aspect of the heart

Mediastinum

The area where the heart is located in the middle region of the thoracic cavity

Apex

The pointy inferior tip of the heart that points to the left side of the body and rests on the diaphragm

Pericardium

A tough, double layered sac that covers the heart

Fibrous pericardium

The outer layer of the pericardium that is composed of dense irregular connective tissue

Serous pericardium

The inner layer of the pericardium that is composed of an outer parietal layer which adheres to the fibrous pericardium and an inner visceral layer (also called the epicardium) which forms the outer layer of the heart wall

Three layers of the heart wall

Epicardium, myocardium, and endocardium

Epicardium

The outer layer of the heart wall composed of simple squamous epithelium, areolar connective tissue, and adipose tissue

Myocardium

The middle layer of the heart wall composed of cardiac muscle tissue

Endocardium

The inner layer of the heart wall composed of simple squamous epithelium on a layer of areolar connective tissue

Atria

Receive blood

Ventricles

Pump blood out

Pulmonary circuit

Circuit that carries deoxygenated blood from the right side of the heart to the lungs, where it unloads carbon dioxide and picks up oxygen returning oxygenated blood to the left side of the heart

Pathway of blood through the pulmonary circuit

1. The right atrium receives deoxygenated blood from the superior and inferior vena cavae, and the coronary sinus.

2. Blood then travels from the right atrium to the right ventricle through the tricuspid valve.

3. Blood is pumped from the right ventricle through the pulmonary SL valve, to the pulmonary trunk and out of the heart.

4. The pulmonary trunk branches into the pulmonary arteries, which deliver deoxygenated blood to the right and left lungs.

5. Oxygenated blood is then returned to the heart through the pulmonary veins.

Systemic circuit

Circuit that carries oxygenated blood from the left side of the heart to the rest of the body, where it unloads oxygen to the tissues. Deoxygenated blood is returned to the right side of the heart in this circuit

Pathway of blood through the systemic circuit

1. The left atrium receives oxygenated blood from the pulmonary veins as it returns from the lungs.
2. Blood then travels from the left atrium to the left ventricle through the bicuspid valve.
3. Blood is pumped from the thick-walled left ventricle through the aortic SL valve, to the aorta and out of the heart, where it is delivered to the body tissues by systemic arteries.

Coronary circulation

Circulation of oxygenated blood to the heart muscle. Coronary arteries originate at the base of the aorta, and deliver oxygenated blood to the heart muscle. Coronary veins drain deoxygenated blood from the heart tissue and return it to the right atrium of the heart.

Intercalated disks

Where cardiac muscle cells join together at gap junctions, allowing rapid communication between cells.

Three layers of the vessel walls of veins and arteries

Tunica intima, tunica media, and tunica externa

Tunica intima

Outer layer composed of endothelium anchored to a thin basement membrane.
The simple squamous endothelial cells create a smooth inner surface lining of the blood vessel that helps prevent cells in the blood from sticking to it and creates smooth blood flow.

Tunica media

Middle layer, composed of smooth muscle and elastic fibers. The smooth
muscle fibers are arranged circularly around the vessel wall: constriction of these fibers
decreases the diameter of the vessel. The elastic fibers allow the vessel wall to stretch and recoil in response to the pressure of the blood inside

Tunica externa

Outer tunic, composed of connective tissue with collagen and elastic fibers.
It anchors the wall of the vessel to the surrounding tissues.

Elastic arteries

Vessels found closest to the heart and are the largest arteries in the body. Have a thick tunica media where elastic fibers predominate, allowing for expansion and recoil of the vessels as large volumes of blood leave the heart and enter these arteries. Includes the aorta, pulmonary trunk, and major branches of the aorta

Muscular arteries

Elastic arteries branch into these medium-sized vessels that account for most of the vessels in the body. Their diameter is smaller than elastic arteries

Arterioles

Tiny vessels that deliver blood into the capillary networks throughout the body. ll three layers of the vessel wall are thin. The very large number of arterioles in the body means that constriction and dilation of these vessels contributes substantially to the overall blood pressure.

Capillaries

microscopic vessels where gas exchange occurs between the blood and tissue cells.
Capillaries contain only a thin layer of tunica intima.

Venules

the smallest veins and receive blood from capillary beds in tissues and organs. The layers of the vessel wall are thin and distensible, making them reservoirs for the blood in the body

Veins

receive blood from the venules and return blood to the heart via the superior or inferior vena cava. Although veins are larger than venules, their structure is similar. The three tunics comprising the vessel wall are thin, making them distensible. Many veins have valves that prevent backflow of blood, similar to the valves in the heart.

Hepatic portal system

Carries nutrient-rich blood from the digestive organs to the liver. Blood draining from the stomach, intestines and spleen is first carried to the liver by way of the hepatic portal vein. The hepatic portal vein receives blood from the capillaries of the gastrointestinal organs and conveys it to the sinusoids (capillaries) in the liver. The liver processes the blood from the hepatic portal vein, removing excess nutrients and storing them for later use, and filtering out waste products before the blood returns to the inferior vena cava

Lymphocyte

Agranulocyte that plays a role in adaptive immunity and eventually develop into T cells and B cells

Monocyte

Agranulocyte that develops into macrophages in the tissues. Phagocytize pathogens and debris

Neutrophil

Granulocyte that phagocytizes pathogens. Particularly effective against bacteria

Eosinophil

Granulocyte that is particularly effective against parasitic infections

Basophil

Granulocyte that promotes inflammation by releasing histamine and other inflammatory mediators

Anterior Pituitary Hormones

GH, Prolactin, ACTH, LH, FSH, TSH

Growth Hormone

Promotes growth of body tissues

Prolactin

Promotes milk production

Adrenocorticotropic hormone (ACTH)

Stimulates hormone release by adrenal cortex

Luteinizing hormone (LH)

Stimulates androgen production by gonads

Follicle-stimulating hormone (FSH)

Stimulates gamete production

Thyroid-stimulating hormone (TSH)

Stimulates thyroid hormone release

Posterior Pituitary Hormones

ADH, Oxytocin

Antidiuretic hormone (ADH)

Stimulates water reabsorption by kidneys

Oxytocin

Stimulates uterine contractions during childbirth

Thyroid and Parathyroid hormones

Thyroid hormones, calcitonin, parathyroid hormone

Triiodothyronine (T3)

Active form of thyroid hormone that increases cell metabolism

Thyroxine (T4)

Inactive form of T3

Calcitonin

Reduces blood calcium levels

Parathyroid hormone (PTH)

Increases blood calcium levels

Adrenal gland hormones

Aldosterone, cortisol, androgens, epinephrine and norepinephrine

Aldosterone (zona glomerulosa)

Increases blood sodium levels

Cortisol (zona fasciculata)

Increases blood glucose levels

Androgens (zona reticularis)

Testosterone and estrogens

Epinephrine and norepinephrine (adrenal medulla)

Stimulate fight or flight response

Pancreatic hormones

Insulin, glucagon

Insulin

Reduces blood glucose levels

Glucagon

Increases blood glucose levels

Gonadal (sex) hormones

Estrogens, testosterone

Estrogens (ovaries)

Stimulate development of sex characteristics including the development of adipose and breast tissue, and prepare the body for childbirth

Testosterone (testes)

Stimulates development of sex characteristics including a deeper voice, increased muscle mass, development of body hair, and sperm production

Hypophysis

The pituitary gland, which secretes hormones that regulate the activity of other endocrine glands

Infundibulum

Connects the pituitary gland to the hypothalamus

Adenohypophysis

The anterior pituitary, which is true glandular tissue that stores, secretes, and releases hormones from its cells.

Neurohypophysis

The posterior pituitary, which is an extension the brain tissue in the hypothalamus. The posterior lobe is actually nervous tissue which stores hormones from the hypothalamus

Hypophyseal portal system

A system of blood vessels that send hypothalamic hormones directly to the anterior pituitary

Pancreatic islet

Clusters of endocrine cells scattered throughout the tissue of the pancreas

Zona glomerulosa

Most superficial layer of the adrenal cortex, secretes mineralocorticoids

Zona fasciculata

Middle layer of the adrenal cortex, secretes glucocorticoids

Zona reticularis

Deepest layer of the adrenal cortex, secretes androgens

Cardiac Cycle

The events that take place during one complete heartbeat, during which both the atria and ventricles contract and then relax, causing changes in internal pressure

When ventricular pressure is greater than atrial pressure:

The AV valves are forced closed; occurs during ventricular systole

When ventricular pressure is greater than the pressure in the aorta:

The aortic SL valve opens

Systole

Ventricular contraction

Diastole

Ventricular relaxation

Auscultation

The process of listening to the sounds made by organs

S1 (lub)

AV valves closing at the beginning of ventricular systole

S2 (dup)

Semilunar valves closing at the beginning of ventricular diastole

Pulse

Alternating surges of pressure produced by arteries recoiling due to the force of blood on the vessel wall increasing and decreasing that can be felt in superficial arteries

Blood pressure

The hydrostatic pressure of the blood on the walls of the blood vessels

Systolic pressure

The pressure on the artery walls during ventricular contraction (systole)

Diastolic pressure

The pressure on the artery walls during ventricular relaxation (diastole)

Normal Blood Pressure

120/80 mmHg

Pulse pressure

The mathematical difference between the systolic pressure and diastolic pressure

Stroke volume

The volume of blood ejected from the heart with each beat, directly related to pulse pressure

Normal stroke volume

70-80 mL per beat

Normal cardiac output

4-8 L/min

Normal heart rate

60-100 bpm

Cardiac output formula

HR x SV

Korotkoff sounds

The sounds produced when checking for blood pressure manually

When korotkoff sounds are first heard

Gives the systolic pressure

When korotkoff sounds are last heard

Gives the diastolic pressure

Electrocardiogram (ECG)

a graphic representation over time of the electrical changes (depolarization and repolarization of cardiac muscle cells) occurring in the heart.

P wave

Atrial depolarization

PR segment

Atrial depolarization is complete, and the impulse is delayed at the AV node. Atrial contraction occurs

QRS complex

Ventricular depolarization, atrial repolarization occurs. Electrical signal moves down the bundle branches and into the purkinje fibers

ST segment

Ventricular depolarization is complete, ventricles contract

T wave

Ventricular repolarization, ventricular contraction ends

TP segment

Ventricular repolarization is complete, both chambers are in diastole

RR interval

Represents a complete cardiac cycle (heartbeat)

Cardiac pacemaker cells

Specialized heart cells that generate the electrical signals that produce contraction