HAPII Lab exam 1

Target cells

Cells affected by the hormones secreted by the endocrine system

Hypophysis

Pituitary Gland

Infundibulum

Connects the hypothalamus and pituitary gland

Adenohypophysis

The anterior pituitary gland, made up of true glandular tissue

Neurohypophysis

The posterior pituitary gland, which is made of nervous tissue since it is an extension of the brain tissue in the hypothalamus

Six hormones released from the anterior pituitary

Growth hormone, prolactin, follicle stimulating hormone, luteinizing hormone, adrenocorticotropic hormone, and thyroid stimulating hormone

Hypophyseal portal system

The system of blood vessels that sends hypothalamic hormones directly to the anterior pituitary

Two hormones released from the posterior pituitary

Antidiuretic hormone and oxytocin

Thyroid hormones

Triiodothyronine and thyroxine,T3 and t4. Act on many cells in the body and have many effects, including increasing basal metabolic rate and regulating tissue growth and development

Calcitonin

Hormone synthesized by parafollicular cells in the thyroid that plays a role in calcium homeostasis in the body

Parathyroid hormone

Released by the parathyroid glands in response to low levels of calcium in plasma, activates osteoclasts to dissolve existing bone tissue, increasing blood calcium ion levels.

Two regions of the adrenal glands

Outer adrenal cortex and inner adrenal medulla

3 layers of adrenal cortex

Zona glomerulosa, zona fasciculata, and zona reticularis

Zona glomerulosa

The most superficial layer of the adrenal glands, secretes mineralocorticoids that play an important role in fluid homeostasis

Zona fasciculata

The middle layer of the adrenal glands, secretes glucocorticoids that play a role in the body’s response to stress

Zona reticularis

The deepest layer of the adrenal cortex that secretes androgens AKA sex hormones

Adrenal medulla

Deepest region of the adrenal gland that consists of modified sympathetic nerves. Secretes epinephrine and norepinephrine

Pancreatic islets

Clusters of endocrine cells throughout the pancreas that secrete insulin and glucagon

Insulin

Released from beta cells in the pancreatic islets and increases the uptake of glucose from the blood into the body’s cells

Glucagon

Released from alpha cells and stimulates release of glucose from body cells into the blood

Estrogens

Regulate the ovarian and menstrual cycles and are also important in the development of secondary sex characteristics

Progesterone

Plays an important role in preparing the body for pregnancy

Testosterone

Stimulates sperm production and plays an important role in the development of secondary sex characteristics in males

Mediastinum

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

Base of the heart

The broad superior aspect of the heart

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