Endocrine System and Blood
Unlike the nervous system, which uses neurotransmitters, the endocrine system communicates using chemical messengers called
hormones
In a thyroid follicle, the ________ epithelium of follicle cells surrounds the acellular colloid
simple cuboidal
Hormones are secreted in response to a disturbance in homeostasis, such as changes in blood pressure, blood glucose concentration, or ________
body temperature
The fluid portion of blood, which makes up about 55% of total blood volume, is called ________.
Plasma
Before a blood transfusion, a patient’s blood type must be determined to avoid a dangerous reaction called ________.
transfusion reaction
The two hormones stored and released by the posterior pituitary gland are ________ and ________.
oxytocin and antidiuretic hormone
The large, pale-stained cells located between or adjacent to thyroid follicles are known as ________ cells
parafollicular
A hormone acts on ________ target cells to restore a physiological variable to its normal range.
distant
The three main types of formed elements in blood are erythrocytes, thrombocytes, and ________.
leukocytes
If a donor’s erythrocytes have antigens that the recipient's immune system recognizes as foreign, the recipient’s antibodies will cause the donor cells to clump together in a process called ________.
Agglutination
The thyroid gland secretes ________, the most active thyroid hormone, which helps regulate metabolism and heart rate.
triiodothyronine or T3
The ________ is the outermost layer of the adrenal cortex, where cells are arranged in small round clusters.
zona glomerulosa
The process by which a hormone’s secretion decreases once homeostasis is restored is called a ________.
negative feedback loop
Erythrocytes transport oxygen using an iron-containing protein called ________.
hemoglobin
People with type A blood have A antigens and produce ________ antibodies.
anti-B
The pancreas regulates blood sugar levels by secreting ________, which increases blood glucose, and ________, which decreases blood glucose.
glucagon and insulin
The adrenal medulla is distinguished from the adrenal cortex by its ________, which are loosely arranged throughout the tissue.
blood vessels
When a hormone’s secretion drops, a ________ hormone's secretion rises to stimulate an endocrine organ to produce more hormone
stimulating
The percentage of blood volume occupied by erythrocytes is called the ________, which is typically higher in males than in females.
hematocrit
People with type O blood have no A or B antigens, but they produce ________ antibodies.
anti-A and anti-B
The adrenal cortex has three layers: the zona glomerulosa, which secretes ________, the zona fasciculata, which secretes ________, and the zona reticularis, which secretes ________.
mineralocorticoids (e.g., aldosterone), glucocorticoids (e.g., cortisol), and gonadocorticoids
The endocrine ________ appear as small, lighter-colored islands within the pancreas, while the surrounding ________cells make up most of the pancreatic tissue
pancreatic islets and acinar
When blood glucose levels fall, the pancreas releases ________, which stimulates the liver to break down glycogen and restore normal glucose levels
glucagon
Thrombocytes, also known as ________, are small cellular fragments involved in blood clotting and make up less than 1% of total blood volume
platelets
A person with blood type ________ can receive blood from any donor.
AB+