Ex. 28 Endocrine System pt

Question 1

Difference between endocrine and exocrine glands?

Answer 1

Endocrine glands release hormones right into the blood stream. Example: Thyroid and parathyroid. Exocrine glands secrete their substances through a duct into a lumen or onto a surface. Example: sweat gland, oil gland, mammory glands.

Question 2

What is a hormone and describe what it acts on?

Answer 2

A hormone is a chemical messenger that is secreted by endocrine glands into the blood and acts on target cells, target tissues, or target organs.

Question 3

Pineal gland does what?

Answer 3

produces melatonin. Its function is to regulate our sleep cycle (circadian rhythm).

Question 4

Hypothalamus:

Answer 4

Controls hormone release by secreting stimulating and or inhibiting hormones
-Non endocrine functions include: body temperature, sleep/awake, hunger thirst, memory, blood pressure, heart rate

Question 5

What 2 organs are considered the control center of the endocrine system - all other endocrine organs?

Answer 5

Pituitary gland and hypothalamus

Question 6

Pituitary gland?

Answer 6

• hypophysis
• connected to the hypothalamus by the infundibulum
• two lobes: adenohypophysis (anterior lobe)
  neurohypophysis (posterior lobe)

Question 7

Adenohypophysis?

Answer 7

anterior lobe of pituitary gland

- composed of endocrine tissue (simple cuboidal)

Question 8

Neurohypophysis?

Answer 8

posterior lobe of pituitary gland

• composed of nervous tissue
• hormones are produced in the hypothalamus and transported to the neurohypophysis
• it stres and releases the hormones, while the anterior produces?

Question 9

Thyroid gland?

Answer 9

• produces T3 and T4
• T3 and T4 set your metabolic rate
• Produces calcitonin, which decreases blood calcium by depositing it in bone.

Question 10

Thyroid gland appearance?

Answer 10

Thyroid is composed of follicle and parafollicular cells. Follicle is the entire thing. Follicular cells are the boarder cells. The inside of the follicle is the colloid. Parafollicular cells are between the follicles.

Question 11

Parathyroid glands?

Answer 11

usually 4 glands

• on posterior of thyroid gland
• produce parathyroid hormone, which increases blood calcium by getting calcium from bones.

Question 12

Thymus?

Answer 12

• “shrinking” gland
• produces thymosins, which is a big group of hormones
• Its very important for your immune system because it is where your T cells (of WBC’s) mature at.
• By 60 or 70, the thymus is replaced by scar tissue

Question 13

Pancreas?

Answer 13

• Has endocrine and exocrine functions
• endocrine: pancreatic islets produce insule and glucagon
• exocrine: acinar cells produce pancreatic juice (enzymes) for digestion. It secrets through a duct.
• pancreatic islet’s are lighter and less dense, while acinar cells stain darker

Question 14

Pancreas hormones?

Answer 14

insulin - lowers blood glucose

glucagon - increase blood glucose

Question 15

Adrenal glands structure?

Answer 15

cortex - external

medulla - internal

Question 16

Adrenal gland cortex?

Answer 16

cortex produces corticosteroid hormones.
Function of corticosteroid hormones is water and electrolyte balance; metabolism, also produces sex hormones (androgens and estrogens).

Question 17

Adrenal gland medulla?

Answer 17

medulla produces epinephrine and norepinephrine. 
Function is fight or flight.
- increased heart rate
- pupil dialation
- slows down digestion
- increases blood flow to muscles
- dialate airways
- increase respiration

Question 18

Ovaries?

Answer 18

have endocrine and exocrine functions.
follicles contain:
- granulosa cells: produce estrogen (and progesterone)
- Oocyte (aka. Egg)
Progesterone is released when egg is released

Question 19

Blood characteristics?

Answer 19

• connective tissue
• pH = 7.35 to 7.45
• Two basic components
  1. Plasma (55%)
  2. Formed elements (45%) - mostly RBC’s

Question 20

About blood plasma?

Answer 20

Over 90% water
Function of plasma: transport
Transports all of these below:
- proteins
* Albumin (most abundant)- Albumin is a transporter protein, acts as a buffer to resist pH change in blood. helps draw fluid back from tissue via colloid osmotic pressure
* Globulin (second most abundant) - Globulin is a transporter protein, specific class of globulins that are your antibodies.
* Fibrinogen (not much. like 4%) - eventually becomes fibrin when blood needs to from a clot. precursor to fibrin, which is sticky.
Misc: electrolytes, hormones, gases, nutrients, wastes

Question 21

How many formed elements are there?

Answer 21

3: Erythrocytes (RBC), Thrombocytes (platelets), Leukocytes (WBC)

Question 22

Erythrocytes:

Answer 22

• Contain hemoglobin, which transports oxygen
• Size: -7.5 um (smallest cell)
• Shape: biconcave disk - Gives them more surface area and makes them more flexible
• Average count: 4.2 - 6.2 million/uL

Question 23

Does a mature RBC have a nucleus?

Answer 23

no, it does as its maturing, but at some point it pushes the nucleus out and makes room for more hemoglobin. As a result they don’t live as long

Question 24

Thrombocytes:

Answer 24

Platelets

• they clot the blood
• Platelets are considered cell fragments. One platelet is not considered a cell.
• These fragments secret hormones, secrete chemicals that cause vasoconstriction, help convert fibrinogen to fibrin.

Question 25

Leukocytes:

Answer 25

5 different kinds of WBCs.
They fight infections. immune function.
Granulocytes: visible granules
Agranulocytes: non-visible granules

Average count: 5,000 to 10,000 per uL