Hoofdstuk 2

Question 1

Endocrine System

Answer 1

consists of a set of glands that often work in close association with the autonomic nervous system
- where the nervous system uses electrical + chemical messages, endocrine system uses only chemical (hormones)
- the nervous system is linked to the endocrine system by connections between the hypothalamus (sends messages) and the pituitary gland (releases pituitary hormones into the blood –> stimulate other endocrine glands
(Pituitary gland = the Master Gland)

Question 2

Emergency Process

Answer 2

Hypothalamus - Pituitary - Adrenal Axis

• hypothalamus sends hormone to pituitary gland. this causes to release ACTH into the blood, travels throughout the body, stimulates a variety of hormones, especially those of the adrenal gland

Question 3

Adrenal Glands

Answer 3

are located on top of the kidneys
- releases cortisol
- epinephrine (adrenaline)
- norepinephrine (noradrenaline)

Question 4

Thymus Gland (chest)

Answer 4

important role early in life for the development of antibodies and immunities

Question 5

Thyroid Gland (neck)

Answer 5

regulates the body’s general activity level + growth

Question 6

Pancreas (below stomach)

Answer 6

regulate levels of blood sugar (glucose)
- glucagon - raises concentration of glucose
- insulin - lowers concentration of glucose

Question 7

Disorders Digestive System

Answer 7

• peptic ulcers (stomach, duodenum = small intestine)
• hepatitis A - contaminated food/water/utensils
• hepatitis B + C - sexual contact/transfusions with infected blood

cirrhosis (liver) - alcohol abuse

Question 8

Metabolism refers to all reactions that occur in the body’s cells

Answer 8

3 principal outcomes
1) synthesis of new cell material from proteins and minerals to build and repair the body
2) regulation of body processes - by producing enzymes and hormones for example - through the use of proteins, minerals and vitamins
3) energy, to heat the body and fuel its activities

Question 9

1 calorie

Answer 9

the amount of heat needed to rais one gram of water 1 degree celcius

Question 10

Basal Metabolic Rate

Answer 10

number of calories we burn up in rest

Question 11

2 protective mechanisms Respiratory System

Answer 11

1) reflexes
2) mucociliary escalator (sticky mucus)

Question 12

Heart

Answer 12

the muscular portion of the heartwall is called the myocardium
- coronary arteries service the myocardium (bringing oxygen and nutrients to it and taking co2 away)
- arteries carry blood FROM the heart
- veins carry blood TO it

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Question 13

Resting force in arteries =

Answer 13

Diastolic Pressure
Maximum force in arteries = Systolic Pressure

• blood pressure readings are standardized in units of mmHg, to reflext the number of milimeters (mm) the pressure can raise a colomn of Mercury (Hg)

Question 14

5 aspects of fluid dynamics that affect blood pressure

Answer 14

1) cardiac output: the volume of luid being pumped/minute (blood pressure increases as cardiac output rises)

2) Blood volume: the total amount of blood circulating in the system (the greater the volume, the higher the blood pressure needed to move it

3) Peripheral resistance: the difficulty fluid encounters in passing through narrow tubes or openings (resistance is greater in small-diameter arteries than in larger ones)

4) elasticity (describes the ease in expanding and contracting) : when blood vessels become less elastic, blood pressure -systolic pressure- rises

5) viscosity: refers to the thickness of the fluid. The viscosity of blood depends on its composition, such as whether it contains high levels of red blood cells.
Thicker blood flows less easily than thinner blood and requires more blood pressure for it to circulate through the cardiovascular system

Question 15

What affects blood pressure

Answer 15

1) temperature environment (high degrees = vessels enlarge. cardiac output and diastolic pressure falls)

2) activity (exercise increases blood pressure)
3) emotional experience
- sympathetic nervous system activated
- cardiac output
- systolic and diastolic pressure increases

Question 16

Hypertension

Answer 16

high blood pressure consistently over a period of several weeks or more (above 130 systolic, over 80 diastolic)

Question 17

Blood has 2 components: Formed Elements and Plasma

Answer 17

Formed Elements: are the cells and cell-like structures in the blood that constitute about 45% of our blood volume. 3 types:

1) red blood cells
-most abundant cells
-formed in bone marrow
- lifetime 3 months
- contain hemoglobin (=protein substance that attaches to oxygen and transports this element to body cells and tissues)
- ANEMIA = level of blood cells/ hemoglobin is below normal

2) Leukocytes
- white blood cells
- engulf/destroy bacteria
- produced in bone marrow and various organs
- least abundant

3) Platelets
- granular fragments produced by bone marrow to enable body to prevent blood loss

Question 18

PLASMA

Answer 18

liquid substance that comprises about 55% of our blood
- 90% of plasma = water
- plasma proteins increase blood thickness
- remaining elements (10%) include hormones, enzymes, waste products, but also nutrients from digestion

Question 19

Fatty materials make up the broad class of substances in the blood called LIPIDS

Answer 19

1) triglycerides (fat. most abundant lipid)
2) cholesterol

Question 20

Atherosclerosis

Answer 20

fatty plaques in arteries (that tend to harden)
- causes ARTEROSCLEROSIS, where the diameter and elasticity of the arteries is reduced

Question 21

Antigen

Answer 21

any substance that can trigger an immune response

Question 22

Organs of Immune system

Answer 22

lymphatic/lymphoid organs
- produce lymphocytes (=white blood cells)
- lymph nodes and vessels play an important role in cleansing the body of antigen

Question 23

The Spleen filters out antigen and serves as a home base for white blood cells

Answer 23

removes ineffective/worn out red blood cells from the body
Lymphocytes + Phagocytes

Question 24

Specific Immune Processes

Answer 24

1) cell-mediated immunity
- operates at the level of the cell
- soldier: lymphocytes called T-cells (matured in Thymus)
- Killer T-cells (CD8 cells)
- Memory T-cells (remember previous invaders)
- Delayed hyper-sensitivity T-cells (delayed immune reaction and produce protein “lymphokines” to help T-cells grow/reproduce/attack
- Helper T-cells (CD4) rush to spleen + lymph nodes to stimulate lymphocytes to attack
- Surpressor T-cells slows/stops cell-mediated and antibody-mediated immunity processes

2) antibody-mediated “humoral” immunity
- B-cells (give rise to plasma cells that produce antibodies
- antibodies (protein molecules called immunoglobins, are sophisticated weapons) 5 classes of antibodies

Question 25

What is antibody- mediated immunity and how is it different from the cell-mediated immunity process?

Answer 25

antibody-mediated immunity attacks bacteria, fungi, protozoa and viruses while they are still in body fluid, and before they invade bodycells.
Cell-mediated attacks infected cells

Question 26

Body’s first line of defense =

Answer 26

skin + mucous membranes that line the respiratory and digestive tracts

2nd line = nonspecific + specific immune processes (phagocytes –> B-cells + Helper T-cells, antibodies)

3rd line = Killer T-cells