Introduction to Physiology

Question 1

Name the 4 levels of organization.

Answer 1

• cell
• tissue
• organ
• organ system

Question 2

How many different cell types are there?

Answer 2

200

Question 3

What are the 4 groups that cells can be classified into?

Answer 3

• neurons
• muscle cells
• epithelial cells
• connective tissue cells

Question 4

What do neurons and nerve tissues do?

Answer 4

• transmit signals for communication

- some neurons process information

Question 5

How do neurons and nerve tissues perform their functions?

Answer 5

• have branches to receive or transmit messages
• receive information from receptors
• transmit information to muscles and other organs

Question 6

What do muscle cells do?

Answer 6

• specialized to contract

- voluntary or involuntary

Question 7

What are the 3 types of muscle cells?

Answer 7

• skeletal
• smooth
• cardiac

Question 8

What is the epithelium?

Answer 8

• sheet-like layer of cells

- lines external body surfaces and hollow organs or vessels

Question 9

What is the interior epithelium called?

Answer 9

lumen

Question 10

What is the function of the epithelium?

Answer 10

• barrier

- transport membrane

Question 11

What is formed from the epithelium?

Answer 11

glands

Question 12

Describe and give examples of each of the major classes of glands.

Answer 12

• exocrine glands: have ducts. ex. sweat, salivary

- endocrine glands: no ducts, hormone released into blood. ex. pituitary, adrenal

Question 13

What is the most diverse of the 4 tissues?

Answer 13

connective tissue

Question 14

Describe connective tissue.

Answer 14

• characterized by an extracellular matrix
• anchors and links structures of the body
• ex. bone, tendons, fat, blood

Question 15

Define organs.

Answer 15

at least two tissue types performing specific functions

Question 16

Define organ systems.

Answer 16

collection of organs performing a particular task

Question 17

Define external environment and give examples.

Answer 17

• external side of the epithelial body barrier
• ex. surroundings external to the skin
• ex. air in the lungs
• ex. food in the stomach
• ex. urine in the bladder

Question 18

Describe internal environment.

Answer 18

• immediate environment of most cells

- includes tissue fluid and plasma

Question 19

What is tissue fluid (interstitial fluid)?

Answer 19

fluid around all cells other than blood cells

Question 20

What is plasma?

Answer 20

fluid around blood cells

Question 21

Exchange of nutrients occurs from _____ –> ____ –> ____–> ______.

Answer 21

external environment to plasma to tissue fluid to cell

Question 22

What goes in and what goes out of a cell?

Answer 22

• nutrients and oxygen goes in

- wastes and unneeded material goes out

Question 23

What are the 3 mechanisms of exchange via blood exchange?

Answer 23

• across the lungs
• across gastrointestinal tract (absorption, secretion)
• across kidneys (filtration, reabsorption, secretion)

Question 24

What is homeostasis?

Answer 24

ability to maintain a relatively constant internal environment

Question 25

What are the 3 components of the internal environment that are regulated?

Answer 25

- temperature - volume - composition

Question 26

Disruption of homeostasis is?

Answer 26

the basis for disease and death

Question 27

What is the regulated variable in homeostasis?

Answer 27

the aspect which is maintained

Question 28

Give examples of homeostasis.

Answer 28

- speed of a car - blood glucose concentration - blood pH - plasma levels of sodium

Question 29

Define negative feedback.

Answer 29

- if a regulated variable decreases, the system responds to make it increase, and vice versa - self-correcting

Question 30

Define and give examples of set point.

Answer 30

- expected value of a regulated variable - ex. core body temperature = 37 degrees - ex. blood glucose (sugar) = Cdn fasting < 6.1 mmol/L - ex. blood pH = 7.4

Question 31

Define error signal.

Answer 31

difference between the value of the set point and the value of the regulated variable

Question 32

Give 4 examples of structures that enable homeostasis

Answer 32

- receptors - integrating centres - effectors - signals

Question 33

What are receptors? Give examples.

Answer 33

- sensors that detect stimuli - ex. thermoreceptors - ex. chemoreceptors - ex. baroreceptors

Question 34

What does the integrating centre do? Where are they found?

Answer 34

- sets up an appropriate response | - many found in the brain

Question 35

What are effectors? Give examples.

Answer 35

- responsible for body responses - ex. muscles (smooth, striated, cardiac) - ex. glands

Question 36

What are signals?

Answer 36

- allow components to communicate | - signals are chemical messages or sent via neurons

Question 37

Input signal is from a ______ to an ______ ______.

Answer 37

from a receptor to an integrating centre

Question 38

Output signal is from an _____ ______ to an _____.

Answer 38

from an integrating centre to an effector

Question 39

What is thermoregulation?

Answer 39

temperature balance of core body temperature

Question 40

What is normal temperature for humans? What is considered dangerous? Deadly?

Answer 40

- normal: 37 degrees C - dangerous: >41 degrees C - deadly: >43 degrees C

Question 41

Define hypothermia and hyperthermia.

Answer 41

- hypothermia: decrease in body temperature | - hyperthermia: increase in body temperature

Question 42

Name 4 mechanisms of heat transfer between the body and the external environment.

Answer 42

- radiation - conduction - evaporation - convection

Question 43

Describe radiation.

Answer 43

thermal energy through electromagnetic waves

Question 44

Describe conduction.

Answer 44

thermal energy through contact

Question 45

Describe evaporation.

Answer 45

- insensible water loss | - sweating

Question 46

Describe convection.

Answer 46

heat transfer by movement of fluid or air

Question 47

In the regulation of body temperature, what is the integrating centre?

Answer 47

thermoregulatory centre in hypothalamus

Question 48

In the regulation of body temperature, what are the receptors?

Answer 48

- thermoreceptors - central: found in CNS (hypothalamus) - peripheral: found in PNS (mainly skin)

Question 49

In the regulation of body temperature, what are the effectors?

Answer 49

- sweat glands | - muscles (smooth muscle of cutaneous blood vessels/skeletal)

Question 50

What is the thermo neutral zone?

Answer 50

- environmental temperature range: 25-30 degrees C | - cutaneous blood flow changes enough to regulate body temperature

Question 51

What happens when body temperature increases?

Answer 51

- cutaneous vasodilation | - increased blood flow to skin, causing heat loss

Question 52

What happens when body temperature decreases?

Answer 52

- cutaneous vasoconstriction | - decreased blood flow to skin, causing heat retention

Question 53

Describe heat generation in a cold environment.

Answer 53

- below 25 degrees C - core temperature cannot be maintained with vasoconstriction alone - heat generating mechanisms: shivering thermogenesis, non shivering thermogenesis (metabolism)

Question 54

Describe heat loss in a warm environment.

Answer 54

- above >30 degrees C - core temperature cannot be maintained with vasodilation alone - sweat production from sweat glands

Question 55

How does a fever alter set point for thermoregulation?

Answer 55

- rise in core body temperature - accompanies infection - white blood cells induce fever by chemical secretion - body temperature set point increases - fever enhances immune responses

Question 56

What is an example of something that alters set point for thermoregulation?

Answer 56

- exercise disrupts homeostasis | - type of feedback mechanism: