Unit 1 - Introduction

Question 1

What is physiology?

Answer 1

study of structure and function of a living organism and its components

Question 2

State the level of organisation of living organisms

Answer 2

• chemical: atoms and mols
• cellular: neuron, lymphocytes
• tissue: collection of cells (e.g. connective tissue)
• organ: collection of tissues (e.g. heart)
• organ system: group of organs
• organism: individual form of life

Question 3

How are cells held together?

Answer 3

Cell junctions

Question 4

Name the different types of cell junctions:

Answer 4

• anchoring junctions
• gap junctions
• tight junctions

Question 5

Name the primary tissue types found in the human body

Answer 5

• epithelial
• connective
• muscle
• neural

Question 6

What is the function of the epithelia?

Answer 6

to protect the internal environment of an individual

Question 7

What is the overarching function of epithelium tissue?

Answer 7

to regulate movement of materials between the internal and external environment, everything has to cross an epithelium

Question 8

List the types of epithelia and their functions:

Answer 8

• exchange: rapid exchange of material
• ciliated: line airways and female reproductive tract
• secretory: synthesize and release products into the external environment/blood
• transporting: selective transport of material
• protective: found on surface of the body

Question 9

Name the function of the connective tissue

Answer 9

to provide for structural support and barriers

Question 10

The connective tissue has extensive extracellular matric (ECM). What does the ECM contain?

Answer 10

• proteoglycans
• collagen
• elastin
• fibronectin

Question 11

Name the types of connective tissues and their functions:

Answer 11

• loose: elastic tissue (e.g. skin tissue)
• dense: strength (e.g. tendons)
• adipose: contains adipocytes (e.g. white and brown fat)
• blood: watery matrix lacking insoluble protein fibers
• supporting: dense substances (e.g. cartilage, bones)

Question 12

What is the function of muscles?

Answer 12

contraction to produce force and movement

Question 13

Name the types of muscles:

Answer 13

• skeletal: gross body movement
• smooth: influence movement of substances into/out of/within the body
• cardiac: only in heart, contraction to move blood

Question 14

What is the function of neural tissue?

Answer 14

to carry info from one part of the body to another

Question 15

Name the types of cells in neural tissue and their functions:

Answer 15

• glial cells: supporting cells for neurons

- neurons: carry info as electrical or chemical signals

Question 16

Define “function” and “mechanism” as interrelated concepts in physiology:

Answer 16

• function refers to why a system exists, while mechanism refers to how a system works
• we study the mechanism to understand the function

Question 17

What is homeostasis?

Answer 17

maintenance of a stable internal environment

Question 18

Homeostatic control is oscillation around a set-point. How can the set-point change with time?

Answer 18

• acclimatization: e.g. acclimatization to altitude
  environmentally induced change in physiological function w/o genetic change
• circadian rhythms: daily biological rhythms
  e. g. sleep-wake cycles, hormonal cycles

Question 19

Name the 4 basic mechanisms of cell-to-cell communication:

Answer 19

• gap junctions
• contact dependent signals
• local communication
• long distance communication

Question 20

What are gap junctions also known as?

Answer 20

direct cell to cell communication

Question 21

Where are gap junctions found?

Answer 21

heart, lungs, liver, neurons

Question 22

How does communication happen in gap junctions?

Answer 22

• via protein channels (connexons) between adjacent cells

Question 23

TRUE OR FALSE:

Gap junctions are capable of opening and closing

Answer 23

TRUE

Question 24

What is contact dependent signalling?

Answer 24

• interaction between membrane mols on 2 cells (e.g. surface mol of C1 binds to receptor protein in C2)

Question 25

Where can contact dependent signalling be found?

Answer 25

- immune system - during development: neural cells send out long extensions that must grow from central axis to distal ends of developing limbs

Question 26

What is local communication?

Answer 26

- communication with neighbouring cells - via autocrine and paracrine signals - autocrine: chemicals that act on the cell that produced them - paracrine: chemicals secreted that acts on neighbouring cells

Question 27

Give an example of a paracrine signalling molecule

Answer 27

histamine: vasodilator

Question 28

What engages in long distance communication?

Answer 28

- nervous and endocrine system

Question 29

How is nervous system different from endocrine system in communication?

Answer 29

nervous system: use both electrical and chemical signals (e.g. neurohormones, neurotransmitters) endocrine system: use only chemical signals: hormones

Question 30

what are the 3 main domains of membrane spanning regions?

Answer 30

- extracellular: involved in binding the ligand - transmembrane: hydrophobic - intracellular: activates cellular response to ligand binding

Question 31

TRUE OR FALSE: Any molecule that can bind to a receptor and induce activity will elicit the response of the receptor

Answer 31

TRUE

Question 32

membrane proteins act as ____

Answer 32

transducers

Question 33

Name and define the 2 types of homeostatic control:

Answer 33

- local control: effects are exerted on neighbouring cells e. g. paracrine control of blood vessel diameter in response to low O2 - reflex control: reaction in one or more organs controlled from elsewhere in the body e. g. can be any of the long distance paths of the nervous and/or endocrine systems

Question 34

What are the different types of feedback/control systems to regulate response loops?

Answer 34

negative feedback - opposes or removes the signal, thus returning the variable to its original value - homeostatic - keeps the system near or at set-point - e.g. blood pressure Positive feedback - reinforces stimulus, sends variable further away from set point - needs external factor to turn off response - not homeostatic - e.g. labour Feedforward control - anticipatory control - predicts change is about to happen, starts response loop, prevents change e. g. sight or smell of food