Atoms, molecules and cells

Question 1

skeletal muscle

Answer 1

under voluntary control
attached through other structures to skin or bone

Question 2

cardiac muscle

Answer 2

heart
involuntary control

Question 3

smooth muscle

Answer 3

surround many tubes in body
involuntary control

Question 4

types of connective tissue

Answer 4

Loose Connective (e.g., meshwork of cells and fibers underlying tissues)
2) Dense Connective (e.g., rigid tissue making up ligaments and tendons)
3) Bone and Cartilage
4) Adipose
5) Blood

Question 5

functions of matrix

Answer 5

scaffold for cellular attachments
transmits information to cells to regulate activity

Question 6

proteins in matrix

Answer 6

ropelike collagen fibres
elastin fibres

Question 7

organ composition

Answer 7

at least 2 of these tissues:
blood vessels
smooth muscle
endothelial cells
fibroblasts
can be divided into small functioning units and grouped into organ systems

Question 8

interstitium

Answer 8

space containing interstitial fluid

Question 9

homeostasis

Answer 9

state of reasonably
stable balance between physiological variables

Question 10

dynamic constancy

Answer 10

variable fluctuates in the body short term but is stable and predictable long term

Question 11

steady state system

Answer 11

a system in which a particular variable is not changing but energy input is required to maintain a stable, homeostatic condition

Question 12

equilibrium

Answer 12

a particular variable is unchanging and no input of energy is required to maintain the constancy

Question 13

negative feedback

Answer 13

an increase/decrease in the variable being regulated brings about responses that tend to move the variable in the direction opposite to the direction of the original change.

Question 14

positive feedback

Answer 14

an initial change in a particular variable subsequently leads to an even greater change in that variable

Question 15

resetting of set points

Answer 15

, eg during a fever a higher body temperature is maintained to inhibit the proliferation of some pathogens
The set point for body temperature is higher during the day when we are active

Question 16

feedfoward control

Answer 16

changes in regulated variables are anticipated and prepared for before they occur

Question 17

paracrine substances

Answer 17

are involved in local communication between cells. They are synthesised by and released by cells (once given a stimulus) into the extracellular fluid where they diffuse to neighbouring/target cells. They are not inactivated by enzymes after their function is done so are not released into the blood stream in large quantities

Question 18

autocrine substances

Answer 18

secreted by a cell into the extracellular fluid but then act upon that very cell that produced it.

Question 19

adaption

Answer 19

a characteristic that favours survival in specific environments

Question 20

acclimatisation

Answer 20

improved functioning of an already existing homeostatic system by prolonged exposure to an environmental change. Normally reversible. Involve an increase in the number/size/sensitivity of one or more of the cell types in that homeostatic system

Question 21

biological rhythms

Answer 21

feedforward system
Enables homeostatic mechanisms to be utilised immediately and automatically by activating them at times when a challenge is likely to occur
Biological rhythms are not driven by a environmental factors but they do influence their timing
eg cicadian rhythm

Question 22

pacemaker

Answer 22

a collection of neurones in the hypothalamus that acts as the time clock for circadian rhythms. Appears to involve rhythmic turning on and off of critical genes in the pacemaker cells.

Question 23

pool

Answer 23

the bodys readily available quantity of the substance and is often identical to the amount present in the extracellular fluid. It receives substances and redistributes them to all pathways

Question 24

negative balance

Answer 24

loss exceed gain

Question 25

positive balance

Answer 25

gain exceeds loss