Biological Rhythms

Question 1

Biological rhythms

Answer 1

Cyclical patterns within biological systems, evolved in response to environmental influences.
2 key factors- exogenous zeitgebers and endogenous pacemakers

Question 2

Circadian rhythm’s

Answer 2

• 24 hour which resets by levels of light
• EG. Sleep wake cycle, when humans and animals should be asleep and awake
  
  • first detected by eye and send message concerning level of brightness to suprachuasmatic nuclei
• EG. Body temperature
  
  • lowest early hours of the morning and highest in early evening

Question 3

Endogenous pacemakers

Answer 3

Internal mechanism , internal biological clocks
Altered and affected by environment
- suprachiasmatic nucleus closely linked to pineal gland
- controls biological rhythms, receives information about light level
Increase production of melatonin

Question 4

Exogenous zeitgebers

Answer 4

Environmental events that are responsible for resetting biological clock of an organism, include social clues such as meal times.
Most important zeitgebers is light
-SNC contains receptors are sensitivite to light and external cue

Question 5

Infradian rhythms

Answer 5

Last longer than 24 hours and can be weekly, monthly or annually
- EG. Monthly rhythm is female menstrual cycle

Question 6

Ultradian rhythms

Answer 6

Last fewer than 24 hours found in pattern of human sleep
Alternates between rapid eye movement and non rapid movement
Five stages:
1. Stage 1&2 light sleep stages, brainwave patterns become slower starting with alpha progressing to theta waves
2. Stages 3&4 deep sleep stages, diffficut to wake someone up, delta waves
3. Stage 5 REM stage, body is paralysed
Entire cycle repeats Every 90 minutes, expeierces up to 5 full cycles