Module 2, Week 2 (week 5) Flashcards
What is homeostasis?
Balance/equilibrium on the inside of the body, maintenance of body systems within a limited range associated with health.
List 3 x functions regulated by homeostasis mechanisms?
Blood volume
Temperature regulation
Rate of breathing
List 3 x common endocrine disorders:
Hyper/hypothyroidism
Addisons Disease
Polycystic ovary syndrome
Which 4 x body fluids are cavity dependent?
Blood plasma - in blood vessels
Synovial fluid - in joints
Cerebrospinal fluid - spinal cord
Aqueous humour/vitreous body - eyes
What is the interstitial fluid referred to?
The body’s internal environment.
LIst 4 factors that can interrupt homeostasis over longer periods:
Illness/chronic infections
Surgery
Poisoning
Extreme temperatures
Which two body systems are involved in homeostasis?
The nervous system
The endocrine system
What is the endocrine system’s main way of communication with body organs?
Hormones
Are hormones a fast or slower method of communication?
Slower - much slower than nerve impulses
How do hormones move around the body?
In the blood
List the 5 x steps in the feedback system:
- Observation - how are body systems are functioning (sensory neurons)
- Analysis - are modifications required? (control centre)
3 Adjustment - Apply modifications (effector cells - muscles/glands/organs) - More observation - how is system responding to modifications? (sensory neurons)
- More analysis - are further modifications required (control centre)
What are the three steps that repeat themselves with the feedback system?
Observation
Analysis
Adjustment
or
Monitored
Evaluated
Changed
What is the meaning of the term ‘controlled condition”?
The controlled condition is the range of function within certain limits - the limits that are connected to maintaining good health and are the boundaries that the body’s negative feedback systems maintain.
In regards to the negative feedback system, what is a stimulus?
Anything that causes an internal change and may shift the balance in body systems
List the three main roles/parts of the feedback loop:
Receptor (sensory neuron/receptor) Control centre (brain) Effector (muscle/gland/organ that responds to output from brain - makes the changes required)
What does afferent mean?
Refers to the sensory nervous system and relates to information that is carried towards the CNS - input from receptors/nerves to brain.
What does efferent mean?
Efferent is output, information or directive sent from the CNS to the effector cells - skin cells, muscles, glands etc
What is the afferent pathway?
The communication from nerve endings to the CNS ‘to the brain’
What is the efferent pathway?
The communication from the brain to effector cells ‘from the brain’
Describe a receptor in the feedback system:
- The nerve ending in sensory neuron - notices changes in internal conditions
- Sends information of change to CNS
- The message is sent in the form of nerve impulses or chemical signals
- Message/signals are referred to as input
- Example - skin receptors - detect change in external temperature of air/water on skin - body responds - sweating/shivering
In the feedback system, what is the control centre and what does it do?
- The brain is the control centre
- Brain establishes range of acceptable limits for certain conditions - set point
- Brain evaluates input and compares to established set points to determine whether adjustments are needed
- Brain sends signals/directions of adjustments req to effectors (muscles/glands etc) = output
In the feedback system, what is an effector?
An effector is any cell/tissue/organ that responds to messages/adjustments (output) from brain required to maintain homeostasis (setpoint) in a body system. It enacts the changes/modifications required.
Example: temperature drops. Body detects temp change - feels cold. Brain sends signals for muscles to shiver, generating heat, raising body temp.
List the stages of the feedback system (circular - from diagram)
Controlled condition - observed
Receptor - sends input to control centre
Control centre - receives info/analyses it/sends response info to effectors
Effectors - puts changes into effect
Response occurs
Return to homeostasis - brings conditions back into acceptable range/setpoint
What is the aim of the negative feedback system?
Reverse changes instigated by stimulus that upsets ideal conditions/setpoint - bring body system (controlled condition) back to setpoint/homeostasis.