ANP1105 Homeostasis

Question 1

What is Homeostasis

Answer 1

the ability to maintain relatively stable internal conditions even though the outside world changes continuously.

REMAIN @ AN EQUILIBRIUM

Question 2

What two systems play a major role in maintaining homeostasis?

Answer 2

Nervous and Endocrine

Question 3

What do the nervous and endocrine systems use to communicate within the body?

Answer 3

Neural electrical impulses or bloodborne hormones, as information carriers

Question 4

The VARIABLE – of at least three components that work together for homeostasis

Answer 4

1. Receptor
2. Control Center
3. Effector

Question 5

Receptor

Answer 5

Senses change (STIMULUS) and sends info (AFFERENT PATHWAY) to the control center

Question 6

Control Center

Answer 6

Determines the SET POINT (normal level) for variable maintenance

and

Receives and analyzes INPUT from RECEPTOR and DETERMINES appropriate response

Question 7

Effector

Answer 7

Receives OUTPUT from Control Center

Provides means for response

Feedback (negative feedback) or enhances stimulus (Positive feedback) allows for regulation within a range/enhances response

Question 8

Negative Feedback Mechanisms

Answer 8

1. MOST USED feedback mechanism
2. response REDUCES or SHUTS OFF original stimulus

Question 9

What is the goal of a negative feedback mechanism?

Answer 9

Prevent sudden, sever changes

Question 10

Examples of stimuli

Answer 10

Heat or Cold

Question 11

What is an example of a negative feedback mechanism

Answer 11

Thermoregulation: This is what our bodies do to regulate our temperature

Question 12

Positive Feedback Mechanism

Answer 12

Response ENHANCES or EXAGGERATES the original stimulus, so the output is further stimulated, occurs in the SAME DIRECTION as original response

Question 13

What is an example of a positive feedback mechanism?

Answer 13

Blood clotting - add more to spot that is broken (more platelets are added)

Contractions and birth

Question 14

Homeostatic imbalance

Answer 14

A DISTURBANCE of homeostasis

Question 15

What is a change associated with homeostatic imbalance?

Answer 15

Aging!
When control systems become less efficient, there is a greater risk for illness

Question 16

Autonomic nervous system

Answer 16

This is a system of motor neurons

• also called involuntary nervous system or general visceral motor system
• innervate (supplies) smooth muscles, cardiac muscle, and glands

Question 17

Somatic VS Autonomic

Answer 17

Somatic – effects Skeletal muscle, Always stimulatory
Autonomic – effets Smooth muscle, Stimulatory or Inhibitory

Question 18

Somatic - specifics

Answer 18

Has a thick, myelinated axon from spinal cord to skeletal muscle; rapid conduction of impulses (no ganglia)

ACh is the NT at effector

Question 19

ANS

Answer 19

Has both Sympathetic and Parasympathetic neurons
Has a Two-neuron chain from CNS to effector organs

Question 20

Parasympathetic neuron

Answer 20

ACh is the NT
Has a LIGHTLY myelinated preganglionic axon
and a NON-myelinated postganglionic axon

Question 21

Sympathetic neuron

Answer 21

LIGHTLY myelinated preganglionic axons, NON-myelinated postganglionic axon
as well as going to blood vessels – produces NE (neon)

Question 22

Parasympathetic division

Answer 22

REST and DIGEST (more regulation)
“D” system: digestion, defecation, diuresis

Question 23

Sympathetic division

Answer 23

FIGHT or FLIGHT
“E” system: exercise, excitement, emergency, embarrassment

Question 24

True or false - Visceral organs have dual innervation/counterbalance one another

Answer 24

TRUE

Question 25

Give an example of a cooperative interaction

Answer 25

regulation of external genitalia during intercourse PNS: dilation of blood vessels in penis/clitoris SNS: ejaculation, reflex contraction of females vagina

Question 26

Roles of SNS

Answer 26

1. Thermoregulatory responses to heat 2. Renin release from kidneys (increases blood pressure) 3. Metabolic effects (e.g. raises blood glucose levels, increases mental alertness)

Question 27

Anatomical differences between ANS divisions

Answer 27

1. sites or origin or nerves 2. Relative lengths of pre- and post- ganglionic fibers 3. locations of ganglia

Question 28

Brain Stem and Spinal Cord Controls

Answer 28

- motor centres in ventro-lateral medulla (eg. heart rate, blood) - spinal cord controls defecation and micturition but are subject to conscious override

Question 29

Hypothalamic Controls

Answer 29

Hypothalamus = integration centre of ANS

Question 30

Cortical Controls

Answer 30

eg: biofeedback to improve management of migraine headaches, stress and cardiac function

Question 31

In the Endocrine system, what are the 5 things it controls and integrate?

Answer 31

1. reproduction 2. growth and development 3. maintenance of electrolyte, water, and nutrient balance of blood 4. regulation of cellular metabolism and energy balance 5. mobilization of body defenses

Question 32

What is the main difference between Endocrine gland vs Exocrine glands

Answer 32

Endocrine glands secrete substances directly into the Bloodstream whereas exocrine glands secrete substances into a ductal system to an epithelial surface

Question 33

What is a hormone?

Answer 33

a chemical substance released into the ECF that regulates the metabolic function of the other cells in the body