Dr. Amel Eassawi

It’s a generalized, nonspecific response of the body to any factor that overwhelms, or threatens to overwhelm, the body’s compensatory abilities to maintain homeostasis. 2

Types of Stress: 1.Physical (trauma, surgery, intense heat or cold). 2.Chemical (reduced O 2 supply, acid-base imbalance). 3.Physiological (heavy exercise hemorrhagic shock, pain). 4.Infectious (bacterial invasion). 5.Psychological or Emotional (anxiety, fear, sorrow). 6.Social (personal conflicts, change in lifestyle). 3

4

5

Eustress  comes from good sources; (+) stress  It arises at points of increased physical activity, enthusiasm, creativity and when motivation and inspiration is needed. Examples:  Winning the lottery  Passing an exam 6

Distress  comes from bad sources; (-) stress  the stress that the mind and body undergoes when the normal routine is constantly adjusted and altered. Ex: being carnapped holdapped and kidnapped all in a day  There are actually two types of distress: acute stress and chronic stress. 7

Acute stress  Usually for short time and may be due to work pressure, meeting deadlines pressure or minor accident, over exertion, increased physical activity, searching something but you misplaced it, or similar things. Symptoms of this type of tension are headaches, back pain, stomach problems, rapid heartbeat, muscle aches or body pain. 8

Chronic Stress  Prolonged stress that exists for weeks, months, or even years. This stress is due to poverty, broken hearts, stressed families and failed marriages, chronic illness and successive failures in life.  People suffering from this type of stress get used to it and may even not realize that they are under chronic stress.  It is very harmful to their health. 9

General adaptation syndrome, or GAS (FIGHT or FLIGHT system) Universal response to the stressors Involved two major systems of the body, the nervous system and the endocrine (or hormonal) system. 10

Three distinctive stages : Stage 1: Alarm Reaction (AR) The immediate reaction to a stressor (physical or psychological) The body releases adrenaline and a variety of other psychological mechanisms to combat the stress and to stay in control that is, to bring about the fight or flight response. 11

Fight or Flight Responses: Increased heart rate Constriction of blood vessels of most viscera and skin Dilation of blood vessels of heart, lungs and skeletal muscles Contraction of spleen Conversion of glycogen into glucose in liver Sweating Dilation of airways Decrease in digestive activities Water retention and elevated blood pressure 12

Stage 2: Stage of Resistance (SR) Might also be named the stage of adaptation, instead of the stage of resistance During this phase, if the stress continues, the body adapts to the stressors it is exposed to Changes at many levels take place in order to reduce the effect of the stressor 13

Resistance Responses: Cortisol Lypolysis (breakdown of fat stored in fat cells ) Glyconeogenesis (metabolic pathway that results in the generation of glucose from non-carbohydrate carbon substrates such as pyruvate, lactate, glycerol, and glucogenic amino acids) Protein catabolism Sensitive blood vessels Reduce inflammation IGF Lipolysis Glycogenolysis (the catabolism of glycogen by cleavage of a glucose monomer through cleavage with inorganic phosphate to produce glucose-1-phosphate) TH increased use of glucose to produce ATP 14

Stage 3: Stage of Exhaustion (SE) The body has run out of its reserve of body energy and immunity. Mental, physical and emotional resources suffer heavily. Body experiences "adrenal exhaustion". Blood sugar levels decrease as the adrenals become depleted, leading to decreased stress tolerance, progressive mental and physical exhaustion, illness and collapse. In both cases, your body can not adapt and thus exhaustion follows. 15

16

17

Components of Nervous System During the Stress Response 1. Hypothalamus 2. Pituitary gland -anterior -posterior 3. Adrenal gland -medulla -cortex 18

 Regulates homeostatic functions: -body temperature -thirst/urine output -food intake  Influences emotional and behavioral patterns -changes physiological responses based on emotional stimuli (ie: anxiety - heartbeat)  Links the nervous system with the endocrine system -anterior pituitary -posterior pituitary 19

20

Start of response: Hypothalamus – detects stress  begins alarm phase  Autonomic Nervous System - provides the rapid response to stress commonly known as the fight or flight response - engages sympathetic division of the nervous system Sympathetic nerves release adrenaline 21

Adrenaline Rush effects…. 22

In cases of blood lost from injury, kidney help minimize loss.. How? 1. Hypothalamus release (1.)antidiuretics hormone (ADH) Purpose: to make the kidney take water from the urine and put it back into the blood 2. Adrenal glands can also make the kidneys move fluid from the urine back into the blood. 23

Renin - release by the kidney when their blood supply is reduced during alarm phase. Renin + other protein in the blood = angiotensin (which means "blood vessel constricting"). Aldosterone – release by the adrenal cortex of the adrenal gland due to stimulation of angiotensin - makes the kidneys secrete potassium into the urine and reabsorb sodium and water into the blood. The hypothalamus and adrenal cortex work together in the resistance phase to replace lost blood volume and send food to damaged cells. 24

To heal damaged cell:  It uses up its stored glucose. It will need to use its stored carbohydrates, fat, and proteins Hypothalamus and adrenal glands – serve as instructors A. Hypothalamus releases growth hormone B. Adrenal cortex releases cortisol *Both of these hormones tell the body to release stored compounds from body fat, muscles, and the liver. 25

26

27

28

29

30

 Human physiology, Lauralee Sherwood, seventh edition.  Text book physiology by Guyton &Hall,11 th edition.  Text book of physiology by Linda.S.Costanzo third edition 31