Loading....
Coupon Accepted Successfully!

Physiology

Open Flashcards

Basic Concepts

Question
64 out of 95
 

In an unacclimatised person suddenly exposed to cold atmosphere, changes seen are



A Increase in systolic BP

B Shift of blood from shell to core

C Non — thermogenic shivering

D Tachycardia

Ans. B Shift of blood from shell to core

Body responses on exposure to cold: ­

Keep its internal temperature constant by increasing heat production or by reducing heat loos.

a. Heat loss in reduced by cutaneous vasoconstriction this reduces the amount of heat transferred by the blood from the body core to the body surface (shell). This may raised the B.P. Heat loss is also reduced by piloerection

b. Heat production ed by: ­

c. es the metabolic rate

d. Adrenaline secretion chemical thermogenesis or non shivering thermogenesis from brown fat (by uncouple oxidative phosphorylation). Since brown fat almost absent in adult, so it is not important in adult. But important in neonates, in which non shivering thermogenesis, increases the heat production by 100%

i. Increased thyroxin productin as a long term cause of increased Heat production it requires several weak

ii. Shivering during maximal shivering body heat production can rise to four to five times normal shivering centre located in dorsomedial portion of the posterior hypothalamus

iii. Voluntary muscular activity.

Basic Concepts Flashcard List

95 flashcards
1)
2)
3)
4)
5)
6)
7)
8)
9)
10)
11)
12)
13)
14)
15)
16)
17)
18)
19)
20)
21)
22)
23)
24)
25)
26)
27)
28)
29)
30)
31)
32)
33)
34)
35)
36)
37)
38)
39)
40)
41)
42)
43)
44)
45)
46)
47)
48)
49)
50)
51)
52)
53)
54)
55)
56)
57)
58)
59)
60)
61)
62)
63)
64)
65)
66)
67)
68)
69)
70)
71)
72)
73)
74)
75)
76)
77)
78)
79)
80)
81)
82)
83)
84)
85)
86)
87)
88)
89)
90)
91)
92)
93)
94)
95)