This document discusses the anatomy and physiology of cutaneous blood flow regulation. It notes that cutaneous blood flow at rest is 10-15 ml/min/100g of skin, falling to 1 ml/min/100g with cold exposure and increasing tenfold with heat exposure. Blood flow is primarily regulated by the sympathetic nervous system. Exposure to heat causes arteriole dilation, cutaneous vessel dilation, sweating, and bradykinin-induced dilation. Exposure to cold triggers vasoconstriction. Various reflexes and cortical mechanisms also influence blood flow regulation and skin color changes.
This is a presentation about splanchinc circulation.
Done by year 3 medical students at the University of Science and Technology, Sana'a, Republic of Yemen.
Spring semester of 2010.
This is a presentation about splanchinc circulation.
Done by year 3 medical students at the University of Science and Technology, Sana'a, Republic of Yemen.
Spring semester of 2010.
Nervous control of blood vessels regulation of arterial pressureAmen Ullah
The main function of the circulatory system is to give local blood flow to the tissue. There arespecial need of the tissue which is:
delivery of oxygen to the tissue
delivery of nutrients to the tissue
removal of carbon dioxide from tissue
maintaining of normal concentration of ions
transform of hormones and other substance to tissue
Cardiac output (The Guyton and Hall Physiology)Maryam Fida
The volume of blood pumped by each ventricle per minute is called cardiac output
Cardiac output = Stroke Volume X Heart Rate
Normal value = 5 Liters /Minute
Cardiac output = Stroke Volume X Heart Rate
The factors which regulate stroke volume and Heart rate are basically regulating Cardiac output
Volume of blood ejected by each ventricle in single systole; Normal Value = 70 ml/beat
Stroke Volume = End diastolic Volume – End Systolic Volume
So stroke volume is mainly controlled by
EDV
ESV
VENOUS RETURN: What ever blood volume returns to the heart, same is pumped forward through the Frank’s Starlings Law. According to this law 13- 15 liters of blood volume can be pumped out without cardiac stimulation.
DURATION OF DIASTOLE OR FILLING TIME: ventricular filling occurs during diastole, so there must be adequate ventricular filling time.
DISTENSIBILITY OF THE VENTRICLES: Normally ventricles are distensible to accommodate adequate blood volume. Infarction decreases the distensibility which decreases the EDV.
ATRIAL CONTRACTION: There must be adequate atrial contraction to have adequate EDV. If atrial function is not adequate then EDV will decrease.
E.S.V is basically CONTROLLED BY MYOCARDIAL CONTRACTION
FORCE OF MYOCARDIAL CONTRACTION: It depends upon the initial length of muscle fibers according to frank’s starlings law.
PRELOAD: The effect of EDV on initial length is called preload. So EDV also effects the ESV.
AFTER LOAD: Force of contraction is also dependant upon the resistance against which the ventricles have to pump
CONDITION OF THE MYOCARDIUM : It also effects the force of contraction.
AUTONOMIC NERVES : Sympathetic stimulation increases and parasympathetic stimulation decreases force of contraction
HORMONES: Catecholamines, thyroxine, glucagon, digitalis, calcium, increased temp, caffeine, theophyline increase the force.
Force decreases by hypoxia, acidosis, barniturates, procainamide and quinidine decrease the force of contraction.
Receptor by Pandian M, Tutor, Dept of Physiology, DYPMCKOP, MH. This PPT for ...Pandian M
Introduction
SENSORY RECEPTORS
Structurally 3 types of receptors
Transducers
CLASSIFICATION OF RECEPTORS
A. Depending on the source of stimulus(Sherrington’s classification)
B. Depending upon type of stimulus
C. Clinical or anatomical classification of receptors
Production of receptor potential
Properties of receptors
Properties of receptor potential
A brief overview of the physiology of the neuromuscular junction.It includes a video towards the end sourced from the internet with the copyright watermarks intact.
HEART RATE
REGULATION OF HEART RATE
VASOMOTOR CENTER – CARDIAC CENTER
MOTOR (EFFERENT) NERVE FIBERS TO HEART
FACTORS AFFECTING VASOMOTOR CENTER
for all medical & health care students
Nervous control of blood vessels regulation of arterial pressureAmen Ullah
The main function of the circulatory system is to give local blood flow to the tissue. There arespecial need of the tissue which is:
delivery of oxygen to the tissue
delivery of nutrients to the tissue
removal of carbon dioxide from tissue
maintaining of normal concentration of ions
transform of hormones and other substance to tissue
Cardiac output (The Guyton and Hall Physiology)Maryam Fida
The volume of blood pumped by each ventricle per minute is called cardiac output
Cardiac output = Stroke Volume X Heart Rate
Normal value = 5 Liters /Minute
Cardiac output = Stroke Volume X Heart Rate
The factors which regulate stroke volume and Heart rate are basically regulating Cardiac output
Volume of blood ejected by each ventricle in single systole; Normal Value = 70 ml/beat
Stroke Volume = End diastolic Volume – End Systolic Volume
So stroke volume is mainly controlled by
EDV
ESV
VENOUS RETURN: What ever blood volume returns to the heart, same is pumped forward through the Frank’s Starlings Law. According to this law 13- 15 liters of blood volume can be pumped out without cardiac stimulation.
DURATION OF DIASTOLE OR FILLING TIME: ventricular filling occurs during diastole, so there must be adequate ventricular filling time.
DISTENSIBILITY OF THE VENTRICLES: Normally ventricles are distensible to accommodate adequate blood volume. Infarction decreases the distensibility which decreases the EDV.
ATRIAL CONTRACTION: There must be adequate atrial contraction to have adequate EDV. If atrial function is not adequate then EDV will decrease.
E.S.V is basically CONTROLLED BY MYOCARDIAL CONTRACTION
FORCE OF MYOCARDIAL CONTRACTION: It depends upon the initial length of muscle fibers according to frank’s starlings law.
PRELOAD: The effect of EDV on initial length is called preload. So EDV also effects the ESV.
AFTER LOAD: Force of contraction is also dependant upon the resistance against which the ventricles have to pump
CONDITION OF THE MYOCARDIUM : It also effects the force of contraction.
AUTONOMIC NERVES : Sympathetic stimulation increases and parasympathetic stimulation decreases force of contraction
HORMONES: Catecholamines, thyroxine, glucagon, digitalis, calcium, increased temp, caffeine, theophyline increase the force.
Force decreases by hypoxia, acidosis, barniturates, procainamide and quinidine decrease the force of contraction.
Receptor by Pandian M, Tutor, Dept of Physiology, DYPMCKOP, MH. This PPT for ...Pandian M
Introduction
SENSORY RECEPTORS
Structurally 3 types of receptors
Transducers
CLASSIFICATION OF RECEPTORS
A. Depending on the source of stimulus(Sherrington’s classification)
B. Depending upon type of stimulus
C. Clinical or anatomical classification of receptors
Production of receptor potential
Properties of receptors
Properties of receptor potential
A brief overview of the physiology of the neuromuscular junction.It includes a video towards the end sourced from the internet with the copyright watermarks intact.
HEART RATE
REGULATION OF HEART RATE
VASOMOTOR CENTER – CARDIAC CENTER
MOTOR (EFFERENT) NERVE FIBERS TO HEART
FACTORS AFFECTING VASOMOTOR CENTER
for all medical & health care students
3. Cutaneous arterioles
Meta arterioles – resistance vessels
Capillaries – large surface area for heat
exchange
Venules – large sub papillary venous
plexus
AV anastamosis – more prominent in
acral regions
4.
5.
6. Resting blood flow - 10-15ml/ min/100g of
skin
Exposure to cold – falls to one tenth of
resting flow i.e 1ml/min/100g
Exposure to heat – increase ten times ,
produces heavy circulatory load –
unconciouness
Regional variation in Cutaneous blood
flow
Skin color and blood flow
7. Skin needs little O2
0.3ml/min/100g (compared to )
So nervous >metabolic control
Nervous control – sympathetic supply
alone
8. Under resting condition
During exposure to heat – four steps
AV anastomoses dilate
Progressive Cutaneous dilation
sweat gland activation
Bradykinin produces dilation
During exposure to cold
9.
10.
11. Baroreceptor reflex
Cortical control mechanism
Blanching of skin
Phenomenon of blushing
12.
13.
14. White reaction – due to vasoconstriction
& appears about 15 sec
15. Red reaction- within 10 sec , due to
histamine and bradykinn , local response
Flare – spreading redness, after few min,
mediated by axon reflex
diffusely spreading irregular
redness
Wheal - local exudation and edema due
to histamine and substance p