pulse rate in adult person

Pulse rate in adult person

The pulse rate in adult person was found to be 40bpm . Which of the following conditions is less likely to be observed (T/F)

a) Hypothyroidism
b) Athletic bradycardia
c) Hemorrhage
d) Sleeping
e) Awake state

Cushing reflex

Physiological basis for Cushing reflex

Cushing reflex (Cushing effect, Cushing reaction, Cushing phenomenon, Cushing response)

• Increase systolic blood pressure and reduce heart rate ( bradycardia) due to increased intracranial pressure 

Cerebral blood flow depends on

• Local constriction and dilation of  cerebral arteriols 
• Intracranial pressure 
• Mean arterial pressure 
• Mean venous pressure 
• Viscosity of blood 

valsalva maneuver

Physiological changes in  valsalva maneuver

Valsalva maneuver

•  Forced expiration against a closed glottis

Stage 1

• Due to forceful expiration against closed glottis intrathoracic pressure increase
• Initially increase thoracic pressure transmit to aorta and increase blood pressure

peripheral cyanosis

Physiological basis for peripheral  cyanosis  in hypovolemic shock

Cyanosis

• Dusky bluish discoloration of tissue 
• Due to increased deoxygenated Hb in blood 
• More than 5 g/dl 

Hypovolemic shock

• Inadequate tissue perfusion 
• Due to relative or absolute reduction of cardiac output 
• Hypovolemic shock occurs due to reduction of total blood ( fluid ) volume 

Physiological basis for carotid bruit

Physiological basis for carotid bruit

Laminar flow

• Fluid flows in parallel layers 
• Each layer remains in constant distance form the vessel wall 
• Fluid layer close to the wall has a lowest velocity 
• Fluid layer at the center of a vessel has highest velocity 
• Laminar flow is silent 
• When blood flows in long, smooth straight vessels it flow as laminar flow

Describe the ionic changes which leads to the the action potentials

Describe the ionic changes which leads to the the action potentials
1. In the non conducting tissues
2. In the auto rhythmic cells

Compare and contrast the cardiac muscle and skeletal muscle

Compare and contrast
1. The electrical activity
2. Excitation : contraction coupling
Of the cardiac muscle and skeletal muscle

Explain the physiological basis of the following.

(1). Explain the physiological basis of the following.
Two ECGs were taken on a healthy adult on two separate occasions.
At rest: R-R interval was 0.8 seconds.

On massaging both sides of the neck: R-R interval was 1.0 seconds and he felt faintish