Random questions Flashcards
What drug is used to treat hypertension and why?
Thiazine diuretics- increase Na+ and water loss by the kidneys which decreases fluid volume, venous return and cardiac output.
How do you calculate the mean arterial pressure?
Diastolic pressure + 1/3 pulse pressure
What is the name given to the pressure pushing water back into plasma?
Colloid osmotic pressure
What is the name given to the pressure pushing water out into the interstitial fluid?
Hydrostatic pressure
What are Mechanoreceptors?
They are lung receptors which respond to stretch.
3 types:
-rapidly adapting receptors (cough reflex)
-slowly adapting receptors (HeringBreur reflex prevents over inflating)
-C-fibre receptors (defence mechanism)
All 3 innervated by fibres of the vagus nerve.
What is emphysema?
Irreversible destruction of the alveoli, generally caused by smoking.
- limited gas exchange
- area for O2 and CO2 is limited so CO2 can build up
What is Bradycardia
- Decreased heart rate
- Resting heart rate <60bpm
- Seldom symptomatic until rate drops below 50bpm
What is the equation for cardiac output?
Cardiac output= Stroke volume x heart rate
Describe some features of eosinophils
- high affinity to the red dye ‘eosin’.
- contribute to between 2-4% of all white blood cells.
- usually between 10-12m in diameter
- contain a bilobular nucleus.
- combat of parasitic infections within the body
- play role in body’s allergic responses and in conditions such as asthma
Describe some features of basophils
-affinity to a blue dye, often referred to as a ’basic dye’
-are the least common of all leukocytes within the body, contributing to less than 1% of all white blood cells.
-usually between 8-10m in diameter
-feature a bilobed ‘S’ shaped nucleus
-the granules within the cells cytoplasm contain
chemicals such as histamine and heparin.
What does Histamine do?
Histamine initiates inflammation and the contraction of smooth muscle
What does Heparin do?
Heparin is an anticoagulant and hence its function in the body is to prevent the formation of blood clots. Heparin is often used in surgery to prevent blood clots forming during certain procedures.
What organs are bypassed in foetus?
-Lungs
-liver
-gastrointestinal tract
as they are not sufficiently developed
What vessels supply the liver with blood?
- hepatic portal vein 70%
- hepatic artery-branch of the abdominal aorta 30%
What are the four main functions of the hepatic portal system?
- storage
- metabolic conversion (stores of glucose)
- detoxification (breaking down drugs)
- destroys bacteria
What duct drains the right side of the neck, head, thorax and upper limb, and what vein does this enter?
-right lymphatic duct which enters the right subclavian vein
What are the trabeculae?
Strand of collagen that extend inwards towards lymph node from capsule
What is the Hilum?
- small indentation where blood vessels and nerves enter the lymph node.
- where lymph leaves lymph node and enters afferent lymphatic vessel
In which type of fluid is the concentration of potassium at its highest?
Intracellular fluid
What are the components of extracellular fluid?
Interstitial fluid
Plasma
Transcellular fluid
Why does a foetus need specialised circulation?
Lungs and liver of foetus are non-functional and are bypassed.
Foetus receives oxygen and nutrients and gets rid of waste at placenta through maternal blood.
What are anastomoses?
When a number of supplies to an organ or a tissue join together, If one area is blocked, heart an still receive blood from the other arteries.
What are the 3 specialised connections within foetal circulation?
- 30% blood from right atrium–> left atrium via FORAMEN OVALE
- 70% blood bypasses lungs from pulmonary trunk to aorta DUCTUS ARTERIOSUS
- DUCTUS VENOSUS-branch with hepatic portal vein so some goes to liver but majority bypasses.
Describe the pathway of an action potential throughout the heart.
- Sinoatrial node generates action potential
- ap spreads rapidly across both atrium
- atrioventricular node rapidly depolarises at end of atrial contraction, sending ap to ventricles
- Bundle of His
- Ap travels down right bundle and left bundle
- reaches apex and reaches Purkinje fibres
- spreads ap to rest of ventricle causing contraction of ventricles once atria have finished contraction.
What are the names of the 3 special foetal connections in an adult?
Ductus Venosus –> Ligamentum Venosum
Foramen Ovale –> Fossa Ovalis
Ductus Arteriosus –> Ligamentum Arteriosum
What do we call the lower surface of heart?
inferior- diaphragmatic surface
What factors influence rate and depth of breathing?
- changing body demands e.g. exercise
- altitude- acute mountain sickness
- disease
- changing levels of CO2, H+,02 in arterial blood
What are the anatomical terms for the following words:
- head
- neck
- arm
- back of knee
- arm pit
head-cephalic neck- jugular arm- brachium back of knee- popliteal fossa arm pit- axillary fossa
Transitional epithelium can be found in the: A. Oesophagus B. Small intestine C. Trachea D. Urinary bladder
D. Urinary bladder
The majority of erythropoietin is produced in the: A. bone marrow B. kidneys C. liver D. spleen
B. kidneys
