Chapter 18-23 Flashcards
What causes the normal heart sounds?
Two sounds (lub-dup) associated with the closing of heart valves
Why is the left ventricle thicker than right?
Pumps with greater pressure than the right ventricle
What is a heart block?
- Few (partial) or no (total) impulses reach ventricles
- usually caused by the AV node
What are the characteristics of arteries?
smaller lumen, no valves, thicker walls,
What do capillaries do ?
capillaries are very thin-walled blood vessels that exchange oxygen and other materials across the vessel wall.
What are the effects of exercise on blood flow?
- Coronary vessels dilate in response to local accumulation of vasodilators
- Blood flow may increase three to four times
When the thymus is most active?
The thymus is most active during youth
The major lymphatic ducts and what they drain
Right lymphatic duct drains right upper arm and right side of head and thorax
Thoracic duct arises as cisterna chyli; drains rest of body
Functions of the lymphatic system
Returns fluids that leaked from blood vessels back to blood
Three parts:
Network of lymphatic vessels (lymphatics)
Lymph – fluid in vessels
Lymph nodes – cleanse lymph
Types of T cells
- Cytotoxic T Cells( CD8 cells)-Destroys host cells that harbour anything foreign. They are directly responsible for cell-mediated immunity
- Helper T Cells(CD4 cells)-Modulate activities of OTHER immune cells
- Regulatory T cells (TReg cells) are a special subset of T cells that prevent other immune cells from attacking the body’s own tissues and other harmless environmental materials
Where B and T cells develop immunocompetence?
Thymus
What are haptens
- Are small molecules not immunogenic by themselves.
- can be immunogenic if attached to body proteins and a combination is marked foreign
- poison ivy
Types of tissue grafts
- Autografts: from one body site to another in the same person
- Isografts: between identical twins
- Allografts: between individuals who are not identical twins
- Xenografts: from another animal species
What determines what our immune system can recognize and resist
Genes
Characteristics of primary immune response
- Cell proliferation and differentiation upon first antigen exposure
- Lag period: three to six days
- Peak levels of plasma antibody are reached in 10 days
- Antibody levels then decline
Types of immunity and how they are acquired
Active immunity refers to the process of exposing the body to an antigen to generate an adaptive immune response (naturally accurried, getting sick and artifical- vaccine)
Passive immunity refers to the process of providing IgG antibodies to protect against infection ( naturally accuried- mother, artifical-rabies in humans)
What are allergies?
- Acute (type I) hypersensitivities
What is the most powerful respiratory stimulus for breathing?
Rising CO2 levels most powerful respiratory stimulant
What makes respiratory exchange for the fetus?
Gas exchange takes place via placenta
Characteristics of tuberculosis
An infectious disease caused by bacterium Mycobacterium tuberculosis
Symptoms-
- fever
- night sweats
- weight loss
- a racking cough
- coughing up blood
Characteristics Emphysema
Permanent enlargement of alveoli; destruction of alveolar walls; decreased lung elasticity, exhaustion from energy usage, Hyperinflation, flattened diaphragm, reduced ventilation efficiency, Damaged pulmonary capillaries, enlarged right ventricle
Characteristics of bronchitis
chronic excessive mucus, Inflamed and fibrosed lower respiratory passageways, Obstructed airways, Impaired lung ventilation and gas exchange, Frequent pulmonary infections
What increases the surface area of the small intestine?
- Circular folds (plicae circulares)
- Villi
- Microvilli
Characteristics of Saliva
- Functions:
- Cleanses mouth
- Dissolves food chemicals for taste
- Moistens food; compacts into bolus
- Begins breakdown of starch with enzymes
- 97–99.5% water, slightly acidic
- Electrolytes—Na+, K+, Cl–, PO4 2–, HCO3–
- Salivary amylase and lingual lipase
- Mucin
- Metabolic wastes—urea and uric acid
- 1500 ml/day
- pH 6.75 – 7.00
What cells secrete HCL?
Parietal cell
What do bacteria in your large intestine?
- Colonize colon
- Synthesize B complex vitamins and vitamin K
- Metabolize some host-derived molecules (mucin, heparin, hyaluronic acid)
- Ferment indigestible carbohydrates
- Release irritating acids and gases (~500 ml/day)
