cvs histology Flashcards
What is the innermost layer of the heart called?
Endocardium
It lines all four chambers of the heart.
What type of epithelium is the endothelium of the circulatory system?
Simple squamous epithelium
It is the innermost lining of blood vessels.
What are the three layers of the heart?
- Endocardium
- Myocardium
- Epicardium
What is the function of the cardiac skeleton?
Supports heart valves and anchors muscle fibers
It ensures that ventricles contract separately, allowing proper coordination of heartbeats.
What are the components of the cardiac skeleton?
- Annuli fibrosi
- Septum membranoceum
- Trigona fibrosa
What is the function of endothelium in blood vessels?
- Selective permeability
- Anticoagulant properties
- Regulation of blood flow
What are the three types of blood vessels?
- Arteries
- Veins
- Capillaries
What is the tunica intima?
Innermost layer of blood vessels made of a single layer of endothelial cells
It includes a layer of subendothelia.
What is the tunica media composed of?
Smooth muscle and elastic fibers
It regulates blood flow by controlling vessel diameter.
What are the three types of arteries based on size?
- Large arteries
- Medium-sized arteries
- Arterioles
What is the function of arterioles?
Regulate blood distribution and systemic blood pressure
They can constrict or dilate.
What are capillaries made of?
Single layer of endothelial cells
They facilitate the exchange of oxygen, nutrients, and waste products.
What are the three types of capillaries?
- Continuous capillaries
- Fenestrated capillaries
- Discontinuous capillaries (sinusoids)
What distinguishes fenestrated capillaries?
They have small pores (fenestrations) in their endothelial lining
This allows for more permeability than continuous capillaries.
What is the primary function of pericytes?
Help regulate blood flow and serve as stem cells for repair
They can differentiate into smooth muscle or connective tissue cells.
What is the role of valves in veins?
Prevent blood from flowing backward
They act like gates that close when blood tries to move the wrong way.
What are the types of veins based on size?
- Venules
- Medium-sized veins
- Large veins
What is thrombosis?
Formation of a blood clot inside a vein
It blocks blood flow and can cause swelling and congestion.
What is the main purpose of the lymphatic system?
Collect excess interstitial fluid and return it to the bloodstream
This prevents tissue swelling.
What are lymph capillaries?
Tiny tubes that start in tissues and are blind-ended
They collect excess fluid from tissues.
What are the main parts of the lymphatic system?
- Lymph capillaries
- Lymphatic vessels
- Lymphatic ducts
What is the structure of lymphatic vessels?
They resemble veins but have thinner walls and contain valves
They help maintain one-way flow of lymph.
What do lymph nodes do?
Filter lymph and trap harmful substances like bacteria
They also contain immune cells to fight infections.
What shape do lymph nodes resemble?
Bean-shaped
What is the primary function of lymph nodes?
Act as filters for lymph, trapping harmful substances like bacteria and cancer cells
What type of cells do lymph nodes contain to fight infections?
Immune cells
How does lymph flow through the body?
Helped by valves in vessels and muscle movement
What do valves in lymphatic vessels prevent?
Backflow
What role does muscle movement play in lymph flow?
Squeezes lymph vessels to push fluid one direction—from tissues to the heart
What is a clinical importance of the lymphatic system related to cancer?
Cancer cells can travel through lymphatic vessels and settle in lymph nodes
What can cause lymph nodes to swell?
Cancer cells settling in lymph nodes
What is lymphedema?
Swelling caused by lymph nodes being blocked or removed
What is lymph?
Fluid collected from tissues
What are lymph capillaries?
Tiny vessels that absorb lymph
What are lymphatic vessels?
Larger vessels that carry lymph and have valves
What are lymphatic ducts?
Big ducts that return lymph to the bloodstream
What is the function of lymph nodes?
Filter harmful substances and fight infections
