Unit 5 (Free Response)

What are the tissue layers of the heart? What is the histology of each layer? What is the function of each layer?

Pericardium (outer) Serous membrane and dense irregular connective tissue

• Function : produces serous fluid to reduce friction

Myocardium (middle) Cardiac muscle tissue

• Function : pumps blood

Endocardium (inner) - Simple squamous epithelium

• Function : decreases friction of blood cells against wall

What are the valves of the heart? Where is each valve located? What is the specific function of each valve?

Heart valves are flaps of strong connective tissue inside the heart that act like one-way doors. 

Atrioventricular(AV) Valves - between atria and ventricles 

​​Right =tricuspid

 Prevent backflow into the right atrium (between right atrium and right ventricle)

• Left = bicuspid 

• Prevent backflow into the left atrium (between left atrium and left ventricle)

Main func: Prevent backflow into left and right atrium 

SemiLunar(SL) Valves - 

​​Right =pulmonary SL valve

• Between the right ventricle and the pulmonary artery - location

• Prevent backflow into the rignt ventricle func

 Left = aortic SL valv

• Between the left ventricle and aorta - location

• Prevent backflow into the left ventricle func

For cardiac systole and diastole, explain what is happening to the: atria, ventricles, atrioventricular valves, and semilunar valves

Cardiac Systole:

Atria are relaxed

Ventricles contract

ᯓ➤ AV Valves are closed

ᯓ➤ SL valves are open

Cardiac Diastole:

Atria contract

Ventricles are relaxed

ᯓ➤ AV valves are open

ᯓ➤ SL are closed

Using a flow chart, diagram blood flow through the heart

Right side (deoxygenated blood):
Deoxygenated blood enters the right atrium via the superior vena cava, inferior vena cava, and coronary sinus → Right atrioventricular (tricuspid) valve → Right ventricle → Pulmonary semilunar valve → Pulmonary trunk → Right and left pulmonary arteries → Lungs (becomes oxygenated)

Left side (oxygenated blood):
Lungs (oxygenated blood) → Pulmonary veins → Left atrium → Left atrioventricular (bicuspid/mitral) valve → Left ventricle → Aortic semilunar valve → Aorta → Body

What are the tissue layers of the blood vessels? What is the histology of each layer? What is the function of each layer?

Tunica Interna (innermost) - simple squamous epithelium

Func: to prevent friction from blood cells

Tunica Media (middle) - Smooth muscle tissue 

Func: Vasoconstriction and Vasodilation

Tunica Externa (outermost) : Elastic cartilage CT and collagen fibers 

Func: protects, strengthens, and anchors vessels to surrounding structures 

What are the two structural differences between arteries and veins?

Arteries have a thicker tunica Media

Veins have valves

What are the types of plasma proteins? What are their functions?

Albumin: maintain osmotic pressure

Globulins: create antibodies

Fibrinogen and prothrombin: blood clotting

What are the types of white blood cells? What are the functions of each? (7 cells)

Neutrophils

• Phagocytic to bacteria 

Basophils

• Release histamine

Eosinphils 

• Fight parasitic worms, play a role in allergies

Dendritic cells

• Capture microbes then stimulate other white blood cells for defense

Macrophages

• Phagocyte

T lymphocytes (T cells)

• Fight tumors and viruses

B lymphocytes (B cells)

• Produce antibodies

At what locations do the lymph vessels enter the bloodstream in the human body? Where does the lymph come from in each location?

Thoracic Duct 

• Lymph enters bloodstream at the junction of the left subclavian/left jugular vein

• Carries lymph from the entire left and lower right side of the body

Right Lymphatic Duct

• Lymph enters blood stream at junction of right subclavian vein/right jugular vein

• Carries lymph from the upper right side of the body only

What are the different components of spleen structure? What is the function of each?

White pulp

• Source of lymphocytes that manufacture and release antibodies

• Destroys blood born antigens

Red pulp

• Stores developing  erythrocytes

• Phagocytizes old defective erythrocytes, platelets, and bacteria

What is the function of the nasal cavities? What structures are responsible for those functions?

Blood capillary- warming

Mucus - moistening

Nose hairs and mucus - filtering

For all components of the lower respiratory system, state their histology

• Larynx –

External: Hyaline cartilage

Internal: Pseudostratified ciliated columnar epithelium

• Trachea –

External: Hyaline cartilage

Internal: Pseudostratified ciliated columnar epithelium

• Primary bronchi –

External: Hyaline cartilage

Internal: Pseudostratified ciliated columnar epithelium

• Secondary/Tertiary bronchi –

External: Smooth muscle + cartilage plates

Internal: Pseudostratified ciliated columnar epithelium

• Bronchioles –

External: Smooth muscle

Internal: Simple ciliated columnar epithelium (larger bronchioles) → Simple ciliated cuboidal epithelium (terminal bronchioles)

• Alveoli –

Internal: Simple squamous epithelium

Use a flow chart to diagram the complete flow through the respiratory system

Mouth/nose ➜ naso/oro/laryngopharynx ➜ larynx ➜ trachea ➜ secondary bronchi ➜ tertiary bronchi ➜ bronchioles ➜ alveoli