ANAT 35 Lecture 14-16 The Heart + Blood Vessels + Blood

What are the primary functions of the atria?

Receiving chambers that receive blood into the heart from veins

thin walled, derived from veins

Where does the right atrium receive blood?

vena cava

coronary sinus

Where does the left atrium receive blood?

pulmonary veins

What is the function of the L/R auricles?

they help to increase volume into the atria to accommodate blood returning to the heart while the AV valves are closed during ventricular contraction

What is the pectinate muscle?

the muscle of the wall of atria, looks like a honeycomb

What is the general function of the ventricles?

pumping chambers, receive blood from the atria

thick walled, derived from arteries

Where does the right ventricle pump blood to?

to the lungs

blood is pumped at a lower pressure

Where does the left ventricle pump blood to?

to the aorta, then to tissues of the body

blood is pumped at a higher pressure

Which ventricle has thicker walls?

the left ventricle

What is the trabeculae carnae?

the muscle of the walls of the ventricles

What are the AV valves?

tricuspid valve

mitral valve

What are the SL Valves?

pulmonary valve

aortic valve

When the ventricles relax, what happens to the AV and SL valves?

AV valves are open

SL valves are closed

When the ventricles contract, what happens to the AV and SL valves?

AV valves are closed

SL valved are open

What are the stimulating tissue of the heart called, and what is their composition?

SA Node

AV Node

modified myocardium

What is the function of conducting tissue and what is it made of?

transmit impulses to produce coordinated contractions

modified myocardium

What are the types of blood vessels?

Arteries

Veins

Capillaries

What do arteries do and their characteristics?

carry blood away from heart

resistance vessels

under high pressure

What do veins do and their characteristics?

carry blood to the heart

capacitance vessels

under low pressure

What are the function of capillaries?

exchange vessels

perfusion

Do arteries and veins have similar anatomy to other tubes in the body?

Yes

How do arteries and veins different anatomically?

proportion of muscle to connective tissue is different:

• arteries = thickest layer is smooth muscle

• veins = thicket layer is connective tissue

What are capillaries made of?

endothelum and basement membrane

What are the layers of arteries and veins?

tunica adventitia/externa

tunica media

tunica intima

What are the three types of arteries?

elastic

muscular

arterioles

What do elastic arteries do?

transport large volumes of blood away from the heart

What do muscular arteries do?

transport blood to skeletal muscle and internal organs

What do arterioles do?

deliver/regulate blood flow to capillaries

What are the 3 types of capillaries?

continuous

fenestrated

sinusoidal

Characteristics of continuous capillaries

Smallest blood vessel in body

most common

no perfusion, tight junctions

Characteristics of fenestrated capillaries

intracellular perforations

allow movement through fenestrations

Characteristics of sinusoidal capillaries

open spaces between endothelial cells

very permeable

permit bulk flow

Location of continuous capillaries

nervous system

fat

muscle

Location of fenestrated capillaries

kidneys

endocrine glands

small intestine

Location of sinusoidal capillaries

liver

spleen

bone marrow

What is the difference between normal circuits and portal circuits of blood flow?

normal: one capillary bed in circuit

portal: two capillary beds in series

Where are the 3 portal circuits in the body?

hepatic

renal

hypothalamo-pitutary

What does the hepatic portal system connect?

connects the capillaries of the digestive tube to the capillaries of the liver

What does the renal portal system connect?

connects the capillaries of the glomerulus to the capillaries of the cortex or medulla of kidney

What does the hypothalamohypophyseal portal system connect?

connects the capillaries of the infundibulum to the capillaries of the anterior pituitary

What are the three types of veins?

Large

Medium

Venules

What are the characteristics and function of veins?

relatively large diameter

thin tunica media

thick tunica externa

large veins have valves

return blood to the heart

What is the function of the lymphatic system?

maintain fluid balance in tissues

immune function

lipid transport

What are the lymphatic organs?

primary:

• bone marrow

• thymus

secondary:

• lymph nodes

• spleen

• tonsils

• lymphatic nodules

What are the components of plasma?

primarily water

other:

• glucose

• lipids

• dissolved gases

• ions

• bicarbonate

• amino acids

What are plasma proteins and where are they made in?

predominantly made in liver

• albumins

• lipoproteins

• fibrinogen

• globulins

What are the formed elements in blood?

red blood cells - erythrocytes

white blood cells - leukocytes

platelets - thrombocytes

Characteristics of bone marrow

all blood cells are produced in bone marrow

fills space in spongy bone tissue

2 types: red and yellow

more red bone marrow in child vs adults

What is red bone marrow?

myeloid tissue

hematopoietic - gives rise to all blood cell types

What is yellow bone marrow?

fatty marrow stores adipose

replaces most red bone marrow in adults

not hematopoietic, but can revert back to red bone marrow

Characteristics of erythrocytes

red blood cells

mature cells lack mitochondria

function is oxygen transport and delivery to tissues

Hemoglobin characteristics

quaternary protein produced by red blood cells

each subunit contains a heme group containing iron

What are leukocytes and the 5 types?

white blood cells

granular:

• neutrophils

• eosinophils

• basophils

agranular:

• monocytes

• lymphocytes

Characteristics of neutrophils

polymorphic nuclei

most numerous WBC

first WBC at infection site

microphage

Characteristics of basophils

least numerous WBC in plasma

not phagocytic; degranulate to release heparin and histamine

responsible for inflammatory response (allergies)

Characteristics of monocytes

can differentiate to macrophage or dendritic cells

will move out of blood to tissues

phagocytize microbes and clear cellular debris

antigen presenting cell (APC)

Characteristics of lymphocytes

2nd most numerous WBC in plasma

primary cells of lymphatic system

responsible for immunity (T, B, NK cells)

Characteristics of platelets

formed by fragmentation of megakaryocytes in bone marrow

released in plasma

required for blood clotting repsonse

Characteristics of spleen

secondary lymph organ

2 types of tissue: red and white pulp

red pulp filters blood to remove from circulation

white pulp stores naive, mature, monocytes and b cells