Lab

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Lab 6
Functions of Vessels, Lymphatic System, Blood
Vessels, and Blood Pressure
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Interstitial Fluid

• As blood flows through the capillaries,
  nutrients, water, and O2 are exchanged
• At this time fluid from the plasma leaves the
  capillaries and bathes the adjacent tissue cells
• This fluid is called interstitial fluid
• Interstitial fluid is like plasma except without
  plasma proteins or formed elements

Interstitial fluid
Interstitial fluid provides nutrients and removes
wastes from the tissues of the body
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Lymph

• Interstitial fluid is mainly reabsorbed by the
  capillaries, but the remainder is picked up by
  lymph capillaries and eventually returned to the
  circulatory system
• Interstitial fluid reabsorbed into lymph
  capillaries is now called lymph

Lymph capillaries carry lymph through lymphatic
vessels and eventually to lymph nodes where
cellular wastes and foreign material (bacteria
and viruses) are cleaned out
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Other Functions of Lymph

• Absorption of lipids from the digestive system
• Lipids in the small intestine are converted to
  chylomicrons in the cells that line the digestive
  tract
• Chylomicrons are conducted into the lymphatic
  system and taken back to the cardiovascular system

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Lymph

• Contents of Lymph
• Lipids
• Chylomicrons, important in lipid absorption
• Nutrients
• glucose, electrolytes
• Wastes
• wastes urea, etc., cellular debris
• Pathogens
• viruses, bacteria, etc.

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Lymphatic System

• The lymphatic system is composed of several
  elements
• Lymph capillaries
• Lymph nodes
• Lymphatic vessels
• Lymph organs
• Lymphatic tissue

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Lymphatic System

• Lymph capillaries
• NOT continuous, blunt ended
• have valves
• low pressure system
• Lymph nodes
• enclosed in a sheath of tissue called a capsule
• have two regions cortex, medulla
• Cortex outer region with many lymph nodules
• Medulla inner region cords and sinuses filter
  out foreign particles and cellular debris -
  vascular
• Afferent lymph vessels take lymph to the node
• Efferent lymph vessels take lymph away from the
  node
• Veins and arteries in medulla

lymphatic capillary
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Lymph Node
Medulla
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Lymph nodule
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Lymphatic System

• Lymph vessels
• similar to blood vessels have all three tissue
  layers
• vessels collapse at death, making it hard to
  study them
• most of body is drained by the thoracic duct,
  returned at the left subclavian vein
• right side of the head and neck, drained by the
  right lymphatic duct, returned at the right
  subclavian vein

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Right Lymphatic Duct
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Lymphatic Vessels

• Carry lymph to lymph nodes located at the
• Inguinal region (groin)
• Axilla (arm pit)
• Antecubital fossa (elbow pit)
• Popliteal region (knee pit)
• Neck
• Thorax
• Abdomen

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Lymphatic System

• Lymph Organs
• Tonsils
• Have crypts lined with lymph nodules that are 1st
  line of defense against invading pathogens from
  mouth and nose
• Palatine along sides of the oropharynx
• Lingual back of the tongue
• Pharyngeal top of nasopharynx

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Pharyngeal
Palatine
Lingual
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Lymphatic System

• Lymph Organs
• Spleen
• in juveniles, responsible for RBC production
• RBC graveyard, filters blood, removes foreign
  particles
• red pulp concentrated RBCs, appears red under
  slide, filter
• white pulp lymphocyte activation and
  production, appears purple under slide
• Very vascular, loosely put together with
  reticular tissue

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Lymphatic System

• Lymph Organs
• Thymus (also part of..)
• Large in juveniles
• T-Cells mature here (in the blood thymus barrier)
• Divided into lobules with cortex and medulla
• Held together with connective tissue
• Shrinks with age

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Thymus
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Infant
Older individual
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Blood Pressure

• Important for the health of the heart and proper
  functioning of organs
• High BP increases workload of the heart
• Low BP does not maintain adequate blood flow to
  the brain
• May lead to fainting or dizziness
• Skeletal muscle pump

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Blood Pressure

• In todays lab you will take each others blood
  pressure
• Blood pressure is measured as systolic/diastolic
• This means a BP reading gives you the pressure
  required to get blood through a pinched vessel
  over the pressure at which there is no more
  tension in the vessel walls
• Sphygmomanometer blood pressure cuff

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Korotkoff Sounds

• Listen closely in the crook of the elbow with
  provided stethoscope
• 1st woosh sound is heard at the systolic
  pressure
• Last woosh sound (after you no longer hear the
  beats) is heard at the diastolic pressure