A&P II Lab Practical 2

Palatine tonsil

Crypt of a palatine tonsil

Connective tissue of a palatine tonsil

Lymphatic nodule of a palatine tonsil

Ileum Payer’s Patches

Microvilli of the ileum

Villi of the ileum (40x)

Goblet cell of the ileum (40x)

Lymph fluid of a lymphatic vessel

Simple squamous epithelium of a lymphatic vessel

Lymphatic vessel valve

Microvilli of the colon

Peyer’s patches of the colon

MALT of the colon

Trabeculae of the spleen

Red pulp of the spleen

Red pulp of the spleen

Lymphatic nodule of a lymph node

Perinodal fat of a lymph node

Capsule of a lymph node

Lymphatic capillaries

Microscopic vessels that absorb interstitial fluid → lymph

Lymph

Clear liquid with a varying protein composition, contains water blood cells, bacteria/viruses, hormones, etc.

Lymphatic tissue

MALT and lymphoid nodules; have NO capsule

MALT

Mucosa-associated lymphoid tissue

Lymphatic vessels

Transport lymph → lymphatic organs → blood plasma

Functions of the lymphatic system (3)

Recovery of interstitial fluid, absorption of dietary lipids (lacteals), immunity

Lymphocytes (3)

B, T, natural killer (NK) cells

B lymphocytes

Mature in red bone marrow → produce antibodies and memory B cells

T lymphocytes

Mature in the thymus → produce effector cells (helper T and cytotoxic T) → attack foreign/infected cells

Natural killer (NK) cells

Attack infected cells and destroy them

Antigen-presenting cells (APCs) (3)

Macrophages, dendritic cells, reticular cells

Primary lymphatic organs (2)

Thymus and red bone marrow; where lymphocytes mature

Secondary lymphatic organs (3)

Spleen, thymus, tonsils; where lymphocytes go after they’ve matured

Lymphatic capillaries/terminal lymphatics

Close-ended vessels that collect excess interstitial fluid → lymphatic system. Present in all tissue types except bone, bone marrow, cartilage, corneas

Layers of lymphatic vessels (3)

Tunica interna, tunica media, tunica externa

Tunica interna composition

Simple squamous endothelium and one-way valves

Tunica media composition

Smooth muscle and elastic fibers

Tunica externa composition

Collagen and elastic fibers (thin layer)

Lymphatic vessel pumps

Skeletal muscle, smooth muscle, respiratory, pulse of arteries, fast blood flow in the subclavian

Flow of lymph through vessels

Lymphatic capillaries → collecting vessels → (11) lymphatic trunks → (2) collecting ducts → subclavian veins/blood

Lymphatic trunks (11)

• Jugular (2)

• Subclavian (2)

• Bronchomediastinal (2)

• Intercostal (2)

• Lumbar (2)

• Intestinal (1)

Cisterna chyli

Lymphatic vessel collection between the lumbar and intestinal trunks

Collecting ducts (2)

Left thoracic, right lymphatic

Lymph nodes

Filter lymph; ~450 in the adult body

Afferent lymphatics

Multiple bring lymph in to lymph nodes

Efferent lymphatics

One takes lymph out of lymph nodes

Antibody (Ab)

Recognize and bind antigens (Ag) for destruction

Antigen (Ag)

Non-self markers → immune response by the body

Major components of lymphatic organs (2)

Cortex and medulla

Flow of lymph through lymph nodes

Afferent vessel → lymphatic nodule → cortical sinus → efferent vessels

Arteries of the head and neck (3)

• R/L common carotid

• Vertebral

R/L common carotid arteries

Vertebral artery

Branches of the aorta in cats (2)

Brachiocephalic artery, left subclavian artery

Branches of the aorta in humans (3)

Brachiocephalic artery, left common carotid artery, left subclavian artery

Veins of the head and neck (6)

• R/L brachiocephalic

• R/L external jugular

• R/L internal jugular

R/L brachiocephalic veins

R/L external jugular veins

R/L internal jugular veins

Arteries of the thorax (7)

• Left subclavian

• Right subclavian

• R/L thyrocervical

• Aortic arch

• Brachiocephalic

• Descending thoracic aorta

Left subclavian artery

Right subclavian artery

R/L thyrocervical arteries

Aortic arch

Brachiocephalic artery

Descending thoracic aorta

Veins of the thorax

• R/L subclavian

• Superior vena cava

• Azygos vein

R/L subclavian veins

Superior vena cava

Azygos vein

Upper extremity arteries

• R/L axillary

• R/L brachial

R/L axillary arteries

R/L brachial arteries

Upper extremity veins

• R/L axillary

• R/L brachial

• R/L radial

• R/L ulnar

R/L axillary veins

R/L brachial veins

R/L radial veins

R/L ulnar veins

Abdominal arteries

• R/L renal

• Descending abdominal aorta

• Celiac trunk

• Superior mesenteric

• Inferior mesenteric

R/L renal arteries

Descending abdominal aorta

Celiac trunk

Superior mesenteric artery

Inferior mesenteric artery

Abdominal veins

• R/L renal

• Inferior vena cava

• Hepatic portal

R/L renal veins

Inferior vena cava

Hepatic portal vein

Pelvic arteries

• R/L external iliac

• R/L internal iliac

• Medial sacral (caudal) artery

R/L external iliac arteries

R/L internal iliac arteries

Medial sacral (caudal) artery

Pelvic veins

• R/L common iliac

• R/L external iliac

• R/L internal iliac

R/L common iliac veins

R/L external iliac veins

R/L internal iliac veins

Lower extremity arteries

R/L femoral

R/L femoral arteries

Lower extremity veins

• R/L femoral

• R/L deep femoral

• R/L popliteal

• R/L great saphenous

R/L femoral veins