Cornell Veterinary Medicine - Week One

epithelial tissue

adhere closely to one another to form continuous sheets that cover body surfaces

role: protection, absorption, secretion

connective tissue

Cells do not adhere to each other as they are surrounded externally by an extracellular matrix, which provides support and structure to organs and other tissues.

muscle tissue

tissue composed of cells that can contract and are responsible for movement of the body and its organs.

nervous tissue

specialized tissue that transmits electrical impulses throughout the body, facilitating communication between different body parts.

central axis

passes through the head, neck, trunk + divides the body into symmetric left/right halves

median plane (whole body)

a plane extending along the central axis that divides the body into left and right parts.

sagittal plane (whole body)

parallel to the median plane

transverse plane (whole body)

a plane that divides the body into cranial and caudal parts, perpendicular to the median and sagittal planes.

dorsal plane (whole body)

a plane that divides the body into ventral and dorsal parts, perpendicular to the median and transverse planes.

transverse plane (limbs)

a plane that divides a limb into proximal and distal parts

sagittal plane (limbs)

a plane that divides a limb into left and right parts, parallel to the median plane.

dorsal plane (limb)

a plane that divides a limb into dorsal and palmar (or plantar) parts

medial

closer to the median plane

lateral

further from the median plane

intermediate

between medial and lateral

sagittal

relating to a plane that divides the body into left and right portions

transverse

relating to a plane that divides the body into upper and lower portions

cranial

relating to the skull or head region

caudal

relating to the tail or lower part

dorsal

closer to the dorsum (back) + corresponding surface of the head

ventral

closer to the ground (if the animal is standing)

proximal

closer to the body

distal

further from the body

palmer

the part of the front paw (manus/carpus) that contacts the ground

plantar

the part of the hind paw (pedis/tarus) that contacts the ground

rostral

closer to the muzzle (nose) use when talking about head

posterior

closer to the tail

superior

further from the ground

inferior

closer to the ground

lateral rotation

angular motion in the transversal plane to the left/right (ex. turning head to say “no”

flexion

angular motion in the median (sagittal) plane that brings structures closer together

extension

motion that brings structures further apart

lateral flexion

angular motion in the dorsal plane to the left/right that bring structures closer together (bringing ear closer to the shoulder)

circumduction

complex movement of a part of the body when outlining the surface of a cone (ex. drawing a circle)

pronation

medial rotation of the appendage from the supine position, so that the palmer/plantar surface will face the substrate (opposite of supination

supination

lateral rotation of the appendage so that the palmer/plantar surface of the paw faces medially (scooping soup)

protraction

translatory motion that moves a structure rostrally in a dorsal plane (ex. sticking out the tongue)

retraction

translatory motion that moves a structure caudally in a dorsal plane

abduction

movement of a part of the body away from the median plane

adduction

movement of a part of the body toward median plane

plasma

liquid proportion of blood

makes ~55% of blood

serum

Liquid remaining after blood clots naturally 

Does not contain clotting factors

Serum = plasma - clotting factors

red blood cells

Makes up ~45% of the blood

Also called erythrocytes

• Function: transport oxygen + carbon dioxide

• Principal component: hemoglobin (Hb)

  • Each molecule of hemoglobin is responsible for carrying molecules of oxygen

• Lifespan: 2-4 months

  • Mature in the bone marrow from reticulocytes (larger and contains less hemoglobin

buffy

• Makes up ~1% of blood

• White blood cells

• Platelets

anemia

decrease in red blood cells

• Hemorrhage (loss of RBCs)

• Hemolysis (destruction of RBCs)

• Non-regenerative anemia

hemorrage

loss of RBCs

hemolysis

destruction of RBCs

Non-regenerative anemia

decreased production

Erythrocytosis

increase in red blood cells

• Overproduction by the bone marrow

• Compensation for chronic hypoxia (low oxygen levels) or high altitudes

white blood cells

• Also called leukocytes

• Function: Responsible for defending the body against infection

• Less numerous than RBCs 

• Classifications of leukocytes:

  • Granulocytes (contain granules) → Neutrophils, Basophils, Eosinophils

  • Agranulocytes (lacks granules) → Lymphocytes, Monocytes

leukocytosis

increase in WBCs

leukopenia

decrease in WBCs

Neutrophils

• Most abundant of the leukocytes/white blood cells

• Function: fights against disease

• Appearance: lobulated nucleus with granulated cytoplasm

  • Mature: segmented nucleus

  • Immature: “band” nucleus

• Lifespan: 5-10 hours

neutrophilia

increase in neutrophils

neutropenia

decrease in neutrophils

Eosinophils

• Function: Parasite defense, allergic reactions, enzyme inactivate histamine

• Appearance: lobulated nucleus with eosinophilic (pink) granules

• Lifespan: minutes to hours

  • Migrate into tissue → survive for weeks

eosinophilia

increase in eosinophils

eosinopenia

decrease in eosinophils

Basophils

• Function: parasite defence, regulate allergic reactions (release histamine → pro-inflammatory)

• Appearance: lobulated nucleus with basophilic (purple) granules

• Lifespan: ~ 6 hours

  • Migrate into tissue → survive for weeks

basophilia

increase in basophils

basopenia

decrease in basophils

Monocytes

• Largest of all leukocytes

• Function: Phagocytic cells that kill microorganisms, ingest foreign material, and remove dead cells

• Appearance: variable morphology

• Lifespan: 12-24 hours

• Migrate into the tissues → mature into macrophages OR dendritic cells

monocytosis

increase in monocytes

monocytopenia

decrease in monocytes

Lymphocytes

• Second most common type of leukocyte

• Function: Main cell type of the immune system (B and T cells)

• Appearance: Round nucleus with little cytoplasm

• Lifespan: hours to years

B-Cells

Plasma cells → antibody production

T-Cells

cytotoxic T cells kill infected cells; helper T cells recognize infected cells and recruit other cells

lymphocytosis

increase of lymphocytes

lymphopenia (seen w stress)

decrease of lymphocytes

Platelets

• Also called thrombocytes

• Function: formatted of blood clots, prevents bleeding out after vessel injury, Aggregate to the site of injury and form a “platelet plug”

• Appearance: very small, disc-shaped

  • A nucleated cell fragments

• Lifespan: 1-2 weeks

  • Produced in the bone marrow

thrombocytosis

increase in platelets/thrombocytes

thrombocytopenia

decrease in platelets/thrombocytes

• Can lead to increased bleeding and bruising

Purple Top (blood tubes)

Contains EDTA (anticoagulant) + used for complete blood count (CBC)

green top (blood tube)

Contains heparin (anticoagulant) + used for chemistry panels

blue top (blood tube)

Contains citrate (anticoagulant) + used for coagulation panels

red top (blood tube)

No additives + used for chemistry panels

CBC test

Analyzes the number and types of blood cells (complete blood count)

Chemistry Panel

Analyzes the non-cellular component of blood (protein, electrolytes, minerals)

Blood smear

Show morphology of blood cells

epiphysis

Each end of the long bone + covered by articular cartilage

diaphysis

central shaft of the long bone

metaphysis

flared area between the diaphysis and epiphys

Cranial cruciate ligament rupture

can be a partial or complete tear of the ligament

osteoarthritis

Osteoarthritis (OA) is a chronic and degenerative disease of synovial joint