Histology q1

What are the components of blood?

Plasma component & cellular/serum component

What does the Plasma component of blood include?

Albumin, globulins, & fibrinogen

What does the Cellular/serum component of blood include?

Erythrocytes, leukocytes, & platelets

What is Hematocrit?

Measures the volume of packed red blood cells per unit volume of total blood after centrifugation

Blood contains 55% ___ & 45% ___

Plasma; erythrocytes

What is the shape of a mature erythrocyte?

Biconcave disks

What is the life span of an Erythrocyte?

120 days

What are Reticulocytes?

Immature erythrocytes with small levels of rRNA

What is Hemoglobin composed of?

2 alpha chains, 2 beta chains, & 4 heme groups that bind to O2

What is Anemia?

Decreased concentration of hemoglobin in blood that can result from loss of blood, reduced prod. of RBCs, RBC that contain insufficient hemoglobin, & accelerated RBC destruction

What is Pernicious anemia?

Decreased secretion of intrinsic factor by cells of the intestinal mucosa, reduced level of vit. B12 = decreased erythrocyte production

What is Sickle cell anemia?

Point mutation of the beta globin gene, resulting in an AA substitution in the hemoglobulin molecule (HbS)

What is Thalassemia?

Deficient synthesis of the alpha & beta chain of hemoglobin

What can Thalassemia result in?

Asymptomatic anemia

What is Absolute polycythemia?

Excessive levels of erythrocytes caused by an overactive production of these cells within the bone marrow

What is Relative polycythemia?

Decreased plasma level without increased erythrocyte prod.

What are Leukocytes involved in?

Cellular & humoral (antibody mediated) defense against foreign material

Which cells are Granulocytes?

Neutrophils, eosinophils, & basophils

Which cells are Agranulocytes?

Monocytes

Which cells are Lymphocytes?

B cells, T cells, & NK cells

Which cell would be increased in an allergic reaction (phagocytosis of bacteria)

Neutrophils

Which cell is this?

Neutrophil

What is the most abundant Granulocyte in the body?

Neutrophil

Which type of cell would increase in a parasitic infection?

Eosinophils

Which cell would be increased in an allergic reaction?

Basophils

What do the granules of Basophils contain?

Heparin & histamine

Which immunoglobulin is expressed on Basophil’s surface?

IgE

Which cell is this?

Small & large lymphocytes

Where do the precursor cells to lymphocytes originate in?

Bone marrow

Which cell is important for humoral immunity?

B cells

Which cell is important for cell-mediated immunity?

T cells

Antigen stimulated B cells differentiate into ___ that secrete antibodies

Plasma cells

Where do T cells differentiate into & how much of lymphocytes do they comprise?

Thymus & 80%

Which cells are Null cells?

NK cells & stem cells

Which cell is this?

Monocyte

When do Monocytes differentiate into macrophages?

After migrating from bone marrow to CT like alveolar macrophages in the lung & Kupffer cells in the liver

What are Platelets/thrombocytes?

Specialized cells that bind to & coat damaged vessel walls, plug small defects in blood vessel walls & help activate the blood-clotting cascade

Where are Platelets formed in adults?

Bone marrow

What is Thombocytopenia?

A disorder marked by reduced level of circulating platelets

What is Thrombocytopenic purpura?

Chronic autoimmune disease where antibodies to platelets interfere with their blood-clotting function

Which illness is associated with low vit. B12 & cancer drugs?

Thrombocytopenias

What is Hemophilia A?

Clotting factor VIII is reduced

What is Hemophilia B?

Factor XI is a nonfunctional or deficient

What does Cartilage consist of?

Fibers, cellular elements, & amorphous ground substance

Is Cartilage vascular or avascular &how are things transported?

Avascular & materials are transported via passive diffusion

Appositional & interstitial cartilage grow together in early stages but which growth can also occur separately later?

Appositional

The matrix is ___ of Cartilage while the amorphous ground substance is ___

40%; 60%

What is the matrix made of?

Type II collagen & elastin

What does Ground substance consist of?

Glycosaminoglycans, chondroitin-6-sulfate & chondroitin-4-sulfate, hyaluronic acid, & keratin sulfate

What are Chondroblasts?

Cells found at the surface of cartilage derived from mesenchymal cells that are capable of elaborating a matrix

What are Chondrocytes?

Mature chondroblasts that are enclosed in the territorial matrix

Where do Chondrocytes reside?

Lacuna

What do proliferating Chondrocytes form?

Cartilaginous epiphyseal plates between the epiphysis & the shaft of a developing long bone

Which cells are large & responsible for absorption of cartilage?

Chondroblasts

What is the importance of the outer layer of the Perichondrium?

Encloses hyaline & elastic cartilage & consists of collagen fibers & fibroblasts

What is the importance of the inner layer of the Perichondrium?

Contains Collagen fibers, undifferentiated mesenchymal cells, & capillaries

Where does Appositional growth occurs?

Surface of cartilage or perichondrium

Where does Interstitial growth occur?

Between chondrocytes

When is Interstitial growth active?

Endochondrial ossification

Step 1 of Interstitial growth:

Chondrocyte's in lacuna exhibit mitotic activity

Step 2 of Interstitial growth:

Two chondroblasts are produced by mitosis from one chondrocyte & occupy one lacuna

Step 3 of Interstitial growth:

Each cell produces new matrix & begins to separate. The separated cell is a Chondrocyte

Step 4 of Interstitial growth:

Cartilage continues to grow

Step 1 of Appositional growth:

Mitotic activity occurs in stem cells within the Perichondrium

Step 2 of Appositional growth:

New undifferentiated stem cells & committed cells that differentiate into Chondroblasts are formed. They produce new matrix at the periphery

Step 3 of Appositional growth:

Bc of the new matrix, Chondroblasts push apart & become Chondrocytes which continue to produce more matrix at the periphery

What are the 3 types of Cartilage?

Hyaline, elastic, & fibrous

Where is Hyaline cartilage found?

Nasal septum, larynx, trachea, sternal ends of the ribs, articular cartilage at joints & tracheal ring

What type of collagen is in Hyaline cartilage?

Type II Collagen

What is a Chondroma?

Benign tumor of hyaline cartilage that develops within the substance of/at the periphery of cartilage

What is Chondromalacia?

Softening of articular cartilage such as the ant. surface of the patella & epiphyseal cartilage of still born fetuses

What can Chondromalacia cause?

Inflammation & bursitis

Where is Elastic cartilage found?

Pinna of ear, auditory/eustachian tube, epiglottis, & corniculate & cuneiform cartilages of the larynx

What type of collagen is found in Elastic cartilage?

Type II Collagen

Where is Fibrocartilage found?

Intervertebral discs, cartilage at the pubic symphysis, & insertions of tendons & ligaments

Which type of collagen is found in Fibrocartilage?

Type 1 Collagen

Which cartilage gives firm support & tensile strength?

Fibrocartilage

What are Chondroblastomas?

Benign tumors that are derived from immature cartilage cells

What are Chondrosarcomas?

Malignant tumors of cartilage cells or immediate precursor cells & occur in bones of the pelvic & shoulder of older individuals

Where do Chondroblastomas favor?

Epiphysis in the skeletally immature patient

Where do round cell lesions favor?

Diaphysis

Which CT tissues are CT proper?

Loose CT (areolar) & Dense regular & irregular CT

Which CT tissues are specialized CT?

Cartilage, bone, adipose tissue, blood, hemopoietic tissue, lymphatic tissue, reticular

What are Reticular tissues?

Made up of Type III collagen & serves as the Stroma for hemopoietic tissue, liver, spleen, & lymph nodes

What is the Stroma?

Cells & tissues that support & give structure to organs, glands, or other tissues in the body. Made up mostly of CT, blood vessels, lymphatic vessels, & nerves. Provides nutrients to the tissues or organ & removes waste & extra fluid

What is the Parenchyma?

The functional tissue of an organ as distinguished from the connective/supporting tissue

Where is Loose CT found?

Surrounds small blood vessels, beneath the epithelia that covers body surfaces & line the internal surfaces of the body, & associated with epithelium of glands

Where is Dense irregular CT found?

Skin: thick deep layer of the dermis. Hollow organs: intestinal tract & submucosa which allows the organ to resist excessive stretching & distention

Where is Dense regular CT?

Tendons, ligaments, & aponeurosis

Loose CT has more ____ than ____

Ground substance; collagen

What are the functions of CT?

Physical support & connection to form the organs of the body. Mechanical strength (tendons & ligaments). Space filling (sculpting body shape). Metabolic support (interstitial fluid = medium for diffusion of nutrients & waste products). Body defense. Healing.

What are the components of CT?

Ground substance, protein fibers, & cells

What are the components of the ground substance of CT?

Glycosaminoglycans (GAGs), Proteoglycans, & multiadhesive glycoproteins (fibronectin & laminin)

What are the components of the protein fibers of CT?

Elastic fibers, collagen fibers, & reticular fibers

Which cells are components of CT?

Resident = fibroblasts & adult mesenchymal cells. Wandering = immune cells

What are the functions of GAGs?

Resist compression & absorb shock

What are the functions of Proteoglycans?

Regulate molecular trafficking in the ECM

What are the functions of Multiadhesive glycoproteins?

Promote binding sites for cell membranes ... cell migration & positioning

What is a Proteoglycan made of?

A core protein & glycosaminoglycans

Chondroitin sulfate & keratin sulfate are examples of?

GAGs