Midterm Flashcards
1
Q
Structure of the Cell Membrane
A
- 8 to 10 nm in width
- contains phospholipids, proteins and a glycocalyx coat
- 2 leaflets of phospholipid molecules
- their polar, hydrophilic heads face both cytoplasm and extracellular space
- their non-polar, hydrophobic tails oppose each other
- proteins associated with the lipid bilayer are integral transmembrane proteins and peripheral membrane proteins
2
Q
Development of the Basic Limb Structure
A
- As the limb bud elongates, it becomes flattened in the dorsoventral plane of the embryo
- The distal part acquires a paddle shape
- Later, a constriction divides the cylindrical
proximal region into two segments - In the forelimb, these two segments represent the primordia of the arm and forearm and in the hind limb the thigh and leg
3
Q
Amnion
A
- Develops from the extraembryonic somatopleure, which gradually overgrows the embryo and finally fuses together
- The fluid accumulates in the amniotic cavity and forms the fluid filled sac around the embryo
- Hydroamnion is the excess amount of amniotic fluid
4
Q
Zonary Placenta
A
- based on the shape
- The chorionic villi form a band around the chorionic sac
Ex: carnivores
5
Q
Medulla of Lymph Nodes
A
- stroma and parenchyma are loosely arranged here
- the lymphatic tissue is arranged in medullary cords that branch and anastomose throughout the medulla
- medullary cords are composed of lymphocytes, plasma cells and macrophages
- the medullary cords are separated by a network of endothelial-lined sinuses and connective tissue
- In the pig, the cortical and medullary tissues are reversed
6
Q
Fibrocartilage
A
- present in the intervertebral disc and menisci
- the perichondrium is poorly developed, although it is surrounded by collagen fibers
- Stained blue with trichrome Stain
- abundance of collagen fibers
- few chondrocytes
7
Q
Stereocilia
A
- long and rigid microvilli
- mainly present in the sense organs
- > inner ear
8
Q
Order of Ossification
A
- Periosteal collar
- Shaft
- Extremity
- Epiphyseal Cartilage (last)
9
Q
Ribosomes
A
- electron dense basophilic particles
- 15-25 nm
- contain RNA
- it is acidic, or basophilic
- if in groups called polyribosomes, or polysomes
- function is for protein synthesis
- found in the cytoplasm, rough ER, and the outer layer of the nuclear envelope
10
Q
Cerebellum
A
- outer grey and inner white matters are arranged in a highly folded structure
- > folia
- White Matter is composed of nerve fibers of the cortex
- Cerebellar Cortex has 3 layers
1. Outer Molecular Layer - neuropil arranged horizontally
- Intermediate Purkinje cell layer
- a single layer of piriform cells, which send their ramified dendrites into the molecular layer and axons into the white matter*
3. Inner Granular Layer - densely packed small neurons with intensely stained nuclei
11
Q
Oligodendrocytes
A
- produces myelin which provides electrical insulation for neurons in the CNS
- wrap around the axons in the CNS
12
Q
Cardiac Skeleton
A
- three parts
1. Fibrous Rings - surround the AV, aorta and pulmonary trunk openings
2. Fibrous Triangle (fibrous ring - pulmonary aorta) - fills the space between the AV openings and the base of the aorta
- *predominantly
- > Dense irregular CT: Pigs and cats
- > Fibrocartilage: Dogs
- > Hyaline Cartilage: Horse
- > Bone: Large Ruminants(cow)*
3. Fibrous part of the interventriculer septum - collagen fiber bundles
13
Q
Echinocytes, or Crenated Cells
A
- irregular wavy border on RBC
14
Q
Cardiac Muscle
A
- centrally located single nucleus
- intercalated disc present at the junction of adjacent cells creating a syncytium
- *Contain modified cardiac muscle for impulse conduction called Purkinje Fibers
- > centrally located nucleus
- > myofibrils (contractile filaments) are fewer and found only peripherally*
15
Q
Allantois
A
- Develops from the extraembryonic splanchnopleure as a diverticulum of hindgut
- It is a reservoir for excretory products of fetus
- It fuses with chorion to develop the chorio-allantoic placenta
- The blood vessels that develop in the allantois are termed umbilical vessels
- allantoic calculi, or hipomane in mares and cows
- > small, circular, flat, smooth bodies found in the allantois fluid especially in mares and cows
- Hydroallantois
16
Q
Reticular Tissue
A
- Adult CT
- present in lymphatic organs, liver and endocrine glands
- composed of numerous reticular cells and a network of reticular fibers
17
Q
White Pulp of the Spleen
A
- consists of Periarterial Lymphatic Sheaths (PALS)
- T-Lymphocytes predominate near the artery
- B lymphocytes predominate peripherally
- the reticular fibers and reticular cells form a 3D network (stroma) containing lymphocytes and macrophages (parenchyma)
- > In the white pulp there is NO erythrocytes (RBC)
18
Q
Chondrodystrophy
A
- abnormal interstitial growth of cartilage
- premature cessation of growth leads to the shortening of bones, especially the limbs, base of the skull and vertebral column
19
Q
Parenchyma (Immune cells, or Immunocytes)
A
- functional cell of the immune system
1. Lymphocytes - T-lymphocytes
- B-lymphocytes
- Plasma Cells
- NK Cells
2. Neutrophils
3. Macrophages
20
Q
Loose, or Areolar Connective
A
- Adult CT
- abundant in ground substances
- present below the epidermis/epithelium around blood vessels
- loose network of fine collagenous, reticular and elastic fibers
21
Q
Limb Field
A
- An area of somatopleure committed to forming a limb
22
Q
Connective Tissue
A
- connects other tissue and provides a framework to support the entire body by cartilage and bones
- composed of cells, fibers and amorphous ground substances
23
Q
Amelia
A
- complete absence of a limb
24
Q
- Gestation Periods*
- mare
- cow
- ewe
- sow
- bitch
- queen
A
- Mare = 335-345 days (11 mos)
- Cow = 279-282 days (9 mos)
- Ewe & Goat = 148-150 days (5 mos)
- sheep and goat - Sow = 114-120 days (4 mos)
- Bitch = 60-65 days (2 mos)
- female dog - Queen = 60 days (2 mos)
- female cat
25
Q
Osteoclasts
A
- bone eating (phagocytic) cells
- a large multinucleated cell
- located in the area of bone resportion or remodeling
- > absorbs bone tissue during growth and healing for bone remodeling
26
Q
Macula Adherens, or Desmosomes
A
- transmembrane proteins link neighboring cells together with the assistance of an electron-dense plaque and intermediate filaments that form a hairpin loop
- found in the epidermis
27
Q
Adipose Tissue
A
- Adult CT
- consists of adipocytes within the loose CT of blood vessels, nerves and mesenteries
- Unilocular (white) adipose tissue and Multilocular (brown) adipose tissue
28
Q
Locations of: Compound Alveolar (Acinar Gland), and Compound Tubulo-alveolar
A
- Compound Alveolar (Acinar Gland)
- parotid gland - Compound Tubulo-alveolar
- pancreas
29
Q
Muscle Types
A
- Skeletal Muscle
- striated and voluntary
- muscle attached to the bones of the skeleton
- strong and quick discontinuous contraction - Cardiac Muscle
- striated and involuntary
- walls of the heart
- strong and quick continuous contraction - Smooth Muscle
- non striated and involuntary
- Walls of most viscera
- > GI tract, urinary, uterus, etc
- weak and slow contraction
30
Q
Neuroglial Cells (gliocytes)
A
- provide structural and functional support
1. In the CNS: - astrocytes
- oligodendrocytes
- microglial cells
- ependymal cells
- > microglial cells derived from the mesoderm, all other cells are derived from the neural ectoderm
2. In the PNS - Neurolemmocytes (Schwann Cells)
- > derived from the neural crest
31
Q
Myocardium
A
- thickest layer composed of:
1. Cardiac muscle cells
2. **SA and AV nodes - composed of nodal cells
- impulse generating modified cardiac muscle cells**
3. Purkinje Fibers - impulse conducting
4. Cardiac Skeleton
32
Q
Teratology
A
- the branch of embryology concerned with the study of malformations, or abnormalities
33
Q
Developmental Periods
A
- Prenatal Period
- the period of development before birth
- development proceeds rapidly with more drastic morphological changes - Postnatal Period
- the period of development after birth
- changes take place more gradually and are followed by aging
34
Q
Pulmonary stenosis
A
- Pulmonary stenosis at the valvular and infundibular level
- The characteristic poststenotic dilation of the pulmonary trunk, right ventricular dilation and hypertrophy
35
Q
What is the cardiovascular system derived from?
A
- mesoderm
36
Q
Pigment Cells
A
- melanocytes
- cells containing pigments (melanin)
37
Q
Erythrocytes Structure
A
- have a “pallor” in the center
- surrounded by a plasmalemma
- contain 33% of Hb (oxygen carrying protein)
- lose their mitochondria, ribosomes and many cytoplasmic enzymes during maturation
38
Q
Transposition of Great Vessels
A
- Aorta from the right ventricle
- Pulmonary artery from the left ventricle
a. Interatrial septal defect,
b. Ductus arteriosus,
c. I-V septal defects
39
Q
Intramembranous Ossification
A
- all of the skull bones except the bone at the base of the skull
- mesenchymal cells aggregate into small clusters then differentiate into osteoblast cells
- osteoblast cells secrete a protein matrix (osteoid), then mineralization of the osteoid occurs
40
Q
Extraembryonic Germ Layers
A
- Due to rapid growth of embryonic disc, it is transformed from ovoid into elongated disc in shape
- The rapidly proliferating cells spread outwards from the embryonic disc to line the internal aspect of the trophoblast
- The part of the germ layer which underlies the embryonic disc is called intra-embryonic germ layer
- The cells lying peripherally under the trophoblast is called the extra-embryonic germ layer
41
Q
Vitelline Vein
A
- left side regresses
- right side
- > hepatic segment of the caudal vena cava
- > hepatic sinusoids
- > portal venous system
- –> all related to the development of the liver, or venous system of the liver
42
Q
Ribs Development
A
- arise from segmental sclerotome derived from condensation of mesenchymal cells lateral to the thoracic vertebrae
- Ribs and vertebrae are derived from mesenchymal cells
43
Q
Aortic Arches in the dog
A
- both the common carotid artery and right subclavian join to form the brachiochephalic trunk
- Whereas, the left subclavian will develop directly from the aorta
44
Q
Elastic Fibers
A
- present in the aorta and nuchal ligament
- as well as the muscular arteries, pinna of the ear, and lungs
- > present in structures that require elasticity
- stained light pink by orcein and resorchin-fuchsin
- composed of elastin protein for elasticity
45
Q
Intermediate Mesoderm
A
- the junction between the paraxial and lateral mesoderm
- gives rise to the urogenital system
46
Q
Bronchi
A
- subdivided into primary, lobar and segmented bronchi
- lined by pseudostratified ciliated columnar with goblet cells
- > Proximodistally in the pseudostratified columnar epithelium, the epithelial height and number of goblet cells decrease whereas Clara cells (exocrine gland) increase in number
- the hyaline cartilage is in the form of irregular plates and smooth muscle is interspersed between the plates
- > Proximodistally in the hyaline cartilage, cartilages decrease, whereas smooth muscles increase
- propria-submucosa contains loose CT with submucosal glands that decrease distally
- ONLY the Smooth Muscle Increases, all other factors decrease
- > height of epithelium, thickness of propria-submucosa, gland density, and cartilage decrease
- Tunica adventitia comprised of loose CT with collagen and elastic fibers
47
Q
Limb Formation
A
- Limbs grow outside from the body wall somatopleure as limb buds
- Bone, cartilage, and related connective tissue arise from the somatic mesoderm of the limb bud
- Dermis comes from the dermatome
- Skeletal muscles are derived from the myotome through migration of its cells into the limb
48
Q
Elastic Fibers
A
- present in the aorta and nuchal ligament
- > present in structures that require elasticity
- stained light pink by orcein and resorchin-fuchsin
- composed of elastin protein for elasticity
49
Q
Cardiac Tube
A
- both the left and the right tubes merge and develop into five parts
1. Truncus Arteriosus
2. Bulbus
3. Ventricle
4. Atrium
5. Sinus Horn - > from cranial to caudal direction
- > blood flows from the sinus horn towards the truncus
- the cardiac tube differentiates into the endocardium, myocardium and epicardial layer
50
Q
Discoidal Placenta
A
- based on shape
- The chorionic villi form one or two disc-shaped area
Ex: primates, rodents and bats
51
Q
Sinuses of Lymph Nodes
A
- subcapsular sinus, trabecular sinus and medullar sinus
- lined by endothelium like reticular cells
- the lumen of the sinuses are transversed by a dense network of reticular cells and reticular fibers
- lymphocytes and macrophages lie free within the stromal mesh and in the sinus lumen
- most lymph circulates through the subcapsular, trabecular and medullary sinuses, but some percolate through the cortex and medullary cords to reach the medullar sinus
52
Q
Changes after birth due to Prostaglandin
A
- prostaglandin from the placenta keeps the ductus arteriosus open before birth
- after birth due to the discontinued prostaglandin, the ductus arteriosus closes
53
Q
Satellite Cells
A
- represent inactive myoblasts
- > can be activated upon injury for regeneration of muscle fibers
54
Q
Basic Tissue Types
A
- ONLY four basic types
1. Epithelium
2. Connective Tissue
3. Muscular Tissue
4. Nervous Tissue
55
Q
Mucous, or Gelatinous Connective Tissue
A
- Embryonic CT
- found in the umbilical cord and bovine glans penis
- composed of fibroblasts, gel-like ground substance and collagen fibers
56
Q
Parenchyma vs Stroma of Lymph Nodes
A
- stroma and parenchyma are LOOSELY arranged in subcapsular sinus and medulla
- whereas stroma and parenchyma are TIGHTLY packed in the cortex
- Parenchyma
- lymphocytes, plasma cells and macrophages enmeshed in a network constitute the parenchyma*
2. Stroma - reticular cells and fibers (reticular connective tissue) form a 3D network
57
Q
Differences Between Veins and Arteries
A
- Tunica Media
- relatively thinner
* 2. Tunica External
- relatively thicker* - Total wall thickness is relatively reduced
- Greater Luminal Diameter
- Veins are equipped with flap-like usually paired semilunar valves
58
Q
Blood Vessel Structure
A
- Tunica Intima
- Internal Elastic Membrane
- Tunica Media
- predominance of smooth muscle
- elastic and collagen fibers - External Elastic Membrane
- Tunica Externa (tunica adventitia)
- collagen and elastic fibers
- contains vasa vasorum and nervi vasorum
59
Q
Monozygous
A
- When one ovum is fertilized but subsequently divides at the blastocyst stage into two genetically identical masses
- > therefore always of the same sex and same blood group
- identical twins
- Three Ways this can happen:
1. Amniotic cavity and placenta is separate - safest bc everything separate
2. Amniotic cavity separate, but placenta is common
3. Common amniotic cavity and common placenta - Most dangerous
60
Q
Origin of Primordial Germ Cells
A
- the primordial germ cells, which are destined to develop into gametes, are originated in the wall of the yolk sac, from where they migrate to get established in the developing gonad.
- initiates the rise of gametes
61
Q
Zonula Adherens Junction
A
- transmembrane proteins link neighboring cells together with the assistance of actin
- found in the basal intestines
62
Q
Compact Bone
A
- forms the outer shells of the diaphyses and epiphyses
- between the periosteum and endosteum
- consists of osteons, or Haversian systems
- > as well as outer and inner circumferential lamellae and interstitial lamellae
- each osteon consists of a central canal (Haversian Canal) surrounded by concentric lamellae
- the central canals are connected by perforating canals (Volkmann’s Canal)
63
Q
Simple Cuboidal Epithelium
A
- a single layer of cuboidal cells with a centrally placed nucleus
- rounded nucleus
- mainly present in the collecting ducts of the kidney
64
Q
Organelles vs. Inclusions
A
- Organelles
- functional part of the cell - Inclusions
- structural part of the cell
65
Q
Villous Placenta
A
- based on branching of the chorionic villi
- When there is a simple branching of chorionic villi
Ex: sow, mare and ruminants
66
Q
Diffuse Placenta
A
- based on the shape
- The chorionic villi are uniformly distributed over the entire sac Ex: mare and sow
- > In the sow, further development of the folds of different order increases the surface area for feto-maternal exchange
67
Q
Fetal Circulation
A
- Oxygenated blood
a. Umbilical Vein
b. Ductus Venosus
c. Caudal Vena cava
d. Right atrium
e. Foramen Ovale
f. Left Atrium
g. Aorta - Deoxygenated Blood
a. Cranial Vena Cava
b. Right atrium
c. Right ventricle
d. Pulmonary aorta
e. Ductus Arteriosus
f. Aorta
68
Q
Small and Medium Sized Lymph Vessels
A
- have a continuous membrane
- with increasing diameter, first a small amount of CT and then one or two layers of smooth muscle and elastic fibers are added
- > Continuous tissue plus 1-2 layers of smooth muscle and elastic fiber in the Tunica media
- No Tunica externa
69
Q
Primary vs Secondary Centers of ossification
A
- in the dog ossification starts from about 38 days of gestation
1. Primary - one in the body
- one in each half of the neural arch
2. Secondary - develops postnatally
Ex: transverse and spinous processes
70
Q
Nondeciduate Placenta
A
- Based on Loss of Maternal Tissues at Parturition
- There is little loss of maternal tissue due to relatively simple feto-maternal contact
Ex: sow, mare and ruminants
71
Q
Dorsal Mesocardium
A
- transverse pericardial sinus
- the developing heart tube bulges into the pericardial cavity and remains attached to the dorsal side of the pericardial cavity by a fold of mesodermal tissues called the dorsal mesocardium
- with further development, the dorsal mesocardium disappears creating the transverse pericardial sinus that connects both sides of the pericardial cavity
72
Q
Limb bud
A
- Localized proliferation of mesoderm
- covered by ectoderm
73
Q
Trachea in the Avian Respiratory System
A
- Trachea is similar to mammals except:
- > The Cartilaginous rings are complete and the Intraepithelial glands are numerous.
74
Q
Stromal Cells
A
- supporting cells of the immune system
- stroma = network
1. Reticular Cells
2. Epithelial Reticular Cells
3. Dendritic Cells
75
Q
Meroamelia
A
- means the absence of one or more parts of a limb
- for example, in crural meromelia, the tibia and fibula are absent
76
Q
Major Types of GAGs
A
- Hyaluronic acid
- in the vitreous body of eye and in synovial fluid - Chondroitin sulphate
- in cartilage, bone, and large blood vessels - Dermatin
- sulphate in tendons and ligaments - Keratin
- sulphate in cartilage and bones - Heparin sulphate
- in arteries and lungs
77
Q
Osteocytes
A
- mature resting bone cells
- derived from osteoblasts
- lies in a lacuna
78
Q
Tight Junctions
A
- have anastamosing ridges of transmembrane proteins that seal neighboring cells together in a belt-like fashion (loop)
- found in the apical intestines and epithelial cells
79
Q
Red Pulp of the Spleen
A
- Similar to the construction of the parenchyma and stroma, BUT has erythrocytes (RBC)
- composed of:
1. The Splenic Cords - reticular fibers with reticular cells (stroma) enmeshed with erythrocytes (RBC), macrophages, lymphocytes, plasma cells and other leucocytes (parenchyma)
2. The Splenic, or Venous Sinuses - wide vascular channels between the splenic cords
- > lined with endothelial cells that contain contractile microfilaments which on contraction create gaps allowing erythrocytes to pass between splenic cords and splenic sinuses
80
Q
Lateral Mesoderm
A
- the laterally proliferating cells form the lateral plate, or lateral mesoderm
- the lateral mesoderm splits into two layers, the somatic and splanchnic mesoderm
- the space between the two layers forms a cavity called the coelom
- the somatic mesoderm is associated with the ectoderm to form somatopleure
- the splanchnic mesoderm is associated with the endoderm to form splanchnopleure
81
Q
Partitioning of the Ventricles
A
- with the enlargement of the future halves of the ventricle, a median partition grows as a crescentic plate forming the, muscular interventricular septum
- initially this septum makes an incomplete partition and the communication between the two ventricles is known as the interventricular foramen
- The Inter-ventricular foramen is closed by the ventral growth of septum intermedium and spiral septum forming the membranous inter-ventricular septum
82
Q
Fertilization
A
- is the fusion of the sperm and ovum to initiate the development of a new individual
- it is preceded by ovulation and then insemination
83
Q
Cerebral Cortex
A
Grey Matter - present in gyri and sulci - 6 layers from superficial to deep 1. Molecular Layer - composed of processes of the stellate or pyramidal neurons (neuropil), arranged tangentially 2. External Granular Layer - small pyramidal neurons 3. External Pyramidal Layer - small and med pyramidal neurons 4. Internal Granular Layer - small stellate neurons 5. Internal Pyramidal Layer - medium to large pyramidal neurons that send axons into the white matter 6. Fusiform Layer - many spindle shaped neurons White Matter - composed of nerve fibers going to and coming from the cortex
84
Q
Anisocytosis, Poikilocytosis and Anemia
A
- Anisocytosis
- variation in the size of RBC - Poikilocytosis
- variation in the shape of RBC - Anemia
- an absolute decrease in the red cell mass as measured by RBC count, the hemoglobin concentration, PCV (plasma cell volume)
85
Q
Micromelia
A
- the reduced size of a limb
- all parts of the limb are present, but it is significantly smaller in size
86
Q
Nasal Cavity in the Avian Respiratory System
A
- The nasal cavity is lined by the same types of epithelia characteristic of the mammals
- > Stratified squamous epithelium rostrally
- > Olfactory epithelium dorsocaudally
- > Respiratory epithelial lining for most of the remaining areas.
87
Q
Dendritic Cells
A
- develop from bone marrow
- form the stroma of lymphatic tissue
- major function is to capture and present antigens to lymphocytes
- stellate shaped cells present in nearly all tissues
- four types
1. Follicular Dendritic Cells
2. Interdigitating dendritic cells
3. Intraepidermal macrophage (Langerhans cell)
4. Veiled cells
88
Q
Vascular Ring Anomalies
A
- a persistent right aortic arch results in the vascular ring anomalies
- vascular ring encircles the esophagus and the trachea, therefore it can cause choking
89
Q
Fibroblast Cells
A
- synthesis of fibers for wound repair
- most common cells
- Myofibroblasts are fibroblasts that contain actin filament
- > contraction during wound healing
- two stages of activity:
1. Active - called a fibroblast
- contains rough ER and therefore ribosomes
2. Quiescent/inactive - called a fibrocyte
90
Q
Mesenchymal Cells
A
- Irregularly shaped with multiple processes
- primitive, or stem cells
- found near blood vessels
- can differentiate into other types of cells
91
Q
Continuous Capillaries
A
- most common type of capillary
- present in muscles
- the endothelial cells are held together by tight junctions
- transcytotic vesicles are common
92
Q
Unicellular Glands
A
- the only unicellular gland is the goblet cell
- > it secretes mucus
93
Q
Intervertebral Disc Development
A
- Annulus Fibrosus (outer)
- develops from the mesenchyme of the sclerotome
- main support - Nucleus Pulposus (center)
- develops from the notochord
94
Q
Paraxial Mesoderm
A
- parallel to the central axis
- the dorsally proliferating mesodermal cells on either side of the notochord become thickened to form this
- later forms a series of mesodermal thickenings called somites
- each somite subsequently differentiates into myotomes, dermatome and sclerotomes
- the somites are organized around the notochord and extend as far as the rostral extent of the notochord
- somites constitute the vertebral column (sclerotome), its associated muscles (myotomes) and connective tissue (dermatome)
95
Q
Development of the Valves
A
- both the left and right atrioventricular valves develop around the margin of atrioventricular orifices as localized mesenchymal thickening (tubercle)
- > these become hollowed out and form endocardial cusps
- three cusps developing at the right atrioventricular orifice and two cusps developing at the left atrioventricular orifice
- There are semilunar valves at the pulmonary and aortic orifices
96
Q
Mitochondria
A
- chief source of energy (ATP synthesis)
- double layered membrane
- > inner layer has folds called cristae that contain enzymes that function in oxidative phosphorylation
- stained with Janus Green B in living cells
- the only cell outside the nucleus that has its own DNA and ribosomes, or protein!
97
Q
Establishment of Body Form Is Mainly Accomplished By?
A
- The longitudinal folding of embryo in cephalo-caudal direction
- This folding is more pronounced in the cranial and caudal end of the embryo, thus the head and tail fold are formed - The transverse or lateral folding of embryonic disc obtains a cylindrical appearance and lateral and ventral body wall of the embryo is established
98
Q
Cardiogenic Area, or Plates
A
- develops from the splanchnic mesoderm as a paired structure on the left and right side
- several vesicles develop in the cardiogenic plates which later unite to form a hollow tube called the cardiac tube
99
Q
Thymus
A
- has a connective tissue septa capsule that penetrates the parenchyma and divides it into lobules
- > each lobule has an outer cortex (peripheral dark zone) and an inner medulla (central light zone)
100
Q
Conus Arteriosus
A
- area around the origin of the pulmonary artery in the right ventricle
- the undivided distal part of the Bublis cordis that is incorporated into the right ventricle
101
Q
Tetr0logy of Fallot
A
- Dextroaorta
- Pulmonary stenosis
- I-V septal defect
- Dilation and hypertrophy of the right ventricle
- all four conditions at the same time
102
Q
Central NS vs Peripheral NS vs Autonomic NS
A
- CNS
- brain and spinal cord - PNS
- cranial and spinal nerves - ANS
- innervates visceral organs
103
Q
Dizygous
A
- when two separate ova are fertilized
- fraternal twins
- can be two different sexes
- Two ways this can happen:
1. Separate amniotic cavity and separate placenta
2. Separate amniotic cavity and common placenta
104
Q
Interarterial Septal Defects
A
- Foramen secundum, Foramen ovale.
- Dilation and hypertrophy of right ventricle, right atrium and left atrium
105
Q
Lateral Mesoderm Further Development
A
- Split into Somatic and Splanchnic Mesoderm
- > the Coelom is the cavity between these two layers
1. Ectoderm + Somatic Mesoderm = Somatopleure
2. Endoderm + Splanchnic Mesoderm = Splanchnopleure
106
Q
Mesenchymal Connective Tissue
A
- ONLY Embryonic CT
- > mesenchymal cells are present in embryonic and adult CT
- composed of mesenchymal cells and a fluid-like ground substance
- differentiates into various types of adult CT
107
Q
Cartilage
A
- special CT
- consists of cartilage cells (chrondroblasts and chondrocytes) and a matrix
- lacks blood vessels, therefore it is slow to heal
108
Q
Stratified Cuboidal Epithelium & Stratified Columnar Epithelium
A
- Stratified Cuboidal Epithelium
- found lining the excretory ducts of glands
- Generally 2 layers, maximum of three but it is rare - Stratified Columnar Epithelium
- in parotid and mandibular gland ducts
- larger ducts
109
Q
Elastic Tissue
A
- Adult CT
- ONLY present in the nuchal ligament and vocal ligament
- > elastic fibers are present throughout the body
- characterized by numerous regularly and irregularly arranged elastic fibers
110
Q
Number of Chromosomes in the Different Species
A
- ovum/oocyte and sperm have half this number (haploid)
- > these are diploid
1. Horse = 64 (32 pairs)
2. Ox = 60 (30 pairs)
3. Goat = 60 (30 pairs)
4. Sheep = 54 (27 pairs)
5. Pig = 38 (19 pairs)
6. Dog = 78 (39 pairs) - dogs have the most
7. Cat = 38 (19 pairs)
8. Human = 46 (23 pairs)
111
Q
Arterioles Structure
A
-
open either directly into capillaries through pre-capillary sphincter of smooth muscles, or into meta-arterioles (mesenteric circulation)
1. Tunica Intima
2. Internal Elastic Membrane - fenestrated and eventually disappears in smaller arterioles
- Tunica Media
- 1 to 3 layers of smooth muscle*
4. External Elastic Membrane - absent
5. Tunica Externa - composed of loose CT
112
Q
Structure of the Spleen
A
- Surrounded by a capsule composed of connective tissue and smooth muscle
- Capsule sends out trabeculae that contain arteries, veins, lymph vessels and nerves
- The capsule, trabeculae and reticular fibers support the splenic parenchyma
- splenic parenchyma is composed of red and white pulp
113
Q
Bone Marrow Types
A
- two types
1. Red Marrow - actively involved in hematopoisis
2. Yellow Marrow - inactive and contains fat
114
Q
Freemartin
A
- In Cattle
- In Dizygous twinning the development of a common circulation by placental anastomosis usually occurs
- If the twins are of opposite sex, the development of the genital system is retarded in the female embryo due to the influence of the testosterone produced by the male embryo
- > Therefore, the female born is infertile and known as freemartin
- also develop male characteristics
115
Q
Marginal Zone of the Spleen
A
- lies between the red and white pulp
- plays a key role in the filtration of the blood
- periphery of the white pulp is bounded by a circumferential reticular network with B cells and macrophages
- the reticular network of the marginal zone received capillaries from the white and red pulp
- the capillaries empty into the marginal sinus and the blood is drained toward the venous sinuses, or venules
of the red pulp
116
Q
Cardinal Vein
A
- in embryonic circulation, the cranial and caudal cardinal veins join the common cardinal vein which enters the sinus venosus
1. Cranial Cardinal Veins - become the brachiocephalic vein and the cranial vena cava
2. Caudal cardinal vein - regresses
3. Subcardinal Vein - becomes the caudal vena cava and the renal vein
4. The Supracardinal vein fuses together with the caudal cardinal vein - develops into the azygos vein
117
Q
Capacitation
A
- involves removal of the glycoprotein coat and seminal plasma protein from the plasma membranes that overlies the acrosomal region of the spermatozoa
118
Q
Cilia
A
- for movement
- composed of microtubules
- found in the respiratory, or male/female genital tracts
119
Q
Pericytes
A
- elongated cells that contain actin and myosin
- potential to transform into other cells
- participate in the healing process
- line small blood vessels
120
Q
Alveoli
A
- Pulmonary macrophages (derived from monocytes) are phagocytic cells present in the alveolar lumen
- Interalveolar CT consists of a capillary plexus, fibrocytes, pericytes, lymphocytes and plasma cells, collagen and elastic fibers
- *Alveolar epithelial lining presents two cell types.
1. Pneumocyte type I (95%) - is a squamous epithelial cell with a central nucleus
- anchored to a continuous basal lamina
2. Pneumocyte type II (5%), or Granular Alveolar Cell - is a cuboidal cell with microvilli that is responsible for the production of pulmonary surfactant*
121
Q
Locations of: Simple Alveolar(Acinar Gland), Simple Branched Acinar(Alveolar gland), and Simple Tubulo-acinar (Alveolus Gland)
A
- Simple Alveolar, or Acinar Gland
- sebaceous gland - Simple Branched Acinar, or Alveolar gland
- large sebaceous gland - Simple Tubulo-acinar, or Alveolus Gland
- minor salivary gland of the oral cavity
122
Q
Basophils
A
- segmented, or irregularly shaped heterochromatic nuclei
- cytoplasmic granules are metachromatic
- > stain reddish violet and are water soluble
- In dogs, basophils are larger and fewer granules than those of cows and horses
- Rod-shaped in cats
- plays a major role in mediating inflammatory reactions
- > release histamine and heparin
123
Q
Formation of the Mesoderm
A
- Most of the cells between the ectoderm and endoderm give rise to mesodermal cells
- Arranged in 4 different ways:
1. Notochord
2. Paraxial mesoderm
3. Lateral mesoderm
4. Intermediate mesoderm
124
Q
Parabronchi of the Lungs
A
- The parabronchi are lined by Simple cuboidal epithelium
- Numerous extensions (atria) of the parabronchial lumen give rise to the air capillaries
- Atria are lined by a simple squamous or cuboidal epithelium
- Air capillaries are lined by simple squamous epithelium
- The air capillaries are responsible for gas exchange
125
Q
Collagen Fibers
A
- present in the tendon, ligament and organ capsule
- abundant in mature CT
- from fibroblast with synthesis of collagen protein
- > composed of fibrous protein, or collagen
- have a wavy arrangement
- stained red with Van Gieson’s Methods
- strong and flexible, but inelastic
126
Q
The ovulated egg pathway
A
- The ovulated egg is received at the fimbriated end (abdominal ostium) of the oviduct through a constant stream of the peritoneal fluid which enters the uterine tube
- It is transported towards the uterus through ciliary movement and muscular contraction of the uterine tube
127
Q
Interstitial Implantation
A
- The embryonic sac penetrates and is embedded into the uterine wall
Ex: guinea pig, carnivores, bats and man
128
Q
Hematopoisis
A
- Hemocytoblasts (pluripotent stem cell)
- comes from mesenchymal cells
A. Lymphoid Stem Cells
- Lymphocytes come from here
- Thymus -> T-lymphocyte
- NK Lymphocyte
- B lymphocyte -> Plasma cells
B. Myeloid Stem Cells
- Erythrocyte
-> Reticulocyte (Immature RBC)
- Megakaryocyte (blood clotting) -> blood platelets
- Monocyte -> macrophage
- granulocytes -> Band cells -> neutrophils, basophils and eosinophils
129
Q
Partitioning of the Truncus Arteriosus and Bulbus Cordis
A
- two prominent longitudinal thickenings develop in the endocardial lining of the bulbus and truncus
- two thickenings meet and fuse, thus creating a septum that divides the bulbus and truncus into the aorta and pulmonary trunk
- spiral, or aortico-pulmonary septum
- atrium grows towards the right
- truncus grows towards the left
130
Q
Conus Arteriosus
A
- area of origin for the pulmonary artery
131
Q
Post-capillary Venules
A
- similar in structure to capillaries, but larger in diameter
- have continuous or fenestrated endothelial cells.
- *They have functional significance in lymphoid organs
- have simple cuboidal epithelium *
132
Q
Cartilage Matrix
A
- composed of fibers and ground substances containing proteoglycans and GAGs, also includes the adhesive molecules
- the matrix shows marked metachromasia
133
Q
Formation of the Endoderm
A
- A group of cells from the inner cell mass, or embryonic disc becomes detached from its inner surface to form a new continuous sheet lining the interior of the blastocyst
- This new layer is the endoderm and it’s enclosed cavity is called the primitive gut or archenteron
- The process of detachment of the cells from the inner cell mass is called delamination
134
Q
Dorsal Intersegmental Arteries
A
- Arise bilaterally between the somites
- form the intercostal and lumbar arteries
135
Q
Myofibrils
A
- composed of thick and thin myofilaments
- thick filaments have myosin
- thin filaments have actin, troponin and tropomyosin
- A Band = darker, thick and thin filaments overlap
- I Band = Lighter, Only thin filaments
- > alternating light and dark bands are responsible for striation
- each I band is bisected by a darker transverse line, the Z line
- Z line is made up of dense protein lines which connect the actin filaments from adjacent sarcomeres
- Each A band shows a lighter zone in the center, the H band, which is bisected by the M line
- The smallest unit of contractile apparatus is the sarcomere, which is between two adjacent Z lines
136
Q
Endosteum
A
- only osteogenic layer
- lines the marrow cavity with a single layer of squamous cells
- osteoblast and osteoclasts
137
Q
Septation of the Atrio-ventricular canal
A
- The dorsal and ventral endocardial cushions fuse together to form the septum intermedium
- > this creates the left and right atrioventricular orifices
138
Q
Leucocytes
A
- monocytes, lymphocytes and granulocytes (blood cells) that migrate from blood vessels to connective tissue
139
Q
Mucous Gland
A
- a thick, viscous (mucin) secretion that forms a protective covering
Ex: nasal discharge
140
Q
Ectopic Cordis
A
- When heart is in an abnormal location
141
Q
Vascular Endothelium
A
- the peripheral cells of the blood islands join together and form this lining
142
Q
Umbilical Cord
A
- The unclosed area on the ventral surface of the embryo at the junction of embryonic and extraembryonic territories constitute the umbilical cord
- contains:
1. All fetal, or extraembryonic membranes
2. Yolk sac, or vitelline blood vessels
3. Allantois, or umbilical blood vessels
143
Q
Leucocytes (WBC) Divisions/Differential Leukocyte Count
A
1. Polymorphonuclear Granulocytes: A. Neutrophils - dogs have the most out of all the species - *dogs, cats and horses have a predominance of neutrophils out of other types* B. Eosinophils - chickens have the most C. Basophils - chickens have the most 2. Mononuclear Agranulocytes: A. Lymphocytes - dogs have the least - cow and sheep have the most - *cow, sheep, pigs, goats, and chickens have a predominance of this type* B. Monocytes - chicken have the most
144
Q
Nervous System
A
- regulates the animals ability to respond appropriately to changes in its environment
- formed by nervous tissue, which consists of neurons and supportive cells called neuroglia
145
Q
Hypomeres
A
- Innervated by ventral rami of spinal nerves
- Lateral and ventral flexors of thoracic and abdominal musculature
- > hypoaxial muscles
146
Q
Aortic Arches
A
- arises from the aortic sac, the most cranial part of the truncus arteriosus
- 6 pairs of arches develop, but are not all present at the same time
1. 1st and 2nd - None
- do not develop into anything and regress
2. 3rd - develop into the common, or internal carotid artery
3. 4th - Right side: develops into the right subclavian artery
- left side: continues as the descending aorta
4. 5th - none
5. 6th - subdivision of the right and left pulmonary artery
- the left 6th retains its connection to the aorta as the ductus arteriosus
147
Q
Chorioallantoic Placentation
A
- placenta based on fetal membranes involved
- When the allantois fuses with chorion an chorioallantoic is formed
- This is most common type in domestic animals
Ex: ruminant, pig, carnivores and equine
148
Q
What does the early embryonic circulation consist of?
A
- A single tubular heart continuous with aortic arches that empty/open into paired dorsal aorta
- A pair of vitelline arteries from dorsal aortae to the yolk sac
- > derived from the extraembryonic mesoderm - A pair of umbillical arteries from dorsal aortae to the allantois
- > derived from the extraembryonic mesoderm - Three pairs of venous channels that drain into the sinus venosus
a. the Vitelline Veins (omphalomesenteric)
b. The umbilical veins
c. The cardinal veins
149
Q
Cardiac Longitudinal (head) folding
A
- Initially, the cardiogenic plate is located cranial to the neural plate
- During head folding, the heart becomes located first in the cervical region and finally in the thorax
150
Q
Parenchyma vs Stroma of the Thymus
A
- parenchyma and stroma are tightly packed in the cortex and loosely arranged in the medulla
1. Parenchyma - lymphoblasts, lymphocytes and macrophages
2. Stroma - epithelial reticular cells and its processes
- epithelial reticular cells are stellate shaped with lightly stained oval nuclei
- > their long processes are connected to each other by desmosomes
151
Q
Eosinophils
A
- bilobed nucleus
- cytoplasm contains only specific eosinophilic granules
- > to kill parasitic larvae and inactivate histamine
- *In horses, these eosinophilic granules are extremely large and tightly packed giving a mulberry-like appearance
- play a role in allergic and anaphylactic reaction and in parasitic infestation*
152
Q
Secondary Bronchi of the Lungs
A
- The secondary bronchi are lined by simple columnar or cuboidal cells
- > NO goblet cells
- The lamina propria is composed of areolar CT
- > NO lymphatic tissue
- The lamina muscularis is interrupted and multidirectionally oriented
- NO cartilage present
153
Q
General Structure of Tubular Organs
A
- Four Layers
1. Tunica Mucosa (inner layer) - epithelium
- > glands are derived from this
- Lamina Propria
- > mainly used for connective tissue
- Lamina Muscularis
- > thin sheet
2. Submucosa
3. Tunica Muscularis - muscles
4. Tunica Serosa, or Adventitia
154
Q
What must spermatozoa undergo to fertilize the oocyte?
A
- Spermatozoa upon arrival in the female genital tract are not capable of fertilizing the oocyte
- They must undergo the process of capacitation and acrosomal reaction
155
Q
Microglial Cells
A
- phagocytic cells
- they phagocytize microorganisms (antigen), myelin and other unwanted cellular debris of the nervous tissue of the CNS
- derived from the mesoderm
156
Q
Eisenmenger Complex
A
- Dextroaorta
- I-V septal defect
- Dilation and hypertrophy of the right ventricle
- same as tetrology fallot, but without pulmonary stenosis
157
Q
Where do B lymphocytes Mature and where are Epithelial Reticular Cells present?
A
- B-Lymphocytes
- mature in the Cloacal Bursa and Bone Marrow - Epithelial Reticular Cells
- only present in the Thymus and the Cloacal Bursa
- > Thymus degenerates, but cloacal bursa does not
158
Q
Blood Vessels of the Lymph Nodes
A
- The main artery enters the lymph node at the hilus, whereas smaller vessels penetrate the capsule at various sites
- *The post capillary venules are located in the deep cortex (lymphoid organ)
- > are characterized by cuboidal columnar epithelium*
- > lymphocytes from the bone marrow and thymus reach the lymph nodes through post capillary venules
- > these venules join veins in the medullary trabeculae, which in turn empty into large veins that leave the hilus
- -> point of entry point for lymphocytes in the lymph node
159
Q
Ependymal Cells
A
- line the ventricles of the brain and central canal of the spinal cord
- facilitate the movement of the cerebrospinal fluid
160
Q
Embryonic Structures -> Adult Structures
1. Truncus arteriosus
2. Bulbus Cordis
3. Primitive ventricle
4. Primitive Atrium
5. Sinus venosus
A. right horn
B. left horn
A
Gives rise to... 1. Aorta and Pulmonary artery 2. Aorta, Pulmonary artery and Conus arteriosus 3. Left and right ventricle 4. Left and right atrium 5A. Sinus venerum of the right atrium 5B. Coronary Sinus of the right atrium
161
Q
Sternum Development
A
- develops independently from the somatic mesoderm (primordia)
- > separately on the ventral side
- The two sternal bands are formed on either side of the midline
- These later fuse to form cartilaginous model of sternum
- Sternebrae later ossify to form a common unpaired body of the sternum which joins the distal end of the ribs
162
Q
Hemocytoblast
A
- the central cells of the blood islands
- differentiate into blood cells in the early embryo
163
Q
Stage at Ovulation
A
- In most domestic animals, a secondary oocyte and first polar body are released, or ovulated from the follicle
- > The secondary oocyte must be penetrated by a spermatozoon before the second meiotic division is completed
- In the horse and the dog, a primary oocyte resting in prophase is ovulated and both meiotic divisions occur after the stimulation of penetration by sperm
164
Q
Microtubules
A
- the transport of vesicles
- the major component of the centriole and plays a role in cell division
- forms the centriole, cilia and flagellum
- > the centriole acts as a microtubule organizing center
165
Q
Apocrine
A
- membrane bounded granule, together with the apical cytoplasm and plasmalemma, is released from the apex of the cell
Ex: sweat and mammary glands
166
Q
Meninges
A
- Dura mater, or pachymenix
- Arachnoid + pia mater = leptomeninges
- Epidural space
- Subarachnoid space for cerebrospinal fluid collection
167
Q
Functions of the Spleen
A
- It is a lymphatic tissue involved in immune responses against blood-borne antigens
- It serves as a filter for blood by removing abnormal, or worn out erythrocytes
- To store erythrocytes and platelets, as well as iron for reuse in hemoglobin synthesis.
- Erythropoiesis in fetus.
168
Q
Reticular Cells
A
- reticular cells + fibers = reticular connective tissue
- forms the framework/reticulum (stroma) in the lymphatic organs, except in the thymus and cloacal bursa
- function is formation of the reticular fibers
169
Q
Superficial, or Central Implantation
A
- The embryonic sac lies in the uterine lumen or cavity
Ex: ruminants, equines and porcine
170
Q
Epitheliochorial Placenta
A
- Based on Histological Layers
- Chorionic epithelium is in contact with uterine epithelium
- All six layers are present
Ex: sow and mare
