Lymphoid & Epithelial structures Flashcards
which two types of leukocytes are found in lymph nodes
Lymphocytes & macrophages
what are the structures that lymph flows as it enters and then leaves a lymph node
- The subcapsular sinus drains to the trabecular sinuses
- The trabecular sinuses empty into the medullary
sinuses - The lymph flows out of the medullary sinuses via the
efferent lymph vessels - The concave side of the lymph node is called the hilus
what is the main cell type in germinal centers of lymph nodes?
B cells
which type of white blood cells are most common in the outer (superficial) cortex; the deeper (paracortex) cortex; the medulla?
- Outer (superficial) cortex:
o B cells - Depper (paracortex) cortex:
o T lymphocytes - Medulla:
o Plasma cells
o Macrophages
o B cells
What three lymph nodes drain the head?
- Parotid lymphocenter
- Mandibular lympyhocenter
- Retropharyngeal lymphocenter
which lymph node drains the first three mammary glands in the dog
axillary lymph node
which lymph nodes drain the udder of a cow
superficial inguinal lymph nodes
which structures are drained by the thoracic duct
Deep cervical lymph nodes
a. Along the trachea
b. Drains the deep/ventral structures of the neck to
the thoracic duct on the left side or the lymphatic
duct on the right
which structures are drained by the right lymphatic duct
Right and left tracheal (jugular) trunks
a. Travel along the trachea and drain the lymph nodes
of the head/neck
b. Empty into the thoracic duct on the left side, the
right lymphatic duct or the vessels of the thoracic
inlet
what structures drain into the visceral trunk (3 lymphocenters)
Drains the celiac, cranial and caudal mesenteric lymphocenters to the cisterna chyli
what side of the body is the spleen on?
left
what is an ellipsoid? What is another name for it?
Sheathed capillaries aka “ellipsoid”
- Surrounded by open-filled spaces of the splenic cord
- Accumulations by B lymphocytes & macrophages
what specific site of the spleen does erythrocyte phagocytosis occur?
splenic cords
what branch of the aorta supplies the spleen?
splenic artery
difference between red pulp and white pulp of the spleen
Red pulp:
- Makes up the bulk of the spleen
White pulp:
- Lymphatic tissue
- Forms nodules and sheaths of lymphocytes around
arteries and arterioles
marginal zone
- Adjacent to the pulp
- Most blood enters the red pulp in the marginal zone
which organ in the lymphoid system filters blood
spleen
organ is the primary lymphatic organ of mammals?
thymus
what is the main type of lymphocyte found in germinal centers? What is produced by germinal centers?
- B-lymphocytes are the main lymphocyte found in germinal centers
- Antibody secreting plasma cells & memory B cells
Do germinal centers form in the thymus?
NO
what are the three principle cell types found in the thymus?
- Thymocytes
- Macrophages
- Epithelio-reticular cells
what are Hassal’s corpuscles? What organ are they found in?
Hassal’s corpuscles: concentric mass of epithelial cells
- Only present in mammals
- Located in the thymus
What are the 5 layers of stratified squamous epithelium?
- Stratum corneum (horned layer)
- Stratum lucidum (clear layer)
- Stratum granulosum (grainy layer)
- Stratum spinosum (spiny layer)
- Stratum basale (basal layer)
what are the 2 layers of skin? How are they different?
Epidermis & dermis
- The epidermis is the outer layer of the skin and contains no blood cells or nerves
- The dermis is the inner layer of the skin and contains blood vessels, lymph vessels, nerves, glands, hair follicles, and muscle fibers
What are the 5 layers of epidermis (in the skin)? Know their key features
what are the 2 main types of dermal glands? Which one are mammary glands derived from?
- sweat glands and sebaceous glands
o mammary glands are derived from sweat glands
what are the 2 types of sweat glands, and how are they different?
- Eccrine sweat gland:
o Small, widely distributed glands
o Mechanism for cooling - Apocrine sweat gland:
o Larger
o Oily and foamy secretions
o Most common in the groin, axilla and scrotum of dogs and cats
o Most numerous in the horse
o This is the most common type of sweat gland in domestic animals
what are the 5 types of sensory receptors in the dermis of the skin?
- Merkel cells- respond to very light pressure
o Found in small numbers near the stratum basale - Meissner’s corpuscles (tactile corpuscles) are sensitive to touch and are found in delicate areas such as the lips and fingertips (2)
- Pacinian corpuscles detect pressure, vibrations
o Lamellated
o Rapidly adapting - Ruffini corpuscles
o Slowly adapting
o Stretch (4) - Free nerve endings sense pain, heat and cold, as well as touch (1)
o Rapidly adapting
what are the three parts of a hair (cross section).
- Outer cuticle:
o single layer of flat keratinized cells - Cortex:
o compact dead cell layer under the cuticle - Medulla:
o central region of the shaft, cuboidal or flat cells
what is the difference between wool and hair
- Wool (compound follicle):
o several hairs emerge from a single opening
o Found in dog, cat, sheep (wool growing areas)
o Consists of a long principal (guard) hair and a number of smaller (wool) hairs, little medulla - Hair ((Single (simple) follicle)):
o one hair emerges from a single opening
o Found in horse, cattle, pig and sheep
How many teats are on each quarter (normally)?
4 depending on species
each species, know how many teats there are and what location (thoraco, abdomino, inguinal) they are in.
- Bitch: 10 (thoracoabdominoinguinal)
- Queen: 8 (thoracoabdominal)
- Sow: 10-18 (Thoracoabdominoinguinal)
- Goat/sheep: 2 (inguinal)
- Mare: 2 (inguinal)
what are 5 components of the suspensory system of the bovine udder
- Skin/superficial fascia
- 4-quarter attachment
o Coarse cord like tissue - Sub pelvic tendon
- Lateral suspensory ligament
o Superficial & deep - Median suspensory ligament
o (most important)
where, specifically, is milk produced
produced in the alveoli
what are the 4 lymph nodes that drain the bovine udder
- subiliac lymph node
- mammary superficial inguinal lymph node
- ischial lymph node
- deep inguinal lymph node
difference between hypsodont and brachydont teeth. Know which animals have which?
Brachydont teeth: (low-crowned)
- the simple teeth of man, carnivores, pig, ruminant incisors and horse deciduous incisors.
- They consist of a crown, neck, and root.
Hypsodont teeth:
- the teeth having no distinct neck, as seen in all permanent horse teeth, the ruminant cheek teeth, and the tusks of pigs.
- Apart from the horse’s canine teeth, they continue to erupt throughout life.
three substances that compose teeth, and their location in brachydont teeth and hypsodont teeth
- Cementum: a thin, bone-like covering
o Low-crowned (brachydont) teeth:
the cementum covers the root only.
o High-crowned (hypsodont) teeth:
covers the entire tooth, superficial to the
enamel - Enamel: the hardest substance in the body
o Densely calcified tissue; acellualar
o Low-crowned (brachydont) teeth:
the enamel covers only the crown.
o High-crowned (hypsodont) teeth:
enamel envelops the body (crown & body), but
not the root. - Dentin:
o a hard substance similar to bone forming the bulk of the tooth and surrounding the pulp cavity.
o Calcified, yet collagen-rich
different types of teeth (e.g. incisor, etc.)
- Incisors
- Canines
- Premolars
- molars
Know the directional terms used to describe the surfaces of teeth
when Galvayne’s groove first appears in the equine mouth?
Galvayne’s groove appears around age 10yrs old in the equine mouth
Memorize the dental formula of the dog and horse (permanent) and dog (deciduous)
dental formula (HORSE):
permanent- 2(I 3/3 C 1(0)/1(0) P 3(4)/3 M) = 36-42
dental formula (DOG):
deciduous- 2(I 3/3 C 1/1 P 3/3)= 28
Arrector pili
Smooth muscle fibers that can contract to pull the hair perpendicular to the skin surface by the nervous system in times of stress or cold
Teat cistern
“Teat sinus”- the large milk storage cavity within the teat and the glandular body
Gland cistern
“Udder”
Intermammary groove
external groove separating the two halves of the udder
Streak canal
“Teat canal”
- duct leading from the teat sinus to the teat opening
- stratified squamous epithelium
- cells produce a sebaceous plug in the teat canal
White line
Stratum externum of hoof
Dental cup
Dental star
pulp cavity; first appears ~ 8 y
PULP
the soft tissue filling the pulp cavity, including sensory nerves, arteries, veins, lymphatics, and primitive connective tissue
CUSP
the individual bumps on the occlusal (chewing) surface of teeth
alveoli
the bony sockets of the incisive, mandible, and maxillary bones in which the root” of teeth are embedded.
