Anatomy Exam 1

What are cells bound by

the lipid bilayer (cell membrane)

Membranes contain __ that regulates what?

membranes contain protein structures that regulate intracellular contents relative to extracellular composition

What do the organelle membranes regulate?

concentration gradients between the cytoplasm and organelle interior

Organization of cell types in tissue confer what

functional and physiological attributes

Key features of Neurons

secreting neurotransmitters, transporting vesicles, and maintaining structural integrity. Needs significant amount of atp for ionic transport and neurotransmission

Expected key organelles/structures in Neurons

mitochondria, vesicles, robust cytoskeleton

Key features of muscle cells

membrane infoldings, ionic transport to aid contraction, cell to cell communication to aid contraction

expected organelles/structures of muscle cells

mitochondria, ion channels, cytoskeletal support, junctional complexes or gaps

Key features of parietal cells

membrane infoldings, ionic transport to aid contraction, and acid secretion

Expected key organelles and structures of parietal cells

mitochondria, ion channels, proton pumps, cytoskeletal reorganization for surface area when active

Components of the cytoskeleton

microtubules, neurofilaments, actin

What is the role of the cytoskeleton?

determine cell shape, maintain structural integrity for physiological functions

What cytoskeletal structure would be preferred in a cell such as a fibroblast, which is abundant in connective tissue and needs mechanical stability

Actin

Which cytoskeletal element would would be preferred in a cell such as a neuron, which needs long chains that can be broken and reassembled?

tubulin

Physiologic increases in organ size

enlargement of the uterus during pregnancy

hyperplasia

increased cell count causing an organ to grow physiologically

hypertrophy

increase in cell size causing a physiologic increase in organ size

pathologic increases in organ size

can be hypertrophic or hyperplasic

enlargement of the prostate, cardiomegaly, hepatomegaly

Physiologic decrease in organ size

decrease in muscle mass as a result of fasting

Pathologic decrease in organ size

atrophy: the decrease in muscle mass as result of denervation, paralysis, or cell death.

Metaplasia

a process in which one type of mature tissue is replaced by another mature tissue that is not indigenous to the organ or tissue

What are simple squamous cells? Where are they found?

Simple squamous are single layers of flat cells. Best for areas with mild mechanical activity with some lubricant such as the pleura and peritoneum

What are stratified squamous cells? Where are they found?

Several layers of flat cells. best for areas with robust mechanical activity that will see wear and tear without lubrication, such as the skin, esophagus, and anus

What is the difference in the stratified squamous cells in the skin vs the esophagus? Why?

Skin cells are keratinized to further protect against wear and tear

What are simple cuboidal cells? where are they found?

one row of square cells, thyroid gland

What are simple columnar cells?Where are they found?

single rows of tall and skinny cells, can be found on the trachea and small intestines

What is the difference between ciliated columnar cells of the trachea and the microvilled columnar cells of the small intestines

cilia are structures used for movement and to prevent foreign bodies from entering an area (such as the lungs)

microvilli are actual extensions of the cell that are used to increase surface area for secreting and absorbing in the small intestines

What is meant by “oncology recapitulates phylogeny?”

1st Pharyngeal arch

controls mastication, nerve supply comes from the mandibular portion of the trigeminal nerve (CNV III)

2nd Pharyngeal arche

facial expression, nerve supply comes from facial nerve (CN VII)

1-4 arch

lingual (tongue), supplied by CNV, CNVII, CNIX, CNXII)

6th arch

Larynx, nerve supply CN X

What structures are formed together from embryonic segments?

vertebra, spinal nerves, muscles, skin

What is segmentation?

The development of of repeating structures that act as the base of an organism. In animals, this is the repetitive nature of the vertebrae and its developmental contents \`\\

What is the dervivative of the neural tube?

Spinal chord

What is the derivative of the hypomere

muscles

What is the derivatives of the dermatome

skin segments

What is the derivative of the epimere

epaxial muscle

What is the derivative of the sclerotome

Skeletal tissue

Blood supply to the foregut derivatives

celiac trunk

blood supply to the midgut derivatives

cranial mesenteric artery

blood supply to the hindgut derivatives

caudal mesenteric artery

What happens in the GI tract after the hindgut at the anorectal junction?

define a morula

a solid ball of cells resulting from the division of a fertilized ovum, from which a bastocyst is formed

how many days does it take for a morula to form a blastocyst in a 60 day gestation

4-8 days

What are the layers of the blastocyst

zona pellucida

trophoblast

blastocoel

embryoblast

zona pellucida

outer covering of the blastocyst

trophoblast

outer cell layer of the blastocyst

blastocoel

cavity within the blastocyst

embryoblast

inner cell mass of the blastocyst

How does a complex multicellular organism develop?

come and stick together, talk in a common language, share responsibilities, assign special duties, support each other

What are the essential processes to generating a complex multicellular organsim

cell proliferation, cell specialization, cell interaction, cell movement

Describe the action of Retinoic acid

an inducer that establishes gradients, trunk organizer that provides instructive signal for posterior neuroectoderm and foregut endoderm, and a permissive signal for trunk mesoderm differentiation.

Development of the eye

asymmetric division

two sister cells born differently, often due to the unequal sharing of cell components

symmetric division

sister cells become different as a result of influences acting on them after birth

What is the action of an inductive signal

causes symmetric division, cells are directed to a new developmental pathway

What kind of molecules are essential for cells in the developing embryo

signaling molecules, which cells send, receive, and interpret

what signal makes a totipotent blastomere into a trophoblast

Cdx2

What is a Totipotent cell?

A cell containing the materials to become an entire functioning embryo if isolated and stimulated properly

What signal makes a totipotent blastomere into a Pluripotent ICM cell

Oct4

What is a pluripotent cell

a cell that, while not capable of forming a complete embryo, can be differentiated into many different kinds of cells based on the chemical signals

What signal makes a pluripotent ICM cell into a hypoblast

GATA-6

What signal makes a pluripotent ICM cell into a Pluripotent epiblast

Nanog

What is meant by the hatching of the blastocyst

the loss o the zone pellucida, expansion of blastocyst

development of the bilaminar embryonic disk sets which axis?

dorsal/ventral

What is the role of the hypoblast

influences orientation and inhibits primitive streak formation to prevent the formation of multiple streaks

What directly precedes gastrulation

development of a bilaminar embryonic disc

What is the order of primitive formation during gastrulation

primitive groove, primitive node, primitive pit, primitive streak

What forms the primitive groove? What is its function

begins with an accumulation of epiblast cells within the posterior embryonic disc.

Firmly establishes the cranial/caudal and medial/lateral axes

will eventually regress

What creates the primitive pit?

Epiblast cells ingressing at a faster rate on the cranial end of the groove

What creates the primitive node? What is its role?

epiblast cells migrating to the primitive pit and creating a mass

Primary tissue organizer/inducer

How is the primitive streak formed?

epiblast cells invaginating along either side of the primitive groove

Which three primitive structures often exist at the same time in the embryo?

pit, node, groove

Define invagination

the migration of epithelial-to-mesenchymal cells into the primitive streak

Define ingression

the migration of epithelial-to-mesenchymal cells down the primitive streak

Define endoderm

formed by the first set of epiblastic mesenchymal cells that move down the primitive streak and integrate into the hypoblast later

These become cells such as pancreatic, thyroid, and lung

Define Mesoderm

formed by the second set of cells to detach and ingress, and will fill the space between the endoderm and epiblast layer

Will eventually give rise to the umbilical cord, notochord, and lateral plate mesoderm

Define Ectoderm

formed by the remaining epiblast cells, forms the skin cells, neurons, and pigment cells

Define Neurulation

The formation of the nervous system from the notochord and ectoderm using chemical and physical interactions

Describe the process of the notochord forming the neural tube

the notochord induces the local proliferation of the ectoderm

as ectoderm cells build up, the neural fold is formed along the dorsal midline of the neural groove

The two sides of the neural folds fuse, closing the groove and forming the neural tube

What will be missing if the closure of the neural tube fails?

The central nervous system!

What is the derivative of the neural tube?

CNS

cranial- brain

caudal- spinal cord

What are the derivatives of the neural crest

Peripheral nervous system

(peripheral nerves and sheaths, ganglia, medulla of adrenal gland, sensory cells, pigment cells/melanoblasts, connective tissue of the head, odontoblasts)

Describe the process of failing neurulation

neural folds do not fuse at the dorsal midline over the neural groove, and thus the crests never form. The neural tube is left open

without the formation of the crests, no sensory cells develop over the open neural tube so the body does not know to enclose the area and the neural arches of the vertebrae do not close and the spine is left open

What is the disease caused by failing neurulation>

Spinal bifida

What is the role of the paraxial medoderm

segmentation and the formation of somites, used for aging early embryos

What is the role of the intermediate mesoderm

formation of the urogenital system

How does the lateral mesoderm split and what parts does it create?

splits horizontally to form the parietal and visceral lamiae

What is the parietal lamina

attaches to the ectoderm to form the future wall of the embryo and the trophoblast

parietal = body cavity

What is the visceral lamina

attaches to the endoderm to form the the wall of the GI tract and lower respiratory tract

visceral = organ

What is the space between the parietal and visceral laminae

coelom or coelomic cavity, which acts as the precursor of serous cavities

What gives rise to somites

segmentation of the paraxial mesoderm, occuring in the craniocaudal direction

How are somites differentated

dermatomyotome and sclerotome

What does the dermatomyotome separate into

dermatome and myotome

What tissue is derived from the somite

primordial tissues of the musculoskeletal system

what part of the somite becomes the sclerotome? What do sclerotome cells become?

vetromedial portion

stem cells of the catilages and bones of the axial skeleton

what part of the somite becomes the dermatomyotome

dorsolateral

What do the dermatome cells generate

connective tissue of the skin, dermis and subcutis, external fascia of the trunk

what do the myotome cells generate

skeletal muscles

divide and become myoblasts, which align to form myotubes, which become skeletal muscle cells. Each skeletal muscle is innervated by a spinal or cranial nerve

the lateral plate mesoderm is the main origin of what?

limb bud skeletal system including tendons, ligaments, cartilage, and bone tissue