BIOL 348 Exam 1

Rickets became very common with children in the late 1700's. What is rickets and why do you think this happened?

Rickets is the softening and weakening of bones in children, usually because of an extreme and prolonged vitamin D deficiency. kids working in factories RICKETS, A DISEASE CHARACTERIZED BY OVERPRODUCTION AND DEFICIENT CALCIFICATION OF OSTEOD TISSUE, CAUSED BY A LACK OF SUFFICIENT VITAMIN D

Endochondral ossification steps

(formation of bone from a cartilaginous model) 1.) hyaline cartilage model develops 2) cartilage calcifies and a bone collar forms 3) ossification center forms in the diaphysis 4) ossification centers form in the epiphyses 5) bone replaces cartilage 6) epiphyseal plates ossify cartilage model forms, bone collar forms, 1st ossification center, medullary cavity, 2 ossification center, growth continues

Stages and Trimesters

1st trimester - period of embryological and early fetal development, rudiments of all major organ systems appear 2nd trimester - development of organs and organ systems 3rd - rapid fetal growth and deposition of adipose tissue, most major organs are fully functional

Which of the following is the connection point between the axial skeleton and appendicular skeleton

A point of contact between the axial and appendicular skeletons is the manubrium.

First trimester development

Cleavage , implantation, placentation, embryogenesis Timing - first 3 months Implantation - 7 days after fertilization, blastocyst reaches uterine lining, trophoblast Gastrulation - 12 days, forms all 3 primary germ layers from epiblast cells (ectoderm, mesoderm, endoderm) Placenta

A hypodermic needle would penetrate the skin in which order?

Epidermis, papillary layer of the dermis, reticular layer of the dermis

why doesn't epithelium have blood vessels?

Epithelial itself does not have a blood vessel, the cells are too tightly packed together to accommodate blood vessels.

T/F: The axis articulates with the occipital condyles

FALSE ATLAS ARTCIULATES WITH OCCIPITAL CONDYLES

What would happen if two sperm penetrated the oocyte?

Fertilization of an egg by two sperms results in the presence of a triploid chromosome set, including three sex chromosomes.

Why are ribs considered flat bones instead of long bones?

Flat bones are bones whose principal function is either extensive protection or the provision of broad surfaces for muscular attachment. Flat bones have marrow, but they do not have a bone marrow cavity.

In humans and other bipedal organisms, ventral is the same as

anterior

Effects of hormones

calcitriol, synthesized in kidneys, requires vitamin D3 calcitonin and parathyroid hormone estrogens and androgens growth hormone and thyroxine

Long straight, unbranched fiber found in the type of tissues shown here is known as

collagen fibers (type 1) type of connective tissue fiber

What determines skin color?

combination of melanin, hemoglobin, and carotene depends on MELANIN PRODUCTION (not number of melanocytes)

Which of the following describes the occipital bone

cranial bone foramen magnum connects cranial and spinal cavities occipital condyles

The wrist is located ________ to the elbow.

distal

A frontal section is in a plane that

divides the body into anterior and posterior sections

How do bones grow?

endochondral ossification

Layers of the cutaneous membrane

epidermis (superficial) dermis (deep to epidermis) - papillary layer (superficial) - reticular layer (deep) cutaneous membrane = skin

Why does your face become flushed when you exercise?

erythema, push blood close to surface flush/flush, reddish

T/F: The metaphysis contains the medullary cavity

false, medullary cavity is in the diaphysis

What would happen without serous membranes?

friction

the branch of science that studies groups of specialized cells and how they work together is called

histology

Sex differences

in height estrogens (girls) and androgens (guys)

Middle aged men with beer bellies often have back problems due to this abnormal curvature of the lumbar vertebrae

lordosis

Pregnancy can cause which of the following abnormal curvatures of the back

lordosis

Which bones of the pectoral girdle articulates with the manubrium?

manubrium is superior portion of the sternum rib 1 articulaes with the t1 vertebra and the manubrium of the sternum

Most complex to simplest

organism, organ system, organ, tissue, cell, molecule

Why is endochondral ossification so complicated? Why can't it just form in the fetus?

ossifies bones that originates as cartilage, most bones, intramembranous ossification - dermal ossification, flat bones of skull, mesenchymal tissue model,

Types of Bone cells and functions

osteoprogenitor cell - mesechymal stem cells in endosteum and periosteum osteoblasts - secrete osteoid, CELLS THAT PRODUCE NEW BONE TISSUE BY SECRETING MATRIX osteocytes - maintain matrix and detect mechanical stress on a bone osteoclasts - large, multinuclear cells, secrete hydrochloric acid and enzymes that dissolve matrix, BREAK DOWN BONE BY SECRETING HCL AND ENZYMES THAT DISSOLVE THE MATRIX

positive feedback during deliver

oxytocin and contractions

Serous membranes

parietal layer - lines cavities visceral layer. - covers organs

Why do long bones have both spongy and compact bone? What function does spongy bone provide? Why not just compact bone?

spongy bone has a latticework structure that makes it strong and lightweight compact bone - solid and relatively dense, external surfaces of long and flat bones, made up of osteons, osteocytes arranged in concentric lamellae spongy bone - trabeculae, internal surface of bones

A person lying on the bed and gazing at the ceiling is in

supine position

Anatomy of a long bone

the medullary cavity of a long bone is lined with a thin layer of connective tissue called endosteum long bones have epiphyseal plate shaft of a lone bone - diaphysis (compact bone, medullary cavity/yellow marrow) ends of long bone - epiphyses (mostly spongy bone, surrounded by compact bone) metaphysis - where diaphysis and epiphysis meet blood vessels enter the diaphysis of a long bone through a opening called the nutrient foramen spongy bone - no osteons, open network of trabeculae, red bone marrow

Why does thick skin lack hair follicles and sebaceous glands?

thick skin - covers the palms of he hands and soles of the feet, has 5 layers of kertatinocytes thick skin has the STRATUM LUCIDUM clear layer) 3-5 layers of dead keratinocytes thick skin - more limited in distribution, 0.4-0.6 mm, has sweat glands

Which type of epithelium can be found in places that regularly expand and contract such as the urinary bladder?

transitional epithelium

Merocrine sweat glands

widely distributed on body surface discharge directly onto skin surface, 99% water sensible perspiration, excretes water and electrolytes flushes microorganisms and harmful chemicals from skin

Zones in epiphyses

zone of resting cartilage, zone of profliferation, zone of hypertrophy, zone of calcification, ossified bone