Chapter 4 body organization & homeostasis

what type of tissue is blood?

Blood is a connective tissue with a liquid matrix ( plasma).

Describe the the body' homeostatic mechanism for raising and lowering core body temp?

Body temperature regulation is a negative feedback system. When body temperature rises above the set point, receptors in the skin send a message to the hypothalamus in the brain. The hypothalamus then sends a message to the sweat glands to produce sweat and cool the body. When body temperature drops below the set point, receptors in the skin send a message to the hypothalamus. The hypothalamus then sends a message to blood vessels to constrict, reduc-ing blood flow to the arms and legs and thereby conserving heat. In addition, metabolism is increased to produce more heat.

why does bone heal more rapidly than cartilage?

Bone is well supplied by blood vessels whereas cartilage is not, so bone receives nutrients for growth and repair more rapidly than cartilage, which depends on diffusion for nutrients.

Contrast the organization of epithelial & connective tissues.How are differences in the matrix of different types of connective tissue related to their functions?

Epithelial tissue is formed from cells that are packed closely together, forming layers of cells of varying thickness. This type of organization makes epithelial tissue good for coverings such as the skin and for lining organs or body cavities. Connective tissue cells secrete a matrix that is found between the cells. The type of matrix dictates the function of the connective tissue. For example, the protein fibers in the gelatinous matrix of cartilage make it resilient and strong, which is ideal for strong, flex-ible support. The hard matrix of bone makes it a good support material. The liquid matrix of blood ( plasma) allows for the tissue to flow.

what are the 4 types of tissues found in the human body?

Epithelial tissue, connective tissue, muscle tissue & nervous tissue

what type of cells are found in the nervous tissue? what are their function?

Nerve tissue is composed of neurons that con-duct and transmit nerve impulses ( via dendrites and axons) and of neuroglia cells that protect, support, and insulate the neurons.

___ are functions of epithelia.

Providing physical protection, producing specialized secretions, absorption.

A gland is composed of ___tissue.

epithelial

The lining of the intestine is composed primarily of

epithelial cells

Functions of connective tissues include....

establishing a structural framework for the body, transporting fluids & dissolving materials, storing energy.

Connective tissue

gets its characteristics from a matrix rather than cells.

Tendon

is an example of dense connective tissue.

Which type of membrane lines passageways that open to the exterior of the body

mucous

the 4 basic tissue types in the body are..

neural, epithelial, muscle, connective

What are functions of the integumentary system...

protection of underlying tissues, synthesis of vitamin D, regulation of body temp.

Cartilage

___ cells form disks that cushion the vertebrae.

Smooth muscle cells

___ propels substances or objects through internal passageways.

Gap junction

____ allows cells to communicate by allowing small molecules to pass from cell to cell.

Endocrine

____ glands secrete hormones into the blood via tissue fluids.

contrast skeletal, cardiac, & smooth muscle with respect to structure & function.

a. Skeletal muscle is composed of long, cylinder-shaped cells with many nuclei and mitochon-dria ( for energy). It is called striated muscle because of the visible striations of actin and myosin filaments. Skeletal muscle tissue is usually attached to bone and has the ability to contract voluntarily. b. Cardiac muscle is composed of cells with only one nucleus that have striations and branch. They are found only in the heart and contract involuntarily continuously. c. Smooth muscle is composed of tapered cells with only one nucleus and lacks striations. Smooth muscle is found in blood vessels and airways or organs such as the stomach, and it contracts involuntarily when needed.