Dermis

(Thermoregulation) The dermis controls body temperature through its blood vessels & sweat glands

Vasodilation, Vasoconstriction

(Innervation) The dermis contains a rich network of sensory nerves

Meissners corpuscles, Pacinian corpuscles, Free nerve endings, Ruffini endings

Apocrine

Found where many hair follicles are, Activate during puberty, Secrete a thicker fluid into hair follicles, lipid composition attract Bacteria and break down this fluid into body odor

Eccrine

Most common, water sweat for cooling, Open directly into the skin, sudoriferous

Skin appendages in the reticular layer

Hair follicles, Sebaceous glands, Sudoriferous glands, Pacinian corpuscles, Ruffini endings

Blood vessels

Support temperature regulation, healing, & nutrient delivery

Macrophages

Phagocytic immune cells that clean up debris, bacteria, & damaged tissue

Mast cells

Release histamine & inflammatory chemicals

Fibroblasts

Cells that produce collagen, elastic fibers, & extracellular matrix

Elastic fibers

Stretching & flexibility, Decrease with age, loose connective tissue

Collagen fibers

Provide tensile strength, Protect the skin from tearing

Key structures of the reticular layer

Collagen fibers, Elastic fibers, Fibroblasts, Mast cells, Macrophages, Blood vessels

What is the reticular layer composed of?

Dense irregular connective tissue, packed with collagen fibers

Epidermal ridges

where the epidermis conforms to the dermal papillae, Increased grip & tactile sensitivity

Vasoconstriction

Heat conserved

Vasodilation

More heat released

Capillary loops

Tiny blood vessels inside the dermal papillae, Provide nutrients & oxygen to the basal layers, Help with thermoregulation

Dermal papillae

Strengthen adhesion between the epidermis and the dermis

Key structures of the papillary layer

Dermal papillae, Capillary loops, Meissner's corpuscles, Free nerve endings, Epidermal ridges

What is the papillary layer composed of?

Areolar connective tissue, which contains loosely arranged collagen & elastic fibers

Overall functions of the dermis layer

Vascular, Contains glands, hair structures, Provides the skin with strength & elasticity

Dermis Layer

The thick, strong, flexible middle layer of skin found beneath the epidermis

what enhances grip

papillary layer (fingerprints)

importance of sweat glands

homeostasis, skin flexibility, barrier against bacteria and dehydration

importance of sebaceous glands

lubricate and protect skin and hair

what is sebum made of

lipids, fragmented cells

homeostasis in low temperature

receptor cells in skin sense cold, sends stimulus to brain, brain sends response to effectors (sweat glands to constrict and conserve heat and blood vessels to close), muscles constrict and cause shivering

homeostasis in high temperature

receptor cells send signals to brain of heat, brain sends signals to dilate blood vessels and release heat and activate sweat glands

how does wind help with cooling

takes away excess body heat

shape of sweat glands

coiled tubular glands