Lecture 9 Flashcards
Three types of Hair
1.
2.
3.
- Lanugo
- Vellus
- Terminal
Lanugo hair
fine, downy, unpigmented hair that appears on the fetus in the last 3 months of development
Vellus hair
fine, pale hair that replaces lanugo by the time of birth
ex: peach fuzz
Terminal hair
longer, coarser, and more heavily pigmented
ex: hair on head, armpits, and pubic areas
Structure of the Hair and Follicle
3 layers of hair in cross section
1. ________: core of loosely arranged cells and air spaces
2. _______: constitutes bulk of the hair; consists of several layers of elongated keratinized cells; types of pigment granules in these cells gives hair color (_________= brown/black; __________= red and blond)
3. _________: composed of multiple layers of very thin, scaly cells that overlap each other; free edges directed upward
- medulla
- cortex; eumelanin; pheomelanin
- cuticle
Hair growth and loss
1. _________: active growth phase
2. ________: transition phase
3. ________: resting phase 1
4. _________: resting phase 2
anagen
catagen
telogen
return to anagen
Functions of hair
-______________ depends on body region and type of hair
- hair ________ alert us of parasites crawling on skin
hair function
receptors
Anatomy of a fingernail
1.
2.
3.
4.
5.
6.
7.
8.
- Nail plate
- Nail fold
- Nail groove
- Nail bed
- Nail matrix
- Hyponychium
- Lunule
- Eponychium
Three Modes of Exocrine Secretion
1.
2.
3.
- eccrine (merocrine)
- apocrine
- holocrine
Cutaneous (skin) glands
1.
2.
3.
- Sweat gland (apocrine)
- Sweat gland (eccrine)
- Sebaceous gland (holocrine)
Apocrine sweat glands
-Inactive until ________
-Groin, anal region, axilla, areola, beard, area in men
-ducts lead to nearby _________
-produce sweat that is ______ and contains ________
-respond to stress and sexual stimulation
-____________: body odor; bacteria & sweat
-puberty
-hair follicles
-milky; fatty acids
-bromhidrosis
Eccrine (merocrine) sweat glands
-most ________ skin glands: around 3-4 million in adult skin
-especially dense on _____, ______ ,and _______
-simple tubular glands
-______________ that helps cool the body
-numerous
-palms, soles, forehead
-watery perspiration
___________ cells found in both apocrine and eccrine glands
-they contract from sympathetic nervous system stimulation; ________ perspiration up the duct
myoepithelial; squeeze
Sebaceous glands
-_______: oily secretion of sebaceous glands
-keeps skin and hair from becoming dry, brittle, and cracked
-______- sheep sebum
-flask-shaped
-short ducts open to ______
-________ secretion style
-sebum
-lanolin
-hair follicles
-holocrine
Mammary glands
-mammary glands are _______ synonymous with breasts
-produce _____
-develop only during ________ and _________
-modified _________ sweat glands
- rich secretion released through ducts opening at ________
Mammary ridges or milk lines
-_____ rows of mammary glands in most mammals
-primates kept only _____ glands, but a few people have additional nipples along the milk line (_________)
NOT
-milk
-pregnancy; lactation
-apocrine
-nipple
-two
-two; polythelia
Functions of the Skeleton:
1.
2.
3.
4.
5.
6.
7.
- protection
- blood formation
- Acid-base balance (release buffers)
- Electrolyte balance (stores and releases minerals)
- Movement
- Support
- Hormone production
Two types of bone tissue
1. __________ (cancellous) bone: loosely organized bone tissue; spaces filled with red bone marrow
2. _________ (dense or cortical) bone: dense outer shell of bone
spongy; compact
Bone cells
-bone is connective tissue that consist of cells, fibers, and ground substance
Four principal types of bone cells:
1.
2.
3.
4.
- Osteogenic cells
- Osteoblasts
- Osteocytes
- Osteoclasts
Osteoblasts
on bone surface; build (manufacture) bone
Osteocytes
former osteoblasts that have become trapped in the matrix they deposited
Osteoclasts
chew up bone tissue
-have ruffle border
-happens when body need more calcium
-remodeling of bones
-helpful for wound healing; getting rid of damaged bone
Bone Marrow
-soft tissue occupying marrow cavities of long bones and small spaces of spongy bone
-_______ marrow:
-_______ marrow:
-red: create RBCs and WBCs
-yellow: storage of adipose tissue
Bone Development
-__________ or ________: the formation of bone
-In the human fetus and infant, bone develops by two methods
1.
2.
ossification; osteogenesis
1. Intramembranous ossification
2. Endochondral ossification
