Tissues

Question 1

Epithelial tissues in general

Answer 1

Epithelial cell layer on surface (avascular)
Basal lamina (ECM) and a reticular lamina compose the basement membrane.
Connective tissue
Little ECM and often junctional specialization (tight junctions, desmosomes and gap junctions)
Frequent cell division because of exposure to exterior/lumen (called free surface)

Question 2

Simple squamous

Answer 2

Thin = adapted for diffusion (gas, blood, waste, nutrients), filtration (urine in kidney glomeruli) and secretion (lubricating of lining body cavities)
Alveoli lungs, kidney glomeruli (bowman’s capsule), lining heart, blood/lymphatic vessels.

Question 3

Simple cuboidal

Answer 3

Secretion and absorption

Kidney tubules, small glands, ovary

Question 4

Simple columnar

Answer 4

Ciliated= secretion/moving of mucus.
Small bronchi, uterine tubes, uterus.
Non-ciliated= contain microvilli = high absorption. Absorption and secretion in GI tract

Question 5

Simple pseudostratified

Answer 5

Ciliated= Secretion and propulsion of mucus
Trachea, bronchi, respiratory tract.
Non-ciliated= Lining of male urethra

Question 6

Stratified squamous

Answer 6

Thickest of all epithelia = protection
Keratinized= retains water, protects against friction and bacteria. Skin epidermis
Non-keratinized= Lining of wet surfaces like epiglottis, vestibule of mouth, tongue, esophagus, vagina

Question 7

Stratified cuboidal

Answer 7

Protection

Largest ducts of sweat glands, mammary glands, salivary glands and urethra.

Question 8

Stratified columnar

Answer 8

Protection and secretion

Very rare! Lines urethra, Large ducts of some glands and portion of conjunctiva of the eye

Question 9

Stratified transitional

Answer 9

Lining of organs that stretch like bladder, ureters and urethra. Urinary organs

Question 10

Stratified epithelium will be called accordingly

Answer 10

To the layer closest to free surface (lumen)

Question 11

Glandular epithelium

Answer 11

Endocrine: No free surface, secrete Hormones into Blood, most of endocrine glands are epithelial derivatives formed by invagination and during embryo development they lose their ducts.
Exocrine: Release products onto free surface (skin or lumen) like GI, respiratory or reproductive tract.
1. Merocrine: no part of cell is lost (salivary)
2. Apocrine: top of cell is lost with secretion (mammary)
3. Holocrine: whole cell detaches with secretion (sebaceous)

Question 12

Hypothalamus

Answer 12

Endocrine Master gland: Control center, controls anterior pituitary gland hormones

Question 13

Anterior pituitary

Answer 13

Endocrine gland.
TSH: thyroid stimulating hormone: stimulate thyroid to produce Thyroxine (T4) and triiodothyronine (T3): brain development, metabolism, reproduction.
ACTH: adrenocorticotropic hormone: stimulates cortisol secretion from adrenal cortex
GH: growth hormone
FSH: follicle stimulating hormone and LH luteinizing hormone: act on gonads, growth of follicle, ovulation, stimulation of testosterone, fsh in male, androgen binding protein expression BREF sexual cell stimulation!
PRL: prolactin: milk synthesis from mammary glands
MSH: melanocyte stimulating hormone

Question 14

Posterior pituitary

Answer 14

ADH/vasopressine: acts on kidney, water retention

Oxytocin- milk let down and uterine contraction during delivery

Question 15

Smaller endocrine glands (other glands)

Answer 15

Pineal gland: produces melatonin, sleep
Thyroid gland: produces T3,T4, calcitonin. To decrease plasma, controls energy metabolism.
Adrenal cortex: mineralocorticoid like aldosterone (water retention), corticosteroids (increases bp and blood sugar and reduces immune responses, case of stress) and androgens for sex steroids
Adrenal medulla epinephrine and norepinephrine: stress adaptation
Pancreas: insulin, glucagon, somatostatin: nutrient utilization
Gonads: produces testosterone estrogen and progesterone.

Question 16

General functions of connective tissues.

Answer 16

1. Support, binding. ex: Bone, cartilage, ligaments, tendons, connective tissue around other types of tissues.
2. Protection, defense, repair. Ex: Scar tissue, skull.
3. Insulation: fat cells (adipocytes).
4. Transportation. Blood cells.

Question 17

ECM is made of

Answer 17

Ground substance: mineralized (bone), gelatinous(loose,dense, cartilage, adipose), watery (blood). Made of proteoglycans (polysaccharide groups on proteins allow to trap more or less water) and cell adhesion proteins (attach cells to ECM)
Protein fibers: fibronectin reticular (connect cells to ECM and support organs), fibrilin reticular (forms filaments and sheets to support organs), elastin (strech, yellow), collagen (stif but flexible, shiny white)

Question 18

Fibroblasts

Answer 18

cells that secrete ECM in connective tissue proper

Question 19

Chondroblasts

Answer 19

cells that secrete ECM in cartilage. 3 types of cartilage: hyaline (most common,looks like shiny eyes looking at us oo), elastic(elastic fibers), fibrocartilage(collagen fibers). Hyaline cartilage is repaired by fibrocartilage scar tissues.

Question 20

Osteoblasts

Answer 20

cells that secrete ECM in bone

Question 21

Hemocytoblasts

Answer 21

cells that secrete ECM in blood

Question 22

Blood composition

Answer 22

Cells: RBCs (no nucleus), monocyte(neutrophils, moonshaped shadow), lymphocytes (type of WBCs, smaller), eosinophils (2 nuclei)
ECM: water

Question 23

Loose connective tissue

Answer 23

Cells: fibroblasts.
ECM: more ground substance than fibers (collagen, elastic, reticular)
Skin, around blood vessels, organs, under eptithelia

Question 24

Dense irregular connective tissue

Answer 24

Cells: fibroblasts
ECM: more fibers (random collagen) than ground substance
Muscle, nerve sheats

Question 25

Dense regular connective tissue

Answer 25

Cells: fibroblasts
ECM: more fibers (parallel collagen) than ground substance
Tendons, ligaments

Question 26

Adipose tissue

Answer 26

Cells: adipocytes (brown and white)
ECM: little ground substance and no fiber

Question 27

Cartilage

Answer 27

Cells: chondroblasts
ECM: ground substance is hyaluronic acid (firm/flexible) and fibers are collagen

Question 28

Bone

Answer 28

Cells: osteoblasts and osteocytes
ECM: ground substance is mineralized (calcium salts) and fibers are collagen

Question 29

In general, ECM is made of

Answer 29

proteoglycans, fibrous proteins, glycosoaminoglycans

Question 30

What is transcytosis

Answer 30

Transcytosis= endocytosis followed by exocytosis of the same substance.

Question 31

Common muscle tissue characteristics

Answer 31

1. Well vascularized
2. Many cells close together
3. Elongated
4. Contains myofilaments (contractile proteins)

Question 32

Skeletal muscle tissue

Answer 32

Rod-like cells. Striations perpendicular to axis of cells. Several nuclei on periphery of cell. Always generate heat (imp for body temperature)

Question 33

Cardiac muscle tissue

Answer 33

one of many nuclei but always in middle of cell. Striations perpendicular to cell. Intercalated discs for impulse. Found in heart only

Question 34

Smooth muscle tissue

Answer 34

One nucleus in middle of cell. No striation. Spindle shaped-cells. Found in hollow organs

Question 35

Nervous tissue

Answer 35

Made of
Neurons: conduct electrical impulse. Only in grey matter. Made of cell body, dendrites (receive stimuli) and axons (generate nerve impulse and transmit).
Glial cells: support neurons. In grey and white matter.
Nervous tissue are found in brain, spinal cords and nerves.