Lab 7

Question 1

Muscle tissues

• function
• muscle cells called what?

Answer 1

• highly cellular tissues that use ATP to generate force to produce contractions.
• produces most kinds of body movements, maintains posture and generates heat.
• Muscle cells are called muscle fibers, as these cells have an elongated shape

Question 2

The cytoplasm of the muscle cell is the ____

Cell membrane is referred to as the ______

Answer 2

Cytoplasm = sarcoplasm

Cell membrane = sarcolemma.

Question 3

3 types of muscle tissue found in the human body

Answer 3

skeletal muscle tissue
smooth muscle tissue
cardiac muscle tissue

Question 4

Skeletal Muscle Tissue

Answer 4

• long, thick, cylindrical cell
• ends of fibers are blunt
• multiple, nuclei, peripherally located
• contains striations
• sarcomeres are the functional units
• attached to bones and when these muscles contract, movement of the skeleton occurs

LOCATION: skeleton (skeletal muscles
FUNCTION: moves bones of skeleton
CONTROL: voluntary
Unique: number and position of nuc

Question 5

Smooth Muscle Tissue

Answer 5

• shorter spindle-shaped cells, with tapered ends
• cells are tightly packed in a sheet-like arrangement
• single oval nucleus, centrally located
• no striations

LOCATION: GI tract, uterus, eye, blood vessels (within the walls of hollow organs, such as blood vessels and organs of the digestive, urinary, respiratory and reproductive tracts)
FUNCTION: peristalsis, blood pressure, pupil size, erect hair. (contraction moves materials along internal passageways and regulates the diameter of blood vessels and respiratory tracts)
CONTROL: involuntary
Unique: No striations, spindle with tappered ends

Question 6

Cardiac Muscle Tissue

Answer 6

• cells that branch in an irregular pattern
• striations.
• one nucleus, oval and centrally located
• intercalated discs where cells join end-to-end

LOCATION: wall of the heart
FUNCTION: pump blood continuously
CONTROL: involuntary
Unique: fibers branch, intercalated disc

Question 7

striations

Answer 7

• transverse bands or striations, that are visible as light and dark bands within each fiber
• result of the arrangement of parallel structures called myofibrils within the sarcoplasm.

Question 8

sarcomeres

Answer 8

Structural unit of myofibril
-parallel structures make up myofibril, these are in turn made up of the orderly arrangement of even smaller structures called myofilaments, which are arranged in compartments called sarcomeres

Question 9

intercalated discs

Answer 9

• regions where the cell membranes of adjacent cells contact each other and contain desmosomes and gap junctions
• allow for cohesion and rapid electrical conduction
• vital roles in bonding cardiac muscle cells together and in transmitting signals between cells

Question 10

two major divisions of the nervous system

Answer 10

The central nervous system

• the brain
• spinal cord

The peripheral nervous system
-all nervous tissue outside the brain / spinal cord

Question 11

Neurons

Answer 11

• structural and functional units of nervous tissue
• largest and most prominent Ner.Sys cell
• convert stimuli into electrical signals (action potentials)
• Contain
- cell body (soma): nuc, mito, nissil body, ribos, neurofibrils
- dendrites: tapering, branched processes, receive stimuli or information from other neurons
- axon: cytoplasmic process, conduct information to other cells and is often referred to as a nerve fiber

Question 12

Nissl bodies

Answer 12

aggregations of rough endoplasmic reticulum. important elements of the cytoskeleton
the manufacture and release of proteins and amino acids.

Question 13

neurofibrils

Answer 13

found in soma. bundles of protein filaments which are important elements of the cytoskeleton.
play a role in the transport of proteins and other substances within the cytoplasm.

Question 14

myelin

Answer 14

• a fatty sheath, protects and insulates the axon and also increases the speed of conduction of nerve impulses
• PNS: myelin sheath formed by Schwann cells
• CNS: myelin sheath formed by oligodendrocytes
• Schwann cells and oligodendrocytes are types of neuroglia cells.
•

Question 15

nodes of Ranvier

Answer 15

• small gaps in the myelin sheath where the plasma membrane of the axon is exposed
• enable the nerve impulse to jump from node to node, hence increasing the speed at which an impulse travels.

Question 16

telodendrites (axon terminals)

Answer 16

fine branched endings of the axon

Question 17

grey matter and white matter

Answer 17

Grey:

• cell bodies
• thin outer layer of the brain surface and as a “butterfly-shaped”
• centre of the spinal cord
• dendrites, unmyelinated axons, axon terminals, neuroglia

White:

• myelinated axons of neurons
• this is the location of dense collections of whitish-coloured myelinated axons
• layer iside bran
• outside of spinal chord

Question 18

ganglia

Answer 18

• contains clusters of neuron cell bodies
• ovoid structures containing cell bodies of neurons and glial cells supported by connective tissue. Ganglia function like relay stations - one nerve enters and an other exits.

Question 19

3 covering and lining membranes

Answer 19

mucous, serous and cutaneous

continuous multicellular sheets composed of an epithelium bound to an underlying layer of connective tissue

Question 20

Mucous membranes

Answer 20

• line body cavities that open to the exterior such as those of the hollow organs of the digestive, respiratory, reproductive and urinary tracts.
• moist membranes
• various types of epithelia.
• Many contain goblet cells/multicellular mucous glands.
• Ex:

Question 21

Serous membranes

Answer 21

• moist membranes
• line the walls (parietal layer) and cover organs (visceral layer) within the closed ventral body cavities - pericardial, pleural and abdominopelvic cavities.
• A serous membrane consists of a simple squamous epithelium resting on a thin layer of areolar connective tissue.
• Serous fluid is produced by the serous membranes and acts to lubricate the surfaces to reduce friction.

Question 22

cutaneous membrane

Answer 22

• is the skin which is exposed to the air and is a dry membrane.
• The skin is part the integumentary system

Question 23

organ system

Answer 23

Organs that work together to perform a common function

Question 24

integumentary system

Answer 24

complex group of organs that protects the human body from the external environment. This system is composed of the skin and its associated structures such as glands, hair and nails.

Question 25

Skin function

Answer 25

* protection of underlying body parts; * excretion of water, salts and wastes * regulation of body temperature * detection of sensory information, such as touch, temperature, pain.

Question 26

skin is composed of two distinct regions

Answer 26

epidermis - a superficial region dermis - deeper region *note that the hyperdermis (subcutaneous layer) is part of the integument system but is NOT a part of skin

Question 27

Epidermis

Answer 27

* stratified squamous epithelium * where the epidermis is thickest, it is made up of five layers * thickest on the palms of the hands and soles of the feet. * thinnest on the tympanic membrane (the eardrum) and over the eyelids. * stratum corneum - outermost layer filled w keratin * stratum basale - deepest epidermal layer, single row of cells that are undergoing mitosis. * As the cells move into the more superficial layers, they begin to flatten, fill with keratin and die. * no blood vessles, relies on diffusion from dermis

Question 28

Dermis

Answer 28

• divided into two layers: - papillary layer - the thin superficial is areolar connective tissue and - reticular layer - the deeper thicker is dense irregular connective tissue • contains blood vessels, specialized sensory nerve endings, glands, hair follicles and their associated structures. • has dermal papillae in papillary layer (meissner corpuscles) • pacinian corpuscles • sweat glands

Question 29

dermal papillae

Answer 29

* in papilliary layer | * contain capillary loops, free nerve endings (pain receptors) and Meissner’s corpuscles.

Question 30

Meissner’s corpuscles

Answer 30

are receptors that respond to light touch sensations and are most abundant in the skin of the fingertips, lips and eyelids. : nervous tissue, tactile centers, respond to light touch

Question 31

Pacinian corpuscles

Answer 31

* tactile receptors * receptors are much larger than Meissner corpuscles and are located deeper in the dermis. * Sensitive to deep pressure and occur in the skin of the fingers, in the pancreas and in the walls of the urinary bladder. nervous tissue, tactile venter, respond to deep pressure/coarse touch

Question 32

Sweat (sudoriferous) glands

Answer 32

* merocrine/eccrine glands * located in the dermis * release perspiration into hair follicles or onto the skin surface through pores. * coiled tubular glands that secrete mostly water but also ions and some nitrogenous wastes. * internal temp homeostats 35.8-38.2ºC * Stim tell brain your too hot, brain signals sweat glands —> takes lots of heat to turn liquid sweat to gas. Therefore evaporative coolig mechanism. * FUNCTION: role of sweat is to regulate body temperature through evaporation.

Question 33

Hair Follicle

Answer 33

•hair bulb - deep end -Sensory nerve endings (hair root plexus) wrap around the bulb and are stimulated when the hairs are bent. •hair papilla - contains a knot of capillaries that supplies nutrients to the growing hair. •arrector pili muscles - composed of smooth muscle tissue, are responsible for making your hair “stand on end” when you're cold or frightened •sebaceous gland - lubricates the skin and keeps the hair flexible •

Question 34

composed of smooth muscle tissue, are responsible for making your hair “stand on end” when you're cold or frightened if contracts, hair stands on end (when frightened or cold).

Answer 34

arrector pili muscles

Question 35

contains a knot of capillaries that supplies nutrients to the growing hair

Answer 35

hair papilla

Question 36

sebaceous gland

Answer 36

produce an oily secretion known as sebum, which lubricates the skin and keeps the hair flexible.

Question 37

Skin disorders

Answer 37

- A boil (or furuncle): is a round, pus-filled, raised area of the skin caused by a bacterial infection in a hair follicle or sebaceous gland. - Acne can develop when there is an increase in sebum production. One form of acne, often observed in adolescents, is associated with the increase in sex hormone production during puberty. As the secretory activity of sebaceous glands increases with the concentrations of hormones, an obstruction of the sebaceous ducts may result, causing inflammation and infection. - Seborrhea, another disease of the sebaceous glands, is characterized by an excessive discharge of sebum, resulting in an oily coating or crust on the skin.

Question 38

Skin colour | -influenced by the interaction of three pigments

Answer 38

Melanin • Melanin formed in the deepest layers of the epidermis by cells called melanocyte • (UV) radiation in sunlight has a stimulatory effect on the melanocytes, causing an increase in melanin pigment • presence of melanin protects the deeper layers of the skin from the harmful effects of excessive UV • A concentration of melanin in one spot produces a “freckle”. Carotene •a yellow pigment that accumulates in the surface layer of the epidermis. Hemoglobin • the color of the blood in the blood vessels of the dermis produces a pinkish tint • A “flushed” appearance to the skin (reddened skin) is influenced by the degree of oxygenation of the blood in the dermal blood vessels. • When bound to oxygen, the pigment hemoglobin is bright red in color • when the skin is exposed to heat, small dermal blood vessels open up (dilate) and more blood flows through the dermis, producing a more pronounced “flush”.

Question 39

Human Fingerprints

Answer 39

* ridges are due to downward projections of the epidermis into the dermis between the dermal papillae in the upper portion of the skin. * unique to each individual * pattern is inherited * Fingerprints get left behind on smooth surfaces because the ducts of sweat glands open on the surface of the epidermal ridges thus leaving a “sweaty” imprint. * FUNCTION: to increase the grip of the hand by increasing friction

Question 40

Fingerprint patterns may be categorized as 3

Answer 40

Arch - pattern is the simplest in that the ridges rise over the middle of the finger. Loop - pattern contains a blind-ended ridge that is surrounded by ridges that turn back on themselves. Whorl - pattern appears as a series of concentric circles in the center, then broadens out.

Question 41

When testing the ability to distinguish distinct touch sensations with calipers on various skin locations, a decrease in the distance between caliper points is associated with:

Answer 41

an increased density of touch receptors ``` Minimum Distance to Feel Two Stimuli (mm) Fingertip 2.0 Lips 5.0 Forehead 23.0 Back of Hand 31.0 Forearm 41.0 ```

Question 42

Relative Temperature Sense

Answer 42

EXPERIMENT