Human body systems Flashcards
(104 cards)
1
Q
tissue
A
a group of similar cells and cell products that arise from the same region of an embryo and work together to perfrom a specific structural or physiological role in an organ
2
Q
histology
A
the study of tissues and the way they are arranged into organs
3
Q
epithelial tissue
A
tissue composed of layers of closely spaced cells, covers organ surfaces, forms glands and serves for protection, secretion and absorption (e.g. epidermis, lining of digestive tract)
4
Q
types of epithelial tissue
A
- flat or squamous cells
- cube-shaped or cuboidal cells
- tall and cylindrical or columnal cells
5
Q
layers of epithelial tissue
A
- simple epithelium - single layer
- stratified epithelium - two or more layers
- pseudostratified epithelium - appears to have more than one layers, but it is one layer of different height cells
- transitional epithelium - where cells change shape in response to mechanical stretching
6
Q
connective tissue
A
cells embedded within a network of fibers: the matrix
- material surrounding the cells within the matrix = the groud substance
(e.g. tendons, cartilage, fat, bone, blood)
7
Q
types of connective tissue
A
- connective tissue proper - containing various fibers in a semifluid ground substance
- bone tissue
- blood
- cartilage tissue
8
Q
nervous tissue
A
tissue containing excitable cells specialized for rapid transmission of information to other cells (e.g. brain, spinal cord, nerves)
9
Q
muscular tissue
A
tissue composed of elongated, excitable cells specialized for contraction and movement (e.g. skeletal muscles, heart, walls of uterus, bladder, intestines)
10
Q
skeletal system
A
composed of bones, cartilage and ligaments joined tightly to form a strong and flexible framework for the body
11
Q
joint
A
a bone meets another bone
12
Q
cartilage
A
forerunner of most bones in embryonic development; forms a growth zone in the bones of children and covers many joint surfaces in the mature skeleton
13
Q
ligament
A
collagenous band that holds bones together at the joints
14
Q
tendons
A
structurally similar to ligaments but attach muscles to bone
15
Q
bone marrow
A
the soft bloody or fatty material enclosed in the bones
16
Q
functions of the skeletal system
A
- support
- bones of the limbs and vertebral column support the body, the mandible and maxilla support the teeth and some viscera are supported by nearby bones
- protection
- bones enclose and protect the brain, spinal cord, lungs, heart and pelvic viscera
- movement
- bones provide attachment and leverage for the muscular system, allowing for actions such as limb movement and ventilation of the lungs
- blood formation
- red bone marrow is the major producer of blood cells
- storage
- the skeleton is the body’s main reservoir of calcium and phosphorus among other minerals
17
Q
number of bones
A
there are 109 differently named bones of the skeleton (most paired)
→ an adult skeleton typically has 206 individual bones
18
Q
axial region
A
forms the central supporting axis of the body and comprises 80 bones, including: skull, vertebral column, ribs and sternum
19
Q
appendicular region
A
comprises the remaining 126 bones, those of the upper limb and pectoral girdle and of the lower limb and pelvic girdle
20
Q
3 types of muscular tissue
A
- skeletal
- cardiac
- smooth
21
Q
functions of the muscular system (5)
A
- movement
- stability
- control of body openings and passages
- heat generation
- glycemic control
22
Q
structure of a muscle fiber
A
- each muscle fiber has multiple nuclei pressed against the plasma membrane
- deeper part of the cell:
- thick bundles (myofibrils) of contractile protein (myofilaments: actin and myosin)
- packed between myofibrils are numerous mitochondria, a network of sER, deposits of the high-energy glycogen and a red, oxygen-binding pigment - myoglobin
23
Q
properties of cardiac muscle
A
cardiac muscle is limited to the heart, where its function is to pump blood
- involuntary (contracts automatically) and autorhytmic (has a self-maintained rhythm of contraction)
- cardiac muscle cells are short, rectangular and forked at the ends linked at the intercalated discs
24
Q
smooth muscle
A
involuntary, like cardiac but it lacks striations
- smooth muscle cells have only one nucleus near the middle of the cell, are fusiform in shape
- it occurs in the walls of the blood vessels and many body-cavity organs (viscera) such as the respiratory, urinary, digestive and reproductive organs - visceral muscle
- smooth muscle contracts in response to nervous stimulation, stretch (e.g. full bladder), hormones (during labor contractions) and blood levels of CO2, )2 and pH
- smooth muscle is fully capable of mitosis (e.g. pregnant uterus)
25
3 basic components of the circulatory system
1. circulatory fluid
2. a set of interconnecting vessels
3. a muscular pump, the heart
→ the heart powers circulation by using metabolic energy to elevate the circulatory fluid’s hydrostatic pressure
→ the fluid then flows through the vessels and back to the heart
26
circulation in mammals
- O2 from inhaled air diffuses across only two layers of cells in the lungs before reaching the blood
- the circulatory system then carries the oxygen-rich blood to all parts of the body
- as the blood passes throughout the body tissues in tiny blood vessels: O2 in the blood diffuses only a short distance before entering the fluid that directly bathes the cells
27
heart's chambers
- the heart has 4 chambers that receive and eject blood
- the two smaller, superior chambers are the right and left ATRIA → thin-walled receiving chambers for blood returning to the heart by way of the great veins
- the two inferior chambers, the right and left VENTRICLES compose most of the bulk of the heart → strong pumps that eject blood into the arteries and keep it flowing around the body
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heart's valves
- 4 heart valves ensure a one-way flow and prevented backflow of blood
- one between each atrium and its ventricle and one at the exit from each ventricle to its great artery
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atrioventricular valves
control the opening between each atrium and the ventricle below it
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the pulmonary and aortic (semilunar) valves
lie between the ventricles and great arteries
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the pulmonary valve
controls the opening from the RIGHT ventricle into the PULMONARY TRUNK
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the aortic valve
controls the opening from the LEFT ventricle into the AORTA
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pulmonary circuit
carries blood to the lungs for gas exchange and returns it to the heart
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systemic circuit
supplies blood to all organs of the body, including the lungs and the wall of the heart itself → it pumps blood into the largest artery, the AORTA
- the dual circuits operate simultaneously
- the two ventricles contract almost in unison and pump the same volume of blood
- the total volume of the systemic circuit is much greater than that of the pulmonary circuit
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blood vessels - differences
- direction of blood flow
- pressure they withstand
- corresponding histological structure of their walls
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arteries
all vessels that carry blood away from the heart
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veins
all vessels that carry blood back to the heart
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capillaries
microscopic vessels connecting the smallest arteries to the smallest veins
39
respiratory functions
- gas exchange: oxygen enters blood and carbon dioxide leaves
- regulation of blood pH: altered by changing blood carbon dioxide levels
- voice production: movement of air past the vocal folds makes sounds and speech
- olfaction: smell occurs when airborne molecules are drawn into nasal cavity
- protection: against microorganisms by preventing entry and removing them
40
respiratory tract (upper + lower)
air passages from the nose to the lungs and gas-exchange surfaces in the lungs themselves
- upper respiratory tract
- from nose through larynx
- lower respiratory tract
- from trachea through lungs
41
the bronchial tree and alveoli
- a series of branching passages that carry air from trachea to gas-exchange surfaces in the lungs (alveoli)
- bronchi branch into smaller passageways leading to tubes called bronchioles and terminal bronchioles
- each lung contains 150 million alveoli, which provide a large surface area for gas exchange
42
respiratory cycle
- breathing (pulmonary ventilation): inspiration (inhaling) and expiration (exhaling)
- one complete inspiration + expiration = respiratory cycle
43
lymphatic system
a network of tissues, organs and vessels, which: recover tissue fluid, inspect and cleanse it of pathogens, activate immune responses and return the fluid to the bloodstream
44
functions of the lymphatic system
1. fluid recovery
1. fluid continually seeps from the blood capillaries into tissue spaces
2. blood capillaries reabsorb 85% of this fluid and lymphatic system absorbs 15% (2-4l / day)
2. immunity
1. fluid recovered from body tissues is checked by the system for toxins / microbes
2. it guards the openings of the digestive, respiratory and other tracts
3. lipid absorption
1. lymphatic vessels “lacteals” in the small intestine absorb dietary lipids
2. through lymphatic vessels lipids empty into large left subclavian vein
3. from there, bloodstream distributes them for storage or immediate use
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lymph
fluid that the system collects from the tissues and returns to the bloodstream
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lymphatic vessels
resemble veins and transport the lymph
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lymphatic tissue
loose aggregations of lymphocytes in the connective tissues of various organs (e.g. digestive and respiratory tracts)
48
lymphatic organs
structures enclosed in a fibrous capsule and containing organized masses of lymphatic tissue (e.g. tonsils, thymus, spleen and lymph nodes)
49
lymph nodes
small lumps of tissue that contain white blood cells (mainly B & T lymphocytes)
50
functions of the nervous system
1. sensory
1. the ability to respond to stimuli within and around the body and generate signals that carry information about stimuli to spinal cord or brain
2. integrative
1. the ability to receive and process information, store and retrieve it and make decisions as to whether or how to respond to it
3. motor
1. the ability to issue outgoing signals to muscle and gland cells to produce a response
51
central nervous system
brain and spinal cord enclosed and protected by cranium and vertebral column; it carries out the integrative functions of the system
52
peripheral nervous system
nerves leading to and from the CNS; it provides the CNS with pathways of signal input and output, connecting it to the body’s sense organs, muscles and glands; it carries out both sensory and motor functions
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neuron: nucleus
the cell’s site of genetic control
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neuron: soma or cell body
the control center of a neuron
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neuron: dendrites
the receiving end of a neuron (from other neurons)
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neuron: axon
the neuron’s output pathway for signals that it sends to other cells
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action potential
→ plays a central role in cell-to-cell communication:
propagation of signals along a neuron’s axon toward synaptic terminals situated at the ends of an axon
→ these signals can then connect with other neurons at synapses or motor cells or glands
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brain: cerebrum
- sensory perception
- motor control
- consciousness
- learning
- memory (and others)
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brain: thalamus
- role in memory
- emotions
- motor control
- sensation
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brain: hypothalamus
- water balance
- blood pressure
- metabolism
- stress responses
- sleep etc.
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brain: brainstem
- sleep
- automatic functions e.g. breathing
- consciousness
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brain: cerebellum
motor coordination
63
endocrine system
- the endocrine signals are hormones, like neurotransmitters for the nervous system
- chemicals induce changes in many parts of the body
- slow, long-lasting response
64
major organs of the endocrine system
- hypothalamus, pituitary and pineal glands
- thyroid and parathyroid glands
- thymus
- adrenal glands
- pancreas
- ovary, placenta
- testicle
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pituitary gland hormones - growth hormone
promotes tissue growth
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pituitary gland hormones - thyroid-stimulating hormone (TSH) or thyrotropin
stimulates the thyroid gland to secrete thyroid hormone, necessary for regulation of metabolism
67
pituitary gland hormones - oxytocin
the “love hormone” (posterior one)
68
digestive system
the digestive tract + accessory organs; it processes food, extracts nutrients from it and eliminates the residue
69
ingestion
selective intake of food
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digestion
mechanical and chemical breakdown of food into a form usable for the body
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absorption
uptake of nutrient molecules into epithelial cells of digestive tract and then into blood or lymph
72
compaction
absorption of water and consolidation of the indigestible residue into feces
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defecation
elimination of feces
74
digestive tract
- a tube from mouth to anus (5m)
- mouth
- pharynx
- esophagus
- stomach
- small intestine
- large intestine
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gastrointestinal (GI) tract
- stomach
- intestines
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accessory organs
- teeth
- tongue
- salivary glands
- liver
- gallbladder
- pancreas
77
saliva
watery solution of mucus, enzymes and electrolytes ; we make 1-1.5 l per day
78
saliva functions
- moistens the mouth
- cleanses the teeth
- inhibits bacterial growth
- dissolves molecules to stimulate taste buds
- lubricates food and binds particles together into a soft, slippery, easily swallowed mass
79
salivary amylase
digests starch in food
80
major salivary glands
1. parotid
2. submandibular
3. sublingual
81
swallowing phases
1. oral phase
2. pharyngeal phase
3. esophageal phase
82
oral phase of swallowing
the tongue forms a food bolus and pushes it into the laryngopharynx
83
pharyngeal phase of swallowing
the palate, tongue, vocal cords and epiglottis block the oral and nasal cavities and airway while pharyngeal constrictors push the bolus into the esophagus
84
esophageal phase
peristalsis drives the bolus downward and relaxation of the lower esophageal sphincter admits it into the stomach
85
stomach
- food storage organ
- holds 1-4 l
- it mechanically breaks down and liquifies the food, beginning the chemical digestion of proteins and fat
86
small intestine functions
- digestion
- nutrient absorption
87
large intestine
- receives 500 ml per day of indigestible food residue
- reduces it to 150 ml of feces by absorbing water and salts
- eliminates the feces by defecation
88
urinary system - principal organs
- two kidneys
- two ureters
- urinary bladder
- urethra
89
functions of kidneys
- filter blood plasma and excrete toxic metabolic wastes
- regulate blood volume, pressure and osmolarity by regulating water output
- regulate the electrolyte and acid-base balance of body fluids
- secrete erythropoietin, which stimulates production of red blood cells
- synthesize calcitriol (vitamin D)
- detoxify some drugs
90
urine formation
- glomerular filtration rate (GFR) is the amount of filtrate formed per minute by the two kidneys combined
- adult females - 150l per day
- adult males - 180l per day
- an average adult reabsorbs 99% of the filtrate and excretes 1 to 2l of urine per day
91
urine storage and elimination
- valve at the opening of each ureter into the urinary bladder
- contractions occur every few seconds/minutes that milk urine from the renal pelvis down to the bladder
- the urethra conveys urine from the urinary bladder to the external urethral orifice
92
reproductive system
parents produce gametes (sex cells) that meet and combine genes in a zygote (fertilized egg); the offspring receives genes from 2 parents
93
gamete's properties
- mobility to establish contact (sperm)
- nutrients for the embryo (egg (ovum))
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gonads - primary sex organs
the organs that produce the gametes (testes in males and ovaries in females)
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secondary sex organs
the other organs necessary for reproduction - the penis, uterus, mammary glands
96
reproductive organs classification
external and internal genitalia
97
testes
produce sex hormones and sperm, contained in the scrotum
98
epididymis
- site of sperm maturation and storage
- contains a single coiled duct (~6m) embedded in connective tissue
- it reabsorbs 90% of the fluid secreted by the testes
- sperm mature as they travel down the epididymis over a period of 20 days (stored there and in ductus deferens)
99
ovaries
- they produce egg cells (ova) and sex hormones
- each egg develops in its own bubblelike follicle and is released by ovulation, the bursting of the follicle
100
skin - layers
- two principal layers
- a superficial epithelium, the epidermis
- a deeper connective tissue layer, the dermis
- between skin and muscles there is a looser connective tissue layer, the hypodermis
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functions of the ingumentary system
- resistance to trauma and infection
- epidermal cells are packed with keratin
- water retention
- skin prevents the body from losing excess water
- vitamin D synthesis
- epidermal cells synthesize vit. D needed for bone development and maintenance
- sensation
- body’s largest sense organs
- equipped with a variety of nerve endings
- thermoregulation
- increases or reduces blood flow close to the body surface and by sweating in response to overheating
- nonverbal communication
- small facial muscles that act on the dermis to produce subtle and varying expressions
102
hair
a slender filament of keratinized cells that grows from a hair follicle
- hair visible above skin surface is called its shaft
- below the surface, within the follicle is the root with swelling and the bulb
- near the bulb all the hair tissue is dead!
- nerve fibers called hair receptors coil around the follicle and respond to hair movements
103
nails
very thin dead cells, densely packed together and filled with parallel fibers of hard keratin
- serve as strong keratinized tools for digging, grooming, picking things apart
- nail plate, nail bed and nail fold
- nail matrix: growth zone beneath the skin
- fingernails grow at a rate of about 1 mm per week and toenails more slowly
104
cutaneous glands
- merocrine sweat glands
- apocrine sweat glands
- sebaecous glands
- ceruminous glands
- mammary glands
